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thread-9889 | https://3dprinting.stackexchange.com/questions/9889 | Anyone tried Varathane water-based Wood Stain on Hatchbox Wood PLA? | 2019-05-08T22:49:37.970 | # Question
Title: Anyone tried Varathane water-based Wood Stain on Hatchbox Wood PLA?
I printed parts for a Harry Potter wand with HatchBox Wood PLA, now I want to apply stain. I intended to try MinWax PolyShades wood stain, then noticed Varathane water-based wood stain is available at my local Rona hardware store. This seems a "healthier" option, maybe not as fussy to apply as PolyShades, anyone had experience with this product?
# Answer
I ended up using Saman brand water-based wood stain, also from Rona hardware (a brand of Lowe's Canada). The selection of colours for Saman stains was greater than the Varathane stains.
I applied a single coat of colour #117 "Chamois" to the stem portion of the wand, and two coats of colour #120 "Dark Walnut" to the handle. I did not apply a varnish or sealer. The results seem acceptable, given that I Am Not A Carpenter, and this is my first go at printing and finishing wood PLA! Overall, I'm quite happy with the result. I left the PLA mostly unsanded to take advantage of the layers' wood-grain appearance.
> 2 votes
# Answer
Wood stains (as opposed to dyes, paints, etc.) work by having large particles that become lodged in the grain of the wood, yielding a result that varies in intensity with the grain of the wood and thereby brings out its beauty. It's unlikely that they will do what you want, or anything reasonable, on PLA that has wood particles mixed into it. You might be able to find some types of dyes that will work. I've used wood dyes on woods that don't take stain well and have had good results, and if the PLA+wood material consists of a significant amount of wood, it seems plausible that wood dyes might work well on it.
> -2 votes
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Tags: filament, pla, post-processing
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thread-9961 | https://3dprinting.stackexchange.com/questions/9961 | Anycubic Chiron does not print correctly | 2019-05-16T10:01:19.793 | # Question
Title: Anycubic Chiron does not print correctly
I recently got my Anycubic Chiron.
First I was very exited and set up the printer. I started the first manual leveling as described in the instuctions. After that I did the Autoleveling and started the test print - so far so good.
After adjusting by 2 mm, further down I saw the round circle in the middle is not round and it seems that in some areas the printer does not position the nozzle correctly. As I printed a cylinder I saw the circle has two flat areas opposing each other when the build plate moves towards its end position.
Does anybody now how to fix this? Is there anybody with a Cura 4.0 Machine setting and a 0.05 mm with 0.4 mm nozzle profile?
# Answer
It is impossible to give a definitive answer without photographic evidence, since your description of the problem does not give enough information. The most common causes of "circular objects not printing correctly" are loose belts and loose grub screws on the belt drive pulleys.
However, you should note that the printer's firmware will not allow the print head to be moved outside the defined maximum printing area under software (g-code) control. This will cause large objects to be truncated if they extend outside of the defined maximum printing area, and I suspect that this is what is happening.
> 3 votes
---
Tags: print-quality
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thread-8627 | https://3dprinting.stackexchange.com/questions/8627 | Is there any (relatively simple) way to determine whether a stepper is being directed to move by the voltage signal across its winding? | 2019-04-06T03:01:29.817 | # Question
Title: Is there any (relatively simple) way to determine whether a stepper is being directed to move by the voltage signal across its winding?
This may be a long shot, but I was wondering if the signals seen across a stepper motor's windings could indicate whether the stepper was being told to move over some short time period. This is in particular for the stepper used on extruders.
I've read that PWM in used in stepper drivers and controls current patterns to move the motor. And that a current must also be maintained through the windings if the motor is to hold its position. So it would seem that there is always a pulsing waveform across the windings whenever the stepper is energized, correct? When the motor is holding its position, is there anything distinctive about the waveform?
This is for a filament sensor I'd like to make. The sensor would be located at the extruder motor. It would monitor movement/flow of the solid filament. A lack of filament flow could be because of filament runout, tangled or caught filament, or non-extruding travel moves. I'd like to be able to tell the first two causes from the last one (when it's not supposed to be extruding for some hundreds of milliseconds or so). It would also be nice to tell 'no directed movement' from 'very slow movement' which would happen with small nozzles, slow speed or other slow extrusion situations.
I watched the waveforms with an oscilloscope while printing, but travel moves were quick and relatively rare, so I couldn't definitely see if there was something I could use during those times. Could I just filter the pulse waveform (what corner frequency?) to get an approximation of the current waveform going through the coils -- on the idea that the waveform should resemble a DC level during non-extruding but still energized times. Perhaps another low-pass filtering of that DC level, or a high-pass of the waveform to indicate directed extrusion? Using DSP on a micro, of course.
Are there any experts here on the subject of low-level stepper motor control?
# Answer
> 2 votes
> So it would seem that there is always a pulsing waveform across the windings whenever the stepper is energized, correct?
Correct.
> When the motor is holding its position, is there anything distinctive about the waveform?
Yes there is. This video contains a short example of what the current waveforms would look like.
If I understand you correctly: You want to detect filament events based by doing current sensing on the phases of the stepper motor. The simple of it is that, if the motor is not turning then the Back ElectroMotive Force will be zero. As the speed increases the BEMF goes up, which causes the current levels to go down. Is this how stall detection in some driver systems work.
You may be able to determine if what you want to do is even practical by studying the fundamentals of stepper motor driving; both voltage mode and current mode.
Apart from that it may be just as practical to use a rotary encoder upstream of the extruder motor to detect the filament movement, or lack thereof.
In your case detecting if the filament is present but not moving calls for stall detection. If the PWM pulse occurs but the rate at which the voltage increased (the slope) did not change, then there was no BEMF event. The lack of such an event would indicate that the rotor did not move. If there is no filament to push, then when the rotor moves it will *ring* (overshoot it's target position and fluctuate back and forth until it settles into the electrical position that the controller intended), because the mechanical load has changed.
For a NEMA17 stepper, these would be very small change in a very brief event. I would start with installing current sensors on both phases, and then doing some signal processing on top of that.
# Answer
> 0 votes
There is nothing you can do to monitor the extruder stepper motor to assure that filament is being fed when it should be fed. A common condition is where the filament binds but the extruder stepper continues to move as commanded. The drive pully strips the dents it presses in the filament, and grinds down the filament. The extruder still steps, and the filament does not.
You can reduce this for particular filaments by increasing the pressure on the filament by the drive pully, but the optimum pressure varies with the filament. For instance, I've found that PET needs a lesser pressure than PLA.
@User77232 suggests using a separate rotary encoder to detect the motion of the filament through a different sensor. This may be better, since you can detect a filament jam with extruder motion. If you are using a PTFE tube to deliver filament to the extruder, the encoder can be mounted at the other end of the tube. You may need to make allowance for some compression and stretch of the filament in the tube, which could delay detecting "lack of movement".
I had hoped that the Triaminic TMC2100 chips (spec here) would provide detection of drive torque by watching the back EMF, but reading the spec didn't look helpful. There was an old patent (that should be long expired) that detected the current needed to move a stepper motor to achieve faster acceleration and quieter operation, but I didn't find on the Triaminic driver a useful torque limit signal. If one could detect the torque required, one could set a peek torque value that is lower than the initial filament strip torque.
Perhaps one could mount the extruder stepper motor with a compliant mount, perhaps something like a TPU or rubber material, and use a strain gauge to measure the stretch of the mount.
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Tags: extrusion, stepper-driver, stepper, extruder-driver
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thread-9967 | https://3dprinting.stackexchange.com/questions/9967 | Using extruder motor as 4th axis | 2019-05-17T03:32:44.123 | # Question
Title: Using extruder motor as 4th axis
I am currently working with a hobbyist robotic arm (uArm Swift Pro) which runs a modified version of Marlin 3D printing firmware.
The arm can be used as a 3D printer as well thus it has an extruder motor. I am not using it as a 3D printer, instead I am reusing the extruder motor as 4th axis to move the arm along a rail. The problem I have run into is that the extruder motor is accelerating in steps, that is accelerating up to a certain speed holds that speed for a while (1-2 s) and then accelerates up to a higher speed holds that for a while. It then decelerates in the same fashion.
So my question is where in the Marlin code is planing made for the E-axis and is it any different from planing the speed of the other axis?
# Answer
> 3 votes
Movement of the steppers is controlled by the jerk and acceleration settings. Both are controlled/set in the Marlin configuration file.
```
/**
* Default Max Acceleration (change/s) change = mm/s
* (Maximum start speed for accelerated moves)
* Override with M201
* X, Y, Z, E0 [, E1[, E2[, E3[, E4]]]]
*/
#define DEFAULT_MAX_ACCELERATION { 3000, 3000, 100, 10000 }
/**
* Default Acceleration (change/s) change = mm/s
* Override with M204
*
* M204 P Acceleration
* M204 R Retract Acceleration
* M204 T Travel Acceleration
*/
#define DEFAULT_ACCELERATION 3000 // X, Y, Z and E acceleration for printing moves
#define DEFAULT_RETRACT_ACCELERATION 3000 // E acceleration for retracts
#define DEFAULT_TRAVEL_ACCELERATION 3000 // X, Y, Z acceleration for travel (non printing) moves
/**
* Default Jerk (mm/s)
* Override with M205 X Y Z E
*
* "Jerk" specifies the minimum speed change that requires acceleration.
* When changing speed and direction, if the difference is less than the
* value set here, it may happen instantaneously.
*/
#define DEFAULT_XJERK 10.0
#define DEFAULT_YJERK 10.0
#define DEFAULT_ZJERK 0.3
#define DEFAULT_EJERK 5.0
/**
```
---
Tags: marlin, arduino-mega-2650, arduino
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thread-9970 | https://3dprinting.stackexchange.com/questions/9970 | Add a laser module to Reprap Guru Prusa i3 | 2019-05-17T20:19:47.090 | # Question
Title: Add a laser module to Reprap Guru Prusa i3
I have a Reprap Guru Prusa i3 v2 3D printer. Here is a link to the 192 MB manual. And here is the link to the resources page for the Reprap Guru. Page 58 of the manual discusses electronics.
I purchased a 5.5 W laser from an online resource (AliExpress). It has its own controller module. It has one connector with 3 pins
1. 12 V
2. Gnd
3. PWM
I want to now connect the laser module in-place of the 3D printer nozzle. I have been able to install it physically, but not sure how to connect it to the Reprap Guru Prusa i3 board.
I am not an electrical engineer, but I am capable of connecting wires with clear instructions. Any pointers on how to connect this module to the 3D printer board is appreciated.
Updates:
1. The board of my 3D printer is an Arduino Mega 2560 board.
2. I have been able to power the laser on using the fan connections and it can burn stuff (so it works). I have connected to the D9 pins
3. Now need to figure out where to connect the PWM from the laser module to the Arduino Mega 2560 board
# Answer
> 7 votes
By connecting to the D9 output header (see RAMPS 1.4 shield schematic below) you only have 2 wires that represent a scheduled load and ground. You actually need to connect the positive (red) lead to the power supply 12 V and the negative (black) lead to the ground. The third wire (usually a different color) needs to be connected to the actual D9 in your example; note that this one is connected to the MOSFET! And as such not readily available, it is far more easy to use an other free pin.
---
Just use the PWM pin (attached to the MOSFET) of the print cooling fan (that schedules the MOSFET), you can then schedule the laser power with G-code M106, e.g. `M106 S127` to select half the power (`S255` would be max power). Alternatively, and probably a much better solution is that you can use any free (but exposed) pin of your microprocessor; you can set the value of that pin using G-code M42.
> M42 switches a general purpose I/O pin. Use M42 Px Sy to set pin x to value y, when omitting Px the LEDPIN will be used.
The only electrical wiring you need to do is to attach a wire (solder or connect to a header) to bundle that with a power and ground wire and route that to the laser module.
Note that the PWM pins of the Mega are numbered D2 through D13. Also, D44, D45 and D46 are also PWM capable. Checking the RAMPS 1.4 (the board/shield of the Reprap Guru) pinout, you will see that D8, D9 and D10 are used for the MOSFETs (and as such not easily available and would require soldering). E.g. D2 and D3 are used by the X max/min endstops (note that most printers don't use an X-max, so pin D2 may be free on your machine).
For your purpose, any of the following pins can be used: D2, D4-7, D1112-13 and D44-46.
Best option would be the D11 pin (on second thoughts, D4 might be a much better option as the timer associated with PWM on pin D11 is internally used in Marlin for generating interrupts); it has a pin you can connect to the SERVO header pin.
The image shows the location of the pins:
An example to connect a laser module is seen in this image:
---
Tags: prusa-i3, g-code, ramps-1.4, wiring, laser
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thread-8163 | https://3dprinting.stackexchange.com/questions/8163 | Can an extruder rated for 24 V work with 12 V ATX power supply? | 2019-02-04T22:11:56.383 | # Question
Title: Can an extruder rated for 24 V work with 12 V ATX power supply?
Heads up: I'm not good with electronics and only have a vague idea of it's inner workings.
I have a E3D V6 Extruder rated for 24 V, that i plan to use in my 3D printer. Will there be any problems with it if powered by 12 V? Will it take longer to heat up? Will it be able to heat up enough to melt PLA? Will it work at all for that matter? If there are any other quirks or potential problems that I overlooked, please let me know.
# Answer
Electrical engineering can be quite complex, but in this case you can save yourself with same simple equations/relations. Using the following formulae:
* ***Voltage ($\ U$) equals current ($I$) multiplied by the electrical resistance ($R$)***
$$ U=I \times R $$
and
* ***Power ($P$) equals the square of the current multiplied by the electrical resistance***
$$ P=I^2 \times R $$ can be rewritten using the first formula to: $$ P= \frac{U^2}{R} $$
Applying these formulae to a **40 Watt, 24 V** heater element, the electrical resistance (in $\Omega $) is calculated by: $$ \frac{{(24\ V)}^2}{40\ W}=14.4\ \Omega $$
Running this heater element with 12 V will lead to a power of $$ \frac{{(12\ V)}^2}{14.4\ \Omega}=10\ W $$
The heat produced is proportional to the square of the current multiplied by the electrical resistance, ***halving the voltage*** is ***quartering the heat output***. This will heat up very slowly! If it is able to reach the required temperature that is. Calculating the temperature is far more difficult, but if you are interested in doing so, please look into this answer from the Electrical Engineering Stack Exchange.
> 10 votes
# Answer
No, it probably won't work as you want. As explained in another answer, you will only achieve 25% of the expected power. So it will take 4 times as long to heat up, will have a lower 'highest temperature', and most critically will reduce the possible print speed by a factor of around 4 (actually more, since a proportion of the power is lost to the room rather than used to melt filament).
I guess that you *could* print with this setup as a temporary measure (so long as it's PLA, or some other low-ish temperature filament). It would not be a sensible choice, particularly since the extruder only needs a single component to be swapped out to change between 12 V and 24 V operation (the heater cartridge). All the mechanical parts will be identical between the two versions, and these are the 'expensive' elements in the assembly.
> 1 votes
# Answer
No not by itself.
Also you need to check the wires in the ATX power supply as 16 gauge wire might melt depending on how many amps it needs.
You could on the other hand connect 2 ATX power supplies the plus 12v on power supply 1 to the 12v ground on the second power supply. Then use a volt meter to confirm your getting 24v out. On the 2 leads not connected.
This still could run into problems as you have to be careful with the wire gauge. You need 14g wire for 15 amps, and 12g (thicker) for 20 amps. Finding an ATX power supply with better than 12g wire is highly unlikely.
> 1 votes
# Answer
It will take longer to heat up. However if you use a boost converter (like I did on my Anet A8 when I upgraded to a Maxiwatt 24 V hot end), then it will work just fine without any further adjustments; to the power supply or the gauges of the wire etc. I set the boost from 12 to 24 volts. Now my A8 heats up in 56 seconds!
> 0 votes
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Tags: extruder, electronics, power-supply
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thread-9975 | https://3dprinting.stackexchange.com/questions/9975 | Could you use ultrasonic vibrations instead of a roller with an SLS/SLM printer? | 2019-05-19T13:27:15.653 | # Question
Title: Could you use ultrasonic vibrations instead of a roller with an SLS/SLM printer?
I've been thinking, SLS/SLM printers currently use a roller to spread 3d printing substrate, but wouldn't ultrasonic vibrations spread the substrate more cleanly, accurately, and with greater density than a roller?
# Answer
# No
The problem is twofold. Resonance and Granular convection
## Resonance
Let's start with an empty box. We toss in some powder to create the first layer and use an ultrasonic to create a first layer. What happens? The bed starts to resonate depending on the sound you send into it in patterns - and the powder starts to form valleys and ridges along them as one can see in this video.
## Granular Convection
What happens if one shakes a box of fine granulate that contains larger items? Granular convection happens! All items raise simultaneously and the small items start to fall first, resulting in them getting under the larger ones, so as a result end up pushing the large items up.
Because of both effects, there won't be an even layer **and** it would raise the items printed, even if we managed to get good layers.
> 3 votes
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Tags: sls, slm
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thread-9979 | https://3dprinting.stackexchange.com/questions/9979 | Entwined fiber-filled filament stops extruding after a few layers | 2019-05-19T21:26:53.793 | # Question
Title: Entwined fiber-filled filament stops extruding after a few layers
I recently took my first shot at printing with specialty filament -- Entwined by 3-D Fuel -- on a Lulzbot TAZ having an 0.5mm nozzle. *(Note that this is the original Entwined, not the mid-2018 "v2" with smaller fibers; Just purchased from MicroCenter this weekend, and saw a 2017 production date when reading the label).*
While the filament in question can be reliably and consistently extruded at full speed (as with the "Continuous Load" button), I've repeatedly had it stop extruding partway through my prints. This is much worse with lower layer heights. Even when this has happened and several MM have been "printed" with no content, pausing the print, going to the load/unload menu, and telling it to extrude filament at full speed indicates that it's not by any means fully clogged, but only failing to extrude at the configured speed.
Where should I start in tuning to try to get a reliable print with this specialty material?
I'm using Cura LE 3.6.9 for slicing. The center item of the three below was printed at 210C, with the most successful at 0.25mm layer height (Cura's default of 0.1mm had far worse results -- not included in the below photo -- with the base layer almost not being there at all; 0.175 did somewhat better).
I'm using the bed heated to 45C, in line with the manufacturer's guidance (that a heated bed is optional, but should be set to 45-60C).
# Answer
I've managed to get a successful print! The key was to keep the material moving quickly. The settings I've customized are as follows:
* *Print Speed*: 70 mm/s
* *Layer Height*: 0.4 mm
* *Default Printing Temperature*: 215C
...and perhaps not as necessarily:
* *Shell Wall Thickness*: 0.8 mm
* *Wall Line Count*: 3
* *Alternate Extra Wall*: True
Also, I've found it important to print a skirt (perhaps a double-walled one), and watch the first-layer closely and be willing to push more material through and restart: The material in the hotend can easily form a partial clog while the printer runs through its auto-leveling / head-cleaning routine, thus needing to have more material pushed through before the job starts in earnest.
By the way, the model is https://www.thingiverse.com/thing:1993747, by Holodrio on Thingiverse.
> 3 votes
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Tags: filament, ultimaker-cura, lulzbot
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thread-4120 | https://3dprinting.stackexchange.com/questions/4120 | Best method to make dissolvable supports? | 2017-05-21T05:21:40.173 | # Question
Title: Best method to make dissolvable supports?
Sometimes supports are very difficult to remove (physically) when I print with ABS. The image below, from Thingiverse - MOF-5 unit cell, is after significant effort to remove the yellow ABS supports from a black ABS model.
I've learned about polyvinylalcohol (PVA) as a 3D-printing filament which is soluble in water. It seems like a great option for dual-extruder printers, where you can print the model with ABS or PLA and the supports with PVA, then throw the whole thing in water and let the supports dissolve.
I've considered other options since PVA is ~4x more expensive than ABS.
Doing a PLA print with ABS supports, followed by dissolution of ABS with acetone, is my best idea currently.
Has anyone found success with another option?
# Answer
> 7 votes
I've had great success printing with HIPS (high-impact polystyrene) as a support for both PLA and ABS. Most sites recommend it for use with ABS because the materials melt at similar temperatures and work best with heated beds, but I've had good luck using it as a support material with PLA on a bed at 60°C. It doesn't stick as well to PLA as it does to ABS, so supports tend to peel away very readily. The downside is that, if you need the support to anchor your print at all, it doesn’t really stick well enough to accomplish this task. For that, you must pair HIPS with ABS.
When you print with ABS or have complicated interwoven support structures, HIPS can be dissolved with D-limonene, a citrus based cleaner sold under various names like Citrisolv (others exist), or with dipentene (a mixture of L and D-limonene that doesn't smell as pleasant).
Regarding cost: I've found HIPS to be slightly more expensive than PLA/ABS, but only 1.5x the cost, not 4x like PVA. Additionally, it isn't hydroscopic in the same way as PVA so it lasts longer out of the package. Since you're using it as support, you also tend to use far less filament than you do for the main print (sparse support structures as opposed to solid print structures).
Water-soluble alternatives: There are a few proprietary blends of polymers sold by the big commercial printer manufacturers (3DSystems, Stratasys) that only work in their machines… these are generally soluble in basic solutions (water + sodium hydroxide or sodium carbonate). These are usually very expensive and you'd have to rewind the filament on a spool, as they come in cartridges made for specific printers. You'd also have to experiment with the right build conditions and solution blends to remove the material afterward. Airwolf has a support material called Hydrofill that purports to be soluble in plain water… I'm not sure how this is different from standard PVA, though I assume it *is* different. Hopefully more companies will work on developing water-soluble options to help us keep the 3D printing world full of renewable, less-environmentally-harmful options for filaments (both print and support).
## Update:
Ultimaker now has a material called Ultimaker Breakaway. After using it for a few models, it works remarkably well, allowing me, for the first time, to print **nice** rounded surfaces on the bases of my prints. It really does just break away from the surface, much like HIPS but without the lack of adhesion problems between HIPS and PLA.
# Answer
> 3 votes
I haven't tried this myself, but the recommended way I've seen for dealing with the high cost of PVA is to print the support structure in ABS, PLA, or something else cheap, and print only the interface area (the top of the support where it meets the model) in PVA.
# Answer
> 2 votes
I believe this is on-topic because it describes my experience using PVA in a Prusa i3m3-MMU2 machine.
My experience has not been good. I started with a new spool, and dried it between attempts.
The problems may be specific to the Prusa MMU2 printing process, but some are intrinsic in PVA, or at least the PVA filament I've been trying, PrimaSelect PVA+ (link is for reference only. I have no skin in this game.) Aspects that may carry forward to non-MMU2 machines include:
1. filament is very stringy,
2. filament is friable, and crumbles into the drive gear,
3. filament does not adhere to a PEI bed. I had to use Aqua Net hair spray.
4. filament does not stick well to itself. Stacks of support will have internal defects, which may affect the desired print.
5. filament is very hygroscopic. With the MANY manual interventions needed with the MMU2, it may help to bake the filament in the middle of a multi-day print.
Perhaps unique to the Prusa i3m3-MMU2 machine, these lead to some specific problems:
1. the filament may be smaller diameter than 1.75, and it is sometimes not detected by the filament-presence detectors. This not only leads to failures, but it may also lead to large blobs of filament extruded into the purge towers, which leads to "crashes" and compounds the next problem. This may also be because I have too much tension between the drive gears -- something to check.
2. the purge towers are weak where layers of the PVA overlay each other. Purge towers may break during printing, which ruins the print.
3. the MMU2 filament drive gears are frequently fouled by PVA filament bits. I haven't found, though, that cleaning them reduces feed problems.
4. the MMU2 system feeds filament through PTFE tubing. Over time, perhaps with humidity, the friction of the filament passing through the tubes increases, which makes the feed problems worse.
This is not a negative review of the filament itself, or of the Prusa i3m3-MMU2. I may be doing something wrong, and would love to know better. I am quite happy with the MMU2, and have tuned it so that it works very well with PLA filament. This is the result of launching into soluble support, which is a feature I strongly hope to use reliably.
I am still exploring alternatives.
# Answer
> 0 votes
Not sure if frame challenge is on-topic here, but have you tried using different support options in your slicer? In Cura, I've found the experimental support tree mode both reduces the material usage a lot and gives supports that are easier to remove, at least for geometric (vs "organic", where it's sometimes good and sometimes bad) models. Turning off walls for normal (non-tree) support (infill and roofing only) and/or using a thinner line width than your nozzle can also help with removal but whether it provides sufficient support depends a lot on your model's geometry.
# Answer
> -1 votes
While I haven't used PVA yet, think of it this way, it may be 4x the cost but you use significantly less material for support structures even if you have a lot of support.
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Tags: filament, pla, abs, support-structures, support-material
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thread-9981 | https://3dprinting.stackexchange.com/questions/9981 | Why does the painters tape have to be blue? | 2019-05-20T00:35:25.887 | # Question
Title: Why does the painters tape have to be blue?
I have been looking at getting some painters tape to use on the glass plate for better print adhesion, and everything I read suggests the *blue* painters tape, such as this:
However, this white tape is considerably cheaper:
This looks like normal masking tape to me.
Is masking tape ok, or is the blue painter's tape preferable? If the latter, then why is that so? What is so special about the blue tape? Is it a different material?
# Answer
Of course, I don't know what kind of tapes you have. My experience with blue tapes is, that they seem in general softer and "nicer" than white tapes. Their structure appears denser and they seem to have longer "furs" while the white ones are "dryer" and "sharper"
This surface makes the blue tapes I sourced more suitable as the molten filament catches more furs.
Here are magnified photos of my comparable tapes. Unfortunately, my microscope is pretty lame but at least we can take a look on closeups:
This comparison shows the lower density of my white tape better:
to complete the picture here goes angle photos which reveals some more details
above shows that this white tape is made out of flat plastic fiber as they shine when illuminated from different angles
this could lead to another question
is such tape melted in any way in contact with extruded filament?
worth to analyse...
> 5 votes
# Answer
# read first
When you use painters tape, you need to level your printer **with** the tape applied. You need to relevel if you change the tape type.
# Basics
It's not *any* blue tape that printers love. There are basically two factors that make a tape useful:
* It has to stick during printing.
* Its surface has to allow the filament to stick to it.
Let's look at some different tapes and their suitability - from my own experience.
## ScotchBlue
The *original* blue tape is actually ScotchBlue for delicate surfaces by 3M. It has a good surface to stick to and at the same time an adhesive that does not degrade to unsuitability by heating. The delicate surface one is just as good as the all surfaces type. But don't use the outdoor type, it is sealed too much.
## FrogTape
FrogTape has an adhesive that has no problems with heating, the surface is sometimes a little smoother. Its green variant is about as useful as ScotchBlue, while the yellow variant is easier to remove - which can be an issue when the printhead is not calibrated correctly.
## Generic painters tape
*Generic* painters tape is a can of worms - there are so many different ones it is hard to describe. I have had very good off-yellow rolls from the dollar store of the 'fine surface' type - as in the tape had a fine surface - and their adhesive was good and didn't degrade too much under heat. The followup roll was a little thinner of material and released under heat so it can be a hit and miss - it's ok for starting out though.
I also tried a roll of UHU painters tape of the *easy remove* type and it was *horrible*, as it didn't want to stick after the nozzle went over it once even on an unheated bed.
## Generic blue colored tape
I even tried two blue colored tapes from different dollar/hobby stores. One was ok-ish and had a similar result as the good dollar store tape in look, but left a blue shadow on the base of the print after two or three prints. The other was showing similar behavior to other mild-adhesive/easy peel tapes.
## Conclusion
It's not *color* that matters, it is the *formulation*. If you must use blue tape, spend the extra bucks for quality. Some bloggers compared other tapes, tested ScotchBlue vs Kapton, discussed the benefits of either, discussed the ScotchBlue tape in depth.
While in general, I prefer to print on the surface of my (blue) BuildTak (clone), I occasionally whip out painters tape on an unheated surface for very delicate prints: I remove the print together with the tape from the surface, which allows better handling. Sacrificing a layer of tape only costs some cents after all while breaking a print is hours and filament for much more money wasted.
> 15 votes
# Answer
To answer your question, **it doesn't** have to be **blue** tape!
To be honest, tape is not **my** favorite bed adhesion solution, there are plenty other options that work better than tape.
Often you'll see references to blue painters tape (of a certain brand) to be used as a bed adhesion layer because many people have good experience with that. I have tried several tapes, white/cream to blue from various vendors but found that neither of the tapes satisfied my personal needs. To name a few: cleaning, application, preparation, repair, tear-off, no glossy first layer, color of tape sticking to printed part, etc. did not make tape a favorite bed adhesion solution. Instead I've been printing directly onto aluminium and glass using an adhesive (3DLAC or DimaFix) to stick filament to the bed. Use a wet cloth to wipe residue off, spray can to apply a new layer, et voila, just print, it always sticks! Glue stick is also a possibility.
So while the community screams ***"use blue tape"***, you just cannot use ***any*** blue tape from any tape manufacturer. There is no standard to which blue tape has to comply. Generally, speaking from painting experience, many blue tapes release much more easily after use while the white/cream paper tape sticks better and often tears (but this is frequently the tape that is already applied on heated beds of many Chinese printer kits, see image above). Not all tapes are equal: I have used blue tape from a local cheap source that will not stick to the build plate when it heats up, even if properly cleaned.
I'm more inclined to think that the color of the tape is just a way to distinguish yourself from the market back when the first manufacturer introduced the tape. Now that it is more common, others have adopted the color mimicking the tape they want to copy. It is more about the adhesive than it is about the surface of the tape (as in: "tape is rougher than the substrate you stick it on"), also you read that many people using blue tape need to prepare it by cleaning it (remove waxy layer) and sanding it.
IMHO, you just need to experiment yourself with several solutions and see what works best for you, could be that the white/cream tape from a local source also does the job. So basically, your tape does not have to be ***blue***, it has to ***work***!
> 5 votes
# Answer
The second image isn't exactly painter's tape. Both images are types of masking tape, but the common manila/cream-colored masking tape vs the blue or green painter's tape *typically* has three features that make it less desirable for bed adhesion:
1. Stronger glue holding the tape to the bed, that will make it harder to change later.
2. Narrower strips, so it's harder and takes longer to place the tape on the bed.
3. Thicker, softer material. This is *good* for filament adhesion, but bad for separating from the filament after the print and accurately leveling the bed.
Again: those are only typical arrangements. You can get blue painters tape at the same narrow width as manila masking tape, and you can get wider or thin manila tape. It's more a matter of what you'll commonly find for sale, and in all probability the manila/cream-colored tape will work just fine.
> 2 votes
---
Tags: adhesion, masking-tape
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thread-9953 | https://3dprinting.stackexchange.com/questions/9953 | Order of solving printing issues | 2019-05-15T21:42:07.507 | # Question
Title: Order of solving printing issues
3D Printers (those who print, not the machine, dummy)!
I haven't been printing in a while, so when I returned to my Monoprice Select Mini VII, of course it had been sprung out of whack. Some of my first prints would not even come out of the extruder until I realized I had some pretty bad (and worse, unnoticed!) heat creep going on. After fixing that issue, it became apparent that many more persisted.
My question for you all is this: In general, what problems should be addressed first when looking at a complete disaster of a print?
I'm not going to specify any singular problem, but I am interested in seeing the "order of operations" for general problem solving when multiple issues exist. For example, "Fix bed height before anything else; this is a common problem that produces multiple others." Hopefully, this can help others with multiple printing issues, too.
# Answer
> 2 votes
for sure the answer could be dissertation or even a book because there is no simple way to address "all" issues - it's just to wide area
but as the simple troubleshooting i would list it this way
1. is your printer alive so is it
* working at all (check power, cables)
* communicate with the world (check app, drivers, cables)
* moving HE and heating HB (check jams, end-points, belts, screws)
* is it extruding (check heating, temperature, HE jams, filament path)
if all above is "yes" then
2. is your printer making printouts and are those printouts
* starts and continues (check heating HB, HB adhesion, leveling, cooling)
* finished at all (check all above again, stepsticks temerature)
* keeping the shape (check screws and nuts, couplings, stiffness, stability, temperatures)
if all above is "yes" then in general you are half way ;)
3. common issues - printout is
* bent or skewed (check geometry, stiffnes, leveling, belts, vibrations, stepsticks temerature)
* wrapped or overextruded (check temperature, extruding, printout angles)
* underextruded (check filament flow, filament path, stepsticks temerature)
* stringy (check temperatures, app settings)
that is the main path i think. all above is more or less applicable to all DIY printers and all prusa clones and all clones of clones ;)
it can go wrong and fork in all possible moments as there is so many aspects to screw...
# Answer
> 1 votes
# The obvious ones first
This is, well, obvious. It is, what a visual and smell inspection shows. Stuff like missing or ruptured cables, bent rails, ripped or very loose belts, burnt smell or hung up software that is easy to see that it is going on needs to be addressed first.
# The not so obvious next
Next on the list are problems that have no obvious cause and effect. My order of operations to find these is like this:
* Homing
* movement of XYZ
* Bed leveling
* Heating test to 200 °C
* Extrusion of some millimeters
* Retract some millimeters
That solves the basic mechanical side, it shows that the machine technically could print. It is a visual as well as audial inspection. It also prepares the printer for printing.
# A test print next
What's next, after having a machine that theoretically should be able to print is to print.
Start with a simple thing. A cube for example. It shows problems with bed adhesion, surface finish, extrusion, temperature, layer shifting and layer adhesion.
Half of these problems are usually the result of temperature control. The rest but for layer shifting usually as a result of slicer settings.
* Layer shifting, the odd one out, most often would either be caused by a mechanical problem are using speeds which the printer can't cope with.
* Surface imperfections like blobbing shows too much extrusion and heat.
* Ghosting so that the printer is resonating with its movement.
# Answer
> 1 votes
Assuming there's *something* on the print bed, I usually look at at what the result is to determine what to check on the printer next.
Before doing anything physical with the printer, check your settings. You should have a decent understanding of what changes what and how the different numbers affect the print, as well as what they "should" be. Review them and make sure there's nothing that looks out of whack.
**Now for the specifics:**
If it looks like the filament didn't extrude right, for example if it stopped extruding halfway, barely extruded at all, or there's gaps in the print, I would check the hotend. Reload the filament and push it through by hand to make sure it's not jammed. If the nozzle is fine and it still looks like you're having extrusion issues, I would check the following things:
* Wiring to the motor
* Excess tension on the filament before it goes into the extruder (bowden/guide tubes, etc.)
* The nozzle itself. Nozzles do wear out and they're relatively inexpensive so if I can't solve an extrusion issue with reloading the filament, the next thing I do is replace the nozzle.
For mechanical issues, it's a little more complicated. The very first thing I do is pluck the belts on my printers and make sure they're tight. It should play a low note somewhere around a G. If it's a thud, the belt is too loose. If it's a really high sound, the belt is probably too tight. Another thing I check is to make sure all linearly moving parts (such as the print bed, carriages for the nozzle, etc.) only move in the direction they are supposed to. Wiggle them back and forth and make sure nothing is loose on the printer.
If you don't find anything that would obviously indicate what the problem is, run the print again and watch it closely. If it's only messing up in a certain part of a print, make sure you watch what the printer is doing when it gets to those areas. Make note of the nozzle distance to the bed at startup, retraction and hopping during prints, and making sure no wires or anything are getting snagged. Listen to the printer too, if it's making any new noises such as clicking or grinding then you most likely have a problem on your hands.
---
Tags: print-quality, troubleshooting
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thread-9994 | https://3dprinting.stackexchange.com/questions/9994 | No extrusion, but manual extrusion works | 2019-05-21T13:26:03.870 | # Question
Title: No extrusion, but manual extrusion works
I just bought and build my first 3d printer (HE3D K280 with Marlin) and I'm encountering some problems with Cura 4 and Repetier. When I load and slice a part, the printer does not extrude anything during printing. However, when I manually extrude like 100mm (G1 F100 E100) it does work. Now I'm suspecting the problem lies with the gcode file which is generated with Cura since it contains very small values for E:
```
;Layer height: 0.2
;Generated with Cura_SteamEngine 4.0.0
M140 S60
M105
M190 S60
M104 S200
M105
M109 S200
M82 ;absolute extrusion mode
G28 ;Home
G1 Z15.0 F6000 ;Move the platform down 15mm
;Prime the extruder
G92 E0
G1 F200 E3
G92 E0
G92 E0
G1 F1500 E-6.5
;LAYER_COUNT:250
;LAYER:0
M107
G0 F3600 X-7.753 Y4.378 Z0.3
;TYPE:SKIRT
G1 F1500 E0
G1 F1800 X-8.127 Y3.918 E0.01115
G1 X-8.35 Y3.57 E0.01893
G1 X-9.088 Y2.287 E0.04677
G1 X-9.348 Y1.754 E0.05792
G1 X-9.483 Y1.376 E0.06547
G1 X-11.413 Y-4.956 E0.18999
G1 X-11.547 Y-5.534 E0.20115
G1 X-11.602 Y-6.124 E0.2123
Etc...
```
Does anyone know how to fix this?
# Answer
I think that you have the incorrect diameter specified (e.g. 2.85 mm instead of 1.75 mm) in your slicer; this also appears from a calculation, see below. Note that you can calculate from extruded volume entering the hotend, or deposited volume. For the first you could calculate the line width of the deposited line and verify that with the settings; from the second you can verify if the volume for the extruded filament equals filament volume based on extruded filament going into the hotend for an assumed line width. Do note that (certainly for first layers!) modifiers may be in place. This is merely to get a ballpark feeling for the chosen filament diameter.
If you look at the first move from:
```
G0 F3600 X-7.753 Y4.378 Z0.3
```
to:
```
G1 F1800 X-8.127 Y3.918 E0.01115
```
You can calculate the travelled distance $ s = \sqrt{{\Delta X}^2+{\Delta Y}^2} = 0.59\ mm$. Also, from these moves you can see that $0.01115\ mm$ of filament enters the extruder $(E)$.
The deposited volume ($V\_{extruded\_filament}$) of the printed line equals the `cross sectional area` $\times$ `length of the deposited filament path`. Area could be defined as taken from e.g. the Slic3r reference manual to be:
Basically (as we apply conservation of mass) the filament volume $(V\_{filament})$ entering the hotend need to be the same as the extruded filament volume $(V\_{extruded\_filament})$ leaving the nozzle; so $ A\_{filament}\times E = A\_{extruded\ filament}\times s $.
This latter equation can be solved for $w$ by filling out the known parameters. From this calculation follows that for $1.75\ mm$ filament you get a calculated line width of about $0.22\ mm$, and respectively for $2.85\ mm$ filament you get $0.46\ mm$ line widths.
As the nozzle diameter has not been specified in the question, but most commonly used nozzle diameter often is $0.4\ mm$, and modifiers for the first layer are at play to print thicker lines; you most probably have the have the wrong filament diameter set if you have a $1.75\ mm$ extruder setup. Basically it under-extrudes.
> 2 votes
---
Tags: filament, extruder, ultimaker-cura, extrusion, repetier
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thread-9989 | https://3dprinting.stackexchange.com/questions/9989 | What is the correct way to export SVG in order to convert to STL? | 2019-05-20T18:39:48.957 | # Question
Title: What is the correct way to export SVG in order to convert to STL?
I made a simple logo using Inkscape, after saving as an svg file, but when I export that file into Fusion 360 something strange happened.
Multiple times I convert some images (png, svg) to svg file. The process I use is this:
1. Scan logo image (scanner or smartphone)
2. Open image with Inkscape
3. Using the stroke, generate the shape
4. All process for generate and save
This process explained above always works for me, when I copy the shape using the *stroke* in Inkscape.
However, when I was do the process using the *shape generator* \- for example, rectangles, circles, squares, etc. - and export the file into the Fusion 360, it doesn't work.
### 1 - Inkscape logo
### 2 - Logo import to Fusion 360
In the example above, the first word does not appear.
# Answer
Considering the simplicity of your sample design - i.e. basically only two different Z-levels, easily distinguished by color - I'd recommend one of the online image-to-3D model converters. Here are two I've used now and then. You may have to save your image as png or jpg instead of svg.
selva3d and 3dp.rocks
> 1 votes
# Answer
It seems you use Fusion 360. So I will answer for that, based on Autodesk Help:
## Make the SVG
You need to design your SVG to be **just** the **outlines** of your logo. That you can easily do in Inkscape by setting the fill to transparent. Then you need to define a size before exporting it properly.
## Import the SVG
* `Insert` Menu
+ `Insert SVG`
* Select the plane you want to put the SVG on
* Select the folder icon
+ choose the SVG
* adjust the sizing and positioning
* `OK`
> 1 votes
---
Tags: 3d-design, stl, fusion360
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thread-10000 | https://3dprinting.stackexchange.com/questions/10000 | PLA infill/perimeter-layer to mimic real bone hardness | 2019-05-22T05:27:53.360 | # Question
Title: PLA infill/perimeter-layer to mimic real bone hardness
I friend of mine is in need to have human bone printed for educational purpose. Of what I understood they will use it for practicing drilling in it and thus need the printed bone to mimic a real bone. He specified that he wanted them as hollow as possible and with the same (or close to the) density of real bone
Is there anyone who had done a similar print, what material did you choose and how much infill/perimiter-layer did you use.
# Answer
Generally, if you care about achieving a specific structure inside the "interior" part of a model to be printed, that structure needs to be *part of your model* rather than generated by a slicer. If it were me, I would programmatically generate a generic pattern for the pockets of hollowness in OpenSCAD over a region slightly larger than the bone, then subtract it from the solid bone. After that, slicer settings will be mostly irrelevant since it will be constrained by reproducing the layer outlines with lots of holes in them.
I haven't done this, or anything really comparable, but it should work.
> 1 votes
---
Tags: slic3r, material, medical
--- |
thread-4824 | https://3dprinting.stackexchange.com/questions/4824 | How to express dwell time in G-code | 2017-10-29T01:00:22.167 | # Question
Title: How to express dwell time in G-code
I am writing some G-code for my DIY 3D printer. From what I understand, `G4` is dwell and its expressed in milliseconds. So my extruder takes about 30 seconds to heat up. Do I just type
```
G04 30000
```
# Answer
You are correct about needing to specify the dwell value in milliseconds. However, the RepRap Wiki indicates that you need to use the `Pn` argument, and not just an unadorned number as the argument to the command. To adapt the Wiki's own example, you will need to use:
```
G4 P30000
```
This should cause the firmware to dwell (pause) for 30 seconds.
RepRap Wiki: G4: Dwell
> 2 votes
# Answer
Depending on your G-code flavor you may be able to use `M109` (heat and wait) instead. If supported M109 will wait until the target temperature is achieved.
> 4 votes
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Tags: g-code
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thread-10001 | https://3dprinting.stackexchange.com/questions/10001 | Are SLA prints also susceptible to say microbes like FFF prints are with the microscopic flaws? | 2019-05-22T10:56:06.283 | # Question
Title: Are SLA prints also susceptible to say microbes like FFF prints are with the microscopic flaws?
Say if one were to use foodsafe and or medical grade materials, would (m)SLA print be any less hazardous than one created with FFF printer, being eventually suscectible to bacteria buildup?
# Answer
> 1 votes
The best information I could find was this article from Formlabs about food safe 3d printing. It has a fairly detailed discussion of the different food safe requirements and the conclusion basically is that SLA prints are not food safe by default and can create conditions for mold and bacteria growth. SLA resins are toxic when uncured.
The article goes on to list a few options that can increase the food safety of printed objects.
1. Dipping in a food safe coating such as a food grade epoxy or polyurethane. But it does note that this may not make the object food safe as the coating may be compromised.
2. Making a mold from the 3d printed part and using the mold for food contact.
3. Electroplating the printed object with metal.
4. Printing with ceramic filled resins, burning out the resin in a kiln, and glazing the part with food safe glaze.
---
Tags: fdm, sla
--- |
thread-10008 | https://3dprinting.stackexchange.com/questions/10008 | Printer cover for noise abatement, cleanliness, temperature control | 2019-05-23T16:53:19.307 | # Question
Title: Printer cover for noise abatement, cleanliness, temperature control
Has anyone made a cover for their 3D printer? Edit: What kind of Max temperature should be allowed? From the comments, I understand the control board and power supply should be outside the enclosure. I don't see a way to have the stepper motors outside. I do have a thermocouple probe and can monitor the temperature inside the enclosure; what can the motors be allowed to go up to?
I have a Migbot i3 (prusa clone), looks like it will need a 24" x 24" x 16" cover (leaves room to put a spool on a holder inside also). I bought some 18" x 24" polycarbonate sheets to make a square box, but it's looking like it will be a bigger project than it was to get the printer running! I need to cut one down to 6" and join it length wise to get a full 24" for the top. And then print a bunch of corner blocks and drill holes for screws/nuts to secure it all together. Maybe make the front hinge up to lay on top to access the bed and the reel and the finished pieces.
I'm hoping the cover will block out some of the fan and motor movement noise, and as a side benefit keep cat fur & dust out of the mechanism, and perhaps even help keep the ambient temperature a little more even. I'm not sure that ambient temperature drifting makes much difference with PLA, but ABS is allegedly sensitive to that, and perhaps other materials as well.
Edit 5/25/19: Well, I went ahead built one, it's nearing completion. Found 18x24" Lexan polycarbonate sheets, and printed up corner brackets from thingiverse. Top back has a 6" wide space I can hinge up like the front cover to allow more airflow should things get too warm from the power supply or the 0.4mm nozzle. Have been printing PLA on a cold bed with Vertex PEI material clamped on it (waiting for WhamBam system with spring steel and PEX material, couple weeks out on delivery).
Will be securing it to a base so it doesn't get knocked off the folding work bench (again). Some wood added inside for some stiffness, the Lexan is kind of wobbly in big pieces like that. Looking at some magnets to replace the wing nuts/screws on the front cover, they're kind awkward to undo.
Taking off the Lexan protective film soon, might wait until securing to a base piece of wood is worked out. Think I have some thin OSB in the garage left over from another project.
Edit 5/26/19: Printed an hour+ component with doors closed and thermocouple hanging below the LCD screen. Minimal temp rise seen, just 3-4 degreeC, with ambient room temperature also rising some as the sun rose. Printing PLA on unheated bed.
Also changed door closure to have magnets hold closed door in place, works very nice. Wing nuts worked well, but screws stuck out and were hard to open once the screws went thru the door.
(not sure why these are rotated right 90 degrees, they looked fine when I cropped them on my PC)
# Answer
If you want to have an enclosure without actually building one, you can try a server cabinet. Just take out the server racks and use it as an enclosure. And, as there are many server cabinets available, you could probably find one that suits your needs. Currently, I have my FlyingBear P902 3d printer enclosed in a server cabinet. And, although the doors and removable sides might have air gaps, you can always just tape that off (or use an insulation strip). Hope this works.
You could also look at this website: Perfect 3D printer enclosure for Prusa i3 MK3
>
> 2 votes
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Tags: enclosure
--- |
thread-8709 | https://3dprinting.stackexchange.com/questions/8709 | How do I get circles on small interior holes to adhere to the bed? | 2019-04-16T21:12:54.427 | # Question
Title: How do I get circles on small interior holes to adhere to the bed?
I’m using a RepRap printer, PLA (Hatchbox 1.75 mm), SketchUp, and Slic3r. The heated bed is covered with a blue polyester sticker. When I print small holes (1 to 1.5 mm radius), slicer software considers the holes outside edges for the first layer and prints them before the internal first layer. The problem is, unlike the actual outer edges, the holes have no brim and the small first layer circles stick to the extruder rather than the bed. The rest of the first layer print sticks and the print eventually recovers with slight defects depending on where the lifted circles end up. If I could print the first layer circles after the surrounding first layer was printed, this wouldn’t be an issue. I’ve tried different bed and extrusion temperatures. All four holes in different locations do the same. First layer is 0.3 mm thick. Second layer is 0.2 mm thick.
# Answer
are you using hairspray or tape to help with bed adhesion? If not that might help.
Also try printing the first layer slower or try adjusting the bed level offset so you are squishing the first layer down a bit more.
> 1 votes
# Answer
I would use a very slow print speed for the first layer, something like 20mm/s or less.
This will make your first layer so slow you will be tempted to bite the steel rods.
If you were using Cura (I don’t know if Slic3r has a similar feature) you can change this parameter only for those areas where you have these small holes: with the Custom Supports plugin you can specify a different print speed for a specific area
> 1 votes
# Answer
You didn't say what type of bed you have, but I'm guessing glass. Do you have a BuildTak or comparable generic surface you could clip on and use? I've never had adhesion problems like this with my Ender 3, which came with a BuildTak clone; PLA just sticks, with no brim, no glue, no hairspray, etc.
> 0 votes
# Answer
Print at 5% of the print speed, and ramp up cooling to 100%. This should give the plastic time to shrink and adhere to the bed. If not then use a raft.
> 0 votes
---
Tags: pla, slic3r, adhesion
--- |
thread-4980 | https://3dprinting.stackexchange.com/questions/4980 | How do you assure that you print layers that bond correctly? | 2017-11-15T11:26:41.307 | # Question
Title: How do you assure that you print layers that bond correctly?
I'm fairly new to 3D printing but I'm getting the steam up and I chug out pieces without much hassle. One thing though is that I have the impression that sometimes, parts are easily broken, and I suspect bad adhesion between layers.
I'm printing eSun PLA at 208 °C (212 °C first layer), bed at 50 °C first layer then 30 °C.
When I print the Benchy boat, it feels extremely sturdy (even the small chimney is unbreakable by hand), but if I make, say, a 50 mm diameter cylinder with 4 mm wall thickness, It breaks fairly easy along some layer. I don't see any specific error, it "looks" okay.
So my question is:
How do you assure that you print layers that bond enough?
\[Edit\] I already know that might actually cause bad bonding (low heat, underextrusion, ...) but I'm looking for a way to see when it happens.
Here is an image from when I stopped mid print (you can see the little ooze string just at the start at the crack) for checking dimensions. The next layer didn't bond well because, I guess, the already printed part had cooled down when I un-paused the print (say 1 minute later) or maybe the z-axis went off a bit when I touched the build plate.
Is the only way of knowing layers bonded correctly, to try to break the part apart?
# Answer
I think the reason why the large cylinder is breaking much easier than the smokestack would is because of leverage. If you print the same cylinder at a much smaller scale it might be more difficult to break it. Think of taking a wooden stick, if you try to snap it by holding both hands near the center, it would be difficult but if you push on the very ends, the leverage will make it easier to snap. I have the tug boat on my desk right now and I was unable to snap it, instead I broke the cabin section just right above the steering wheel.
Now to answer your question. One of the faults in larger prints having weak layer adhesion could be a number of things. I think a common fault is under extrusion. If the nozzle has a high enough gap from the previous layer and it extrudes just enough filament to touch the layer but not necessarily push it snug, it could be a weak bond. This is like tape, usually when you want to make sure it will stay stuck, you press hard and rub it in. So I imagine filament shouldn't loosely flow onto layers but instead be pressed hard against the previous layers. Visually this is hard to judge but I noticed getting my first layer very close to the print bed makes every other layer stick very stronger on the previous one. You get a small skirt on the first layer but it does tend to give me a stronger bond between layers. You can easily slice off the skirt with a blade. Increasing the extrusion multiplier could give the same affect without needing to adjust bed height/leveling, but this can end up giving you some nasty walls.
Another thing I recommend is to check your Z-axis. This is difficult to measure and best to find out by print quality on tall structures. On my first printer I had the issue where my threaded Z-rods would bind and cause one of the two rods to get a slight bit ahead. This caused a layer split focused on the side opposite of the faulty rod. This made many prints very prone to breaking at that point. I had to rebuild my Z-axis assembly to correct this.
Print temperature can help, try raising it up by 5 to see if this improves the bonding.
Lastly, try another filament. Filament tends to go bad due to moisture exposure, that is why usually you receive it airtight with a small bag of silica to absorb moisture. If I use filament which has been sitting out for months, just squeezing my part separates the layers in almost a slinky kind of way.
> 6 votes
# Answer
No matter what you do, the adhesion between layers will never be as strong as the adhesion in the direction of layer application. It's analogous to a wooden baseball bat (for those old enough to remember them :-) ). If you apply force perpendicular to the "grain," i.e. growth layers, it's strong. If you apply force along the grain, it'll snap pretty easily.
Now, if you print a cylinder vertically, it snaps between layers. If you print it horizontally, the layers run along the cylinder axis and it won't break. That's of course a much more difficult print with extrusion systems, and cosmetically less desirable as well.
> 3 votes
# Answer
(Note: I realize this question is old, but I came across it looking for information on related topics and it didn't seem to have any sufficiently good answers yet.)
To me, this looks exactly like what I'd expect printing with layers almost as thick as the nozzle diameter and insufficient hotend temperature or excessive speed. I've had problems like this at sizes 0.3 to 1/3 mm using an 0.4 mm nozzle even at my usual PLA temperature of 210, and can imagine it would be much worse at lower temperatures. If you didn't see the problem on benchy with a smaller cylinder, it's probably either because acceleration limits (which will be dominant on small details) prevented reaching high speeds, or (less likely in my opinion) because the deposited material had not had as much time to cool before the next layer was reached.
In order for layers to bond the newly deposited material needs to be pressed against the material already present, while melted, with sufficient heat transferred into the already-deposited material to make it amenable to bonding (naively I would guess this means it needs to reach around the glass transition temp, but that may be wrong). With layer thickness near the nozzle diameter, the nozzle will be putting less pressure on the existing material, making this harder. Also, if there has been underextrusion anywhere in the supporting wall below, the already-deposited material can simply compress downward into the gaps when new material is extruded against it, rather than them getting pressed together.
For 0.3 mm layers, I'd go with the highest temperature the filament manufacturer rates it for, or even slightly higher if you have reason to believe the material is okay at higher temperatures. Some people say lowering the fan speed or turning it off is an option, but I've had really bad results with precision and/or stringing whenever I try that.
Significantly lowering the print speed is also an option. That will greatly reduce the chance of underextrusion, and results in more heat transfer from the nozzle into already-deposited material. However lowering the speed generally defeats the purpose of 0.3 mm layers; you could instead just drop down to 0.25 mm or 0.2 mm and get much better quality at the same total print time.
> 2 votes
# Answer
From my experience the most profound difference is in the material. Especially with eSun PLA that I have used over 10 spools I have found huge inconsistencies. In one spool the printing adhesion was fine on other spools it was very very bad. My first advise is try another branded filament, I would recomend Colorfabb, Polymaker and Formfutura for PLAs. Secondly if you want to use the eSUN try higher temperatures, go above 210 or even 220.
> 1 votes
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Tags: pla, print-strength
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thread-10041 | https://3dprinting.stackexchange.com/questions/10041 | Dual Filament Mixer Marble Effect | 2019-05-28T08:19:31.967 | # Question
Title: Dual Filament Mixer Marble Effect
I'm looking for some software, that could create marble effect on product from two filaments, not just gradient, but evolving color change.
Do you know some slicer or some tool that can generate printer file like this from model?
# Answer
> 2 votes
E3D has a Cyclops product which mixes two filaments inside a melt chamber. Clones of the E3D Cyclops can be found through the usual outlets. E3D also has software recommendations for using their Cyclops product, which are found here. They suggest cura as the slicer.
The RepRap firmware (and possibly others as well) allow two extruders steppers to be used in an extrusion move, proportionally mixing two filaments.
In case you want to go further, to get a broad color gamut, you will need five filaments mixed into one extrusion bead. Cyan (sky-blue), magenta (or bright purple), yellow, white, and black filament can be mixed to make most colors. "2D" printing is done with four colors (cyan, magenta, yellow, and black), but for 3D printing, you also need white. 2D printing uses white, but it is the white of the paper. Black is needed to get dark colors, as well as to form neutral gray colors.
Based on the OPs comments, I understand that the software sought is a shader that creates a marble effect on the surface of a print. I don't know of such software, but, as a software engineer, I imagine it would take roughly this form:
1. Slice the object conventionally, producing G-code for the object. Identify all exterior extrusions with a special extruder number. Multi-material slicers should provide this option (Slic3r-PE does).
2. Project a 2d image or synthetic pattern onto the 3D external surface of the object.
3. For each voxel (volume pixel) of the exterior extrusion, determine what it's color should be based on the shading.
4. With previously determined propagation delay from when the mix is set to when the color is extruded, back up along the extrusion path the correct distance.
5. Split the extrusion command at the point where the mix must be changed. Insert new extrusion values.
6. Output the modified g-code.
I've left out many implementation details.
The scheme depends on how predictable is the delay (in extrusion distance) from when the extrusion mix is changed to when the change comes out of the nozzle. The variation (if any) in that distance will make the output look jagged and fuzzy. In some ways, that variations limits the 2D bandwidth of the color information.
Schemes that require sharp, line-to-line coherence may require a purging process. I assume that for a marble pattern, which I characterize as having soft color changes on a scale that is larger than the extrusion width, purging on every change is not desired or possible.
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Tags: print-material
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thread-10050 | https://3dprinting.stackexchange.com/questions/10050 | Weird lines and smaller height | 2019-05-28T22:57:56.980 | # Question
Title: Weird lines and smaller height
I finished my first print and it came out like this
I calibrated all my axis steps and manual movement gives perfect numbers.
I am printing with these slicer settings:
>
I don't even know where is the problem to begin searching for a solution. It's my very first print after a couple fails and a lot of calibration to Z axis and bed leveling.
Update the printer without the heatbed as it's an older picture:
The Z axis moves on 2 lead screws and 2 rods with bearings all of which attached to the plate.
# Answer
I'd say that your axis aren't square, aren't tightened enough and you seem to have overextrusion as well. That would explain why all your layers are wobbly and not neatly stacked on top of each other, why your cube is far being being a cube (the picture of the X face shows it clearly) and the quality of surface finish on the top.
I do not know what kind of printer you are using, but I would advise you to check that the X and Y axis are correctly calibrated and that they're perfectly square, which would ensure that each layer is correctly stacked on top of the previous one to produce a nice cube. And make sure to tighten the axles to avoid the noise in the print due to the vibration produced by the printing.
As for the overextrusion, you'll need to make more test with your printer and the material you're using, changing temperature, and print speed until you find the right combination that will extrude just enough material through your nozzle.
> 2 votes
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Tags: print-quality, diy-3d-printer
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thread-5962 | https://3dprinting.stackexchange.com/questions/5962 | Problem with swapping E0 for E1 (TEVO TARANTULA MARLIN 1.1.x) | 2018-05-13T14:38:40.067 | # Question
Title: Problem with swapping E0 for E1 (TEVO TARANTULA MARLIN 1.1.x)
Looking at the following code, from Line 139, pins\_RAMPS.h
Here is the actual code:
```
#if ENABLED(EXTRUDER_USE_E1)
#define E0_STEP_PIN 36
#define E0_DIR_PIN 34
#define E0_ENABLE_PIN 30
#ifndef E0_CS_PIN
#define E0_CS_PIN 44
#endif
#else
#define E0_STEP_PIN 26
#define E0_DIR_PIN 28
#define E0_ENABLE_PIN 24
#ifndef E0_CS_PIN
#define E0_CS_PIN 42
#endif
#endif
#if DISABLED(X_AXIS_USE_E1) && DISABLED(Y_AXIS_USE_E1) && DISABLED(Z_AXIS_USE_E1) && DISABLED(EXTRUDER_USE_E1)
#define E1_STEP_PIN 36
#define E1_DIR_PIN 34
#define E1_ENABLE_PIN 30
#ifndef E1_CS_PIN
#define E1_CS_PIN 44
#endif
#endif
```
I've already tried everything that the online community tells me to do to solve this problem, but that all doesn't help me. Almost everyone is saying that I just have to swap these lines of code and it will work, but it's not working. Any ideas ?
By the way E0 is not working because I've burnt a pot on it :)
# Answer
> 1 votes
At first it was unclear from where the snippet you posted is taken from as it was not stated in the question (*this has now been addressed by a moderator edit*).
Depending on the value of `EXTRUDER_USE_E1` (and where and how it is set) the underlying code of the if statement will be carried out. Albeit said, swapping lines will not work, if you want to use the E1 connector of your motherboard, you have to make the printer think that it is using the E0 while it is redirecting to E1! This implies that you need to assign the pins of the E1 to the E0 extruder (so swap the pins, not the lines). This has been explained before in this topic by editing the correct pin layout file of the Marlin firmware.
---
**EDIT :** Further investigation shows that you have a custom Marlin for the TEVO Tarantula and are using the fork of Marlin maintained by JimBrown (**this is essential information** for your question). I have looked into the files, the only thing you would need to do is define the constant `EXTRUDER_USE_E1` in your configuration.h file:
```
//#define EXTRUDER_USE_E1
```
to:
```
#define EXTRUDER_USE_E1
```
So do not swap anything. Once this constant is defined, the pin re-allocation is done for you automatically! (see the pins\_RAMPS.h file)
Basically, this is exactly the same as is explained in topic How to change E0 to E1 on Marlin 1.1? and hence a duplicate. ;)
# Answer
> 0 votes
I simply swapped the pins
```
#define E1_STEP_PIN 26 //swapping to E1 FRED
#define E1_DIR_PIN 28
#define E1_ENABLE_PIN 24
#ifndef E1_CS_PIN
#define E1_CS_PIN 42
#endif
#define E0_STEP_PIN 36 //swapping to E0 FRED
#define E0_DIR_PIN 34
#define E0_ENABLE_PIN 30
#ifndef E0_CS_PIN
#define E0_CS_PIN 44
#endif
```
Which worked for the basic operation, however now that I've tried to add Autoleveling it stopped moving E1 motor. My configuration.h file does not have:
`#define EXTRUDER_USE_E1` apparently as its an older version also, just like RAMPS.h doesn't have those conditional statements.
---
Tags: extruder, marlin, tevo-tarantula
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thread-10045 | https://3dprinting.stackexchange.com/questions/10045 | Short circuit on RAMPS 1.6 board? | 2019-05-28T18:57:20.927 | # Question
Title: Short circuit on RAMPS 1.6 board?
I have a RAMPS 1.6 board. After soldering my stepper drivers, I probed them for bridging and found a short where none should be. Digging deaper into it, my multimeter shows continuity between the 12V +/- connectors (on occasion).
I have scanned the whole board repeatedly for solder bridges, but could not find any. Are there any known weaknesses that I should look for or any specific place I should look at to repair it?
# Answer
Your multimeter showing continuity doesn't necessarily mean there is a short.
All your multimeter is doing is applying a small voltage and then, if the current that flows is over a certain threshold, reporting that there is continuity.
The components (stepper drivers, microprocessor) on the board, draw current. That's normal. The current draw might be enough for your multimeter to report continuity. Because the multimeter is only using a small voltage to test (and not the required 12V), the current draw may be intermittent (not enough voltage for the microprocessor to actually start working), and capacitors getting (dis-)charged may also affect things.
The multimeter *not* reporting continuity is a guarantee of no short. However, the multimeter reporting continuity does not mean there is a short. The only way to find out is to apply 12V. If you use a current-limited power supply the possibility of damage if there is a short circuit is limited.
> 2 votes
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Tags: electronics, ramps, ramps-1.6
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thread-10055 | https://3dprinting.stackexchange.com/questions/10055 | Laser LA03-5000 wiring to RAMPS 1.4 | 2019-05-29T11:51:22.883 | # Question
Title: Laser LA03-5000 wiring to RAMPS 1.4
I'm totally lost. I have been searching about two days how to correctly wire Blue Laser LA03-5000 to RAMPS 1.4 board.
This laser has 12 V input and separates PWM/TTL wires. I have found out how to control laser with no PWM (just hook it to D9 same as a fan), but how do I correctly wire this type of laser? I really want to wire it correctly for safety reasons.
# Answer
Please look into this question, this is a very similar question and also involves PWM and a RAMPS 1.4 shield.
In your case you connect the top red wire on the right bottom connector to the D4 pin and adjust the firmware accordingly as described in this answer.
The bottom 2 wires of the lower right connector should be connected to ground and 12 V (resp. black and red).
> 1 votes
---
Tags: marlin, ramps-1.4, laser, cnc
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thread-10018 | https://3dprinting.stackexchange.com/questions/10018 | Minimum material deposit threshold in slic3r | 2019-05-24T13:09:46.600 | # Question
Title: Minimum material deposit threshold in slic3r
I've been using Slic3r for a while now, and for the most part am happy with the results it produces. I mostly use the standard profiles provided by Prusa for my i3 mk3.
However, when watching the 3D printer at work, executing GCODE produced by Slic3r, I notice that frequently the printer makes large travel moves, deposits an absolutely tiny amount of material and does this several times in a row. Sometimes this is so small, barely any material actually comes out of the extruder. I'm convinced the end result would be no different if these operations were simply skipped. In some instances it might even improve print quality, due to reduced stringing.
It strikes me that print time and printer wear-and-tear could be significantly reduced if there was an option to simply skip deposits of material below a certain threshold of volume.
Despite having gone through all the Slic3r options, I've never found something which does this, unless there is a way to achieve it with some combination of settings which I have not understood.
My question is therefore: how can I tell Slic3r not to make individual material deposit moves, below a certain volume?
# Answer
It does this in small corners.
For example, this model, when sliced has this on layer ~7:
Tiny tiny bit of blue infill.
There seems to be no feature to explicitely disable this. But sometimes an additional perimeter solves it.
> 1 votes
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Tags: slicing, slic3r
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thread-3771 | https://3dprinting.stackexchange.com/questions/3771 | Commercially available 3D printer fume and UFP extractor | 2017-03-19T14:24:01.617 | # Question
Title: Commercially available 3D printer fume and UFP extractor
Is there a commercially available fume and nano particle extractor for a 3D printer, like the Ultimaker3 extended? I'm looking for a safe solution, to use at home, for around $800.
# Answer
> 7 votes
Following on from Harvey Lim's answer, to give a concrete example of a DIY filter, which uses active carbon, see ABS 3d Printer Nanoparticle and Chemical Exhaust Air Filter:
> ###Description Enclose your 3d printer and use this exhaust air filter along with a recirculating air filter to eliminate nanoparticles and chemical fumes. 95 to 99.5% of partilces up to 0.1 micron in size are filtered before air is exhausted into your 3d printing room. This is 3 times better than HEPA filtration. Chemical fumes such as phenols, hydrogen bromide, hydrogen cyanide, and styrene are also filtered out. The amount of chemicals filtered out depends on the amount of carbon filtration media you put into the unit and the strength of the fan you install on the unit. If you are using this for business purposes, you'll have to experiment a bit to have it pass inspection. If you are using it for personal purposes, know that the human nose is extremely sensitive. People who have the gene for hydrogen cyanide detection can smell it down to a concentration of 2 to 10 ppm. Suffice it to say, that if you can smell no evil, you are probably not experiencing evil. This has totally cleared my 3d printing room of nasty fumes. I invite you to try it out for yourself as the cost is very low since I've designed it to use surgical masks and aquarium activated carbon filtration media, which is very affordable. You should change the filtration media and surgical mask every month or 50 hours of printing, whichever comes first. I offer no warranty of any kind as this is an experimental device.
This filter is mentioned in tbm0115's answer to What are the best air filtration options for enclosures?
# Answer
> 2 votes
At the current moment, commercial fume extractors are quite rare in the market, but there are companies releasing some this year (like the 3DKreator's SYNE system). However all commercial forms of it are quite expensive.
What I would do would be using an active carbon filter with a fan.
# Answer
> 2 votes
Dust collectors, fume extractors, and mist collectors for other industrial processes like welding, machining, and woodworking start at a few thousand dollars.
The Allerair AirMedic Pro 6 (formerly 6000 series) is available from as low as $600. It is marketed in some places as an air purifier but others as a general purpose air filter. In any case it uses activated carbon and a HEPA filter.
# Answer
> 1 votes
Matterhackers and Printedsolid both carry the BoFa Print Pro filters. The Print Pro 3 has the benefit of recirculating the filtered air so that it doesn’t drop the enclosure temperature as much. Printed solid has it for \\$899 currently. The filters are about \\$300 to replace the prefilter and the combined Hepa/carbon filter.
Greenonline's answer gives a DIY solution that seems like a good option. Surgical masks won’t have a very high filter capacity though.
None of the other answers give a commercial filter solution that is available without also buying an enclosure.
# Answer
> 0 votes
To try to answer your question, I found these enclosures on 3DPrintClean, by browsing the Ultimaker forum. I'm not sure it fits your needs since you did not give any details about which Ultimaker you have, nor the amount of money you are willing to spend.
# Answer
> 0 votes
There are two main options you could consider. The first being a diy filter and the second being a commercially available fume extractor.
---
**Option 1**
You could make a filter yourself. On Thingiverse, there are many ideas that you could implement. A few examples are these :
https://www.thingiverse.com/thing:1992079
https://www.thingiverse.com/thing:2285882
https://www.thingiverse.com/thing:2105113
---
**Option 2**
Buy a commercially available fume filter. An example that would be well below your budget ($178) would be the Zimpure (https://www.zimple3d.com/zimpure/). This is a device that will vacuum the fumes right by the nozzle and filter them. Additionally, you could get this filter from Matterhackers : MatterHackers. This could be an option if you are willing to go a little bit above your budget. If you would rather have a filter for 30 bucks, you can also look at this filter that attaches to your enclosure : https://www.3dupfitters.com/products/fan-and-charcoal-air-filter.
Lastly, if you wanted to go all out, you could also get this enclosure : https://www.3dprintclean.com/.
---
I hope any of these solutions named might be beneficial to you :). For even more options, visit this post : What air filtration options exist for enclosures?
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Tags: diy-3d-printer, safety, enclosure
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thread-9996 | https://3dprinting.stackexchange.com/questions/9996 | PID autotune fails under all conditions so far. Any ideas I haven't tried? | 2019-05-21T17:35:11.247 | # Question
Title: PID autotune fails under all conditions so far. Any ideas I haven't tried?
I got some Prusa i3 clones with Melzi boards with Marlin, or nearly so. One of them performed very well (considering that the board would reboot whenever power was applied to the build plate. But I digress) until finally the hot end failed, possibly due to me running it for two days with little respite. The replacement, a typical MK8 clone, installed almost painlessly but failed to start due to over-temperature conditions (we're talking as much as 45 °C over set temperature). I tried the known solutions, continually reducing my P value (got down to 7 before I gave up) and attempting autotune. I also tried autotuning to both higher (230 °C) and lower (150 °C) temperatures.
None of these seemed to produce an autotune successfully, and the same error message `temp to[sic] high` appeared in all cases. Can anyone suggest something besides a new hot end (I have one on order, but what if I have the same problem with another new one)?
# Answer
Turns out I'm using a 12V hot end and should be using 24V. I looked up the resistance to be sure; so no amount of tuning the PID would fix that.
> 0 votes
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Tags: prusa-i3, hotend, pid
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thread-4575 | https://3dprinting.stackexchange.com/questions/4575 | What could be causing this spotty extrusion? | 2017-08-31T23:17:18.843 | # Question
Title: What could be causing this spotty extrusion?
I'm getting this printing where it's not laying the plastic down very well. What could be causing this? I've printed with these settings before, and it turned out just fine. If you need any other info to properly diagnose this, let me know.
I'm using a Robo3D R1+
\[
# Answer
I´ve seen this in my Prusa due two parameters that may vary your results depending on climate if your printer has not a temperature chamber or having a mechanical issue too.
Lack of extrusion is due a cold filament which it can't reach the melting temperature due a fast extrusion feed; I mean in normal conditions we can print @70 mm/s with 195 °C but on wet or colder days is not possible so I need to slow down the speed (feed rate) with 10 % less than normal to get @60 mm/s or less until get a good flow with out modifying the G-code. If I try to print faster on normal conditions I will get the same lack of material due 195 °C is a low temperature (this is an example).
If I set the temperature 200 °C or 210 °C I will get a better flow and also print faster than @80 mm/s (not affected too much on climate on 100 % feed rate).
For first layer I´m using an speed of 40 mm/s to allow a good adhesion and Z height 90 % of layer height (0.22 typically or 0.18).
Mechanical side: The extruder is not feeding all the filament due a missing pression on the traction gear (filament slip).
> 4 votes
# Answer
I had this problem also. After a few hours of troubleshooting and changing the extruder temp, printing speed, layer height, and infill density. I realized that I had set the PLA diameter at 2.85 mm when it was 1.75 mm. Changing that fixed all my problems.
> 1 votes
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Tags: print-quality
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thread-10081 | https://3dprinting.stackexchange.com/questions/10081 | Tronxy Marlin boards (two of them) reboot when asked to heat bed | 2019-05-30T03:13:06.703 | # Question
Title: Tronxy Marlin boards (two of them) reboot when asked to heat bed
I have two Tronxy 2.0 V5 Marlin boards that reboot whenever heat is applied to the bed. The bed has been swapped (because I thought that was the problem) for a new shiny one. The thermistors, too, of course. The same boards (both) work when the beds remain unheated (setpoint = 0 °C).
Any ideas what might be causing this, or what I might do to figure it out?
Note: I really have no idea which Tronxy board this is; the "2.0" is stenciled on the board, so that's all I can figure out. I shamefully admit I tagged it with Tronxy x1 to see if I could generate any interest, and because a "Tronxy" tag is not available.
# Answer
It sounds like a power-related problem. Always use an external MOSFET to drive a heated bed, and consider investing in a decent power supply. Inevitably, the Tronxy PSU will be barely adequate.
Edit: I've just noticed the tag. Be aware that the stock (60 Watt) PSU for the Tronxy X1 cannot power a heated bed (the printer does not have one). Trying to do so will overload the PSU and cause an immediate reset.
> 6 votes
# Answer
First, check the power supply. Although it may be specified to deliver the required power, it is possible that the power supply has failed in a way that it can not deliver the rated power. At lower load, the voltage may be correct, but under higher load, it either droops or cuts out completely.
To check this, use a voltmeter on the power as it enters the CPU board, not where it leaves the power supply. This accomplishes one additional check. If the voltage droops rather than cuts off, it may be that the connections have corroded and have a higher resistance.
If you have any kind of oscilloscope, I would recommend it over a simple voltmeter, because the power interruption or droop time may be very short. When the CPU resets it will switch off the load that causes the problem, and the power may quickly resume the correct value.
Second, check that there is not a short in the bed wiring. You might detect that with an ohm meter. You have used two different CPU boards, to it is unlikely to be a common fault on both boards, but you might be using the same wiring.
Third, check the routing of the bed heater wires to see that they are not near other wires which connect with the CPU, including thermistor wires and wires to the UI. High-current switching in the bed wires could be coupling into other wires and conducting a RESET signal to the CPU. Ideally, the heater wires will be twisted together with about 3 (or more) twists per inch, and not twisted together with other wires.
> 2 votes
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Tags: marlin, heated-bed, firmware, tronxy
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thread-10090 | https://3dprinting.stackexchange.com/questions/10090 | Can commodity 3D printer extrusion hardware and filament be used for injection molding? | 2019-05-30T17:24:08.737 | # Question
Title: Can commodity 3D printer extrusion hardware and filament be used for injection molding?
Assuming you have a suitable oven to maintain temperature at the filament melting point and a suitable mold that can handle the temperature, is a commodity 3D printer hotend and extruder, with large nozzle, suitable for injecting material into the mold? I'm thinking of a setup like having the hotend mounted through a wall of the oven, braced against a hole in the mold inside the oven, and feeding filament via motor or manual cranking outside. Or is much higher pressure needed to make something like this work?
Certainly there are better setups to do this for manufacturing at scale, but the point of this question is whether you can do it with minimal setup effort and cost using commodity parts and filaments rather than needing expensive or custom-built equipment and material sourcing.
For relevance to the site in case it's questionable: certainly if this technique is possible, it could be used along with initial 3D printing of a design and using that to produce a (e.g. high-temperature epoxy) mold.
# Answer
Injection molding requires two major components: pressure and heat. So your question can be broken down into those two halves: can your average extruder handle injection molding temperatures, and can it handle injection molding pressures?
**Let's start with pressure.** Per this page on the University of Minnesota's site, plastic injection molding tends to require pressures of around 2 to 8 tons per square inch. Assuming you're using a 0.4 mm nozzle, which has a cross-section of 0.126 mm², that works out to be 0.000195 (1.95E-4) square inches, which translates to about 3 lb of pressure total at the nozzle assuming you're going for the high end of 8 tons (16,000 lb). However because of the way that you're treating the molten filament in the extruder as a hydraulic fluid, you've got to deal with the fact that the "piston" on one end is actually quite a lot larger area, which means you have to multiply the force by that difference in size. The cross-section of 1.75 mm filament is approx. 9.62 mm², or 0.149 in². That's 76.4 times larger, which means you need to be pushing on the end of that filament with roundabout 230 pounds, or 105 kg, of force.
For reference, the Nema 17 that's on my extruder is spec'd at 76 oz-in of torque, geared down 4:1 through a Wade's extruder, and then acting on a hobbed gear with a 6 mm effective diameter (3 mm radius). Much to my own surprise, as I write this, that means that my little plastic extruder is actually capable of just north of 160 lb of pressure force! All these numbers would need to be recalculated for 3 mm filament, and I have no experience with 3 mm, so we're going to skip that one for now.
Now, that being said, my extruder is also capable of shredding filament if conditions aren't just right. The main two problems you'll have to overcome is 1) gripping the filament hard enough without destroying it, and 2) keeping the filament from buckling. I think if you got clever with some gears keeping multiple hobbed gears synced up, and a polished aluminum or steel feed tube, you could absolutely make your own extruder that's capable of consistently putting 300+ pounds of force on your plastic filament without it buckling or stripping. The downside is that your feed rates are going to be fairly slow, so each injection molding is likely going to take you quite a bit of time. A larger motor such as a beefy NEMA23 might help offset that by giving you much higher torque at higher speeds, so long as you can melt the filament fast enough. However we'll need to revisit these pressure numbers in a few moments, after I explain a few things about temperature.
**Next, let's look at temperatures.** Obviously we know that we can melt the filament itself as it's moving through the extruder. Using a Volcano nozzle or something, you can even guarantee molten filament at a fairly high extrusion rate. However most printers are designed such that the filament cools to solid (60-80 °C normally) almost immediately. Injection molding designs require that the entire mass of plastic be kept molten. Fortunately, ABS and PLA melting temps are easily reached by literally any toaster oven, so stick your setup in there and you're golden, right?
**But wait, there's more!** One of the problems you'll run into immediately is that extruders are carefully designed so that the plastic is molten for as little time as possible, because molten plastic against a metal tube introduces a bunch of friction, hence the need for super high pressures during injection molding. If the plastic melts too soon, then you'll clog up your heatsink (the "cold" side of the extruder), and won't be able to extrude at all. This is a fairly common source of jams in 3D printing, where you're extruding too slowly and there's not enough cooling on the heatsink. Fortunately, E3D sells a water-cooled Titan extruder that would keep the heatsink cool. However the rest of your gearing assembly, and the motor, will also need active cooling, as heat damages the permanent magnets in the rotors, and the printed geared assembly obviously will melt if put inside an oven. Your best bet might be a water-cooled Bowden setup, assuming you can find tube fittings that can withstand several hundred pounds of force. You might look into using solid tubes like brake line rather than your normal PTFE shenanigans.
**TL;DR:** Get you a water-cooled extruder, make a super-strong Bowden setup, and gear down a huge motor with a bunch of synchronized hobbed gears, and you might actually pull it off! There's plenty of Thingiverse extruder files you can use as a starting point.
As far as commercially available extruders go, however, I don't think you're going to find anything that's immediately available that can handle what you need it to without some level of modification depending on your selected injection pressures.
> 8 votes
# Answer
An injection molding injector melts all the plastic needed for the shot and pushes it into the mold and through the sprue very quickly. Perhaps that is why it is called a "shot".
Injection molding machines do not heat the mold to plastic-melting temperatures. This works because the plastic is injected quickly, and fills the mold before the plastic cools. Molds are designed so that this happens, and often include multiple thick sprues to direct plastic to all parts of the hold.
Injecting with a 3D printer extruder will be a slow process. If the mold is not above the melting point, the plastic will cool and likely become a tangle of thread at the entrance of the mold. To combat that, you could heat the mold. This is doable, and will suitable insulation the temperature of the cold end and the extruder should be acceptable.
With the mold heated, you would inject plastic until the mold is full. The mold heater would then be disabled and the mold would cool. This would take a long time.
Injection molding machines typically have water-cooled molds to cool the plastic more quickly. Time is money for an injection molding factory, and cooling quickly is key to productivity.
For the 3D printer injection molding machine, the time when the plastic is hot could be fairly long -- longer than would typically be found in injection molding. I am concerned that some plastics, perhaps such as PLA, would degrade or burn during the long molten time. Experience would be required.
> 1 votes
# Answer
Yes, technically you can but only for small parts.
However the size of the object would be limited (about the size of a button). It has to do with the power of the heater element. Its too small to deliver enough thermal energy to heat enough plastic fast enough to fill a large cavity (i.e. anything larger than a button in my humble opinion). The previous answers give a breakdown as to why. Normally in an injection molding machine, the plastic starts cooling when it hits the walls. As the first set of plastic hits the wall of the mold, it sticks and starts cooling. You have to get the rest of the plastic in before that area cools back down and solidifies. Practical for a small part, but not for a large part.
As for your idea about keeping the mold itself hot, yes that would work, if you could keep the temp within range. Overheating the plastic destroys the bonds, weakening the part. Too cold and it will clog.
But I say try it with a Volcano hot end and an actual mold. The plastic will melt faster if you use a preheater (a second hot end, that is upstream), to print the plastic up to 80% temp before it enters the final extruder.
> 1 votes
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Tags: extruder, hotend, print-material, molds
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thread-10061 | https://3dprinting.stackexchange.com/questions/10061 | Are there practical reasons to NOT use a stepper motor with lead screw for the X and or Y axes? | 2019-05-29T21:13:49.873 | # Question
Title: Are there practical reasons to NOT use a stepper motor with lead screw for the X and or Y axes?
After a few months of printing with my Prusa Mk3 (with plans to get a second one soon), I have been wondering about making my third printer a home-built one was a larger print bed than the Mk3. One thing I wondered about is perfectly expressed in the title question.
Are there practical reasons to **not** use a stepper motor with lead screw for the X and or Y axes?
I am certainly happy with the GT2 belts used in my current printer, but I wonder if the design might be simpler with lead-screws on all three axes.
# Answer
I am going to answer this as someone who actually did rework their Prusa i3 fleabay clone to use leadscrews for all axes. Before digging into the matter, the backlash issue can be solved easily with spring-loaded brass nuts, kinda like how ballscrews work. That's the simplest problem to solve though as there are a lot of other issues.
## Short version / tl;dr
1. Hardware can't handle that many microsteps.
2. Crosstalk and motor inductance limit speeds and acceleration.
3. Print quality suffers in really weird ways because of (2).
4. Leadscrews are not made for quick movement over extended periods of time and will wear, even with grease.
5. You'll need additional bearing surfaces to prevent your motors from grinding themselves apart, and to eliminate backlash due to the flex couplings.
6. The system becomes a lot more prone to highly destructive failure modes.
## Long explanations
### First
You're going to notice is that you're constrained to horribly, horribly slow movement and acceleration rates. My screws are 8 mm screws, with 8mm pitch. That means it takes 200 steps to travel 8 mm. Multiply by 1/16th microstepping, and that's 3200 microsteps per 8 millimeter of travel. Multiply by whatever speed you're trying to print at, then the number of axes you're using, and you'll find that your RAMPS board starts to stutter on complex moves if you print fast enough.
### Second
You'll quickly hit the inductance limits of your motors. At "standard" power levels (ones that don't fry my knockoff NEMA17 motors), even after switching to 24 V for the entire setup, the fastest I could spin my motors was about 5 revolutions per second, which translates to 16,000 microsteps per second with 8mm pitch screws. For reference that means that under ZERO load, the fastest my N17 w/ 8 mm pitch could travel, is about 40 mm/s.
You're basically running the motor coils at several kilohertz, which means you have to be really careful about keeping your wires separate and shielded to prevent crosstalk, in addition to the fact that as your step frequency goes up, your step torque goes down dramatically. Not only does this limit the weight of the bed that the motor is capable of pushing at a given speed, but you even have to worry about the inertia of the motor and bed much more than with a belt-driven system. So instead of 30 mm/s jerk with 200 mm/s<sup>2</sup> acceleration, suddenly you're limited to, say, 5 mm/s jerk and 40 mm/s<sup>2</sup> acceleration.
As mentioned, for best results, the whole system needs to be converted to 24 V, and not all boards are configured for this to be easily done. My cheap RAMPS clone only needed a single diode removed and everything else was fine, but YMMV in this regard.
You *could* solve this particular problem by gearing the motors down, but at that point you've now introduced a new source of backlash either between the gear teeth or in the belt drive system, and kinda defeated the point.
### Third
Due to this effect, is that you run into extrusion pressure artifacts. Basically, the plastic in the nozzle is a fluid, a very viscous one, being forced through a small hole. The fluid pressure will "lag" somewhat behind what the extruder motor *thinks* is happening.
The end result is that while you're accelerating, the lines you're laying are thinner than they should be, and will be thicker than they should be while decelerating, and you tend to get weird "globs" on each corner when you come to a stop. For me, with a 0.4 mm nozzle, 0.8 mm line width, and 0.2 mm layer height, these artifacts actually completely offset the additional accuracy I was getting with a tightly-coupled leadscrew with spring loaded dual nuts on it. The parts ended up being even less dimensionally accurate than before, with very strange deformities.
There ARE settings you can use in the firmware to try and combat this specific effect, but the process is tedious and takes a lot of trial-and-error, and recompiling the firmware every 30 seconds is annoying, not to mention the variables are dependent on line width, speed and acceleration settings, and layer height, so you have to recompile your firmware any time you want to change the print quality. Super, super annoying.
### Fourth
Leadscrews aren't actually designed for this. The constant back-and-forth motion will wear the brass nuts and even the steel threads of the screws over time. You end up with a black powdery residue on everything underneath the screw, which, in the X axis, typically also means your print. Nobody wants steel powder messing up their layer adhesion.
In my case I used Superlube, which is a silicone/PTFE grease, to help prevent this problem, but that only works so well when you've got spring-loaded brass nuts. Eventually they push most of the lube out. Additionally, the lube tends to grab and hold any metal powder that does form, accelerating wear in areas that are still lubricated.
### Fifth
Bearings. Turns out motors have internal bearings, that generally suck and aren't made for heavy loads in any direction. I found that out when my Y-axis N17 motor failed because the bearing did, and spread powder all over the coils, some of which got pushed through the enamel and shorted the wires out.
Additionally, because tiny amounts of misalignment turn motors into shrapnel in a hurry, you're almost certainly going to be using flex couplings. Flex couplings have a certain amount of yield to them axially, and are primarily designed to be under compression loads, and tend to fail when stretched repeatedly.
For the Z axis this is normally not an issue because the whole system is held down by gravity, but in the X and Y axes, you'll get some weird offsets of even a millimeter or two each time the carriage or bed switches directions. So you'll want to make sure that the motors aren't load bearing themselves, and the screw remains locked relative to the frame while still being able to rotate.
You can accomplish this by having a ring fastened to each end of the leadscrew that either pushes on a thrust bearing or rides in a regular ball bearing. Ideally, you can do both, but this turns into an expensive venture with a whole lot of brackets in odd places that you may not have space for. I ended up losing about 20 mm of bed travel solving this problem.
### Sixth
You need to think about what happens when a component fails. For me, it was my endstops. The first failure was from the crosstalk issue I mentioned above. Y-stops triggered, bed started shifting towards the front of the printer over time, and eventually the printer started trying to move the bed through the front of the printer frame.
It was successful.
The second time was simply the endstop switch failing mechanically. Belt travel stops at the pulley. Leadscrews go all the way to the end of the screw, and because they're geared so much lower than belts are, there's a lot more torque involved. I destroyed my printer frame three separate times because of this problem, and once more when the Y-axis flex coupling snapped. This allowed the motor to spin the screw easily in one direction but not in another - which this time forced the print bed backwards instead of forwards, yanking the Y motor through its bracket and the frame again.
## Conclusion
X/Y screws are not necessarily a *bad* idea, simply an expensive and tedious one in 3D printing. They're much better suited to low-feedrate applications like CNC mills, mechanical engravers, and the like. You may notice that even high-accuracy applications like laser printers tend to have belt-fed carriages rather than screw-driven ones. Screws are much better suited to high load, low-speed applications, and printers tend to be the opposite of that.
If you're trying to eliminate backlash due to the belts not being tight enough, as I was, the answer is to make a better printer. I couldn't tighten the belts enough to get my prints accurate before the motors started failing, because I didn't have the motor-end pulley supported by a bearing. Start there, literally just support on either side of the pulley on the motor shaft with a small bearing braced against the frame to take the radial load off the motor. If your belts are stretching too much, use steel-core GT2 belt. If your system is overall just sloppy, build a more robust system. My current project is a Hypercube Evo, and I found a supplier that makes steel-core GT2 belt. I'm going to use that to maximize rigidity in the CoreXY belt system. The frame is made from 30x30 mm T-slot extrusions, with 12 mm Z-axis rods and 10 mm X/Y axis rods. Bigger, more expensive components that are way more robust and will flex much less than the 400 mm long 8 mm rods on my cheapo printer.
Hope this helps. (edited to get my math right on the microsteps)
> 16 votes
# Answer
In addition to cost, *backlash*, which can be experienced in the Z-axis where threaded rods and leadscrews are mostly commonly used, would/could become an issue. The elasticity of GT2 belts generally avoids this issue for the X and Y axes.
It would be worth reading Tom's answer to Advantages of GT2 over a rack, which while the question was related to *Rack and Pinion* mechanisms, would also apply to leadscrews, in particular:
> To avoid backlash and get the same kind of "tight" engagement, both the gear and the rack need to be made with very high precision. The carriage also needs to be very well constrained, because any wobble of the rack relative to the gear introduces backlash (or binding). Moreover, you also need to keep the rack and pinion well lubricated lest they wear out prematurely.
> 6 votes
# Answer
Cost would be the primary reason. You can engineer a belt driven system that will be equally accurate, faster, and with longer travel for a lower cost.
Lead screws are comparatively expensive. The cost differential dramatically increases with length of travel and speed with equivalent accuracy.
Lead screws do have a significant advantage of being able to carry a much heavier load while maintaining rigidity which is important for something like a CNC mill but isn't as relevant for 3D printing.
This is on the assumption when you say:
> Are there practical reasons to **not** use a stepper motor with lead screw for the X and or Y axes?
you meant that you are still planning on using stepper motors but considering a lead screw vs. belts.
> 5 votes
# Answer
It is possible to use lead screws; specifically 4 start leadscrews. The only drawback is that you need to be wary of heat.
Let's breakdown the concerns
* Cost. Yes it costs more than belts, and it will last longer at higher speeds, whereas a belt *may* stretch. If cost is a factor then stick to belts.
* Speed. Multi start screws offer a lower pitch than single start ones. As a result you less of a turn reduction. This can bring them on part with belts. The drivers you use will determine how fast you can spin your stepper motor. Voltage mode drivers are as used in 3d printers are good at high torque at low speed (sub 1000rpm). Current mode drivers are better at high rpm (e.g. STMicro's powerStep01)
* Heat. When the lead screw heats, the metal expands. When the metal expands your positional accuracy disappears. Using a metal that has a low coefficient of thermal expansion would be best, however they may cost more.
Just from changing the drivers you should be able to get a speed increase without needing to resort to the heavier multi start lead screw. Increasing the voltage will also help, however you would need a driver that can let you vary the holding current, otherwise the motor will heat up and burn when it is not moving.
> 1 votes
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Tags: diy-3d-printer, lead-screw
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thread-10059 | https://3dprinting.stackexchange.com/questions/10059 | Ender 3 X axis not level | 2019-05-29T17:28:17.730 | # Question
Title: Ender 3 X axis not level
I've been aware ever since I got it that my Ender 3's X-axis isn't level. Measuring from the top of it to the top of the frame, the right-hand (positive) side is about 4.7mm higher than the left.
During assembly, the vertical rails were not entirely parallel, and had to be pulled together to get the X axis on and to bolt the cross beam on the top. I suspect this is related, but I'm not sure.
Anyway, aside from the bed having to be tilted to be level with respect to the X axis, this never seemed to cause any problem, so I've left it alone until now. However I have measured almost exactly a 1% dimensional error in the X direction that I've now compensated for by setting the steps per mm, and wonder if the tilted axis could be the cause. Doing the trig, that doesn't make sense - a 4.7 mm error across the width of the bed should translate to something like one part in 2000, not 1%. But maybe something's wrong in my analysis so I'd like second opinions.
Aside from that, is this something I should try to correct, or just let be? I suspect it's the base that's warped or tapped/cut incorrectly where the vertical rails bolt on, in which case it seems unlikely there's any way to fix it without replacing that part, which is something I'd rather not get into as long as the printer is working. But if there are other possibilities that are non-invasive to try, I might.
Further update: if this is the cause of the dimensional error (which turned out to be more like 0.41% than 1%, thus closer to plausible) I probably need to fix it. Using firmware steps/mm adjustment is not viable because it produces aliasing patterns in skin layers presumably due to step width no longer dividing nozzle size/line width.
# Answer
So I disassembled the printer and first found something very suspicious: the left (Z-motor side) vertical rail was not mounted flush against the base, because the edge of the control board cover panel was under the edge of it. Fixing this made the vertical rails parallel and made the X-axis unit easily slide back on, but it did not fix the issue; the X-axis was still non-level.
Next, I started playing with eccentric nuts, which was probably a mistake. They were already the appropriate tightness, and I might have messed them up, in which case I'll have to go back and tune them more later. I then found a second point of adjustment: the attachment of the roughly-triangular bracket that holds the three roller wheels on the right side to the X-axis aluminum extrusion rail. I as soon as I loosened the bolts, I was able to get a plenty play to level the axis. In order to get it level, with the top beam mounted, I raised both sides so that the top outer wheels would hit the plastic end caps of the top beam. This relied on a dubious assumption that the triangular roller wheel arrangements on both sides are symmetric, but it seems correct, and after re-tightening the bracket, lowering it to the bed, and re-leveling the bed, everything seems fully level.
Further, after the fix, my dimensional accuracy test piece is 119.6 mm instead of 119.5 mm, which works out to the difference before the fix being undersized by 0.084%, very close to my "1 part in 2000" estimate of the error that the non-level axis should cause. Sadly it still wasn't 120.0 mm like it should be, so I went looking for another source of the inaccuracy. Tensioning the X-axis belt seems to have done the job, and I'm now getting 120.0 mm.
I took some pictures in the process, which I'll try to attach later to improve this answer for others who may hit the same problem.
**Caveats:** In the process of doing this, I badly messed up the Z axis. I was getting prints coming out almost 1mm shorter than they should be and having to relevel the bed continually. The whole system is "over-constrained" by all the points at which it can be tightened, so if anything is inconsistent when it's tightened, everything goes catastrophically wrong. This entry on Maker Steve's blog was very helpful in figuring out how to get it back in order. After making the adjustments, however, I still had a problem: a horrible grinding squeal whenever the Z motor moved in the negative direction. It turned out I'd also over-tightened the screws holding the Z lead screw nut on the carriage (after mistakenly removing it during all this), forgetting that the assembly instructions specify that it shouldn't be tightened down. loosening both screws by about half a turn finally got everything working right again.
> 2 votes
# Answer
i've just bought an Ender 3 Pro and on assembly I carefully checked and deburred the uprigh rails on their bottom faces to ensure they did not splay out or in etc.
Once the 2 uprights are loosely attached to the base rails I laid the assembly flat onto a table on the uprights to ensure the uprights were square to one another and tightened the screws.
Check the uprights are parallel to one another by placing the top crossbeam on the top of the uprights and check if the screw holes are alligned...….if the screws are tight to enter their holes the uprights are splayed out or in and need correcting etc......a small amount of pressure "can" make them line up.
The X axis rail slides up and down on the two uprights with two 3 wheeled brackets, one either side, that have 3 wheels on them, one wheel on each bracket is the adjuster and it is easy to have the X axis cross beam out of square if you tighten the one bracket to the rail before you test the rail for squareness.
Firstly, place only the 2 wheel brackets on their uprights and adjust the wheels for smooth running, then attach the X axis rail to each wheel bracket and just nip up the 2 screws loosely to hold them to the cross beam.
Now, check the cross beam for squareness by running it to the top of the uprights and measuring the gap left to right between the X axis rail and the top rail, then tighten the left hand wheel bracket screws to the X axis rail......and then tighten the right hand wheel bracket to the cross beam.
Leave the Z axis leadscrew off for the moment and run the crossbeam up and down on the uprights making sure there are no tight spots due to out of squareness.
if it's all freely moving.....fit the Z axis leadscrew.
The bed plate can only be set once you have the machine itself squared up. Ian.
> 3 votes
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Tags: calibration, creality-ender-3, x-axis
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thread-10084 | https://3dprinting.stackexchange.com/questions/10084 | Prusa MK3 heatbed marks | 2019-05-30T13:05:02.020 | # Question
Title: Prusa MK3 heatbed marks
I've got some curious marks on my heatbed.
It appears to be from my black Sunlu PLA+ (I can just feel it if I scrape my finger nail over it) but I can't scrape it off with the metal spatula.
When I try and print over it the filament won't stick.
Any suggestions as to what it is and how you get rid of it?
# Answer
Prusa ships (or has shipped) with two types of PEI build plates. The original (and what I was shipped in February 2019) is a PEI sheet held in place with an adhesive. The marks I've gotten seem to be places where the adhesive has been displaced slightly from long term pressure by the object being printed.
In your case, it actually looks like scratches in the PEI. If, after cleaning with water, then 95% Isopropyl alcohol, and finally acetone the scratches still appear, I'd check if they are a problem. Do they transfer onto objects printed on the plate?
If you decide you have a problem, I would use a mild kitchen scrubby sponge to "sand" out the scratches. I have two types in my kitchen. The yellow ones are too abrasive. The blue ones are better. Gently use one to make the surface uniform.
If you have an adhesive based plate, Prusa sells replacement PEI sheets, with adhesive. The process of changing them seems onerous. Although I bought two spare sheets when I got the printer, I have never been tempted to use one. When my build plate becomes unusable, I will buy another one.
Prusa3D also offers a textured build plate, which is more expensive and in short supply. These are a powder-coating process and from pictures and their blog, I infer they are particles of PEI which are melted onto the steel surface. I have no experience with these.
I don't know if they are making the current smooth plates with a powder coating process, or if they are still using the adhesive.
The adhesive is the weak link in the heated bed. It is only rated for 110 degrees C, which is the temperature limit of the bed. I find that when I print with a hot bed (such as for PETG), the visible ripples in the surface are worse than when printing PLA on a cooler bed.
> 2 votes
# Answer
Edit: As Trish noted, apparently Prusa printers don't ship with Buildtak stickers like the other printers I've used, so this is probably a bad idea in your specific case. For others reading this, only do the sanding shenanigans with buildtak or other stickers that you can easily replace and don't mind wearing down over time.
Used to happen to me printing PETG on Buildtak. I ended up using a medium grit sanding sponge to remove the PLA layer. Related, you might want to grab some 1k grit sandpaper for the same reason, it does a great job of freshening up your build surface once builds stop sticking well.
> 0 votes
# Answer
It looks like you may be a little bit too close with the nozzle. Does the first layer calibration look alright?
The steel sheet with coating is a consumable. It will get marks. Even with long PLA prints. However, these will slowly fade and should not interfere with print quality.
I can still see my first benchy on my sheet.
When you're no longer satisfied with the state of your sheet, use some acetone to clean to bed.
Note: PETG will case bumps since this sticks a bit too much to IPA cleaned coating. Causing the coating to bubble on removal. These damages can fade. If not too bad. So don't clean with IPA for PETG, use window cleaner.
What you can do is move the print around, instead of always print in the center.
> 0 votes
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Tags: prusa-i3
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thread-10138 | https://3dprinting.stackexchange.com/questions/10138 | Limit to extrusion volume | 2019-05-31T22:12:43.503 | # Question
Title: Limit to extrusion volume
Assuming heat transfer to melt the filament is not an issue, what’s the bottleneck in pushing more filament through the nozzle? Is extrusion volume per time proportional to applied extruder torque?
# Answer
> 3 votes
The molten plastic in the extruder becomes a hydraulic fluid effectively when it gets melted. You're pushing on a fat piston (1.75 mm or 2.85 mm, depending on filament type), and shoving fluid out through a 0.4 mm or so hole. There's a limit to flow rate at a given pressure, but the bigger issue actually tends to be friction. Molten plastic really loves to grab on to metal, and the ratio of surface area to volume is fairly high in the long, skinny tube that is the inside of an extruder. To make matters worse, the not-quite-molten section of the melt zone up at the top normally doesn't make a lot of contact with the walls due to lower pressures not deforming the plastic all that much, but at higher pressures you get much more deformation, increasing the linear distance that the plastic is dragging against the tube walls, and the pressure with which the two surfaces are bonding together. Especially in cheapo clone extruders you'll find roughly bored inner surfaces with many circumferential grooves which exacerbate this issue - this is why most extruders have a PTFE lining as far down as they can go. I had this issue in my $3 "all-steel" extruder barrel, where even printing PLA was an issue because of how readily the plastic formed huge plugs and grabbed the inside of the extruder.
So what you end up with, is that increased torque mostly linearly translates to increased pressure, which results in linearly increased friction inside the barrel, plus a little bit extra due to extra deformation in the top of the melt zone. You can polish the inside of the barrel (heatbreak? seen both terms) to help alleviate internal friction somewhat.
To make things even more fun, there's obviously a limit with how much force you can exert through the mating surface of a single hobbed bolt and the side of the filament. Too much force and the teeth will simply rip off the side of the filament and then you'll have no feeding torque whatsoever. To get much higher torque you'd need to design an extruder that both supports the filament much better than modern designs do, and spreads the force out over a larger surface area, either by using a much larger diameter feed gear, or multiple tightly-coupled feed gears.
I went into some degree of detail on the feed mechanism in this answer that another user asked about using a commercial extruder for plastic injection molding, which overlaps somewhat with your question here.
I know the original question assumed perfect heat transfer that was not a limiting factor to the process, but how that actually works is relevant to the question as well. E3D took one approach with their Volcano design, simply by making the melt zone much longer to increase heat transfer; the downside is there's obviously substantially more friction when you've got 4x the linear distance of molten plastic against metal, assuming you're not using a PTFE liner. This does have the advantage of letting the plastic take its time to reach the target temperature, decreasing how far over your target plastic temperature you need to have the heating element. One thing not often discussed in 3d printers is the fact that the plastic asymptotically approaches the temperature registered on your thermistor. If you're printing very, very slowly, your plastic will nearly be exactly at the target temperature. If you print very quickly with very high volumes, you'll tend to have slightly cooler plastic than intended because it simply wasn't in contact with the heater long enough to come up to temperature. The solution for very small designs might be higher temperatures, but the drawback there is that if you slow down even for a moment, say moving to thinner line widths or picking up and moving the extruder, you'll overheat the plastic. So there's practicality questions that need to be answered to determine how you'll actually heat that much plastic to the right temperature. Increased distance improves reliability at the cost of increased friction (and therefore extruder torque required), and increased temperature mostly bypasses that question at the cost of reliability.
TL;DR Increased extrusion speed requires increased pressure, which increases friction dramatically and in a non-linear fashion and results in stripped filament.
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Tags: extruder
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thread-10142 | https://3dprinting.stackexchange.com/questions/10142 | Uploading files using Octoprint REST API | 2019-06-01T06:08:38.777 | # Question
Title: Uploading files using Octoprint REST API
I'm trying to upload a file using Octoprint REST API - it seems to be possible as per the document described here, Upload file or create folder, but I can't figure it out how to do it with the Python request lib.
Currently what I'm doing is
```
import requests
def def Upload_File():
fle={'location':"j:/max.gcode"}
url='http://localhost:5000/api/files/{}'.format('local')
payload={'select': 'true','print': 'false' }
header={'content-type': 'multipart/form-data','X-Api-Key': 'FD550BD4DA2442BA906AD1850539D6DB' }
response = requests.post(url, files=fle,data=payload,headers=header)
print(response)
if __name__=='__main__':
Upload_File()
```
The response returns status is 400
My working env is:
* Windows 10 and Octoprint running on virtual environment.
# Answer
> 4 votes
I installed octoprint locally to help debug this problem.
1. Your code snippet says "def def Upload\_File" which is a syntax error.
2. If you go into Octoprint, under Settings -\> Logging, and download octoprint.log, you'll notice it says "WARNING - 400 POST /api/files/local (::1): No multipart boundary supplied". A quick google search led me to this StackOverflow question, which states to remove the custom content-type header to fix this problem.
3. You actually need to open() the file, and assign that value to the 'file' field in the fle object definition, not just tell it where it's currently at on your machine. Additionally, you need to provide a filename field in the fle object.
I got your code snippet working as below, went ahead and swapped your API key back into it. You'll need to point the open() call to the actual location of your file on your hard drive, which I assume is j:/max.gcode, rather than mine which is just opening max.gcode from the running directory of the script.
```
import requests
def Upload_File():
fle={'file': open('max.gcode', 'rb'), 'filename': 'max.gcode'}
url='http://localhost:5000/api/files/{}'.format('local')
payload={'select': 'true','print': 'false' }
header={'X-Api-Key': 'FD550BD4DA2442BA906AD1850539D6DB' }
response = requests.post(url, files=fle,data=payload,headers=header)
print(response)
if __name__=='__main__':
Upload_File()
```
Finally, if you're going to be doing a whole lot of REST API shenanigans with your Octoprint server, may I offer a prebuilt library?
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Tags: octoprint
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thread-8435 | https://3dprinting.stackexchange.com/questions/8435 | Extruder Motor Not working during Printing | 2019-03-09T13:58:39.730 | # Question
Title: Extruder Motor Not working during Printing
I am a **newbie** trying to setup and configure a 3D printer following online YouTube videos and tutorials. I am trying to configure a **Hypercube Evolution 3D printer**. I followed Tech2C videos (on YouTube) and was able to configure Marlin firmware to some extent. I am using Pronterface to send test codes and taking files from thingiverse.com for testing.
Configuration :
* CoreXY
* Board : Ramps 1.4
* Extruder Setup Type : Direct drive using Titan e3D
* All end stops, temperature sensors, heaters configured and verified.
What is working :
* X,Y,Z axis movement directly from panel.
* Homing is ok.
* Temperature sensors, heating bed and hot end as expected.
* Extruder motor working with **direct** on panel command.
What is not working :
* When I send a print file (taken from thingiverse.com), the X,Y,Z axis work but there is no extrusion what so ever. I have tried a lot of things but using files from thingiverse, the extrusion of filament is not there whatsoever. It's been 2 months trying to figure out whether the issue is in firmware or the file, however to no use.
Can anyone help me get out of this or point out where I can be going wrong?
# Answer
If the extruder extrudes fine from the control panel, chances are there's a configuration problem somewhere. For example, check your extruder steps/mm in the firmware to make sure it's not a nonsensical value; check the slicer settings to make sure that the filament diameter, line width, and layer height are all correct; make sure you're not trying to extrude in volumetric mode without having configured volumetric printing in your firmware and slicer correctly; and finally check your temperature control settings. When I first set up my fleabay 3d printer, I couldn't get my printer to work because the hotend minimum shutoff temp (thermistor disconnect protection basically) was set to something like 195C and the print temperature was 180C. I had an almost identical issue when I changed my fan assembly and it started blowing on the wrong part of the hotend, causing the firmware to register that entirely too much energy was being put into the extruder. Check the minimum temps for both hotend and heated bed and see if one of them is tripping your failsafes and stopping the extruder before printing even begins.
> 1 votes
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Tags: extruder, diy-3d-printer
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thread-8204 | https://3dprinting.stackexchange.com/questions/8204 | Use Gcode Extrusion Speed in Calculations | 2019-02-08T21:15:36.847 | # Question
Title: Use Gcode Extrusion Speed in Calculations
I have a Rostock Max V2, and I've added a second extruder going into a y-splitter into a single nozzle on my printer. I have both extruders working correctly, but I'm having trouble tuning the retraction settings to prevent stringing when I switch between extruders during a print. My system is essentially identical to the setup seen here. However, I can't get my printer to retract as cleanly as the one in the video
What I'm trying to avoid is the long, thin "tail" that forms when retracting the filament from the hot end. That "tail" binds the other filament during the switch and makes the extruder grind a hollow spot on the filament.
I've had limited success tuning my retraction settings, but I find that I need different settings for different extrusion speeds. For example, after an extrusion like `G1 E20 F240` a 3mm retraction, 3mm extrusion, then a fast retraction creates a nice, clean break (this routine is recommended here by kraeger on the SeeMeCNC forums). However, after an extrusion like `G1 E20 F900` I have to use longer retractions to get a clean break. I think this might have to do with the filament acting like a spring inside the bowden tube. It would make sense to me that the harder you push the filament, the more you need to pull back to compensate for the pent-up spring force.
Here's my question: Is there a way to read the value of the extrusion speed, essentially the "F" term from the gcode commands, and change my retraction routine accordingly.
Example pseudocode:
```
If F value < 500 Then do short retraction
If F value > 500 AND F value < 1000 Then do medium retraction
If F value > 1000 Then do long retraction
```
I'm using the tool change script feature in Simplify3D to store the tool change code.
# Answer
I don't think you're going to find either a firmware feature or a slicer feature that handles specifically what you want to do. The slicer would probably be the best place to put it, and I'd recommend maybe opening a feature request ticket with Ultimaker, because that sounds like an awesome feature.
That being said, there's nothing stopping you from post-processing your GCode file after it's been generated. If you're experienced with python at all, that's the place I'd recommend you start.
You'll probably want to do it via the following:
1. Find the first line number that does a retraction.
2. Sum up all the extrusion distances between that line and the starting point (the beginning of the file)
3. Replace the retraction distance and feedrate with whatever your short/medium/long retraction settings are
4. Store that line number as your new starting point
5. GOTO 1.
If you're using Slic3r, there's actually a post-processing script function built into the app itself, you just need to write the script and give it to the application to make the whole process hands-off. For other slicers you'll probably just have to run the script manually between slicing and printing.
> 0 votes
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Tags: extrusion, simplify3d, multi-material, retraction
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thread-10143 | https://3dprinting.stackexchange.com/questions/10143 | Through what methods and mechanisms can a multi-material FDM printer operate? | 2019-06-01T14:22:34.160 | # Question
Title: Through what methods and mechanisms can a multi-material FDM printer operate?
I now own the Prusa3D MMU2. The benefits, costs, and experience others have had is well documented. I am interested in rebuilding my large, home-designed delta machine to be multi-material, and don't want to overlook strategies I haven't considered.
My original implementation used an E3D Kraken as the hot-end, and handled the inevitable delta tilt by adding two additional degrees of freedom to the head to lower the selected nozzle to the bed. I've been through three generations of mechanisms, and I think the third will work.
But, I feel that I am not seeing obvious and better alternatives.
So, the question: Through what methods and mechanisms can a multi-material (different polymers, different temperatures) FDM printer operate, and are there available designs or examples of best practices for those methods?
# Answer
> 6 votes
Let's look at various methods:
## Multiple Hotends
The oldest version and one of the best to print materials at vastly different print temperatures (like printing a cheaper PLA infill into a Polycarbonate shell - the print temperature difference is 60-100 °C) is to have 2 or more hotends. This way also avoids the need for purging towers. It does, however, limit the maximum size of the used printbed and few 2-printhead machines are cheap.
## Y-Coupler
Using a bowden setup, a Y-coupler could be used to feed the filament from 2 extruders into one hotend. On the switching tool command, E0 would pull the filament back some couple millimeters beyond the coupler and then E1 would push forward back into the meltzone. One will need a purging tower/object.
## Special, multi-entry hotend
Some Hotends had been concieved that have 2 or more ways into the meltzone and the multiple extruders push along them. They generally are quite complex and hard to clean, but they allow to seamlessly blend between two filaments of the same material and create pretty much a controlled fade by precisely directing how much of either side is used on any layer. For clean cuts, a purging tower is necessary.
## Splicing filament
This is what the Palette 2 and the Prusa MMU do: they push pieces of filament into a feeder tube that then are consumed by the printer via its own extruder. If they melt the filaments together like in the PAlette, it's proper splicing, if they just line up the next filament piece without merging into a spliced filament it's more like instant color switching.
This method is good for multi-color prints or using materials that have the same or similar<sup>1</sup> melting temperatures. It might or might not need a purge tower/object to get rid of the residue in the zones between the filaments.
This could btw also be done manually but should be avoided.
<sup>1 - or rather not too dissimilar, if the slicer is set up to do it right. By setting up the slicer cleverly, one can have the extruder retract the filament, then adjust the heat over the purge tower and then resume extruding in the purge object at the changed temperature. PLA/PVA from a Prusa MMU is known and advertised to be doable, PLA/ABS might be possible this way. For extreme dissimilarities like PLA/PC (60-100 °C) I have my doubts though. </sup>
## Usability
All of these variants are basically viable, but some have benefits over others. Service is in this comparison meant as *repairing* a broken extruder, *maintaining* as the operations needed to keep it in printing order.
* multiple *fully independent* hotends is among the easiest to services. It could be direct drive (good for flexible filaments) or bowden. It is however heavy and usually not an option for delta printers. It has a downside that you have to perfectly level two hotend nozzles to be exactly on the same height, putting it in the hard to maintain category.
+ *multiple hotends on the same carrier* is harder to service and maintain in comparison to multiple *independent* hotends as the components are very close together. Especially nozzle height adjustments can be more finicky.
* Y-Coupler needs to be a bowden and has problem with materials that are very stringy. That makes it especially bad for flexible materials. Maintaining is like a normal hotend and servicing is almost the same.
* Special hotends are hard to come by but could be available for direct drive, making them possible for flexible filaments. They are, as already noticed, very hard to service.
* Splicing filament can be done with either direct drive or bowden setups. It is probaby the most convenient to use after setup and has the maintenance and serviceability of a single hotend and a fully separate machine. Their biggest downside is price and setup time needed.
# Answer
> 1 votes
One of the easiest ways that I've seen, which I'm a fan of, is simply putting Y splitters on your Bowden tube and having multiple feeds to a single hot end. The main benefit is that you only need a single hot end, so you don't have to worry about extruder offset or alignment or anything like that, but you do have to worry about material blending somewhat. Basically you end up needing to build a "purge tower" next to your printed items that you use to transition from one material to another.
There's the Diamond hotend setup that basically moves the connections into the hotend itself, which reduces the size of your purge tower but increases the risk of burning if you're trying to print with materials with vastly different printing temps, like PLA and PETG.
You could also have swappable hotends but that requires you to be there to manually swap the print head twice per layer. Don't recommend.
Unfortunately there's only so many solutions to the multi material problem, either you put multiple materials through a single hotend, or you have multiple hotends. I'm a fan of the single hotend approach personally, especially on deltas where weight and space are at a premium and alignment becomes problematic.
# Answer
> 0 votes
Another way to combine the simpler geometry of a single nozzle, and to get the reduced mass of a single extrusion tool would be to make it like a CNC machine with a tool changer. One material is printed, then the hot end, extruder, and feed tube are swapped out for another which is primed and ready with the next material.
Lots of mechanical precision problems exist for arranging for the nozzles to be in the very same place, plus or minus a small tolerance. This is worsened by the presence of filament bits and strings which seem to eventually pollute the workspace.
If that could be worked out, one could have a plethora of extrusion tools, nozzle sizes, materials, multi-material mixing chambers, and other complexities.
E3D was talking about such a printer, but I haven't seen a product... only an invitation to send money as a show of interest in such a printer.
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Tags: delta, multi-material, open-source
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thread-10132 | https://3dprinting.stackexchange.com/questions/10132 | Set the overhang parameter in Blender 3D printing tool box | 2019-05-31T14:40:27.307 | # Question
Title: Set the overhang parameter in Blender 3D printing tool box
I'm working on a cube in Blender. I just deleted one of the faces (the top face) of the cube and added solidify to avoid non manifold edges.
In this case, when I check the design it shows that the bottom face is an overhang face (shown with yellow color). However, if I change the overhang parameter in 3D printing tool box from 45 to 90° and then check the model, it doesn't show any overhang faces and it seems that everything is okay. I don't think increasing the overhang parameter could be a good idea. However, this is my first time that I'm trying to design a model for 3D printing. Can this model with the overhang parameter equal to 90° be printed using a 3D printer? How can I fix the overhang problem in this simple model.
Today I tested another simple model. I used a fill circle and added solidify to the model. Although the model is really simple, check the model shows the same as the previous design - the bottom face is an overhang face. It seems that adding solidify to a shape leads to this problem. I don't know how can I fix this problem. Changing the overhang parameter fixes the overhang problem but it seems that this not a good idea for printing models.
Unfortunately, I can not test the print myself as I do not have a printer myself and I need to outsource the print job.
# Answer
> 3 votes
You are looking at overhangs in the design tool. What matters are overhangs when printing.
When designing the object, the coordinate system is convenient for working with the object. Before slicing, the object can be rotated and repositioned for better printing. Only after is it positioned for printing can the actual overhangs and bridges determined.
Unless you wish to limit yourself to the design tools coordinate system, I wouldn't have the design tool generate support material, and I would ignore its comments about overhang angles. First, bring the object into your slicer, position it on the print bed, and only then evaluate the need for support material.
To be honest, I often have a printing strategy in mind while I am designing an object, but when the object hits the printer I sometimes completely change my plan.
# Answer
> 2 votes
Overhangs that are substantially greater than 45° to the vertical generally require supports, and overhangs of 90° will definitely require supports, unless they are bridges (supported at both ends). Depending on how well you have your printer and filament "dialled in", it is possible to print overhangs up to 70° without supports. However, if your model is a simple cube, it will have no overhangs, so it doesn't really matter what value you give the overhang parameter. Supports are usually generated when the model is sliced, but some modelling software will generate supports as part of the model.
# Answer
> 2 votes
I'm a regular user of Blender and the 3D Printing add-on to design and print stuff. It will always consider the bottom of your model as an overhang, and it should pose no problem when you send it to print.
The add-on will say the bottom is an overhang because, in the virtuality of Blender, the object you're designing, like the cube in your picture, is floating in an empty void and the add-on has no setting to tell it 'this face is a bottom, don't check it for overhang'. I guess it could be programmed, but I'm not sure that it would be a good idea since it would then keep considering this face as the bottom even if you turn the object 180°.
You can safely ignore that particular warning from the 3D printing add-on when you send your object to be printed, as long as it is printed with the same orientation than in Blender. And it should be, since the export in STL will keep the orientation of the object along the X, Y and Z axis.
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Tags: 3d-models, 3d-design, print-preparation, blender
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thread-10040 | https://3dprinting.stackexchange.com/questions/10040 | Advice for 3D modeling peg for sprinkler dripper | 2019-05-28T04:01:33.180 | # Question
Title: Advice for 3D modeling peg for sprinkler dripper
I'm not really sure where to ask this question as I think it is a design question, but also a printing question. So if there is a better place to post, I'd be happy to harass someone else.
I'm (re)designing a sprinkler manifold for a dripper system because the stupid pegs for this stupid manifold are on top of the manifold, which is a prime spot for any old postal person/dog/raindrop to break off. Of course the pegs aren't sold separately so you have to buy a whole new manifold. Seems like a great use for a 3D printer.
I designed a new manifold and decided the pegs were useful in case they broke off. I was thinking having them screw in would be a better design, but for the life of me I can't get them to actually screw in after I print. Here is the fusion 360 file. This is generally what it looks like: And here is the resulting stl file.
After several prints, the pegs won't screw into the manifold base. I push and I turn and turn but the threads just won't bite. The 3/4" pipe threads fit just fine, so I know threads can be printed, but these pegs are stubborn.
I guess my question is, what's a good design for a peg thingy that needs to attach into a manifold, but also pass water? Should I try to replicate the cantilever thing they have going on, or is a screw better? Any ideas why my pegs won't screw into the base of my mushroom? This is my first attempt at 3d modeling so I'm not totally familiar with all the terminology, so any pointers there would be helpful. Thanks!
# Answer
With the suggestions from @R.., I played with a couple of different screw profiles that come with fusion 360, and found these settings to be helpful:
After cutting the hole with these screw settings, I selected all the faces of the hole and off set them by `-0.1 mm`. Originally, I was offsetting the hole by like `-0.02 mm` and the peg wouldn't screw. After learning a bit about tolerances of printers, I expanded this to the `.1` value and it screwed in magically! I haven't yet worked out if the pegs are water tight, so I may have to revert back to the previous thread settings that seem like they would be tighter, or maybe I'll invest in an o-ring. Suggestions welcome.
Thanks to everyone for their input.
> 0 votes
# Answer
I examined and sliced your STL file, and the profile of your threads looks very strange.
It's definitely possible to do very strong, perfectly-fitting threads down to small sizes (at least down to M4 or slightly smaller) using modern inexpensive 3D printers, and contrary to widespread belief (there's a well-known YouTube comparison with a major test fallacy claiming otherwise) they should usually be stronger than threaded inserts against being pulled out. But you need to get the thread profile exactly right.
Most real thread profiles are trapezoidal, but yours peak at points and have round bases. This is unlikely to match the external thread on the part you're trying to fit to it, and it's going to have major dimensional accuracy issues because of the sharp point which can't necessarily be represented in the layer resolution.
I'm not familiar with Fusion 360 so I don't know how to tell you exactly, but most CAD software has libraries for generating threads conforming to standard thread profiles. If you want to do 3D printed threads, you should look at those and figure out which one you're trying to match. Or, if you want to replace the pegs with your own design anyway, just pick a reasonable one for both.
Generally, most modern threads use the basic ISO metric thread profile, even if they're not standard metric diameter or pitch:
Your cross-sections should look roughly like the "internal thread" side of that.
> 6 votes
# Answer
If I may suggest a slight alternative: don't try to make the threads part of the 3Dprint. Instead, thicken the walls where the threads would have been, increasing the ID (inner diameter) of the hole, maybe even "thread" to match the outside of : metal threaded inserts. Those can be screwed in, .
Perhaps a small "T-nut" (pick the size you need) would be sufficient, and you could create holes in your printed part for the penetration tips.
> 1 votes
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Tags: prusa-i3, 3d-design
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thread-10159 | https://3dprinting.stackexchange.com/questions/10159 | How to create supports for the parts hanging above 45 degrees? | 2019-06-03T05:58:00.617 | # Question
Title: How to create supports for the parts hanging above 45 degrees?
Do you have any specific process recommendations to achieve support for the parts hanging above 45 degrees, using open source software?
# Answer
> 1 votes
PrusaSlicer has **support enforcers** you can place on areas that need support.
See this video: Prusa Slicer Support Enforcers.
### Automatic supports
There are automatic supports, in the **Supports** dropdown menu, select **Everywhere**:
Click **Yes** in the resulting dialog:
Click on the **Slice** icon in the bottom left:
You will end up with a *lot* of supports:
However, this method generally results in too much support...
### Custom Suport Enforcers
So turn off **Supports** in the drop down menu, select **None**:
Now, in the **Print Settings** tab, under **Support Material**, disable **Auto Generated Supports** and enable **Generate Support Material**:
Then right click on the model and select **Box** from the **Add Support Enforcer** menu item:
You can move by clicking the **Move** button in the left hand palette,
resize by clicking the **Resize** button
and re-shape the **Box** as necessary, to support the difficult overhanging parts parts only. Here we can see three boxes have been added - pale blue for the previously added boxes and green for the current box:
And a fourth final **Box** for the tail:
Now, when you hit the **Slice** button, there will be much less support structure than when using Automatic supports:
Parts of the model that the slicer thinks still needs support will be highlighted in dark blue (such as the elbow and back of the head):
Add a cylinder support enforcer:
Resize and re-shape as before and move into position below the elbow:
Adding a second cylinder as a support enforcer
Upon hitting **Slice**:
Now in **Print Settings** \- **Support Material** \- **Pattern** change it from **Rectilinear** to **Rectilinear Grid**:
For prints with curves and details **Rectilinear Grid** works better, than **Rectilinear** (which is fine for supporting a plain cube in the air). It is easier to break the support off the print.
Now save your hard work as an AMF file:
This file maintains all of the support enforcers so that they can be modified if the actual print needs some adjustments - without having to re-add all of the support enforcers all over again.
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Tags: 3d-design, diy-3d-printer, support-structures, open-source
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thread-10154 | https://3dprinting.stackexchange.com/questions/10154 | Why have heater blocks on hotends? | 2019-06-02T18:29:56.387 | # Question
Title: Why have heater blocks on hotends?
I understand that heater blocks act as kind of “low-pass-filter” on the temperature change of the hotend, but why do we need that?
Wouldn’t it be better to have as little metal as possible in order to be able to control temperature changes quickly and precisely (using PID, PWM plus maybe some predictions based on printed G-code)?
# Answer
Let's look at the elements and what they do:
The *Heater Cartridge* (blue) is the device that converts electric to thermal energy to melt the plastic. 30 and 40 W are common.
The *Thermosensor* (red) is there to give feedback to the mainboard.
The *Filament Path* (gold) in this area is made up of the *nozzle* and the *heatbreak*, it contains the *meltzone*.
The *Heater Block* (transparent green) is the mounting for all parts. It also acts as the medium to transfer the thermal energy from the *Heater Cartidge* to the *Thermo Sensor* and the *Filament Path*. It also acts as a dampener for the control circuit.
Now, let's put things together and omit the wires and cold end (and internal geometry of the filament path, cause I am lazy):
Now, the construction gives us several reasons for the shape of the heater block:
* Ease of construction. Taking a simple block and adding a couple of holes and one cut allows very fast production.
* Maximum contact surface. To get the maximum contact surface to the heater cartrige, the heater block has to make contact along its whole length, dictating a minimum size in 2 direction. The same is true for the thermosensor.
* The heater block transmits temperature pretty much radially from the heater cartridge. Because it is metal, the gradient between areas is very low, but it is measureable. These would be the thermal equivalent lines on heating up:
You may easily notice that the temperature lines appear more straight as they come closer to the filament path and thermosensor. This helps to give the filament in the heatbreak and nozzle more even heating and better printing.
The mockup I made has a deliberate flaw though: a change in temperature first affects the filament and then shows up on the sensor, making the temperature in the filament path wobble to the extreme. The Heater Block acts pretty much as a transmitter just as much as a time dilation between the heating command and the pickup.
Because this arrangement is not very good, let's swap sensor and filament path around and look at the same lines.
Now we have a much shorter feedback loop, allowing our printer to react quicker to temperature changes and the filament path also gets heated more evenly. The temperature inside the filament path does change less around the target temperature. The whole block now acts mostly as a distribution medium but also as a storage for heat energy:
Up to this point, we did not take into account a very simple fact: the hotend drains thermal energy via two areas:
* The outer surface of the heater block emits heat to the air.
* Filament gets molten and extruded.
Factor 1 is simple and here a bigger heater block actually is positive: The thermal 'storage' capacity is dependant on the volume, so goes with $xyz \approx a^3$. The surface to emit heat from goes with $2\times(xy+xz+yz)\approx 6\times a^2$. Plotting a graph of that shows us the square-cube law: the capacity increase for one unit does increase the surface just by a fraction of that, so the storage gets better the larger the heater block is.
Factor 2 is why we need to have a storage of thermal energy in the first place: the flow of filament is not exactly the same all the time. Of course, we have moments of even flow, but we also have moments of low or no flow when the printer moves between parts of the print. This alteration of the drain of thermal energy from the heater block means that if we would go down to a bare minimum size, we'd heat up the block fast whenever we are on a move action and cool as the extrusion starts till equilibrium is achieved again. The more thermal capacity is there to store energy, the less the lack of extrusion will immediately affect the print and the more even the temperature will be in the filament path.
## Fast printing?!
How is faster printing achieved with a special hotend? Well, 4 factors are used in hotends meant for very fast or very hot printing:
* Longer, more powerful heater cartridge.
* Longer filament path.
* Extra large Heater Block to even out the temperature changes under extrusion more.
* Insulating the Heater Block to the air.
One of the prime examples would be an e3D-Volcano.
> 8 votes
# Answer
I think the idea is to *not* change the temperature fast. You want it to maintain a certain temperature so you have consistent flow. The extra mass at the hot end provides the mass which is needed to maintain the heat. If you don't maintain the heat while you print, you'll have inconsistent filament flow, which will screw up your print.
> 3 votes
# Answer
Heater blocks are used on hot ends because they are the current engineering compromise between the design factors of cost, reliability, lifetime, maintenance, and performance.
Ideally, there would be no heater block, the heater would have infinite wattage, the nozzle would heat and cool instantly while transferring heat to the filament, and the temperature of the molten plastic would be measured instantly.
But as this is engineering instead of magic, none of these conditions is the ideal. The engineering problem is to find the right compromise.
Each of these can be treated separately. How do we measure the temperature of the plastic? Assume we have a tiny thermocouple in the plastic flow. Why thermocouple? Because it is smaller, less prone to manufacturing tolerance, and is good for higher temperatures.
Imagine a heater where the heater wire forms the threads into which the nozzle screws and also where the nozzle has thinner walls to reduce the nozzle's thermal mass. Further, the nozzle is made of diamond which has almost ten times the thermal conductivity of brass. Yes, machining diamond is not easy, and the supply of large enough diamonds is limited, but we're trying not to compromise yet.
In this scheme, there is no heater block. We instantly know the temperature of the plastic, and we can dump large amounts of heat into the system to get a high enough temperature. We still must hold the nozzle in place and connect it with the filament source (typically the job of the "heat break"), so let's make that of thermally insulating ceramic so it stays out of the heat transfer process.
With this, we have a hot-end where we would have great control. We are directly measuring the parameter we care about -- the temperature of the plastic. We can deliver heat rapidly. When the extrusion rate increases, the temperature drops a little and we dump in more heat. The thermocouple is fragile (don't try a cold-pull), and is subject to wear. The nozzle is very expensive and difficult to make.
Ok, move the thermocouple to the outside of the nozzle's tip. Now we have a heater intimately wrapped with the threads of the nozzle. That is probably hard to make, so let's use a conventional heater cartridge that is very close to the nozzle threads. Let's put in as many heaters as we can pack together near the threads. If we angle the heaters they won't hit each other, so suppose we can put in four heaters spaced around the nozzle. More heat, less distance from the heat to the nozzle. Make this new heat block of silver, just like the nozzle. Silver has 80% higher thermal conductivity than aluminum. (Or we could use diamond, but really, who has diamonds that big?)
I was assuming a thermocouple to measure the nozzle temperature, and it is small enough that it could nestle into a small home in the nozzle. We could use a thermister pressed into a hole in the nozzle, but experience has shown that thermisters are fragile. We have found that the tiny glass beads are prone to either breaking of the glass, separating from the thin leads. The electronics to measure temperature with a thermistor is simpler and less expensive than a thermocouple and seems to have good enough resolution, accuracy, and temperature range. If we follow that experience, we will package the thermistor in a cartridge housing that is easier and more reliably placed and protects the thermistor from damage. But the cartridge is too large to connect directly with the nozzle, so we'll put it in the same block with the heaters. After all, they are silver and conduct heat very well.
This may be a better hot-end than the conventional system. It heats faster and more accurately measures the temperature of the plastic. But there are problems. Silver is heavier, and four heaters and their wiring have more mass than one. And, the holes for the heater cartridges are each in a different plane, so it is more expensive to machine. And the price for the silver may be a factor. Silver costs (today) \\$215/lb, where aluminum is $0.80/lb.
In this answer, I have tried to show how heater blocks are useful for coupling the heat from the heaters to the nozzle and to show that there are alternatives with perhaps superior performance but problems with reliability or cost.
Edit: In a comment, the OP asks why we do not machine away extra material that is not required to couple heat to the nozzle, and correctly raised the issue of cost. There may also be a performance issue.
The conventional heater is only on one side of the nozzle. When the heater is cooled by the filament, it draws heat from all sides. The thermal mass on the non-heated side helps with stability by providing a source of heat from which the nozzle can draw.
On the heater side, a factor to consider is the coupling of heat from the heater cartridge to the heater block. Removing additional material should be evaluated to assure that it does not increase the thermal resistance from the heater to the rest of the block and the thermistor. This is important to help with thermal stability, and also to assure that the heaters do not overheat themselves.
For thermal conductivity values, I used this reference. For metals pricing, I used Google to find spot metal prices on 6/3/2019.
> 2 votes
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Tags: hotend
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thread-7572 | https://3dprinting.stackexchange.com/questions/7572 | 0.9° motors for Delta printers? | 2018-12-03T15:23:31.667 | # Question
Title: 0.9° motors for Delta printers?
I built a cheap Delta printer with ATMega board and 1.8° motors. The micro stepping is limitied to 1/16. Beside a decent print quality, I observe a moire effect on flat surfaces. The moire is clearly caused by a combination of both, the 1.8° motors steps and the low microstepping.
I thought about using 0.9° stepper motors together with a combination of board and drivers which support \< 1/32 micro stepping. Is there a comparison somewhere illustrating potential quality differences on larger delta printers and is this the way to remove the moire effect? For cartesian printers I would not bother using such motors, but I noticed that a higher holding torque at smaller steps is desirable for delta printers.
**Example**
Not one of my prints, but this is how it looks
# Answer
Delta bots always need all motors to step to maintain a straight level. Microstepping, is not magic, the **incremental torque** decreases per step so that you will be more likely to miss a few micro-steps. Furthermore, the signal that creates voltages for the micro-step positioning is usually not perfectly sinusoidal (pulse-width voltage modulation is used to achieve micro-stepping by controlling the current; the driver sends two voltage sine waves, 90 degrees out of phase to the motor windings), micro-stepping drives can only **approximate** a **true sine wave**. This means that some torque ripples, resonance, and noise remains and hence resulting in odd stepper behavior, like seen below from this ref. (after the half step the stepper jumps to the full step and maintains that value for a while):
This is seen as a Moiré pattern in your printed products. As an example, if the head is moved in Z direction by micro-step, you will almost certainly notice that the head doesn't move on every micro-step, but only every 3rd or 4th micro-step (as an example). When using higher resolution steppers like the 0.9° stepper motors, you will still miss micro-steps (e.g. the same, so also on every 3rd or 4th micro-step the head moves), but as the micro-step is half the size of that one of a 1.8° stepper motor, the accuracy as in precision and resolution is higher.
In that sense, if you change your stepper drivers for higher micro-stepping drivers (from 1/16 to 1/32 as you mention), it will not help you improve the resolution much because the incremental torque from one to another 1/32 micro-step is lower than for 1/16 micro-steps as can be seen in the figure below (taken from this ref.).
So, using 0.9° motors (and keeping 1/16 micro-stepping) improves positioning accuracy as described above, it will also reduce the noise, because the torque per unit angular error is nearly doubled. Also remember that if you are using 8-bit electronics (you hint to an ATMega board), then even 1/32 micro-stepping burdens the processor to achieve reasonable travel speeds. With 8-bit electronics, it is usually suggested to use 1/16 stepping.
Upgrading an existing printer from 1.8° to 0.9° stepper motors is probably not worth for the majority of users (note that the maximum allowable speed also reduces when using 0.9° stepper motors). Unless you are designing and building a new delta, or aren't on a tight budget you could opt for the additional costs of buying 0.9° stepper motors.
Note that updating to higher micro-stepping values not necessarily implies that the quality of your products also increase. See e.g. this reference.
> 3 votes
# Answer
What you're seeing there is commonly referred to as "salmon skin" and isn't a result of the motor stepping, but due to power backfeeding from the motors. Install a set of flyback diodes on each axis (you can buy these premade specifically for printer motors, normally in sets of 8 diodes per motor) and you should find the issue either minimised or eliminated entirely. It's a very cheap upgrade and I'm surprised it's not a standard feature on printers that have affected drivers these days.
> 3 votes
# Answer
I am looking at the example print you supplied and trying to understand the defects. Was the object printed vertically, so that the object Z-axis is running from top to bottom in the picture?
If so, then the horizontal defects look like resonance artifacts, which could be caused by the issue you raise of the stepper motor not responding to small movement commands. The only thing that will prevent the motor from responding is stiction, or difficulty starting a movement. Stiction is a non-linear aspect of friction in which the "starting" friction is higher than the "sliding" friction. It might be worth checking for surfaces which must slide against each other, and assure they are lubricated with a dry, non-tacky lubricant.
A typical delta machine behaves the same way on each layer. The equations which govern how high on the tower the top of the delta-leg should be for each x,y, and z point is linear in Z, but non-linear in X and Y. With that in mind, I have no hypothesis to describe the defects that would be described as cathedrals if they were wood grain.
Or, perhaps the object was printed so that the surface shown is parallel to the bed? If so, the defects looks like more than a couple of microsteps. Is it possible that one drive is not working correctly? If so, I would suggest that the motor on the tower pointed to (or pointed from) by the cathedrals is not working like the others. It could be binding too tightly to the tower, or the pully may be loose, or the driver isn't working correctly for one of the two coils.
> 1 votes
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Tags: delta, motor
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thread-7963 | https://3dprinting.stackexchange.com/questions/7963 | Small structures are deformed after switching to Duet Wifi | 2019-01-12T21:16:44.563 | # Question
Title: Small structures are deformed after switching to Duet Wifi
I just switched to the Duet Wifi board (used MKS Gen L 1.0 before) and now small structures look terrible. From my observations the hot end moves correctly, but almost no filament gets extruded. On the other hand larger structures look very good. With the MKS board the exact same G-code worked fine. After that I gradually disabled many features like coasting, wiping and even retractions altogether, the quality only improved by a tiny margin.
Example print (the two towers should be cylinders):
Additional information:
* Printer: JGAurora A5
* Material: PETG
* Slicer: Simplify3D
More info (edit):
* Hot end temperature: 225 °C (for the affected layers)
* Bed temperature: 60 °C (I corrected the thermistor data, it's equivalent to 70-75 °C on other JGAurora A5 printers)
* Nozzle diameter: 0.4 mm
* Part cooling fan: 100% (improved cooler duct by Da Hai Zhu)
* Print speed: 50 mm/s (50% for outline)
* The cylinder is printed hollow because of my infill settings
* Lubricant is fresh, belts are tightened, so there should be no mechanical issues
# Answer
The OP found the solution and shared this in comments but has not written a proper answer. The OP found:
> To complete this, the issue was related to the part cooling fan not spinning correctly. After replacing it the problem was gone.
> 3 votes
# Answer
This actually just looks like heating issues. Cura has an option to set a minimum layer time and speed, and any layer that takes less than that amount of time it'll lift the head away from the print to allow the plastic to cool.
Unfortunately, the only things I can find for Simplify3D around head lift and minimum layer times are software feature request posts from 2017, or some features around scaling print speed for small layers, but unfortunately that'll just print the same object much slower and may not properly allow the part to cool as the melting-temperature print head is still sitting directly on top of the part.
I hate to be someone to suggest a software change, but you might try using Cura and seeing if you get better results with features such as this.
> 0 votes
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Tags: print-quality, extrusion, troubleshooting, fdm
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thread-9845 | https://3dprinting.stackexchange.com/questions/9845 | What is causing these strings in the overhangs? | 2019-05-03T22:18:26.900 | # Question
Title: What is causing these strings in the overhangs?
I am consistently getting these strings in the overhangs on models that folks say they are printing without supports. Can anyone tell me what is causing them and what I can do to fix them?
I've attached a picture mid-way during a BB-8 print. I'm using PLA at 75 % speed.
# Answer
While this looks a lot like stringing, it's not what I would call stringing. I usually reserve that term for material that should never have left the nozzle to begin with, due to insufficient or missing retraction or excessive compression of the filament between the extruder and the nozzle. The "strings" you've shown look like desired wall extrusions that did not adhere to the adjacent walls in the same layer or to the previous layer.
This is common when printing concave perimeters that are overhanging, due to a combination of minimal-to-no contact with previous layer and acceleration of the nozzle away from the previous wall in the current layer. Sometimes under-extrusion can also be a factor.
You can often mitigate this by:
* using thinner layers (for the whole print, or "adaptive layer height" that will dynamically adjust as needed). For a given wall slope (fixed rise over run), this will reduce the "rise", and thereby place the walls of the next layer such that they overlap more with the previous layer. Sometimes this makes the difference as to whether they overlap *at all*.
* increasing hotend temperature. This will improve bonding with adjacent wall and with previous layer, if there's any contact with it.
* decreasing print speed, especially for outer walls. This will reduce the effect of the nozzle pulling the wall away from the adjacent wall it's supposed to bond to, and will also deliver more heat to the adjacent wall and previous layer wall you want to bond to.
All three of these will also help if under-extrusion is part of the underlying cause.
If you can't get any of this to work, using supports is always an option, but spherical (as opposed to flattened) domes generally "shouldn't" need support to print.
> 2 votes
# Answer
You did print overhangs without supports. I have printed a Thermal Detonator for StarWars day (May the 4th be with you!), which is pretty much an empty pair of domes. To ensure that the upper layers stay up, I have activated support starting at 40°, and it came out perfectly fine. Without support, the lines would have had nothing to hang on and sag down like in your print.
> 0 votes
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Tags: prusa-i3, pla
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thread-10173 | https://3dprinting.stackexchange.com/questions/10173 | Power consumption of filament extrusion | 2019-06-04T10:17:23.857 | # Question
Title: Power consumption of filament extrusion
I'd like to calculate the power lost through the filament being extruded (or in other words, at how many Watts I'd have to run an ideal heater that loses heat ONLY through filament so that it stays at constant temperature).
* Power is defined in Watts as $\text W =\frac{\text J}{\text s}$
* Specific heat capacity of a material is defined as $C =\frac{\text J}{ \text K \times\text{kg}}$
When extrusion happens, the filament of higher temperature leaves the hotend while the same weight of filament of lower temperature enters the hotend.
Let's say the specific heat capacity of the filament is $C$ and the extrusion rate $r$ is given with units kg/s. The temperatures are $T$.
Is it correct then to say that the power consumption of filament extrusion is $W = (c\times T\_\text{Nozzle} - c\times T\_\text{Environment}) \times r$
meaning that if I would run a heater cartridge at exactly "W" watts and extrude filament with rate "r" and the block would not loose heat through any other means than through the filament extrusion, then the nozzle temperature would stay constant?
# Answer
> 6 votes
This is very simply stated, in fact the specific heat is a function of temperature and state of the material (liquid or solid). Also you need to consider which type of specific heat you use, e.g. the one for constant volume $C\_V$ or for constant pressure $C\_P$. Constant pressure is probably preferred considering the mechanics of the printer (pressing filament into the nozzle-heatbreak assembly).
A very interesting source of information is the PolymerDatabase.com.
This source confirms that:
> In the case of polymers, we have to distinguish between the heat capacity of liquid, rubbery and glassy polymers. The heat capacity increases with increasing temperature, therefore, a liquid or rubbery polymer can hold more energy than a solid polymer. All materials show this increase in heat capacity with temperature.
also:
> Specific heat capacities as a function of temperature have been published for only a limited number of polymers. In many cases, the heat capacity (at constant pressure) as a function of temperature can be approximated by straight lines.
In such cases you can use the value of the specific heat at a predefined temperature (in thermodynamics that is frequently 298 K) to get approximations for your thermoplastic material. These formulae can then be used to integrate over the temperature rise.
Please remember that a cartridge is of a certain value of Watt; to have a lower power, the cartridge modulates voltage to keep the heating block within a predefined temperature range.
# Answer
> 4 votes
# No.
Your formula is quite off, and it starts with the nomenclature:
## Watt
Watt is the **unit** of **energy transfer** which equals **power**.
The commonly used term "wattage" does not exist in science. It is a very despised shorthand *only* used in terms of *electric power* $P=UI$.
Both power $P$ (like work over time) and heat energy transfer $\Delta Q$ (which is one variant of power) use the unit $\text W=\frac {\text J} {\text s}$, which is confusing but a necessary distinction. Always remember that $P\_\text{total}=\sum\_{i=1}^nP\_i$ \- the total power in and out of an object is the sum of all partial powers!
## Heat Energy transfer
The Heat energy transfer through an object is defined as the *change* of the heat energy $Q$ stored inside an object. $Q$ is given in $\text J$, so its change $\Delta Q$ is given in $\text J$ too. To get to the power, the energy change needs to be measured at several spots in time, so we make the derivate over time and get the power in $\text W$. We're looking at $\dot Q=\frac {\delta Q} {\delta t}$.
The absolute change of heat energy of an item is defined as $\Delta Q(t)=m(t) c \Delta T$: Increasing the temperature $T$ of an object with the mass $m$ and specific heat capacity $c$ by $\delta T$ (between times $t\_0$ and $t$) results in a change of the stored energy by $\Delta Q(t-t\_0)$.
So, we know $Q=c m \Delta T$ and $P=\dot Q=\frac \delta {\delta t} c m \Delta T$
## Problem in question
We know that the drain (*loss*) of thermal energy from the system is via three ways:
* melting plastic (phase transition)
* extruding heated plastic
* convective heat loss to the air
* black body radiation of the heater block
We know that the total balance in equilibrium should be $P\_\text{total}=P\_\text{heating}+P\_\text{melting}+P\_\text{extrusion}+P\_\text{convection}+P\_\text{bb}=0$.
## heat deposited into the system
Let's start at the simplest: we simply know the nominal heating power of the cartridge, it is usually written upon the cartridge itself, usually something in the area of 20 to 40 W. In praxis, it is not exactly that, but the ballpark fits. Otherwise, we'd plug in $P\_\text{heating}=\epsilon \frac {U^2} {R}$ for our specific resistor, where $\epsilon$ is a coefficient between 0 and 1 telling us how good it is in converting electric to heat energy. Remember that since $U$ is technically a function of time (it is modulated to control heating behavior), our heating power also is, even though not explicit!
## black body radiation loss $P\_\text{bb}$
Black body radiation: $P\_\text{bb}=A \sigma T^4$ where $A$ is the surface area of the object, $\sigma$ is a constant called Stefan-Boltzmann Constant. That much thermal energy is just lost due to radiation via photons, even if we don't see it glowing.
## convection loss $P\_\text{convection}$
The change of heat energy via heat convection is roughly defined as $H=\theta A (T-T\_f)$ which brings us another coefficient $\theta$ about how good the block heats the air and the temperature of the medium (air) around $T\_f$ \- which we can replace as $(T-T\_f)=\Delta T\_a$.
And then we get to the biggest can of worms: the thermal heat transfer for melting the plastic and how much thermal energy is extruded from the system. For one of them, we can estimate some ballpark numbers, for the other, we will get into problems.
## extrusion loss $P\_\text{extrusion}$
The heat energy removed from the system by extruding plastic we can estimate from what we already established about thermal energy back in the Heat Energy transfer paragraph: $Q=mc(T\_0+\Delta T)$ using the specific heat capacity $c \[\frac {\text{J}}{\text kg K}\] $ of the molten plastic as it is extruded (more about that later). But that's not the loss per time, but the heat energy stored in it in Joules. What factor is changing? In this case, it is the mass $m=r\times t$ where $r=\frac {\text kg} {\text s}$ is the extrusion rate. So $Q\_\text{extrusion}=rtc\ \Delta T\_\text{extrusion}$ and subsequently $P\_\text{extrusion}=rc\ \Delta T\_\text{extrusion}$
This leaves us with the big problem: as 0scar correctly pointed out by directing to the PolymerDatabase the specific heat capacity is *not* a constant and *not* linear but changes depending on the aggregate of the substance. We can make some estimate about it though from how we formulated the total power and adding a few absolutes for convenience:
$$P\_\text{total}=P\_\text{heating}+P\_\text{melting}+P\_\text{extrusion}+H\_\text{convection}+P\_\text{bb}=0$$
$$P\_\text{heating}-H\_\text{convection}-P\_\text{bb}-P\_\text{extrusion}=P\_\text{melting}$$
$$\epsilon \frac {U^2}{R}-\theta A \Delta T\_a-A \sigma T^4-rc\ \Delta T\_\text{extrusion}=P\_\text{melting}$$
Remember, that $U$ is a time-dependent factor (because of the control board activating it or disabling it), $T\_f$ is *also* not a steady thing and changes depending on the airflow (though we can just pin it for our thought experiment) and thus $T$ itself might change over time as a result. $T$ is not equal to $\ \Delta T\_\text{Extrusion}$ but is the temperature of the heater block system as a whole. $\ \Delta T\_\text{Extrusion}$, on the contrary, is the temperature increase *of the filament* and not necessarily the same $\Delta T\_{air}$, the differential between the heater block and the air. Why this differentiation is necessary becomes apparent if one realizes that the path of the filament might benefit from the heat that is *lost* from the heater block along that path, pre-heating the filament.
## Phase Transition $P\_\text{melting}$
<sub>$\propto$ is the proportionality sign and indicates that I might skip factors or constants.</sub>
What is that last part? That $P\_\text{melting}$? It is the power of the Phase Transition. Matter does *not* shift between phases *freely*. There is energy stored in the state itself! So when transitioning from one phase to the other, that energy either has to be added (when going from solid to liquid or liquid to gas) or removed (when going the other way).
The "heat of fusion" is a material constant. For this look, I'll call it $\phi \[\frac {\text{J}} {\text {g}}\]$. We can make an estimation for the power that is put into melting the filament: there's an amount of filament that gets an amount of heat and undergoes the phase transition per time increment $$P\_\text{melting}\propto \frac \delta {\delta t}\phi m\_\text{melting}=\phi\*\dot m$$ Now, we have the product of specific "latent heat" and melting mass derived over time... We had earlier the flow rate of material $m=r\times t$ and the "latent heat" is a constant. So, we pull out $\dot m=r$ again. So in the end we get that the power that is needed to melt our filament is proportional to the flow of the material and the material constant. $$P\_\text{melting}\propto \phi r$$
## Conclusion tl;dr
When eliminating the loss via convection and black body radiation and assuming them 0 or neglectable, we assume our heater is packed in perfect isolation - and call them losses. Assuming $\epsilon=1$ for a perfect heater, we are left with this equilibrium situation:
$\frac {U^2}{R}-P\_\text{losses}=P\_\text{melting}+rc\ \Delta T\_\text{extrusion}$
**The sum of the power of the phase transition (melting of the filament) and the energy stored in the extruded filament per time $(\frac{dQ}{dt})$ is equal to the energy deposited into the hotend over time \[minus losses over time\]**
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Tags: extrusion, heat-management
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thread-10177 | https://3dprinting.stackexchange.com/questions/10177 | Overhangs lift up | 2019-06-04T21:04:36.347 | # Question
Title: Overhangs lift up
My printer is exhibiting a problem wherein it's as if the nozzle pulls up on layers. I don't think it used to do this - it seemed like it manifested after I replaced the broken x-carriage with a printed one, but I don't see how that could have caused the issue. It's possible something else I did or replaced caused it; not sure. Allow me to give an example:
I'm trying to print a worm gear, with a tooth size of about 2mm. The teeth, as they appear in the stl, look kinda like
```
____________
< >
> <
< >
> <
<____________>
```
However, when printed, the edges are pulled upwards, looking more like
```
____________
\ /
_\ /_
\ /
_\ /_
\ /
\________/
```
I originally noticed the pull-up in the surface finish of flat things - there was a grid of raised bumps on the top layer, I believe corresponding to the empty points between infill walls. That wasn't an effect that mattered to me, though. The effect on the worm gear is much more significant.
Anybody know why my printer is pulling up on layers, or whatever it's doing?
# Answer
> 6 votes
If you print (overhanging/slanting) fine edges **too hot** with **too little print part cooling**, they curl up. Please increase the part cooling fan percentage or try printing with a lower hotend temperature. Another possibility is to **print slower**, this way the filament cools better for the same fan RPM settings (fan spends more time in the hot region).
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*The Simplify3d slicer website has a print quality troubleshooting section that describes the up-curl of edges, they also hint to overheating as the source of your problem.*
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Tags: print-quality
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thread-10180 | https://3dprinting.stackexchange.com/questions/10180 | 3D printer and design software for creating propellers for a toy airplane/drone | 2019-06-05T15:03:10.493 | # Question
Title: 3D printer and design software for creating propellers for a toy airplane/drone
I would like to begin designing and 3D printing propellers for both a toy airplane and drone that I own. I want to do this for experimental purposes.
I have never used a 3D printer nor have I used any 3D printing design software. So as a beginner to both of these things, I would like to know what would be the best type of 3D printer to use to create propellers for toy aircraft and I would like to know what is currently regarded as the easiest-to-use 3D design software for creating objects such as airfoils.
Also, at this time, the most I want to pay for a 3D printer is $500.
# Answer
First, welcome to 3D Printing SE. This is a great place to ask questions and get answers from people who have walked the same path. I see from your profile that you are not a stranger to StackExchange and the available sites.
This question may be too broad for this SE Group, as it is asking for opinions rather than facts. We try not to ask questions about "what is the best printer", or "what software is the best". We avoid it both because it will change frequently, and because the answer needs to be gauged in your context, not the answerer's. We have some tools and community guidelines that suggest how to formulate the best questions.
Never-the-less, it is very hard when starting to even know how to make the first step, so with the indulgence of the group and your patience, I will make a suggestion or two. These come from my experience and your's is surely different.
To try out 3D printers you may have resources the don't require buying one yourself. It doesn't seem that 3D printing is the end goal for you. You want to use 3D printing as a way to manufacture several experiments. To access a 3D printer, it could be productive to check for local makerspaces, public libraries, or high schools with 3D printing capability. You may find a friend you 3D prints who would be happy to run some objects for you. You might even find it cost-effective to send designs to a service bureau such as 3D Hubs. **Note:** I have no relationship with the company, although I did use their services once.
With the printing side temporarily in abeyance, you can focus attention on the design side.
If you are familiar with programming, you might be able to use either OpenSCAD or SolidPython as a design tool. If you want something graphical, it might be worth trying OnShape. **NOTE:** I know at least one of the founders of OnShape, but have no investment nor role in the company. There are many design tools available. For designing technical parts, I think you want tools more focused on technical than aesthetic content.
I would avoid purchasing a printer unless you want 3D printing and 3D printers to be part of your project. People have mixed stories with many brands of printer, and lower-cost printers often become projects in themselves. They can be satisfying, rewarding, and learning-driven projects, but can distract you from your prime intention for a long time. In my case, I wanted to print boxes for projects, and prototypes for larger wood carvings. I designed a printer, acquired materials, built it, and spent 3 years playing with it. Along the way, I made some useful prints. Eventually I was tired of not having a reliable 3D printer, and I wanted to reliably make things. I needed a printing appliance. So I bought a mid-range printer (which works very well for me), and I don't mess with it (much).
So, a broad answer in response to a broad question. Welcome to 3D printing, the hobby and the StackExchange site.
> 2 votes
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Tags: 3d-models, 3d-design, software
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thread-10171 | https://3dprinting.stackexchange.com/questions/10171 | How is E value calculated in Slic3r? | 2019-06-04T04:22:43.570 | # Question
Title: How is E value calculated in Slic3r?
I want to know the math behind how Slic3r calculates E values. $E\_{value}$ represents amount of filament in mm (unless volumetric extrusion is selected) that has to be fed into the hotend to obtain a road of specific extrusion width.
Consider an example with following parameters:
* Nozzle diameter = 0.6 mm
* Layer height = 0.35 mm
* Extrusion width = 0.61 mm (for external perimeter)
* Length of the line segment (distance of the deposition path) = 98.2 mm
* Diameter of filament = 1.75 mm
**First part of the question**: How is $E\_{value}$ calculated for this case?
**Second part of the question**: How is velocity of extruder motor calculated for this case?
The Slic3r manual has limited information on flow math but is not comprehensive.
Let's assume volume of plastic fed in equal volume of plastic comes out
$$Volume\_{in} = \pi\times{(\frac{d}{2})}^2 \times E \times x = \frac{\pi\cdot d^2}{4}\times E \times x$$
Where,
* $d$ = diameter of the filament
* $x$ = extrusion multiplier
* $E$ = $E\_{value}$ to solve for
$$Volume\_{out} = (A\_{road} \times L)$$
* Length of path, $L$, is obtained from start and end coordinates
* Area of the road, $A\_{road}$, is calculated according to this link (Slic3r flow math; Section: Extruding on top of a surface). The formula for area of the road according to Slic3r manual is:
$$A\_{road} = (w - h)\times h + \pi\times{(\frac{h}{2})}^2 $$
Where,
* $w$ = Extrusion width
* $h$ = layer height
Seems like I am missing something. Math doesn't yield me same result as Slic3r $E$ value.
---
Many of you have marked this question duplicate. I know the first question is similar to what has asked before (calculating E value) but the answer doesn't match actual E value in G-code.
Also there is a second question on how to calculate extrusion speed given an E value
I have added G-code from actual Slic3r with the same settings as above to check the math.
The advance extrusion width settings in slic3r are as shown in the picture below: The settings are from a Prusa config for 0.6 mm nozzle
Consider a 100 mm x 100 mm x 5 mm part (X x Y x Z dimensions). Following is the output G-code from Slic3r:
```
; generated by Slic3r 1.3.0 on 2019-06-04 at 16:36:24
; external perimeters extrusion width = 0.61mm (6.55mm^3/s)
; perimeters extrusion width = 0.65mm (10.54mm^3/s)
; infill extrusion width = 0.70mm (15.25mm^3/s)
; solid infill extrusion width = 0.65mm (8.78mm^3/s)
; top infill extrusion width = 0.60mm (6.43mm^3/s)
```
------ Values of parameters defined in Slic3r -------
* first\_layer\_acceleration = 1000
* first\_layer\_bed\_temperature = 60
* first\_layer\_extrusion\_width = 0.65
* first\_layer\_speed = 30
* first\_layer\_temperature = 215
* first\_layer\_height = 0.35
* max\_print\_speed = 100
* nozzle\_diameter = 0.6
* external\_perimeter\_extrusion\_width = 0.61
------ some initialization lines above --------
```
G1 F1800
G1 X78.400 Y169.100 E8.21483 ; perimeter
**G1 X78.400 Y70.900 E8.21483 ; perimeter**
G1 X176.600 Y70.900 E8.21483 ; perimeter
G1 X176.600 Y169.010 E8.20731 ; perimeter
G1 X177.175 Y169.675 F10800.000 ; move to first perimeter point
```
The above code snippet refers to the perimeter of the very first layer in the print. Let us consider the highlighted line in above G-code. According to equations we have above, the values of the variables are:
* $d$ = 1.75
* $x$ = 1
* $E$ = $E\_{value}$ to solve for
* $w$ = 0.61
* $h$ = 0.35
* $L$ = 169.100 - 70.900 = 98.2
Area of the depositied road is:
$$A\_{road} = (0.61 - 0.35)\times 0.35 + \pi\times{(\frac{0.35}{2})}^2 $$ $$A\_{road} = 0.187211 mm^2 $$
For calculating $E\_{value}$, We use volume equality
$$Volume\_{in} = Volume\_{out}$$
$$E\_{value} = \frac{A\times L \times 4} {\pi\times d^2 \times x} = \frac{0.187211 \times 98.2 \times 4} {\pi \times 1.75^2 \times 1} = 7.6432 $$
The $E\_{value}$ in the G-code is 8.214
This is a big difference isn't it? I know about the die swell effect and expansion of molten plastic at the tip, but there seems to be no uniform compensation factor for this!
# Answer
**To answer your first question**:
Your calculations are not wrong, they are correct for a **normal layer** (uncorrected) layer. These calculations should get you very near the solution. The problem is that there are **default modifiers at play** that modify the extrusion process which become apparent when you change them or look at the hoover hint in the advanced printer settings section. E.g. see the image below of the "Print Settings" graphical user interface; specifically look at the hoovering hint:
The hoovering hint tells you that there is a 200 % modifier at play. ***What! a default modifier without me knowing?*** Well...., if we had looked at the Slic3r Manual (The Important First Layer) a little better, we read that:
> **Fatter extrusion width.**
> The more material touching the bed, the better the object will adhere to it, and this can be achieved by increasing the extrusion width of the first layer, either by a percentage or a fixed amount. Any spaces between the extrusions are adjusted accordingly.
>
> A value of approximately 200 % is usually recommended, but note that the value is calculated from the layer height and so the value should only be set if the layer height is the highest possible. For example, if the layer height is 0.1 mm, and the extrusion width is set to 200 %, then the actual extruded width will only be 0.2 mm, which is smaller than the nozzle. This would cause poor flow and lead to a failed print. It is therefore highly recommended to combine the high first layer height technique recommended above with this one. Setting the first layer height to 0.35 mm and the first extrusion width to 200 % would result in a nice fat extrusion 0.65 mm wide.
Tada! There we have the modifier from the screenshot; 200 % (this is expressed as a percentage over the layer height, and causes that an additional filament scale factor bigger than 1 is at play; the $x$ in your equations).
**To answer the second question**:
That should be rather straight forward, you know how long the path is and at which speed the head is moving (either at constant speed, decelerating or accelerating) and how much of filament you need to deposit, at the end point all filament needs to be deposited so you can calculate how fast the extrusion needs to be to accomplish that.
---
*If you calculate back from a volume of 8.214 mm<sup>2</sup> and solve for unknown $w$ you see that this yields $ w = 0.65\ mm $, and that is exactly what is stated as first layer width in your Slic3r settings; I quote:*
> first\_layer\_extrusion\_width = 0.65
---
*P.S. When you look into the source code of Slic3r, if you dig deep, you find that extrusion width is bound by minimum and maximum values, it could well be that that is causing the value to differ from 0.70 mm (200 % of 0.35).*
> 4 votes
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Tags: slicing, extrusion, slic3r
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thread-10182 | https://3dprinting.stackexchange.com/questions/10182 | What pins do I use for UART control on a RUMBA board for tmc2208? | 2019-06-05T15:32:24.787 | # Question
Title: What pins do I use for UART control on a RUMBA board for tmc2208?
I have been looking in the Marlin firmware for about an hour or two now to find what pins I should use for UART for my tmc2208 drivers and I have come up with nothing.
Does anyone know what they are or how to assign them? BTW, I am using the regular version of the RUMBA board not the RUMBA+ version.
For somereason i didn't put that i want to control my stepper motor drivers through uart they are tmc2208
# Answer
> 2 votes
The RUMBA schematic is available on the RUMBA wiki.
>
From the schematic, I see that UART3 (with +5V logic levels, not RS232) is presented on the EXP3 connector. I don't know if Marlin firmware can be controlled through a UART other than UART0, which is converted to USB through an FDDI chip. The Arduino bootloader is not expecting another UART, so you may still need to program it through the USB port (and UART0).
---
Tags: marlin, troubleshooting, electronics, stepper-driver
--- |
thread-10013 | https://3dprinting.stackexchange.com/questions/10013 | Ender 3 first print some area is smooth but some is rough? | 2019-05-24T07:56:30.933 | # Question
Title: Ender 3 first print some area is smooth but some is rough?
Please check following image, Dog looks smooth from left side but its rough from right side , similar on back too.
What could have caused this ?
Can it be due to moisture due to Air Conditioner in my room ?
# Answer
> 3 votes
I was making following mistakes
a) X-axis belt needed a tightening ( I calibrated all X,Y,Z and they were perfect)
b) There was under extrusion . ( I had to increase number of steps per mm for extruder motor and store the setting)
XYZ calibration cube was really helpful in debugging the problems .
# Answer
> -2 votes
It is most likely caused by inadequate part-cooling due to poor air-flow. Fit a \[better\] part cooling fan. There are plenty of designs on Thingiverse.
You may also be able to resolve the issue by adjusting the printing temperature, but the easiest solution is to install a good part-cooling fan.
---
Tags: print-quality, creality-ender-3
--- |
thread-6315 | https://3dprinting.stackexchange.com/questions/6315 | Underextrusion after travel moves with PETG/Colorfab XT | 2018-07-07T08:49:43.057 | # Question
Title: Underextrusion after travel moves with PETG/Colorfab XT
I came across several issues which seem to have been lowered. Firstly, I changed from a 0.4 to a 0.5 mm nozzle. Because of the backpressure I was not able to print my PETG (Colorfabb XT filament) below 270°C which caused unresolvable oozing. After that I was able to extrude till 230°C.
The left print below shows the result. I disassembled the hotend, there was no leak or whatsoever. Maybe it was too cold for printing. However, the temperature displayed was 250°C. Then I replaced the cheap aluminum heat block with a copper alloy based one. After that my PIDs did not work anymore. I had to greatly enhance the d-term, otherwise there was a big overshoot. Guess there was a serious heat conducting issue with the old BQ hotend.
Anyway, from there it became better. However, I noticed that I still have severe underextrusion after travel moves (second piece, first picture, first piece, second picture). I use Cura, so I activated retraction with the feature to prime after travel moves. I got the wall closed just after 0.35 mm³.
My Question: Is this underextrusion after travel moves normal for PETG/XT? I did not discover such behavior with PLA or ABS in the past.
Current Site Advice: Despite the weight, copper heat blocks seem to be worth the upgrade.
# Answer
> 3 votes
Have you tried adjusting the Extra Restart Distance in Simplify3D or Retraction Extra Prime in Ultimaker Cura? Most slicers should have a similar setting, perhaps named just slightly differently. A small positive value can help prime the nozzle after a long travel when you've lost back pressure or oozed a little.
# Answer
> 0 votes
Zero retraction is just a special (worst) case of under-retraction. You'll pretty much always lose material to oozing if you don't retract before travel. At best this ends up hidden inside the print (but can still affect weight and weight balance); usually it'll also harm the surface.
Ensure that retraction is set to *always* happen (not skipping short travel), and at least 5-6 mm for bowden extruders. Direct extruders can get away with less but I'm not sure exactly how much less. Less-rigid materials need more retraction to make up for compression of the filament between the extruder gear and the nozzle.
---
Tags: extrusion, colorfabb-xt
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thread-10190 | https://3dprinting.stackexchange.com/questions/10190 | StepStick Protectors | 2019-06-06T11:38:54.677 | # Question
Title: StepStick Protectors
How do StepStick Protectors work and what exactly do they protect?
If I use them with Pololu style stepper drivers, can I unplug for example the motor while the driver is powered without damaging the driver?
# Answer
## To Protect, or Not to Protect
From the web site you reference:
> The SilentStepStick Protector is an add-on module for StepStick and Pololu A4988 compatible stepper motor drivers. The board provides flyback diodes (freewheeling diodes) for the motor outputs, so that they are also protected against induction voltages in the unpowered state of the driver.
>
> The v2 protector also contains a diode from the logic voltage (anode) to the motor voltage (cathode), so that the power supply order of all SilentStepSticks is always guaranteed.
Since I assume you've read this, please indulge some explanation of the electrical engineering.
## Motors
Every motor has a part called the "rotor" that rotates, and a part called the "stator" that is stationary.
In the stepper motors usually used in 3D printers, the rotor is a permanent magnet and the stator consists of coils of wire. In normal operation, the current flowing through the coils creates a magnetic field. The rotor aligns itself with the field of the stator. To move, the stator field is shifted by changing the current in the coils, and the magnetic force causes the rotor to rotate to align the fields.
## Generated Voltages
As Faraday discovered, a changing magnetic field induces a voltage in a wire. There are two ways that the magnetic field changes. The first is that the current changes or stops. That introduces little high voltage blips into the motor coils. The motor drivers are well prepared to handle this blips. The second is when the rotor is forced to turn by an outside force, such as sliding the bed. As these voltages are not related to action the motor driver is causing, some of the techniques used to handle the voltage spikes may not be as robust.
The protection boards you point to consist of diodes to limit the magnitude of the voltages that the coil can produce. This is redundant with the diodes and protections built into the driver chips, but it may offer stronger protection.
## Benefits?
In this responder's opinion, you are unlikely to see a great benefit from these boards, but perhaps there are vulnerabilities I am unaware of. You are also unlikely to do any harm.
You asked specifically if, with the protectors installed, you could unplug the motor while it is passing current. The protectors may help with that, or they may not. Interrupt the connection creates a spark, and arcing through the air, that makes many high-frequency components which may not (or may) be effectively clamped by the diodes. For best results, you could add the protectors, and also avoid interrupting the motor current while powered.
> 5 votes
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Tags: stepper-driver
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thread-10191 | https://3dprinting.stackexchange.com/questions/10191 | Ender 3 Random Axis Shift | 2019-06-06T14:42:44.300 | # Question
Title: Ender 3 Random Axis Shift
My printer has been doing weird things lately. It used to print fine, but now it's like the Y or X axis after a certain percentage time. ie on a 24 hour print: it got off at 5 hours on a 42 print it got off at 16%
Thoughts?
# Answer
> 2 votes
The usual suspects are overheating stepper motor drivers and over-tight belts. It can also be caused by belts coming loose in their mounts.
# Answer
> 2 votes
I've had similar problems printing overnight using a computer and suspected network activity causing the problem. Energy savings settings can also cause it. I print overnight using an SD card to print the gcode file to solve the problem.
---
Tags: creality-ender-3
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thread-9935 | https://3dprinting.stackexchange.com/questions/9935 | Nozzle insulation gone, can the printer be damaged? | 2019-05-14T11:40:41.190 | # Question
Title: Nozzle insulation gone, can the printer be damaged?
During a print a lot of plastic ended up ripping the nozzle's yellow insulation strap.
Can printing without this insulation around the fusion chamber damage the printer?
If there is no chance of damaging the printer, how likely is it that the prints will be affected by the absence of this insulation
# Answer
> 6 votes
Removing the insulation will not damage the printer, although it may affect the quality of the prints. The insulation is, after all, there for a purpose.
Allowing too much heat to escape radiatively from the heater block will reduce the maximum flow rate, since less energy will be available to heat the filament, and you may need to reduce your printing speeds or increase your nozzle temperature.
A bigger problem is that heat radiating from the heater block can cause already extruded filament to sag, especially when printing details and intricate infill. If the nozzle remains too long in any area, already extruded filament is likely to soften and deform. Without adequate insulation, the only way to counteract this is by increasing part cooling, and this will remove even more energy from the heater block.
Either fit new insulating tape or buy some silicone socks, since they are readily available for MK7/8/9 heater blocks. Then print a couple of Benchies, both with and without a sock, and compare the results.
# Answer
> 3 votes
No, without the insulation you can print without a problem. I've been printing for years with (cotton or silicone) and without insulation, works perfectly. Although heat radiates from the heater block, I've never experienced issues that it causes overheating of your printed parts.
Note that the insulation tries to contain the heat in the nozzle preventing heat to leak to the surroundings (less energy is used/wasted). As such you may need to do a new PID tuning (certainly when the print cooling fan is incorrectly positioned as such that it cools the hotend heater block), but printing should just work fine if the print cooling fan is in the correct position.
# Answer
> 0 votes
Insulation of the nozzle is crucial. I removed it and put a silicon sock on a CR-10. I constantly got heat creeps even at 10C lower temp. Then I removed the sock and printed a 12 hour part with significant quality loss. It did finish the job. With silicon it stopped after 5-6 hours. I suppose that with the sock the upper part of the heat block which is uninsulated leaves more energy go up than without a silicon sock. Then I put cotton all around the heat block. I even put the cotton at the side of the thermistor. And kapton tape. The results are really really perfect. Always talking for the CR-10 stock nozzle and fans. If you don't have insulation you need better fans. All the heat goes up to the heatbreak and softens the fillament.
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Tags: creality-cr-10
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thread-8206 | https://3dprinting.stackexchange.com/questions/8206 | Inconsistent inner/outer dimensions | 2019-02-09T02:29:53.833 | # Question
Title: Inconsistent inner/outer dimensions
Using CuraEngine with my Ender 3, I'm getting what I'd call inconsistent inner and outer dimensions - for example, a nominally 3 mm peg is significantly larger than a 3 mm hole, and it takes dimensions something like 2.9 mm for the peg and 3.1 mm for the hole to get them to fit. Is this level of error normal? Is it caused by overextrusion, or does CuraEngine run its paths along the curve of the slice rather than offset by approximately half the nozzle width inside the sliced region? The magnitude of the error being almost exactly 0.2 mm, which is half of the 0.4 mm nozzle diameter, makes me wonder if it's the latter.
# Answer
Cura does correctly account for line extrusion widths wheen positioning the lines, and attempting to fix this with negative `xy_offset` was a mistake that led to lots of problems: in some cases, it completely eliminated tiny components of the model and left gaps in layers. At some point after asking this question, I did a new test with 8mm peg and hole, and I was actually able to force the 8mm peg into the hole (but not remove it) using tools, without cracking the parts, so I think past tiny sizes where dimensional accuracy is very difficult to achieve, everything is just about right.
> 0 votes
# Answer
Filament expands slightly as it is extruded. Also, the width of the extrusion depends on the volume of plastic extruded (not the nozzle size), as well as the amount that it is "squidged" down. Some slicers (e.g. Simplify3D) allow you to specify the width of the extrusion that you desire, but I'm not sure if Cura does this. You can fine tune the width of extrusions by adjusting the flow rate. Note that apertures get larger as nozzles wear out, but this should not affect the width of the extrusion very much since the determining factor is volumetric flow rate.
I would say that if you are getting a dimensional accuracy of +/- 0.1mm, you are doing pretty well. If you want to improve on this, you will need to calibrate your extruder and also monitor closely the average diameter of the filament that you are using. I have included a link to an external article, since doing this is beyond the scope of my answer. However, I doubt if it is possible to get push-fit accuracy with FDM printing without fudging the dimensions of the objects that you want to print.
3D Hubs: How to calibrate, tune and fine tune your printer and filament
> 3 votes
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Tags: print-quality, ultimaker-cura, slicing, creality-ender-3
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thread-10208 | https://3dprinting.stackexchange.com/questions/10208 | Change hotend thermistor input in Marlin | 2019-06-08T18:37:34.153 | # Question
Title: Change hotend thermistor input in Marlin
I have a Marlin driven Prusa i3 clone, by accident I cut through both thermistor wires for the hotend while it was powered on. The Arduino reset and the hotend thermistor no longer work.
Since there is a spare thermistor input on the RAMPS board I was wondering if I can change the input pin assigned to the hotend thermistor in the software? I've looked around (the code and the internet) and so far have only found out how to assign the thermistor type for the spare input, not how to tell Marlin to make `temp_sensor_2` be the input used for the hotend?
If anyone could help me figure out how to change the hotend thermistor input number I would be greatly appreciative!
# Answer
> 4 votes
In pins\_RAMPS.h you find which pins are used for which thermistor:
```
//
// Temperature Sensors
//
#define TEMP_0_PIN 13 // Analog Input
#define TEMP_1_PIN 15 // Analog Input
```
To use the other thermistor, you would need to swap the numbers:
```
//
// Temperature Sensors
//
#define TEMP_0_PIN 15 // Analog Input
#define TEMP_1_PIN 13 // Analog Input
```
---
Tags: prusa-i3, marlin, hotend, thermistor
--- |
thread-10207 | https://3dprinting.stackexchange.com/questions/10207 | How to prevent stringing with 0.25 mm nozzle? | 2019-06-08T18:27:58.657 | # Question
Title: How to prevent stringing with 0.25 mm nozzle?
When I print with a 0.4 mm nozzle I have no problem with stringing at all but because I need a more detailed print I must use a 0.25 mm nozzle.
I use Ultimaker Cura and an Anycubic i3 Mega.
What i tried so far:
* Enable/Disable Z hop
* Tried different retraction distance and speed.
* Tried with lower temperature
* Different wall thickness
If you have any suggestion please let me know.
# Answer
First, you should change the **nozzle diameter** setting, not just the line width setting, in Cura. Both are involved in determining extrusion. Line width can be less than or greater than nozzle size, but setting it much larger or smaller is not going to work well.
I suspect your main problem, though, is print speed. The area of the 0.25 mm nozzle orifice is only 39% of the area of an 0.4 mm nozzle orifice, bounding the material extrusion rate **at best** at 39% of what you could get with the larger nozzle (in practice it will be even lower due to complex fluid dynamics, probably much lower), but at the same linear print speed with narrower lines, you'll be extruding (or trying to extrude) 62.5% as much material per unit time. Now, if that much material can't actually make it out of the nozzle, pressure builds up between the extruder gear and the nozzle, and stringing is the result.
So, try lowering the print speed. **A lot** at first. If that solves the problem, gradually increase it until you find the limit. Increasing retraction and temperature may help you push it a little further. See my question and self-answer on stringing with flexible filaments, which might give you some ideas on other things to try:
Avoiding stringing with flexible filament
> 2 votes
# Answer
What worked well for me in avoiding stringing is to increase the travel move speeds significantly, disable Z-hop and to decrease printing temperature
> 1 votes
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Tags: ultimaker-cura, anycubic-i3-mega
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thread-10202 | https://3dprinting.stackexchange.com/questions/10202 | Low hanging fruit improvements to FDM printers that are patented | 2019-06-07T22:16:07.837 | # Question
Title: Low hanging fruit improvements to FDM printers that are patented
What are some relatively simple improvements to FDM 3D printers that cannot be sold however because they are under patent?
I know a heated build chamber is one such thing: According to the RepRap Wiki Heated\_Build\_Chamber:
> The disclosure on how to fabricate a heated build chamber might also be illegal as it is protected by patent.
So I wonder if there are similar "simple" FDM printer upgrades for which it currently would be forbidden to sell (or even promote?) parts due to patent infringement.
This is exactly the question I am interested in. This is not about a specific printer. A heated build chamber is a simple upgrade that would benefit pretty much any FDM printer. I am interested in other relatively simple upgrades which you won't find on most commercial 3D printers despite their simplicity for the reason that the feature is patented.
What other simple improvements are there, that are protected by patents?
# Answer
* Porosity control
* Seam hiding
* Dissolvable supports
**Porosity Control** \- The ability of a 3d printer to produce a variable infill rate (e.g. 20%) is covered by a Stratasys utility patent.
**Seam Hiding** \- The ability of a 3d printer to start printing from a different point on the perimeter such that no seam appears on the printed part, is covered by a Stratasys utility patent.
**Dissolvable supports** \- The ability of a 3d printer to print with 2 (or more) filaments such that one of the filaments, acting as support material (or scaffolding), can be removed by sustained immersion in water, is covered by a Stratasys utility patent.
Defendant Microboards Technology, LLC d/b/a Afinia's answer to Plaintiff's complaint for patent infringement; Affirmative Defenses; Counterclaims; and Demand for Jury Trial
I could not find a URL with the original Stratasys case, but I saved a copy back when it first came out. The document seems to be behind paywalls now. You can reference it as :
CASE 0:13-cv-03228-DWF-JJG
UNITED STATES DISTRICT COURT DISTRICT OF MINNESOTA
> 2 votes
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Tags: legal
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thread-10219 | https://3dprinting.stackexchange.com/questions/10219 | How to add extruder to RAMBo Mini | 2019-06-10T01:10:17.410 | # Question
Title: How to add extruder to RAMBo Mini
I have given up on getting the RUMBA board to work. I tried to add a P.I.N.D.A. (or PINDA) probe, but that didn’t work. I tried to add a BLTouch sensor, but that didn’t work either. Now the RUMBA board is not communicating with my PC.
So I have moved on to using a Mini-Rambo but the one drawback is that it only has one extruder capability. I would like to know if there is any way to add an extruder to the Mini-Rambo. Whether it be a separate board or soldering or something. I am open to anything.
# Answer
I would say that the clue is in the name, *Mini*RAMBo. The *Mini* part is related to its diminutive size and reduced functionality.
Extending the board would require patching in a secondary board to the MiniRAMBo board via pins<sup>1</sup> that may or may not exist, and would probably be more trouble than it is worth.
Looking at the board layout certainly shows that there are not any readily available connections for such an expansion.
If you want two extruders then the RAMBo would be a better bet, as it has 5 stepper motor driver outputs. It would certainly be easier, and quicker (as well as cheaper) than a MiniRAMBo plus a secondary daughter board).
That said, as the MiniRAMBo has two Z-axis controllers, it *may* be possible to repurpose one of them, *if* they are wired independently of each other and separately controllable. Although these lines suggest otherwise:
> It has 4 stepper drivers and 4 mosfet switched outputs.
and
> ### Differences from Rambo
>
> MiniRambo has:
>
> * 4 stepper drivers vs. 5
and
> Motor Drivers
>
> 4 A4982 1/16th microstep motor drivers(2 connectors on Z for Prusa Mendel and other dual Z printer designs)
So, it would appear that the two Z axis drivers are wired together.
---
<sup>1</sup> By *pins*, I mean external board pins/connectors - rather than the pins of the µController itself
> 3 votes
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Tags: extruder
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thread-10226 | https://3dprinting.stackexchange.com/questions/10226 | How to connect BLTouch sensor to Alunar M508 using LSEE 3D v1.0 board? | 2019-06-11T05:04:22.853 | # Question
Title: How to connect BLTouch sensor to Alunar M508 using LSEE 3D v1.0 board?
In the process of updating my printer (Alunar M508), I decided to add "Auto Bed Leveling" using a BLTouch sensor. After doing a lot of Googling:
1. I found firmware that will upload and work with printer in default configuration (without BLTouch)
2. Adding BLTouch configuration, the software compiles and updates the printer, I see all new options in menu and BLTouch on "power on" does a self test.
I know I have configured the power to the device correctly 2 power sources and ground but where I'm having issues is in identifying `Servo0` and `ZMax/Min` on my board. So far the black and white wire are connected to Z axis "end stop" but I cannot identify where to connect the orange signal wire to. I cannot find pinout anywhere of this board.
# Answer
> 2 votes
The LSEE 3D is basically a RAMPS board (your linked source also shows that the used `MOTHERBOARD` is a RAMPS board: `#define MOTHERBOARD BOARD_RAMPS_14_EFB`), this implies that all pins of your board are the same as a RAMPS board. To connect the 3 pin header of the BLTouch sensor you need to connect the red wire to +5 V and the black wire to ground; the orange wire needs to be connected to an available PWM pin. As the LSEE board does not have many exposed (free) pins for you to use, you need to re-use one of the existing PWM pins that you do not use. An example is the pin nr. 2. From the pins\_RAMPS.h file you see in the limit switches section:
```
//
// Limit Switches
//
#define X_MIN_PIN 3
#ifndef X_MAX_PIN
#define X_MAX_PIN 2
#endif
```
It appears, from the image, that your board does have max limit end stop switches header pins available. What you could do is use the `X_MAX_PIN` for the BLTouch sensor.
This implies that you need to assign the servo pin to pin nr. 2.
From the servos section of the same pins\_RAMPS.h file you see that the servos are either connected to pin 7 or pin 11 (depending on the board, your linked sources use the 1.4 version).
```
//
// Servos
//
#ifdef IS_RAMPS_13
#define SERVO0_PIN 7 // RAMPS_13 // Will conflict with BTN_EN2 on LCD_I2C_VIKI
#else
#define SERVO0_PIN 11
#endif
```
Using the linked sources, the 11 should be replaced with a 2. This implies that you can connect the orange wire to the "signal" pin of the X\_MAX end stop connector.
---
Tags: prusa-i3, marlin, bed-leveling, bltouch, alunar-m508
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thread-10224 | https://3dprinting.stackexchange.com/questions/10224 | 3D Printers imported from China - avoiding asbestos exposure | 2019-06-10T23:21:40.580 | # Question
Title: 3D Printers imported from China - avoiding asbestos exposure
Many 3D printers are made in China, and as asbestos is still legal in China (with large ongoing production it seems).
It is thus quite possible to end up with a 3D Printer that has asbestos parts in it.
Even though asbestos is illegal in some parts of the world (like Australia, though not the USA as far as I know), given the above, and the possible lack of care by suppliers and/or oversights during imports, one may want to do due diligence.
This becomes even more important if you plan to make modifications to your printer.
When speaking with even large producers, you may also get very conflicting answers ("yes part xyz has asbestos in it" vs "no it does not") - which further complicates the matter.
Asbestos testing is usually about 50-70 USD per sample, and often destruction of the tested item is necessary, so that is not a viable way either.
There are also heating elements used in printers which may be shielded with asbestos containing materials (as asbestos has good heat resistance properties).
How to avoid asbestos exposure with a high degree of certitude?
# Answer
> How to avoid asbestos exposure with a high degree of certitude?
If you're not willing to do asbestos testing yourself and can't trust your suppliers either, then this is impossible.
That said, for most of the components on a 3D printer it is easy to verify they're asbestos-free (I've never seen a steel linear shaft containing asbestos). For the remaining components, you may be able to pick an alternative which you know to be safe, for instance an all-metal hotend without insulating tape, or a heated bed that's plain FR4 without insulation. If there are any components that you distrust specifically (such as a heater cartridge) you should source that from a trusted supplier.
> 2 votes
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Tags: diy-3d-printer, printer-building, safety, replacement-parts
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thread-10231 | https://3dprinting.stackexchange.com/questions/10231 | 3 vs 4 bearings for y axis travel | 2019-06-11T13:39:43.343 | # Question
Title: 3 vs 4 bearings for y axis travel
I have a Monoprice Maker Select Plus, where I'm doing the Gulf Coast Robotics carriage plate upgrade. I was watching through an installation video just to find any "gotchas" I might want to watch for, and the guy in video recommends removing one of the carriage bearings, going from 4 to 3. The idea is to get quieter, smoother travels, with less weight on the belt.
Has anyone else here done this for this model printer? Or for the very-similar Maker Select v2/2.1? Are there any downsides I should watch for? Everything I know seems to indicate 3 bearings are just better (the whole "3 points define a plane" thing), but if it's that simple, why go to the cost of shipping with 4?
**Update**
I did end up making the switch, and it has worked well. One thing I've noticed is markedly increased ringing/ghosting. However, it should also be noted I switched to a stronger (heavier) build plate at the same time, and that likely is also contributing.
# Answer
> 4 votes
Ideally you would use three bearings opposed to four. In principle you will only need 3 fixtures to get a stable reference frame. Look at how most Prusa i3 "X" carriages are constructed, they also have just three bearings.
Three bearings are way more easy to line out (especially with tight tolerance bearings), with four bearings you will get binding much more easy than with three.
I've been using three linear (self printed tight tolerance acetal/POM) bearings on the moving bed (Y direction) for quite some time on a Prusa i3 type of printer made from 2040 Aluminium profiles.
---
*A similar reasoning applies to fixating the heated bed/glass slate, only three screws are necessary to define the reference plane. This is how my CoreXY heated bed is connected to the "Z" platform (a slate of glass is perfectly flat as a result of the production process).*
---
Tags: y-axis, bearing, monoprice-maker-select-plus
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thread-4304 | https://3dprinting.stackexchange.com/questions/4304 | Ultimaker Cura infill issues (weird vertical pillars due to underextrusion) | 2017-06-28T22:04:49.930 | # Question
Title: Ultimaker Cura infill issues (weird vertical pillars due to underextrusion)
I have spent ages debugging this problem but I can't figure out what I am doing wrong.
I have a Wanhao duplicator i3 (Prusa i3 clone) and until recently I used Wanhao's adapted version of the Cura slicer. But it's quite an old Cura version and I wanted to make use of the improved supports in the new Cura.
Unfortunately it seems like I just can't get the infill in the newest Cura to work. I copied all the settings from my Wanhao branded Cura version and printed the same file.
**This is the result:**
The infill is shaped like many tiny pillars. They are super fragile and while they do support material to be printed on top, they hardly withstand any pressure.
I have gone through quite a few testing cubes each with some setting altered, but nothing seemed to help.
It can't be the printers fault as I have successfully printed test cubes sliced with the old Cura in between (and not only once). Increasing temperature or slowing down the infill didn't help either. Neither did increasing flow rate or switching to triangular infill pattern. Also I have tried printing with all speeds set to 50mm/s and it still failed.
**My standard settings** *(from which I have created many test cubes with each cube having some settings tweaked)***:**
```
Layer Height: 0.12 mm
Init. Layer Height: 0.10 mm
Wall Line Count: 2
Top Layers: 6
Bottom Layers: 4
Infill Line distance: 5 mm (used to be 20 % in old Cura, but this is very dense in the new Cura)
Infill Pattern: Lines
Infill Overlap Percentage: 20 %
Printing Temperature: 200 °C
Build Plate Temperature: 60 °C
Retraction: Enabled, Distance: 2 mm, Speed: 60 mm/s
Speeds: Print:60 mm/s, Infill: 60 mm/s, Outer Wall: 30 mm/s, Inner Wall: 60 mm/s, Top/Bottom: 40 mm/s, Travel: 100 mm/s, Initial Layer: 20 mm/s
Combing Mode: All
```
# Answer
This problem is most commonly caused by infill speeds which are too high.
Instead of printing lines, the filament is caught on one of the lines of the previous layer, leaves a blob there and only restarts extrusion when it hits the next line. Instead of extruding continuously the filament comes out in blobs at the locations where there's filament on the previous layer.
You can have good infill up to some layer and suddenly start getting this problem as of some layer. When the problem occurs the next layer is more likely to show the problem. It's snowballing.
> 3 votes
# Answer
I am using the same printer and stopped trying to upgrade to higher CURA.
To my knowledge the branding of the Wanhao Cura Edition is that this Cura knows the specific firmware of your printer and thus is able to do printer specific tasks like calculating printing times etc.
I assume that copying the settings does only copy the settings and not the firmware info of your printer. If these settings however build on firmware info in the Cura wanhao edition, things could get messed up.
I would try uninstalling Cura, make sure the folder with the settings is deleted, reinstall and set it up from scratch.
If your motivation for the upgrade is feature-richness, you could also take a look at slic3r instead.
> 2 votes
# Answer
I am using the same printer (v1.2) with some upgrades and have been using the latest Ultimaker Cura (4.1) ever since they came out. For the first few prints I used an imported Ultimaker Cura profile, but after 3-4 bad prints I created a new profile from scratch, using a percentage for infill, with no problems at all.
> 0 votes
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Tags: ultimaker-cura, infill, wanhao
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thread-10229 | https://3dprinting.stackexchange.com/questions/10229 | What grease to use for linear rails? | 2019-06-11T11:29:30.367 | # Question
Title: What grease to use for linear rails?
What grease to use on linear rails to make them stick as little as possible? I've tried so far:
* WD40 (let’s not start a discussion about that please),
* silicon spray and
* some bearing grease called ‘motorex’,
but with all of them the rails stick quite much and don’t slide as easily as I’d hope.
Can someone recommend some good grease for linear rails (specifically the hiwin type, 12-15mm)?
# Answer
**Don't use grease**, it is better to use a **light oil** to lubricate the rods. A light oil will help flush out any dust and filament debris, grease will trap it.
I've used both light machine oil (like used for sewing machines) and PTFE based spray (Teflon). Grease is thick and will collect and trap dust and particles more easily than light machine oil.
---
*Even high-end consumer printers use light machine oil, e.g. the Ultimaker 3 Extended I got came with a bottle of light machine oil for the linear guide rails. Their advice is to regularly add a drop of oil on each shaft once in a while (how frequent depends on how much your printer prints).*
> 9 votes
# Answer
I have (what I thought was Silicon) spray that was given to me by the garage door installer to lube the rollers for my garage doors. I spray some on a paper towel and wipe the X, Y and Z bars with that. It is called Zep 70.
https://www.zep.com/product/zepcorporate/zep-70
> Zep 70 is a soy-based penetrating lubricant that utilizes a renewable soy solvent. It provides excellent long-lasting lubrication, and superior water displacement properties. Zep 70 will penetrate quickly and clean dirt and grease. It will also protect against rust and corrosion. Zep 70 is packaged in a 24 oz. can with a net weight of 18 ounces. Utilizing a soy-based solvent, a renewable source, helps to conserve nonrenewable resources such as petroleum. Non-evaporative solvent extends life of the lubricant. Quickly penetrates parts frozen from rust or corrosion. Displaces moisture and condensation which can cause corrosion. Treated surfaces are protected from rust. Helps clean dirt and grease from metal surfaces.
Reading the can contents, the Lubricant part seems to be TSRN-80100428-5003 The guides seem to slide on the bars with this stuff. Can't find a google hit on it.
I also made a polycarbonate enclosure around my printer to keep dust from settling on everything.
> 0 votes
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Tags: linear-motion
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thread-10234 | https://3dprinting.stackexchange.com/questions/10234 | What do I need to do to recalibrate my printer after updating the firmware? | 2019-06-11T21:58:02.273 | # Question
Title: What do I need to do to recalibrate my printer after updating the firmware?
I just updated my Maker Select Plus from the stock (I believe RepRap-based) firmware to Advi3pp, which is Marlin based. The printer starts up and everything seems okay, but I haven't actually tried a print yet and there was a message during the upgrade about deleting incompatible settings.
What do I need to do to recalibrate the printer following the firmware upgrade?
# Answer
> 1 votes
If it is Marlin based or RepRap based, many parameters are stored in EEPROM memory. A G-code command M502: Read parameters from "configuration.h" would reset all parameters that can be changed to their default value as defined in your configuration file. Don't forget to follow the `M502` command with a `M500` command to store the loaded parameters to EEPROM. This would overwrite all previous settings.
<sub>*From the linked source, `M502`:*</sub>
> This command resets all tunable parameters to their default values, as set in the firmware. This doesn't reset any parameters stored in the EEPROM, so it must be followed with M500 if you want to do that.
You can send these commands over a terminal interface to the printer using applications such as Pronterface, OctoPrint, Repetier-Host, and probably many more, or store the commands in a G-code file (e.g. a text file with a `.g` extension) and print the file using an SD card.
# Answer
> 0 votes
Looks like I don't need to do anything. I printed a 20 mm calibration cube, and aside from some elephant footing it came out as clean and as close to the model dimensions as anything else I've ever put through the machine, with no changes.
So I'll recommend this as a first step to anyone else: start a 20 mm cube going, watch it closely early on to be sure you're getting adequate extrusion and bed adhesion. If it fails here you may need to adjust settings. When it's done, measure it and see where you are. You might not need to do anything else.
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Tags: marlin, calibration, firmware, monoprice-maker-select-plus
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thread-10176 | https://3dprinting.stackexchange.com/questions/10176 | Printing PLA on PEX surface - is heated bed needed? | 2019-06-04T17:28:53.913 | # Question
Title: Printing PLA on PEX surface - is heated bed needed?
I have a WhamBam build system on order. A magnet attaches (glues down I think) to the Aluminium printing bed (or add a glass sheet? Separate question), then PEX material on flexible steel sheet gets slapped down for the print surface.
I have been printing PLA on a cold PEI sheet from Vertex, using 4 binder clips to hold it in place vs peeling the backing off and sticking it down. The print job wants to keep heating the bed to 60 °C, I turn it down, a couple minutes into a job it cranks it back to 60 °C and I turn it down again. A few times I missed the second turn on, and the PEI has been kinda warped now (or maybe it's just the plastic over the sticky backing), and has also peeled off some surface chunks in the middle, so we've been trying to print around the damaged section. The warping has now made the PEI unusable, so I'm hoping the WhamBam arrives soon.
We've been printing for a couple of weeks now (I printed a chess set, largest has 4 cm diameter and is 10 cm tall, some pieces on blue tape, some on the PEI) and are starting to venture into our own designs.
Intended project is box tops & bottoms that are ~90 mm x 65 mm x different heights with openings. We tried one on blue tape (a bottom with no openings) and ended up chiseling it off the bed with a steel putty knife (I don't recall if heat was on or not). We tried a top with openings on the PEI, missed that the heat had turned back on, but between the bed not quite level (forgot to re-check it) and the PEI being warped we killed it after the openings were printed around. It was not going to be usable, but we did print enough to be able to confirm the opening spacings (needs work still) so it was not a total loss. Came off the PEI easily (\<2 mm thick when we stopped), we managed to miss the damaged parts mostly.
So the question: when the WhamBam arrives, is it better to print PLA at 60 °C, or do I keep playing the game of turning it down (and saving the waiting time of it heating up)?
# Answer
> 0 votes
Received and installed the WhamBam system, and it works great! Have been letting it heat to 60C, which I'm pretty sure is not making it all the way thru the magnet, flex steel plate, and the PEX surface, but parts are adhering great and pop right off the PEX just by the act of picking up the plate, even a large box bottom (~68mm x 95mm) came off so easily I thought it had lost adhesion - my wife printed several items earlier and they came off the same way. I am impressed with the system!
We had lost a blade off the hot end fan (and turns out it was 3 blades), initial prints had failed to adhere on the PEX, the PLA didn't appear to be extruding properly, and the fan irregularity was very irritating. Internet searches indicated the plastic melting temp was not accurate enough. Replaced the fan and every print since has been great.
EDIT 6/14/2019 Here is a youtube clip of a freshly printed door knob (screen door latch) coming off a 60C bed, no problem!
And a larger box, ~65 x 98mm, that popped right off.
# Answer
> 2 votes
I print PLA on a PEI bed at 60°C. I have also printed PLA on an aluminum bed at 60°C with Elmer's Glue Stick for bonding, which worked better for me than PLA. I recently switched to Aqua Net Hairspray on the aluminum bed at 60°C, which also worked well.
I have found no reason to avoid bed heating with PLA.
If the object is stuck too tightly on the PEI bed, you could try adding hairspray. It acts as a glue, but also as a release agent, and, being soluble in water, you can help release the object with a few water drops.
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Tags: heated-bed
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thread-10244 | https://3dprinting.stackexchange.com/questions/10244 | What does nozzle size affect besides line width in, e.g., Ultimaker Cura? | 2019-06-12T14:38:44.383 | # Question
Title: What does nozzle size affect besides line width in, e.g., Ultimaker Cura?
The Ultimaker Cura documentation says
> **Tip:** If you use an unavailable third party nozzle size, set the line width to equal the nozzle size.
I sliced an object with a 0.3 mm line width. When the nozzle size is 0.4 mm, the results are *almost* the same as when the nozzle is 0.3 mm. The filament usage is slightly different and the gcode files have similar, but different, coordinates throughout.
What does **nozzle size** really do besides suggest the line width?
# Answer
Searching the CuraEngine source, the only places I can find where nozzle size is used directly involve some arcane logic for merging of infill lines, such as:
https://github.com/Ultimaker/CuraEngine/blob/05e93dabce9e863b8742fd69ed87717e1594e7a9/src/MergeInfillLines.cpp#L124
So essentially, yes, nozzle size mainly serves as a default value for the line width settings.
However, in general it's not always possible for line width different from nozzle size to be honored.
* For line widths smaller than the nozzle, motion along a path where the material being deposited has proper adhesion is required to stretch the material and prevent it from retaining the width extruded from the nozzle, and small lines already printed are likely to be damaged by the nozzle when attempting to print additional small lines in their vicinity. In particular, you won't be able to print small details significantly below the nozzle size just by extruding less material.
* For line widths larger than the nozzle, compression against an existing surface is required to prevent the extra material from just sagging down rather than expanding horizontally. In particular, line widths wider than the nozzle are unlikely to work right in the presence of overhangs.
Also, as noted by Tim Kuipers in comments, there are places outside the source, but rather in the json-based configuration tree, where nozzle size plays a role in the defaults and warning ranges for other parameters. Those are mostly line widths, but
> The nozzle size can affect the values of the following settings besides line width in `fdmprinter.def.json`: Outer Wall Inset, Outer Wall Wipe Distance and Minimum Support XY Distance. Other than that it only influences the conditions under which setting-values give you a warning.
> 7 votes
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Tags: ultimaker-cura, nozzle
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thread-8226 | https://3dprinting.stackexchange.com/questions/8226 | How to make sure we reach the total feedrate despite jerk | 2019-02-11T17:31:25.813 | # Question
Title: How to make sure we reach the total feedrate despite jerk
When printing a G-code at a high speed/feedrate of 12,000 mm/min versus a slower speed we don't always notice a difference since the geometry does not always allow for the full speed to be reached due to the acceleration/deceleration taking most of the length of the segments.
Is the above a correct statement and is there a way to find the sweet spot between length and fastest speed in relation to the jerk values?
# Answer
> 1 votes
The simple answer is that there's no way to guarantee you reach a specific maximum speed, with a given acceleration limit. You have to accelerate and decelerate along the length of a line, so the distance you're accelerating is roughly half the length of the total line. Imagine you can only accelerate at 50 mm/s<sup>2</sup>, and you've got a line that allows you to reach exactly 100 mm/s before you start decelerating. If you have to print a shorter line, you're going to reach a lower speed. Any combination of maximum speed and maximum acceleration can be defeated just by printing a shorter line than you tested with.
As far as a sweet spot goes, I'm not sure quite what you're asking there. There are tradeoffs to be considered for any combination of speed, jerk, and acceleration.
Prints with high jerk settings will be able to "skip" a certain portion of the acceleration and just jump straight to some minimum speed. This tends to result in echo artifacts on the print around corners.
Prints with low acceleration settings tend to exhibit some irregularities in line width over the length of the line due to the interaction between pressure and extrusion rate inside the extruder. I went into some detail on the third section of this previous answer of how and why this happens.
Prints with high top speeds, but low acceleration and jerk, can suffer from under-extrusion if you set your maximum speed too high, and it can be a little difficult to diagnose this in some cases. If you think of the extruder as having an internal "buffer" of molten plastic, that buffer tends to fill at low print speeds, and empty at higher print speeds. You may think you've got your maximum speed set appropriately, when in reality your extruder drains the buffer over maybe 50 mm of max speed printing (hypothetical nonsensical number), and attempting to print very long straight lines may result in the extruder emptying its buffer until it slows down again. My recommendation is to do some trial and error testing to figure out the fastest extrusion rate your printer can support for an extended period of time, and then put that maximum limit into your printer firmware to prevent printing too quickly. Acceleration and jerk settings should be set as high as you can tolerate without causing echoes and other odd artifacts, with attention paid to the printer itself; it gains you nothing to shake your frame to pieces trying to chase some theoretical maximum printing speed limit.
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Tags: g-code
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thread-4706 | https://3dprinting.stackexchange.com/questions/4706 | Could nail polish damage pure PLA? | 2017-10-05T14:04:49.993 | # Question
Title: Could nail polish damage pure PLA?
I would like to use nail polish to paint and smooth a PLA model. Could nail polish damage a model made out of pure PLA?
# Answer
NO if you want to smooth your print, gently heat the plastic and with a utensil smooth out the plastic. A hair dryer is a good way of doing this but be careful to only lightly melt the outside of the model.
> 2 votes
# Answer
This is an ugly question, and an ugly answer.
1. Nail polish doesn't come with an ingredient list. Nor are there MSDS's available to refer to what solvents are in it. So it's "unknown 1"
2. Most every filament company will not give you a list of compounds for colorants or plasticizers used. MSDS is off the table. So, even though we do know what PLA and ABS is inherently, we have no clue about the other ingredients used to make your particular filament. This is "unknown 2".
What both of these comes down to is a very nasty situation indeed. We know for a fact that ABS dissolves into acetone. PLA does not.... Except we have had reports of PLA that does. When we look further into those responses, and ask them to do a burn test, they smell popcorn and something acrid (ABS).
This guarantees unless we have virgin material and MSDS in hand, you only have a close guess at what material you have. And that's to say nothing about "nail polish", and its components.
There are also other solvents that will dissolve PLA. MakerBot back before they turned evil, noted a solution called Beta Solution (90% isopropyl alcohol, 9% KOH, 1% Al(OH)3 ). This stuff is noted for dissolving PLA and leaving ABS intact.
Long story short: "Could Nail Polish damage pure PLA?" We can't guarantee purity of PLA, we can't guarantee contents of nail polish's solvents. The only answer is to print a swatch and test yourself. Calibration cubes are quick and easy.
> 10 votes
# Answer
Nail polish will not damage your PLA model.
1) Let's talk about "gel" nail polish. Gel polish self-levels, does not drip, is cheap, is much more health-friendly than many finishing methods, and only takes 30 seconds under a suitable strength UV/LED lamp to dry, providing a thick smooth coat (clear, color, glitter!, anything) that makes any layer lines disappear.
2) The FDA regulates nail polish in its "cosmetics" category, so, not only are the ingredients known, they have to be printed on the bottle.
3) Gel polish consists of various methacrylate monomers which undergo a radical (in the chemistry sense, although it is pretty darn cool too) polymerization process that is UV-activable. Filament is primarily polyactide, which is polymerized at room temperature. Polymerized polyactide reacts with methylacrylate at the ends of the long strands (not in the middle, which is what you would describe as "damage"). Methylacrylate actually makes the PLA ends less reactive (read: it makes it stronger). As an industrial material, this compound is known as "supertoughened" PLA.
Hope that clears things up a bit. As an aside, if you're not familiar with the different families of nail polishes, and you want to try this, you can tell if the polish you're looking at is "gel" because the bottle will be opaque (keeps UV out).
> 4 votes
# Answer
I would not expect a problem. The greatest problem I would expect would be if the PLA layers were not well bonded, and the coating material could work in between layers. If so, over time the difference in water absorption or thermal expansion could further separate the layers.
> 2 votes
# Answer
Nail polish contains acetone. It melts PLA, so yes you *could* damage it. Google acetone vapor batch to read up on a safer way to do the job.
> 0 votes
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Tags: pla, color, smoothing
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thread-4601 | https://3dprinting.stackexchange.com/questions/4601 | What choices do we have on Clear resins for DLP? | 2017-09-09T14:38:46.850 | # Question
Title: What choices do we have on Clear resins for DLP?
I'm searching for a truly clear DLP resin which can polymerize between 400nm and 405nm.
I found the unpigmented from FunToDo, but it seems to be yellow-clear:
I'm trying to achieve something similar to this:
Is there any resin out there which costs likely the same (about 50€/liter) which will give results like this?
# Answer
Formlabs sells a completely clear resin that they've even made simple lenses from, but it's about $150 for a liter. I have no idea how well it would work with your DLP setup. Looks amazing in the pictures though.
MatterHackers sells PhotoCentric UV Firm Clear for $90 for a liter as well. It's not quite as easy finding pictures of this stuff, but from what it looks like, it's still pretty decent. Assuming you've got a UV DLP
Disclaimer, the PhotoCentric stuff says it's a UV resin (10nm to 400nm IIRC) and I have not the slightest clue what Formlabs designs their resin for, so YMMV.
> 2 votes
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Tags: dlp
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thread-10250 | https://3dprinting.stackexchange.com/questions/10250 | Are large format prints more brittle? | 2019-06-12T21:25:41.080 | # Question
Title: Are large format prints more brittle?
Recently on one of her videos a YouTuber stated that prints from large format printers are more brittle than if you were to print them in parts and glue them together. This seems to contradict the testimonials from the customers of a large format printer, who say that they get good prints from those printers (which print have a print area of a meter square).
Would a print form a larger format printer be more brittle than a print made of smaller pieces super glued together?
(with all other aspects being equal e.g. the nozzle, the temps, the material and the shape of the object).
The YouTube didn't cite any source information to back up her claim.
# Answer
If you break up a large piece into multiple smaller pieces and properly glue them together, you basically add stiffeners (as a result of printing walls). This could lead to a more stiff model; this might have been confused by calling large prints more brittle opposed to constructed models.
If printing is conducted at similar conditions on large printers, there shouldn't be a reason why the model becomes more brittle unless the conditions aren't the same. But that would be true for printing at small printers too, e.g. if one print was printed in a draft.
> 3 votes
# Answer
I'd recommend getting the object to fit together by design, rather than glue - though I tend (if the item is never to be disassembled) use Zap-a-gap - that stuff sticks like crazy though you must not squeeze the parts together but let it naturally sit.
> -2 votes
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Tags: large-format
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thread-6358 | https://3dprinting.stackexchange.com/questions/6358 | Inductive Sensor in 24 V machine? | 2018-07-10T13:49:35.493 | # Question
Title: Inductive Sensor in 24 V machine?
I am getting a 24 V based Ender 3. From the factory, it has an aluminium bed. So I also put this LJ12 A3-4-Z/BX Inductive NPN NO 4 mm with 6-36 V operation current into the box together with a few other spare parts. Now, as I read up on these things something dawns on me: The normal input and output voltage of a simple switch is 5 V, as sensors are ran on 5 V on most boards (and in digital logics). The sensors run on 6 V plus though.
I do not want to fry my machine by putting in 24 V into the sensor input: What do I have to do (besides making a mount)?
# Answer
> 11 votes
The inductive sensors work better when you apply a higher voltage than 5 V. Usually they are rated for 6-36 V, but please do check.
To prevent frying your board when connecting the sensor to (12 or) 24 Volts you could optically isolate the 5 V and the (12 or) 24 V circuit with an OptoCoupler module:
*Image of an optocoupler module*
This module uses an optical switch based on the output of the sensor and should be correctly connected:
*Image of connecting an optocoupler module to the sensor and to the board*
<sub>Please note that the image uses a capacitive sensor rather than a inductive sensor, both are connected similarly</sub>
Note that there are many sorts of sensors, a few are listed here. Generally speaking, the larger the diameter of the sensor, the larger the detection distance to the bed. Note that these work well with metal beds (Iron/steel better than Aluminium), but will not work for glass (capacitive sensors work on glass but are prone to drift by moisture in the air, a touch sensor may then be a better alternative).
# Answer
> 4 votes
Another possibility is to create a voltage divider circuit.
> In electronics, a voltage divider (also known as a potential divider) is a passive linear circuit that produces an output voltage (V<sub>out</sub>) that is a fraction of its input voltage (V<sub>in</sub>). Voltage division is the result of distributing the input voltage among the components of the divider. A simple example of a voltage divider is two resistors connected in series, with the input voltage applied across the resistor pair and the output voltage emerging from the connection between them.
Note that fluctuating voltages of the power supply can have side effects that the voltage of the divider is either too low or high for the pin and could result in either a detection miss or could burn the on board processor.
A voltage divider based on 12 V is depicted below based on this source:
Please note that for different voltage you require a different value, e.g. for 24 V you would require (by calculation) a 2.63 kΩ resistor (which does not exist, so put two resistors in series; a 2.2 kΩ and a 430 Ω to get that value).
---
*NOTE:<br>This is posted as a separate answer as the question by the OP can be answered by different solutions; this solution uses a totally different approach than my other answer. It is up to the OP to decide which of the answers suits the OP best. This is not in contrast to the SE approach as can be taken from various Meta questions on this topic. To incorporated this answer into the other answer (with multiple ways under captions) is per definition not better than having various answers; different solutions should be in different answers so that they can be voted independently of each other*
# Answer
> 2 votes
**Minimalist Solution**
The very simplest possible implementation is to use a single resistor(!) to protect the input pin, as described in this source. The AVR inputs are protected from over/under voltage by internal silicon diodes D1 and D2. The input resistor must be sized such that it will conduct no more than 1 mA when the internal clamping diode, D1, conducts at Vcc+0.5V, or 5.5V in this case. A 22K resistor could work in this case if we use our 24V supply for the sensor. Our current through the clamping diode is calculated by Ohm's Law as (24V - 5.5V)/22K = 0.84 mA.
There is no reason, in this case, to cut so close to the bone though. We do not need particularly high speed detection for this application, so a 100K resistor would be a better choice, and limits diode D1 to 0.19 mA. This gives additional protection for voltage spikes.
This solution works well until the internal diode gets fried by a spike or surge, so it is much better to add redundancy, and use a pair of external Schottky clamping diodes, which have a lower forward voltage drop and will conduct before the internal silicon diodes.
So, my solution, (the one I plan to implement soon on my own Ender 3 Pro\*), is from this source article and looks like this:
Where R1, D3, and D4 are my external components as described, and C1 is omitted for simplicity. (If C1 is used, it forms a low-pass RC filter, so you'd need to size it appropriately. If we find that noise or 'bounce' is an issue, we can add C1 easily later.)
In my opinion a single 100K resistor and two Schottky diodes are adequate protection for this circuit, and the 6-36V proximity sensor will work very well on the available 24V supply.
\*Based on the first comment to this proposed solution, I recognize the need to look carefully at the failsafe property here. Depending on whether the existing Z endstop is included in the loop, and how Marlin handles this too will determine whether this is a satisfactory solution. I'll leave my part of the discussion there for now, until I get closer to design and implementation on my own machine.
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Tags: z-probe, creality-ender-3, inductive-sensor
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thread-10259 | https://3dprinting.stackexchange.com/questions/10259 | Material for printing flowerpots | 2019-06-13T19:49:37.733 | # Question
Title: Material for printing flowerpots
I want to print a flowerpots, for advanced watering system.
Plants are going to be eaten.
What is the most suitable material, when we consider the fact, that we do not want to just make forms and do clay flowerpots(which may seem most healthier), but having them directly printed.
What are the temperatures that makes plastics emit dangerous components in surrounding water, and what are those components?
Is there some "totally safe" material out there? I was thinking of PLA or PETG, because I've already heard that ABS is not safe for edibles.
# Answer
> 3 votes
I printed some pots for sprouting seedlings this year from PLA. A square array of pots with tiny drainage holes in the bottom.
The array filled the bed of a Prusa3d i3m3.
The seeds sprouted, except for the ground cherries, which I think failed because the seeds were bad.
I had good germination rates for tomatoes and basil.
According to the FDA, ABS is generally safe for food, although like any filament the pigment and any added chemicals may be contraindicated for continued health.
# Answer
> 3 votes
Given the tendancy for extrusion 3D prints to be porous, aside from any potential health/ingestion issues, I'd recommend lining your pots after printing. You could use an epoxy that's food-rated, or a thin layer of concrete, or even sheet metal if you have access to a bender (or aluminum foil, for that matter).
So far as temperature-dependent outgassing, that's not an issue unless your garden will reach temperatures over 150 Celsius :-)
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Tags: material, food
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thread-10264 | https://3dprinting.stackexchange.com/questions/10264 | Possible causes of print defects? | 2019-06-14T12:03:44.073 | # Question
Title: Possible causes of print defects?
I'd like some advice regarding defects on my print :
Here some details :
* Printer CR-10 S, nozzle 0.4
* Material PLA
* Bed 60, Hotend 215, 50 mm/s speed
* SLiced with cura 4.1, 5 walls (i can provide more detail of the profile if needed)
* Layer height 0.1
* modeled on fusion 360
* The surface where the defect sits is actually tilted 45 degres
Thanks !
# Answer
There are many possible causes for printing defects, but the easiest one to eliminate is dirt. Always use a filament cleaner to prevent dirt from entering the extruder. There are plenty of designs available on Thingiverse. Always keep your nozzle clean. After pre-heating mine, I clean it (carefully) with a folded paper kitchen towel. It may also be worthwhile doing a "cold pull", if you suspect that you have dirt in your nozzle. Finally, you should check that filament is not leaking out between the nozzle and the heater block.
> 1 votes
# Answer
This could be a problem with the filament rather than the printer.
If the filament contains air bubbles, they will heat and pressurize. The additional pressure can increase the flow rate for a moment as the molten material in front of the bubble is expelled. The flow rate decreases after the bubble pops through the nozzle because the now-empty space needs to be filled by the extruder pressing new filament into the melt zone.
If this is happening, you might hear little pops.
Alternatively, the filament may have absorbed water, which can convert to steam and explode out the nozzle like a bubble would.
Drying filament isn't hard. I use my household oven at it's lowest temperature, which is typically about 160 degrees Farenheit. This is high enough to slightly soften PLA, so don't go any high than you must. Bake the filament for an hour, let it cool before handling it and try again.
The filament may not be quite as round after baking, but the cross-sectional area shouldn't change.
If the problem is from bubbles, there isn't anything you can do to fix it. If it is from water, you can fix the filament. I'd suggest baking the filament and seeing if anything changes.
> 1 votes
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Tags: print-quality, troubleshooting, creality-cr-10
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thread-10272 | https://3dprinting.stackexchange.com/questions/10272 | Should I include fillets on my 3d printed parts? | 2019-06-15T20:37:43.283 | # Question
Title: Should I include fillets on my 3d printed parts?
A fillet is like a rounded corner but on the inside of the corner.
Does it make a difference (structurally) to use fillets on a 3d printed part?
# Answer
If your part needs structural support, then the word is: **absolutely**. Fillets provide the added support when you need it. If your part has a meeting line which is sharp - 90° (or perpendicular), there is a natural stress riser in your design. This is a weak spot where a crack can form. If strength is needed and the fillet won't interfere with the design, it's definitely something you should include with your part.
> 12 votes
# Answer
Fillets in X-Y plane (i.e. between two vertical surfaces) work great for 3D prints and increase the strength a lot. They usually also improve the print quality, because the print head can keep a constant speed in the curve instead of slowing down to a sharp corner.
However fillets that extend in Z direction (i.e. between a vertical and a horizontal surface) suffer from layer artifacts. Sometimes they can look worse than a sharp corner would. While they do still increase the strength significantly, they are not as strong as similarly sized fillets in X-Y plane are.
> 11 votes
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Tags: 3d-models
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thread-10200 | https://3dprinting.stackexchange.com/questions/10200 | 3D printer part clones from china - legality | 2019-06-07T17:01:41.877 | # Question
Title: 3D printer part clones from china - legality
What's the legal status of Chinese 3D printer part clones such as Hiwin linear rail clones or E3D hotends?
While it's clear that Chinese clones are certainly sub-par in quality, no question, what I wonder is whether they violate any laws (they don't use brand names or claim to be the genuine product).
In particular, I’m interested whether it is in any way illegal to order such parts in the U.S.
Given that there's hardly any 3D printer that doesn't contain at least one Chinese part, I really think this is on topic.
I also don't seek legal advice but any information other 3D printer users on here have.
# Answer
This question is really a legal question, and could apply to any cloned parts/devices rather than being 3D printer specific, and a generic counterfeit consumer goods based question should be asked on SE.Law. However, as you rightly state, a lot of 3D printers from China may contain (whether knowingly sourced or not by the manufacturer<sup>1</sup>) counterfeit parts, be that ICs, hotend designs (i.e. E3D clones), controllers (i.e. Arduino Mega boards or stand-alone non-RAMPS Arduino shield boards),or what have you. As such this is an issue that may be faced by any unwittingly innocent consumer.
Prefacing any statement with *I am not a lawyer* (IANAL), these sections from Wikipedia entry on Counterfeit consumer goods might help answer your question:
In short, if they have a mind to, Customs could seize it at the border; if your house was raided (for whatever reason) law enforcement could seize your printer (although this seems unlikely, unless they were explicitly raiding your house for knock-offs); *and* (more worryingly) there is a proposal to fine those people who purchase knock-offs.
Of course this is not the only legal issue that may be encountered when buying Chinese devices/parts from less-than-reputable suppliers o eBay or AliExpress, for example, what if:
* it breaks and what legal recourse do you have as a consumer;
* it produces a poor quality or dangerous print;
* it explodes, what legal recourse do you have;
* and so on, etc.
These questions lead into rather murky grey and legally complex areas, and really would need to be dealt with by a legal professional (solicitor/lawyer).
---
### Other Stack Exchange posts worth reading
These deal more with quality not legality but see
---
<sup>1</sup> A bone fide low end oscilloscope manufacturer got stung by a batch of fake regulator ICs just last year, see Re: JYE Tech DSO150 oscilloscope troubles
> 3 votes
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Tags: legal
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thread-10157 | https://3dprinting.stackexchange.com/questions/10157 | Cura settings for Fabrikator Mini V2 Turnigy or Malyan M100 | 2019-06-02T20:48:38.483 | # Question
Title: Cura settings for Fabrikator Mini V2 Turnigy or Malyan M100
I am trying to run this 3D printer:
* Fabrikator Mini V2 Turnigy/Malyan M100
Does anyone have the Cura settings?
# Answer
I googled your machine name and found this HobbyKing page. There is a link here to CURA settings.
Page with CURA settings
> 1 votes
# Answer
I thought it better if I included the Cura profile settings, pointed to in cmm's answer, here, in case of link death:
```
[profile]
layer_height = 0.2
wall_thickness = 0.8
retraction_enable = True
solid_layer_thickness = 1.2
fill_density = 20
nozzle_size = 0.4
print_speed = 60
print_temperature = 200
print_temperature2 = 0
print_temperature3 = 0
print_temperature4 = 0
print_temperature5 = 0
print_bed_temperature = 60
support = Touching buildplate
platform_adhesion = Brim
support_dual_extrusion = Both
wipe_tower = False
wipe_tower_volume = 15
ooze_shield = False
filament_diameter = 1.75
filament_diameter2 = 0
filament_diameter3 = 0
filament_diameter4 = 0
filament_diameter5 = 0
filament_flow = 100
retraction_speed = 30
retraction_amount = 3
retraction_dual_amount = 16.5
retraction_min_travel = 1.5
retraction_combing = All
retraction_minimal_extrusion = 0.02
retraction_hop = 0.0
bottom_thickness = 0.3
layer0_width_factor = 100
object_sink = 0.0
overlap_dual = 0.15
travel_speed = 100
bottom_layer_speed = 20
infill_speed = 0.0
solidarea_speed = 0.0
inset0_speed = 20
insetx_speed = 0
cool_min_layer_time = 3
fan_enabled = True
skirt_line_count = 2
skirt_gap = 4.0
skirt_minimal_length = 150.0
fan_full_height = 0.5
fan_speed = 100
fan_speed_max = 100
cool_min_feedrate = 10
cool_head_lift = False
solid_top = True
solid_bottom = True
fill_overlap = 15
perimeter_before_infill = False
support_type = Lines
support_angle = 60
support_fill_rate = 15
support_xy_distance = 0.7
support_z_distance = 0.15
spiralize = False
simple_mode = False
brim_line_count = 5
raft_margin = 5.0
raft_line_spacing = 3.0
raft_base_thickness = 0.3
raft_base_linewidth = 1.0
raft_interface_thickness = 0.27
raft_interface_linewidth = 0.4
raft_airgap_all = 0.0
raft_airgap = 0.22
raft_surface_layers = 2
raft_surface_thickness = 0.27
raft_surface_linewidth = 0.4
fix_horrible_union_all_type_a = True
fix_horrible_union_all_type_b = False
fix_horrible_use_open_bits = False
fix_horrible_extensive_stitching = False
plugin_config =
object_center_x = -1
object_center_y = -1
[alterations]
start.gcode = ;Sliced at: {day} {date} {time}
;Basic settings: Layer height: {layer_height} Walls: {wall_thickness} Fill: {fill_density}
;Print time: {print_time}
;Filament used: {filament_amount}m {filament_weight}g
;Filament cost: {filament_cost}
;M190 S{print_bed_temperature} ;Uncomment to add your own bed temperature line
;M109 S{print_temperature} ;Uncomment to add your own temperature line
G21 ;metric values
G90 ;absolute positioning
M82 ;set extruder to absolute mode
M107 ;start with the fan off
G28 X0 Y0 ;move X/Y to min endstops
G28 Z0 ;move Z to min endstops
G1 Z0.2 F{travel_speed} ;move the platform down 15mm
G92 E0 ;zero the extruded length
G1 X75 E10 F{travel_speed} ;extrude 10mm of feed stock
G92 E0 ;zero the extruded length again
G1 F{travel_speed}
end.gcode = ;End GCode
M104 S0 ;extruder heater off
M140 S0 ;heated bed heater off (if you have it)
G91 ;relative positioning
G1 E-1 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressure
G1 Z+0.5 E-5 X-20 Y-20 F{travel_speed} ;move Z up a bit and retract filament even more
G28 X0 Y0 ;move X/Y to min endstops, so the head is out of the way
M84 ;steppers off
G90 ;absolute positioning
;{profile_string}
start2.gcode = ;Sliced at: {day} {date} {time}
;Basic settings: Layer height: {layer_height} Walls: {wall_thickness} Fill: {fill_density}
;Print time: {print_time}
;Filament used: {filament_amount}m {filament_weight}g
;Filament cost: {filament_cost}
;M190 S{print_bed_temperature} ;Uncomment to add your own bed temperature line
;M104 S{print_temperature} ;Uncomment to add your own temperature line
;M109 T1 S{print_temperature2} ;Uncomment to add your own temperature line
;M109 T0 S{print_temperature} ;Uncomment to add your own temperature line
G21 ;metric values
G90 ;absolute positioning
M107 ;start with the fan off
G28 X0 Y0 ;move X/Y to min endstops
G28 Z0 ;move Z to min endstops
G1 Z0.2 F{travel_speed} ;move the platform down 15mm
T1 ;Switch to the 2nd extruder
G92 E0 ;zero the extruded length
G1 X75 E10 F{travel_speed} ;extrude 10mm of feed stock
G92 E0 ;zero the extruded length again
G1 F200 E-{retraction_dual_amount}
T0 ;Switch to the first extruder
G92 E0 ;zero the extruded length
G1 X75 E10 F{travel_speed} ;extrude 10mm of feed stock
G92 E0 ;zero the extruded length again
G1 F{travel_speed}
end2.gcode = ;End GCode
M104 T0 S0 ;extruder heater off
M104 T1 S0 ;extruder heater off
M140 S0 ;heated bed heater off (if you have it)
G91 ;relative positioning
G1 E-1 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressure
G1 Z+0.5 E-5 X-20 Y-20 F{travel_speed} ;move Z up a bit and retract filament even more
G28 X0 Y0 ;move X/Y to min endstops, so the head is out of the way
M84 ;steppers off
G90 ;absolute positioning
;{profile_string}
start3.gcode = ;Sliced at: {day} {date} {time}
;Basic settings: Layer height: {layer_height} Walls: {wall_thickness} Fill: {fill_density}
;Print time: {print_time}
;Filament used: {filament_amount}m {filament_weight}g
;Filament cost: {filament_cost}
;M190 S{print_bed_temperature} ;Uncomment to add your own bed temperature line
;M104 S{print_temperature} ;Uncomment to add your own temperature line
;M109 T1 S{print_temperature2} ;Uncomment to add your own temperature line
;M109 T0 S{print_temperature} ;Uncomment to add your own temperature line
G21 ;metric values
G90 ;absolute positioning
M107 ;start with the fan off
G28 X0 Y0 ;move X/Y to min endstops
G28 Z0 ;move Z to min endstops
G1 Z0.2 F{travel_speed} ;move the platform down 15mm
T2 ;Switch to the 3rd extruder
G92 E0 ;zero the extruded length
G1 X75 E10 F{travel_speed} ;extrude 10mm of feed stock
G92 E0 ;zero the extruded length again
G1 F200 E-{retraction_dual_amount}
T1 ;Switch to the 2nd extruder
G92 E0 ;zero the extruded length
G1 X75 E10 F{travel_speed} ;extrude 10mm of feed stock
G92 E0 ;zero the extruded length again
G1 F200 E-{retraction_dual_amount}
T0 ;Switch to the first extruder
G92 E0 ;zero the extruded length
G1 X75 E10 F{travel_speed} ;extrude 10mm of feed stock
G92 E0 ;zero the extruded length again
G1 F{travel_speed}
;Put printing message on LCD screen
M117 Printing...
end3.gcode = ;End GCode
M104 T0 S0 ;extruder heater off
M104 T1 S0 ;extruder heater off
M104 T2 S0 ;extruder heater off
M140 S0 ;heated bed heater off (if you have it)
G91 ;relative positioning
G1 E-1 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressure
G1 Z+0.5 E-5 X-20 Y-20 F{travel_speed} ;move Z up a bit and retract filament even more
G28 X0 Y0 ;move X/Y to min endstops, so the head is out of the way
M84 ;steppers off
G90 ;absolute positioning
;{profile_string}
start4.gcode = ;Sliced at: {day} {date} {time}
;Basic settings: Layer height: {layer_height} Walls: {wall_thickness} Fill: {fill_density}
;Print time: {print_time}
;Filament used: {filament_amount}m {filament_weight}g
;Filament cost: {filament_cost}
;M190 S{print_bed_temperature} ;Uncomment to add your own bed temperature line
;M104 S{print_temperature} ;Uncomment to add your own temperature line
;M109 T2 S{print_temperature2} ;Uncomment to add your own temperature line
;M109 T1 S{print_temperature2} ;Uncomment to add your own temperature line
;M109 T0 S{print_temperature} ;Uncomment to add your own temperature line
G21 ;metric values
G90 ;absolute positioning
M107 ;start with the fan off
G28 X0 Y0 ;move X/Y to min endstops
G28 Z0 ;move Z to min endstops
G1 Z0.2 F{travel_speed} ;move the platform down 15mm
T3 ;Switch to the 4th extruder
G92 E0 ;zero the extruded length
G1 X75 E10 F{travel_speed} ;extrude 10mm of feed stock
G92 E0 ;zero the extruded length again
G1 F200 E-{retraction_dual_amount}
T2 ;Switch to the 3rd extruder
G92 E0 ;zero the extruded length
G1 X75 E10 F{travel_speed} ;extrude 10mm of feed stock
G92 E0 ;zero the extruded length again
G1 F200 E-{retraction_dual_amount}
T1 ;Switch to the 2nd extruder
G92 E0 ;zero the extruded length
G1 X75 E10 F{travel_speed} ;extrude 10mm of feed stock
G92 E0 ;zero the extruded length again
G1 F200 E-{retraction_dual_amount}
T0 ;Switch to the first extruder
G92 E0 ;zero the extruded length
G1 X75 E10 F{travel_speed} ;extrude 10mm of feed stock
G92 E0 ;zero the extruded length again
G1 F{travel_speed}
;Put printing message on LCD screen
M117 Printing...
end4.gcode = ;End GCode
M104 T0 S0 ;extruder heater off
M104 T1 S0 ;extruder heater off
M104 T2 S0 ;extruder heater off
M104 T3 S0 ;extruder heater off
M140 S0 ;heated bed heater off (if you have it)
G91 ;relative positioning
G1 E-1 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressure
G1 Z+0.5 E-5 X-20 Y-20 F{travel_speed} ;move Z up a bit and retract filament even more
G28 X0 Y0 ;move X/Y to min endstops, so the head is out of the way
M84 ;steppers off
G90 ;absolute positioning
;{profile_string}
support_start.gcode =
support_end.gcode =
cool_start.gcode =
cool_end.gcode =
replace.csv =
preswitchextruder.gcode = ;Switch between the current extruder and the next extruder, when printing with multiple extruders.
;This code is added before the T(n)
postswitchextruder.gcode = ;Switch between the current extruder and the next extruder, when printing with multiple extruders.
;This code is added after the T(n)
```
Note these are some customer uploads, from the HobbyKing page for Mini Fabrikator V2 3D Printer - Silver (US Plug), under the **Upload Files** tab, click the `CURA PROFILE_3.ZIP` zip file.
> 0 votes
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Tags: ultimaker-cura
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thread-10271 | https://3dprinting.stackexchange.com/questions/10271 | Should I cooldown before shutdown? | 2019-06-15T19:41:16.923 | # Question
Title: Should I cooldown before shutdown?
I am working with Ender 3 Pro and in menu it has an option to cooldown. Is there any need to cooldown 3D printer before shutdown or can I just shutdown without cooldown?
# Answer
Depending on what material you print it it most likely a good idea to let the hotend cool down before shutting off the printer (fan).
For example if you shut down the printer right after you print a PLA part, at 190 - 220 degrees Celsius, your hot end will still be that hot and will suffer heat creep without the fan running. The next time you fire up your printer the hotend will be jammed and you will need to clear it before starting a print.
This is obviously situation dependent but in most cases you should let your hot end get below the TG (glass transition temperature) of the material before turning off the printer.
> 8 votes
# Answer
That option you are referring to, is meant to manually shut down power to the heated bed and hotend, there is no timed cool down period other than you timing it. This is a handy option if you fiddled with either the bed or the hotend; e.g. to insert new filament.
A cool down period can be very useful depending on the printer. Those cold-end cooling fans usually are very noisy, so people cut them of (that is not always possible/wise, but is being done out there), disable them after printing or shutting down power of the printer as a whole. Some type of hotends are prone to have heat creep up the hotend and soften the filament so that it can clog up the hotend. I've seen this happen on Ultimaker printers where the cooling fan was not spinning because some fine strings where sucked up.
To minimize the noise level of such cold end cooling fans you can put them on a relay switch and have e.g. OctoPrint schedule the print to be on for e.g. 2 minutes after a print failed or finished, works perfectly, and then you have your cooling down schedule/period.
> 1 votes
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Tags: creality-ender-3
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thread-10284 | https://3dprinting.stackexchange.com/questions/10284 | Monoprice printer: no files found on SD card | 2019-06-16T20:56:37.297 | # Question
Title: Monoprice printer: no files found on SD card
My monoprice printer was working; I then tried to format the SD card on a Mac, then it stopped working. I have now tried three different SD cards after formatting on a Windows PC, and still nothing works. Are there supposed to be files on the SD card itself like some kind of root files?
# Answer
I've no idea why 3D printers don't like SD cards formatted by operating system utilities, but they don't. Use SD Memory Card Formatter to format your memory cards. Unfortunately, you have probably lost any data that was on the original SD card.
The SD cards that are supplied with 3D printers typically contain documentation, test files, and device drivers. However, these files do not need to be present for the correct operation of the printer. All that is needed is a correctly-formatted SD card containing the G-code files that you want to print.
> 2 votes
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Tags: sd, monoprice-select-mini
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thread-4084 | https://3dprinting.stackexchange.com/questions/4084 | Is it a good idea to include thermal fuses in a DIY 3D printer design? | 2017-05-17T05:54:56.123 | # Question
Title: Is it a good idea to include thermal fuses in a DIY 3D printer design?
3D printing should be relatively safe, however, the inherent nature of 3D printers, with all of the heated parts, constitutes a fire risk. A well designed 3D printer should be designed to be as safe as possible, especially one used in the home... Yes, the recommendation is, when printing, to watch the 3D printer at all times and never leave a print unattended. However, with some print times lasting hours and days, this is not always feasible, nor practical. So, some inbuilt safety features should be included, to at least mitigate the risk of fire, to some extent.
* Is the use of thermal fuses<sup>1,2</sup> a good idea<sup>3</sup>?
* Would you use more than one?
* Where should one place a thermal fuse? Next to a particular component, or *free standing*, in the air, to get an average, rather than *highly localised* temperature?
* Against which components should a thermal fuse be placed? There are a number of places to choose from, such as next to:
+ The hotend?
+ The heated bed?
+ The extruder?
+ Each of the stepper motors?
+ The power supply?
+ The RAMPS stepper motor drivers?
* Of lesser import, which type should one use<sup>4</sup>, radial or axial?
Has anyone added thermal fuses to their 3D printers? Or has anyone examined where the thermal fuses are placed in commercial 3D printer designs, if used at all?
---
### Background
I have recently found myself having to repair rice cookers and fans in Thailand. In those, it is very often the thermal fuse (axial thermal fuses for the rice cookers and the square "radial" types for fans) that requires replacing, as they have *blown* before the device got hot enough to start a fire. This got me thinking about their use in a 3D printer.
---
### Footnotes
<sup>1</sup> We are *not* talking about the standard, replaceable, thermo-fuse,or fuse, which blow upon a current surge, short-circuit, etc. These are thermal fuses that contain metal connector within them that melts (permanently) at a specific temperature (typically ~135°C), thereby breaking the circuit.
<sup>2</sup> Nor am I referring to resettable fuses (AKA PPTC, multifuse, polyfuse or polyswitch)
<sup>3</sup> Would a thermal fuse be preferable to thermal cut offs, in the case of fire?
<sup>4</sup> The thermal fuses used in rice cookers are the *axial* type, and in the motors of fans are the *radial* type.
# Answer
> 4 votes
Whether you should use a thermal fuse or not depends on what other safety measures you've taken. You can't look at the safety features of a printer in isolation, you need to look at what other measures are in place.
The main fire hazard in printers is unfortunately (still) the fact that some manufacturers use underrated connectors on their boards, and that some users put bare wires in screw terminals or use inadequate torque when tightening terminals. As the wire works itself loose, it starts arcing and burning the connector. A thermal fuse does not help in this situation (unless you place thermal fuses near all of the connectors, which is impractical). Instead:
* Properly tighten screw terminals, check them, and consider using proper wire termination (crimp lugs).
* Use strain relief on wires. Make sure wires don't rub against anything, and guide them so they do not bend in a tight radius. Since the extruder (or print bed) is constantly moving, those wires are subject to fatigue.
* Make sure connectors (especially those for the heated bed) are rated for the current running through them, and solder wires directly to the board if necessary.
Using a regular fuse may protect against wires shorting against each other should their insulation be damaged. Fuses are usually already integrated into the main board.
Most firmwares include some variant of *thermal runaway protection*, a feature that monitors the heaters and shuts the printer down if it notices something gone wrong. This protects against:
* The thermistor coming loose/reading incorrect values/etc...
but not against:
* Bugs in the firmware itself
* Failure of the MOSFET
Most printers use MOSFETs to switch power to the heating element. Unfortunately, when MOSFETs fail, they usually fail *closed* (i.e. conducting). This means that, even if the firmware detects something has gone wrong, it won't be able to do anything about it. Solid State Relays (TRIACs) can fail in the same way.
To protect against this, mounting a thermal fuse (or resettable bimetallic switch\*) on the heated bed may be a good idea. However, thermal fuses with ratings up to the operating temperature of a hotend do not appear to be available so this is not an option.
Attaching the fuse physically to the part it is monitoring is the most reliable, but for instance with the hotend (if you wanted to protect it all) this might not be feasible to the high temperatures involved so you'd have to settle with monitoring the air temperature close by.
Also consider *thermal balancing*. A thermal fuse is unnecessary if the component can not overheat to begin with. For instance, most MK2 heated beds struggle getting up to even 100C, so even with a shorted MOSFET they present no danger. However, if you have a powerful high wattage (mains-powered) heated bed, you should *definitely* install thermal protection.
E3D supplies their hot ends with 25W, 30W and 40W heaters. The 25W heater is the safer choice, since it limits the maximum temperature the hot end can get to, while with the 40W heater you can reach higher temperatures (and reach them faster). Barring a very unlikely scenario in which simultaneously (1) the power supply fails and starts supplying excessive voltage and (2) the MOSFET and/or firmware fails, a heater that is sized appropriately to the load it is driving can never pose any danger.
I don't think it's common to install thermal fuses on steppers, stepper drives or the power supply (which should have its own protection). For every possible location to place a thermal fuse, you can probably think up a failure mode in which that fuse would save the day, but at a certain point it just becomes overkill. The stepper drivers would likely burn out well before the steppers would get hot enough to pose a threat, and overheating of the stepper driver would probably (violently) destroy it but afterwards it should not pose any threat.
Axial v.s. radial does not matter, just use whatever is convenient for your situation.
<sup>* Note that some bimetallic switches short one of the leads to the (metal) case when tripped, which poses a danger, especially with mains-powered heaters.</sup>
# Answer
> 3 votes
Yes, you should use a thermal fuse. But only to protect the board itself from an overheating condition. PTC fuses however; is a no.
The PTC resettable fuse after it trips the first time, doesn't return to it's former low impedence state for a long time. Sometimes hours, sometimes days, sometimes years. As it maintains its higher resistance even though the system is not in an over heated state, the fuse will trip faster the next time. This could lead to false positives during print or other operation.
> The resetting will often not take place even if the fault alone has been removed with the power still flowing as the operating current may be above the holding current of the PPTC. The device may not return to its original resistance value; it will most likely stabilize at a significantly higher resistance (up to 4 times initial value). It could take hours, days, weeks or even years for the device to return to a resistance value similar to its original value, if at all.
https://en.wikipedia.org/wiki/Resettable\_fuse
Currently, I am investigating the use of a hall effect current sensor and some circuitry. Based on the duration and magnitude of the current, a small capacitor is charged. When a threshold is reached (as determined by a voltage comparitor), the power is withdrawn to let the capacitor discharge (and the heating element cool). This *should* keep the heating element from reaching a temp above a configurable maximum.
# Answer
> 1 votes
Yes, measures which decrease the chance of a fire are a good idea.
In a DIY project, such a fuse is indeed a good idea. I use a printer/software/firmware package which monitors the temperature and fails open (removing current) if readings are out of range; however, there is also hardware protection (a thermal snap switch) just in case the other precautions fail.
# Answer
> 1 votes
IMHO - if you seek hands-off unattended fire safety you'd be looking at something a bit more specific to that job than measuring or limiting the temperature of printer components. That's great, as far as it goes, when it works, but it's not anything like a complete solution. Cutting off the electrical supply won't put out a fire that has progressed to burning plastic, etc. Reasonable over-current protection for a start. Contain the printer inside a metal cabinet or cementboard-lined closet (a non-flammable enclosure), add a heat and/or smoke detector in the top of that enclosure, and rig that to not only cut off power to the printer, but (given things have gone far enough wrong to set that off) also set off an extinguishing means (the effectiveness of which will be enhanced by an enclosure.)
A little bit of looking finds (for predictably high prices, sorry) that there are, indeed, fire extinguishers with a "sprinker-head" valve attached for this type of "spot suppression" job that would cover the "set off an extinguisher" part of the job without need of any power. You'd still want a heat detector that would shut off the electrical supply to the printer in the event of abnormally high temperatures in the enclosure, and you might want a smoke detector doing the same.
This is probably representative of about 0% of actual installations at present, but it would be a good way to reduce the risk in the event of a serious malfunction. Presumably the current distribution of risk looks a lot like the maker stating:
> "the recommendation is, when printing, to watch the 3D printer at all times and never leave a print unattended."
And then the user choosing not to do so, putting the responsibility for any bad result on the user as not following the maker's recommendation, however impractical.
# Answer
> 1 votes
I have a Thing-O-Matic which included a thermal fuse above the heat break.
For my home-brew printer (a large delta machine) I have a smoke alarm and a fire alarm mounted under the top of the print volume. These are wired together and give me a NO and NC dry contact. My plan is to connect this to a power kill circuit. I haven't found a good way to flood the entire machine, including the electronics, with CO2 gas or another extinguisher when the alarm sounds.
I've added some additional information on parts purchasable on DigiKey: The first is a 10 A, 152 C thermal fuse rated for line voltage. This would be appropriate for bonding to a heated bed. The second is rated to trip at 260 C. Both of these are less than $1.50 each.
# Answer
> -1 votes
I haven't found a good way to flood the entire machine, including the electronics, with CO2 gas or another extinguisher when the alarm sounds.
A servo or some other actuator attached to a fire extinguisher, and then attach it to a thermocouple or some other sensor. Maybe a knockoff Arduino, which the small ones are 2 bucks a pop. Since Arduinos are open source, you aren't pirating anything, so clear conscience.
# Answer
> -1 votes
I'm going to set this up for my printer: 3D Printer Safety Shutdown - Smoke Detector
>
Looks like a great solution for preventing fires.
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Tags: printer-building, diy-3d-printer
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thread-7315 | https://3dprinting.stackexchange.com/questions/7315 | Is it ok for stepper motors to be hot? | 2018-10-27T11:01:33.287 | # Question
Title: Is it ok for stepper motors to be hot?
I have been running my i3 MK3 for about 12 hours now and the motor on the extruder is fairly hot, not too hot to touch but I'd guess its about 60c on the outside. Is this within normal operating temperatures or should I let it cool down before starting more prints?
# Answer
The maximum operating temperature can be found in the specifications of your steppers. Usually the ambient temperature operating conditions are limited to 50 °C with a maximum operating temperature in the range of 70 - 100 °C. For instance, the steppers I use are limited to a temperature of 80 °C. It is however advised to keep this temperature lower, e.g. to max. 60 °C to prolong the life. Do note that very high temperatures could be a problem for "self-printed" stepper mounts of the wrong material (materials with a low glass transition temperature).
To answer your question: "Yes, steppers may get hot, but if you want them to get too hot is up to the mounting system and how long you want to use them."
> 3 votes
# Answer
While such temperatures may be OK for extruder motor itself (and probably for extruder body, since it is printed in PETG/ABS), but it can be dangerous for the filament that you are using to print your models. Heat from extruder motor can creep through shaft to Bondtech gears and start to pre-melt filament.
60 °C is enough to soften PLA. Your filament may warp or melt just above heatsink, jamming, and clogging the extruder body.
What you can try to do:
1. Open or remove enclosure;
2. Glue a generic heatsink on your extruder motor with some thermally conductive adhesive or epoxy;
3. Add an active cooling fan for your extruder motor (or for heatsink of your extruder motor). You can power it from Prusa PSU (then you will need 24 V fan), or plug additional PSU for fans and lighting;
4. Upgrade extruder motor to LDO / Moons motor. These run about 10 °C cooler than stock extruder motor;
5. Upgrade to Bondtech extruder. Bondtech extruder features 3:1 gearing ratio, and can be run with lower current (e.g. less heat). Also Bondtech extruder uses plastic gears, so heat can no longer easily move from extruder motor to filament.
> 1 votes
# Answer
I've run my Prusa3D i3m3s for 50 hour prints. My motors get hot-ish but on my instance of the machine, they are not too hot.
> 0 votes
# Answer
50 °C feels very warm, 60 °C feels hot, 80 °C is painful.
I measured the temperature of the steppers on a Prusa mk3last week. They were all around 45..50 °C, except the extruder stepper which runs around 55..57 °C.
The temperature is stable like that. Letting them cool down is useless, because they would quickly go back to these temperatures after starting the next print. Stepper motors tend to dissipate more power when they stopped or slow compared to when they run fast.
I would not worry about it.
> 0 votes
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Tags: prusa-i3, motor
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thread-10189 | https://3dprinting.stackexchange.com/questions/10189 | Pololu - connect motor supply ground and logic supply ground | 2019-06-06T09:59:17.427 | # Question
Title: Pololu - connect motor supply ground and logic supply ground
Is it okay to directly connect together the grounds of the logic supply and the motor supply when using a Pololu style stepper driver?
If yes/no, why so?
# Answer
> 4 votes
(This is more of an electronics.stackexchange.com question btw).
It is not only ok, it is absolutely necessary. The systems won't operate correctly unless all the gnds are tied together. Since this is a stepper motor, you don't have to worry about noise getting back onto the power supply lines for the logic supply, since the stepper board has a decoupling capacitor(s) to keep stabilize the power to the motors and the VCC of the logic supply will be unaffected by the GND of the other supply that its tied to.
# Answer
> 3 votes
That depends on how much noise you have on your motor power supply ground. You definitely want the 100 µF capacitor to have a good high frequency response. Motors turning on and off can be noisy, and that noise can cause false clock signals in your logic circuitry if you tie the grounds together.
# Answer
> 3 votes
I could not find a schematic of the Pololu A4988 stepper motor driver, but I did find a photo of the board that includes the ground planes for both the motor and logic. On the reverse side of the board, they were not connected. They should not be connected on the driver cards.
Instead, all the motor ground lines should be brought together at a point, and the Motor supply ground connected to that point. The V-motor should also be run radially to each stepper driver and connected to the V-motor supply.
There should be a single connection point between the motor ground and logic ground. No motor current should flow through any logic ground wire or circuit board trace. The motors are switching high voltages and high currents. If these currents pass through a logic ground line, they will introduce voltage spikes into the logic which can result in unexpected operation.
The 100 μF capacitor in the schematic is good for supplying low frequency energy needs, but it should be paralleled with a 1 μF capacitor and a 0.01 μF capacitor placed as close to the radial feed points as is practical. A larger capacitor tends to have higher leakage inductance, which limits the high-frequency response. A range of capacitors in parallel will perform better.
# Answer
> 2 votes
> Is it okay to directly connect together the grounds of the logic supply and the motor supply when using a pololu style stepper driver?
Most stepper drivers don't have separate ground pins for the logic and motor supplies. The two ground pins on the A4988 board you've shown are electrically connected on the board. The question is moot.
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Tags: stepper, stepper-driver, grounding
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thread-5530 | https://3dprinting.stackexchange.com/questions/5530 | Inductive kickback protection? | 2018-02-22T13:57:28.667 | # Question
Title: Inductive kickback protection?
Is there an integrated kickback protection in stepper motor drivers or should I make my own? I am afraid the steppers might fry the driver or the arduino when i turn off the power for them. I do that by turning off the power supply. I haven't had an issue yet but it still bothers me.
# Answer
> 2 votes
Kinda, sort of, but not really. I'll look at the A4988 (datasheet).
The motor pins are connected by diodes to ground and Vbb (the motor suppply voltage). Essentially, they act as a bridge rectifier making any back EMF or inductive spikes appear (rectified) on Vbb. If you were to suddenly power down the driver this could cause a rather large spike on Vbb.
According to the datasheet, there is a 40 V Zener on Vbb which will clamp the voltage to that level. (Another popular stepper driver, the DRV8825, does not appear to have this Zener - always check your datasheet!)
So, yes, there is inductive kickback protection. However, it only clamps the voltage to 40 V. Depending on the rest of your circuit, this could be quite damaging.
The datasheet recommends that a 100 μF capacitor be placed on Vbb. If you are driving a typical stepper motor with 2 A and 4 mH coil inductance, the energy stored in the coil is 8 mJ. This energy is only enough to take the capacitor up from 12 V to ~17.5 V, so if you have a large enough capacitor on your stepper driver (as you should!) then you're protected against inductive kickback.
Note that if you move the motors by hand then you can still build up a higher voltage on Vbb. I've heard anecdotes of people who damaged their printers like that.
# Answer
> 0 votes
"Inductive kickback" from motor coils is caused by the inductance of the coils and the wiring. It is not some strange effect. Inductance is charged with current, just as capacitance is changed with voltage. Most bipolar motor drivers use an H-bridge on the output. By driving the H-bridge correctly, the driver can continue to provide a path for the motor current when it is no longer applying voltage, such as by connecting both wires of a motor to ground.
Although some may find it counter-intuitive, connecting the Vmot side of the motor to Gmot, while the other side remains at Gmot, keeps current flowing in the coil more smoothly and with lower losses. The voltage across the motor coil is near zero, so there is little voltage trying to change the motor current. If the coil is undriven and subject to the clamping diodes, the voltage across the motor will me much higher, and the current will stop faster.
The higher ripple current in the motor increases the coil heating, may increase audible noise, and decreases the efficiency of the drive.
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Tags: electronics, stepper-driver
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thread-10299 | https://3dprinting.stackexchange.com/questions/10299 | Must I start over if I change a dimension in Fusion 360 | 2019-06-17T22:08:50.987 | # Question
Title: Must I start over if I change a dimension in Fusion 360
As a newbie, I have done some Fusion 360 tutorials and recognize I made a mistake in the initial dimensions.
Aside from starting the entire sketch over again, can I just modify the (beginning) rectangle dimension?
# Answer
If you enabled the history, you can easily go back in time and change the dimension in the sketch and then go back where you were. It would be even more elegant if you do not use fixed valued dimensions in the sketch, you can use parameters you define yourself and assign them to certain dimensions to create parametric designs. These values can be changed at any time to see your final design adapt to those changed parameters.
> 1 votes
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Tags: fusion360
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thread-10294 | https://3dprinting.stackexchange.com/questions/10294 | How to make menus more responsive in Marlin 1.1.9 | 2019-06-17T16:24:30.433 | # Question
Title: How to make menus more responsive in Marlin 1.1.9
I have an AM8 with an MKS GEN 1.4 board with a Bowden extruder at the moment.
What I would like to do is to make my menus a bit more responsive, similar to what the guy at Lokster Space has done with ver 1.1.5 of Marlin with a tutorial how to do so. I've been through the file `ultralcd.cpp` but nothing matches what the tutorial is telling you to change.
The following link is the details for the upgrade: How to make the Marlin menus more responsive on Anet A8
Could anyone please help with my situation.
# Answer
Supposedly, it's no longer necessary in a recent Marlin version, already the `inline bool handle_adc_keypad()` function from ultralcd.cpp has implemented a smaller (100 ms) time delay. You could lower the value of `#define ADC_MIN_KEY_DELAY 100` to `#define ADC_MIN_KEY_DELAY 50` to see if that has any effect.
Also, look for `next_button_update_ms = now + 300;` (4 instances) which employs a 300 ms time delay after buttons are pressed. Try lowering the 300 ms time delay.
> 1 votes
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Tags: marlin, full-graphic-smart-controller
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thread-10303 | https://3dprinting.stackexchange.com/questions/10303 | Which 3D filament is 100% (or close to being so) food safe and non toxic? | 2019-06-18T17:52:56.797 | # Question
Title: Which 3D filament is 100% (or close to being so) food safe and non toxic?
I've recently bought myself a preassembled Prusa i3 MK3S printed and made my first projects. One of them was making a cup with my name on it. I want to use it to drink tea, water etc. I know, however, that I need to chose my filament wisely, as using the wrong one might be unsafe. I know that PLA for example is Polylactic acid which is a safe substance and occurs naturally in our body. Another thing is the dye, which can is a chemical substance I know nothing about. Do You recommend any specific type/model? Thanks.
# Answer
Answer was moved to this question: Which are the food-safe materials and how do I recognize them?
> 2 votes
# Answer
I think this site will answer some questions about food safe 3D printing: 12 Vital Facts About Food Safe 3D Printing
PLA is not a good choice for hot substances because it will deform at hot water temperatures which is no good for a cup (very dangerous!)
I would recommend a filament like PETG, PETE, HDPE, and LDPE: What Plastics Are Approved for Food Contact Applications?
Those types of plastic require very high printing temperatures and an all metal hot end. You don't want PTFE in your hot end when printing at those temperatures (265 °C) as it will emit toxic gasses.
I've seen food safe filaments for sale so it might be best to search Google for one of them to use.
Please keep in mind that printing anything will cause voids and gaps that will allow bacteria to grow. Personally I don't think I would want to risk it for daily use items but a coffee/tea cup might be alright. This is covered in the first link.
> 1 votes
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Tags: filament, 3d-models, safety, food
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thread-10317 | https://3dprinting.stackexchange.com/questions/10317 | Why is the printed object smaller than original model? | 2019-06-20T03:58:03.767 | # Question
Title: Why is the printed object smaller than original model?
I am printing a small cylinder, but when the object is finished, it's smaller than the measures I used when create the model.
I used thincerkad to make a simple model, the measures are:
* width: 90 mm
* height: 2 mm
After the print was done, the actual dimensions were:
* width: 70 mm
* height: 2 mm
### Pictures
First attempt
The smaller object that's in the drawn circle was the first one printed, the dimensions I used were:
* width: 110 mm
* height: 2 mm
Then I printed it again, and the result was:
# Answer
Let's do the math, you printed something of size 9 cm and got a size of 7 cm. This implies that the scale equals $\frac{7}{9}=0.778$. In order to print it at the correct size, you should have printed the object at scale $\frac{1}{0.778}=1.286$; so 28.6 % bigger, i.e. $1.286\times9=11.6$ cm. You printed at 11 cm, so the print should become smaller than the pencil drawn circle on the paper. This is actually what you see in the image you supplied.
This can imply 2 things, you either scale the prints incorrectly to export to stl (but that is unlikely because the Z height is correct), or the steps per mm are incorrectly set in the firmware of your printer. The rotation of the steppers (usually 200 steps) need to be translated into linear movement; this depends on the used pulleys mounted on the steppers (typically used pulleys are: 16 or 20 teeth for belt driven X and Y axes).
Calibrating the steps per mm of the extruder is answered in this answer. For the X and Y axis this works the same. If you have a Marlin based printer firmware, send G-code `M503` to the printer over a terminal interface as e.g. OctoPrint, Pronterface (as part from Printrun: 3D printing host suite), Repetier-Host have, you can obtain the current values from the reply; these are listed under M92.
That value for X and Y needs to be multiplied by 1.286 (as an example) to get the correct dimensions. You do this by sending G-code `M92` like `M92 X100.00 Y100.00` (see this answer that explains which values you should use based on pulleys you use, either 80 or 100) to the printer, to keep these values they need to be stored in memory using G-code `M500` (note that the values 100.00 should be replaced by the values you get by multiplying the return values for X and Y from `M503` by the 1.286 multiplication factor, only if the error is systematically increasing with print dimensions, otherwise stick to the calculated values from e.g. the Prusa belt calculator).
Without the proper steps per mm, you will not be able to use the full potential of the bed. An alternative as scaling your prints by the appropriate scaling factor will only help if your scaled print is smaller than the bed size divided by that scaling factor, so no use of the full bed. Rather fix the firmware to fit the actual mechanical layout.
> 5 votes
# Answer
Are you using the stock firmware of your printer? Sounds like to me that you have 16 tooth pulleys and your firmware is set to 20 tooth i.e. 80 steps per mm
The calculation behind the steps per mm is $\frac{\text{Steps per Revolution} \times Microsteps}{Teeth \times Pitch}$. The reason for this is that one revolution of the pulley will move the belt the number of teeth times the pitch of the belt. Now take the total number of steps, Steps per Revolution times microsteps, and divide by the distance moved giving the steps per mm.
In $\underline{most}$ hobby 3D printers you have:
* 1.8 degrees steppers which equals $\frac{360}{1.8}=200$ steps per revolution , Less common is 0.9 degrees steppers $\frac{360}{0.9}=400$
* GT2 is the most common belts now which have a pitch of 2mm
* The two most common pulleys are 16 tooth and 20 tooth,
* Depending on what stepper drivers and or configuration you have
+ A4988 $\to$ 16 microsteps
+ DRV8825 $\to$ 32 microsteps
+ Trinamic $\to$ 16-256 mircosteps
In your situation I believe you have a 1.8 degree stepper with 16 microsteps, a gt2 belt, and a 16 tooth pulley. Which means your XY steps per mm should be $\frac{200 \times 16}{16 \times 2} = 100$. While your firmware is expecting 20 tooth pulleys, yielding $\frac{200 \times 16}{20 \times 2} = 80$. This would result in your prints being $\frac{100-80}{100} = 20\\%$ smaller, which explains your results with the circles.
Generalizing, the steppers, microsteps, and pitch don't matter. To go between 16 tooth pulleys to 20 tooth, multiply by $0.8=\frac{16}{20}$. From 20 tooth to 16 tooth, multiply by $1.25=\frac{20}{16}$.
> 7 votes
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Tags: 3d-models
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thread-10323 | https://3dprinting.stackexchange.com/questions/10323 | Rule of thumb for small type | 2019-06-20T19:33:42.107 | # Question
Title: Rule of thumb for small type
Is there a good rule of thumb for small type on 3d printed pieces?
Minimum type size? Good typeface for accurate reproduction?
# Answer
> 4 votes
I've had better luck with fonts that are heavier, usually sans-serif, and usually bold-face. All-caps can help, too, if it makes sense at all for the text. Impact is one widely-available example, though it's far from perfect and rarely has the look I want. I also usually need to turn on the "Print Thin Walls" setting in Cura when handling smaller text.
When looking at how small you can get, we'll start with font sizes. It would be easy to get lost here in a discussion of points and measurements. The thing is, font sizes describe the *vertical height* of the characters. For 3D printing, I believe you'll do better paying more attention to the *horizontal width* of your text. Most characters are taller than they are wide, so if you can produce legible horizontal features, you can probably handle the vertical features, too.
I'll use the letter "H" as an example here, because it shows the full size of the box for a typical character. Specifically, since I'm talking about horizontal features if you look at the bottom of the H, it has a three sections: leg, then gap, then leg. Also notice the gap is about 3 times the size of the legs (you can see this better if you zoom in close). This varies by font, but 3:1 is good average ratio. That gives us 5 units of width for the character itself. Additionally, you want to allow some spacing between individual characters; not every character needs it next to every other character, but I find it useful to allocate a 6th unit here.
Now consider those 6 units in the context of your nozzle size. With a typical .4 mm nozzle, that means the smallest size character you can legibly produce is about 2.4 mm across. Of course, most fonts are not monospace, where a character might be larger or smaller, but I believe this makes a useful average. Count the number of letters in a line of text you want to print, multiply by 2.4 mm, and that's the minimum amount of horizontal space you need.
If you really want to push things, a font specifically designed for 3D printing should theoretically be able to work in terms of 3 nozzle units wide + an extra gap between certain letters. But this is all theory, and for the minimum of what's possible. When you also start to think about what actually looks good, especially if you want to show features like serifs, the real world can really mess this up. In practice, *I've found I need to go significantly larger even than the 6 unit / 2.4 mm option...* but maybe I've just used the wrong font. You can always try a test print of your text in a small rectangle, to make sure it will be legible before using in a larger object.
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Tags: print-quality, 3d-models, 3d-design, graphics
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thread-10321 | https://3dprinting.stackexchange.com/questions/10321 | Migbot extruder loading | 2019-06-20T17:29:50.430 | # Question
Title: Migbot extruder loading
Has anyone seen a printed bottom extruder block with a cone added to get the filament into the hole which then feeds into the metal tube that connects to the heater? We have a hard time getting coiled filament lined up, the filament curves and takes a lot of twists and tries to get into the hole in the bottom plastic block, and lately we've just taken to removing the fan/heatsink at the end of the servo to guide it in my hand, which is a pain in the butt and likely to wear out screw holes or something eventually.
Hopefully this drawing shows what I mean.
It would be the 10th picture here, with a cone added above the hole at the lower left. https://www.thingiverse.com/thing:852591
# Answer
If the question is "has anyone seen..." my answer is yes. It's not precisely what you show in the drawings, but close enough and for the same purpose.
In the case of a Robo3D R1+ printer, replacing the stock "hexagon" hot end with an E3Dv6 hot end provides for a piece of PTFE tubing inserted into the heat sink. The recommendation from the denizens of the 'net is to slice the top of the tubing in the shape you have in the drawing and to have the tubing extend sufficiently to reach the junction of the hob gear and pinch roller. This took some doing, but I was able to get an appropriate taper to the tubing end that does not contact the moving parts.
As the fed-in filament exits the assembly, the small gap between the wheels and the tubing gives the filament nowhere else to go but into the heat sink and hot end.
As your design reference indicates a 3D printed part, it might be practical to engineer into that segment a larger hole to take the PTFE tubing and then size the length after the wheels are in place.
The above image shows the added PTFE tubing surrounding the filament. Even though the slightly diagonal cut appears somewhat as a cone, it is not. The edges are parallel to the rollers/hob gear. The lower portion has been omitted for ease of drawing, but would extend into a hole drilled or printed in the block holding the assembly, based on the thingiverse link provided.
> 1 votes
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Tags: prusa-i3-rework
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thread-10310 | https://3dprinting.stackexchange.com/questions/10310 | Improving triangulation on AutoCAD-generated stl files | 2019-06-19T14:41:55.013 | # Question
Title: Improving triangulation on AutoCAD-generated stl files
In regards to a part that I'm having printed remotely (by two processes:- stereolithography and laser sintering), I've been advised by the 3d printing company that 'the triangulation of the file is rather rough'.
In this particular instance, it probably doesn't matter, but for the future, are there any tips to improving 'triangulation' when generating forms in AutoCAD?
Note, AutoCAD's FACETRES variable is set to 10.
# Answer
> 2 votes
The phrase "triangulation of the file is rather rough" is somewhat vague, but one can interpret it to mean that the surface is what is considered "low poly" in the 3D modeling world.
From Thingiverse, this low poly fox shows an intentionally reduced poly surface. I'm not suggesting that your models appear this distorted, but it may give a hint to what the service is referencing.
Consider to load your model into a program such as Meshmixer, which will show you the triangles in 'W'ireframe mode. If there are few triangles over a surface, you can get the aforementioned effect.
Meshmixer also allows you to increase the mesh count, possibly improving the surface and satisfying the requirements of the printing service.
# Answer
> 2 votes
Most CAD tools generate quite low-res triangulations. The ideal solution is to avoid using the CAD tool to generate them. For example, if the print shop can accept your CAD files directly, they may have other software that can triangulate them. For example, if the shop uses GrabCAD Print to slice your parts, that software can open CAD files directly, and produce much better triangulations than exporting from the CAD software. (In this case they won't be using GCP, which doesn't support the print technologies you mention, but it's just an example: some other vendors' tools have the same functionality.)
If you don't wish to send your original CAD parts, check if your tool can export Parasolid files (.x\_t or .x\_b). They contain the original boundary representation your CAD tool uses to represent geometry, but not the feature structure, constraints, or design intent.
# Answer
> 0 votes
This thread and this article, both on Autodesks website, suggest altering the `FACETRES` system variable to `10` to achieve a higher-quality .stl export.
Alternatively, you can use the `3DPRINT` command for `FACETRES` to be increased automatically, which will then offer an .stl export or to send the file directly to a 3D printing service.
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Tags: print-quality, autodesk
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thread-10331 | https://3dprinting.stackexchange.com/questions/10331 | How precise do models need to be for 3D printing? | 2019-06-21T10:59:30.733 | # Question
Title: How precise do models need to be for 3D printing?
I'm not talking about making something that's outright disproportionate of course. I've been working in Blender and I've use Absolute grid Snap to snap my vertices to the grid. The problem is that it (didn't seem) to always work perfectly for centimeters, and seemed to work better for meters. (edit: I've learned what the problem was and it was simply the placement of the vertices in side view, being at slightly different elevations. I'm going to emphasize that the difference was very slight. It was just enough to show up in the measurements. When I switched from front view to side view I was able to adjust the elevation to the grid and that fixed the problem.)
# Answer
After some trouble shooting I realized what was wrong, and now it seems more like a non issue if anything. There's actually nothing wrong with the grid, and the vertices were snapped to it appropriately in top view. The problem was that that my vertices were not at the same elevation (in side view). The two seemed very close to being snapped appropriately on the grid in side view which is why it wasn't immediately obvious.
> 1 votes
# Answer
It depends on what you're working on. If you're producing mechanical/functional parts (even if that just means having to connect to one another or to some non-printed part), 3 mm (0.3 cm) error is almost surely going to prevent them from working. Even 0.3 mm error might be a problem.
If you're doing standalone prints that don't have to interface with anything else, e.g. art, non-articulated figurines, etc., then it becomes just a question of what's visually acceptable, and that's a matter both of scale and of the detail level you want. For typical tabletop-RPG scale, for example, most of the acutal visual features are going to be smaller than 3 mm, so that much error is not going to work out. It might work for large busts, though.
In any case, I would recommend trying to solve the underlying problem. Either change your grid snap, or work at a larger scale and just scale down the final model.
> 5 votes
# Answer
Welcome to the SE 3D Printing site. Your questions are also welcome, as well as your answers to your questions, and the questions of others.
I am not a Blender user. I use CAD systems because most of what I do I want to have a certain dimensional precision.
If the problem is as simple as "The overall object is designed to be 7.345 centimeters but I want it to be 7.000 centimeters," you can fix that when you print the model. Use the scaling feature of your slicer to scale by $(7.000/7.345)$ or $95.303\\%$. It will print as the size you want.
The problem may be deeper, though, in that you may be having trouble setting points within the model where you want them. In that case, the snap-to-grid feature is distorting your model's appearance and geometry, and there is nothing you can do to fix it.
If it can't be fixed by scaling, I would suggest that you should either turn off the snap-to features or set up a grid that matches the granularity you actually want for your design.
> 2 votes
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Tags: print-quality, 3d-models
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thread-10334 | https://3dprinting.stackexchange.com/questions/10334 | Vacuum storage bags? | 2019-06-21T15:11:35.073 | # Question
Title: Vacuum storage bags?
Does anyone use "space saver" style vacuum storage bags to keep fillament dry? I picked up some Ziploc space bags, but they are larger than ideal. Would probably fit 2.5 spools. I would love a smaller version just big enough for one spool.
# Answer
> 2 votes
I've read people are using them, makes sense, the less air you contain, the less moisture would be in the bag. Myself, I'm using IKEA ziplock bags (and moisture absorbing sachets), they come in many sizes.
# Answer
> 1 votes
I have a commercially available product known as a foodsaver (TM) which removes the air from the bag and really squeezes tightly around the spool. The width of the bags I use barely takes the typical spool but it does fit with a little elbow grease.
I include a bag of desiccant in each bag to pull any residual moisture.
It's a good idea to use the cut-to-length bags on a roll, which allows you to add excess length, as you have to cut and toss away the previous seal each time you use the spool.
I too purchased the big honking bags and never built the structure I planned to use with it.
So many compromises regardless of the method used. I've since switched to Sealtite Storage Bins from Target. They have a gasket around the lid and I've increased the bag of desiccant in each one. They stack well too.
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Tags: filament, storage
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thread-10327 | https://3dprinting.stackexchange.com/questions/10327 | What actual dyes are used in filaments? | 2019-06-21T01:01:48.560 | # Question
Title: What actual dyes are used in filaments?
I've seen several questions about dyes in regards to food-safety, with no conclusive answers, as well as anecdotes on the RepRap wiki about how the mechanical properties of dyed PLA tend to vary by color. The general unsatisfactory answer is that dyes and additives used are proprietary secrets of filament manufacturers. However, 3D printer filament is a sufficiently large industry, with sufficiently many players now, that many of these "secrets" surely have to be "open secrets" to some extent by now.
What is known about what types of dyes and additives that tend to be used in filaments for 3D printing? Is there information on distinguishing between them with optical, chemical, etc. properties?
My thought is that by knowing some of the common dyes used by some manufacturers, it would be possible to:
1. choose those if interested in properties of them, and;
2. devise test procedures to evaluate if a different/"generic" filament seems to be using the same ones.
# Answer
> 3 votes
I spoke with a chemist tonight. He said to start with the SDS (or MSDS) for the filament, which is required to be available for most materials. It should list the pigments and additives if they are not recognized as safe. If they are safe, non-toxic, not flammable, non-reactive, they might not be disclosed on the data sheet.
He warns that sometimes the SDS lists just an industry name for a common pigment, and sometimes is the full chemical name. IMO, Google may help with translation.
The chemist has a deep background in color science and pigments.
# Answer
> 3 votes
## No Dyes at all.
Your question is based on a misconception:
> A dye is a coloured substance that chemically bonds to the substrate to which it is being applied, this distinguishes dyes from pigments which do not chemically bind to the material they colour.<sup>Wikipedia</sup>
The coloration does not chemically bond with the plastic in production. It is thus a pigment that is melted into the filament.
## Pigments
The range of pigments is ginormous. They start as simple as pure carbon black, range over natural occurring ones such as zinc white (ZnO) to products of chemistry like the dark blue copper phthalocyanine. Some pigments of these are toxic (lead white), others are also carcinogenic (chrome yellow), others are atop that radioactive (uranium trioxide, aka uranium yellow).
But what is actually used for coloring the filaments? Usually, manufacturers choose their pigments carefully based on 3 factors:
* thermally stable in the printing range
* as non-toxic as possible (to avoid needing to declare it on the MSDS)
* as cheap as possible to work with
Usually, this rules out all the highly toxic and radioactive ones, as that demands extreme caution to work with, upping prices.
## What's used?
Usually, **we can't know**. While the list of inorganic pigments is rather limited in some areas, it is by far not complete. It's better to take a look at the Forbes Pigment Database, which lists 11 categories of *white* pigments, 9 of them by chemical composition, one by origin and one for 3 samples of unknown composition. The 2 categories of violet pigments contain 20 different samples.
### But why don't we know?
In most cases, the color of plastic does not bring any danger or changes the properties more significant than changing its melting point. As the chosen pigments are inert to most treatments, they don't need to be listed on the MSDS, and thus omitted, allowing the companies to keep them a trade secret that helps them compete against other companies for only they have this one specific color.
Our best indicator for what pigments are used thus is, if they use a trade name for a filament, such as "ultramarine blue", which however might not be in the filament at all.
### When do we know?
In some cases, we might actually know what they put into a roll of filament based on odd characteristics.
For example phosphorescent green filament. It is most commonly made with either zinc sulfide or strontium aluminate, and we can rule out one or the other based on how bright they glow on the dark photo.
Another case in which we know what is in the filament is in the case of metal infused filaments, where it is part of the advertisement, that these filaments contain some amount of one metal powder or another. For example, the rusting filament contains iron. Then there is also filament that contains up to 80 % metal powder. Another similar bucket are wood- and stonefill filaments, where wood fibers or ceramics were added to give color and texture.
# Answer
> 1 votes
I fear your supposition about *secret* --\> *open secret* is too optimistic. Manufacturers are very unlikely to reveal their components, or the mix ratio, used to create a given color.
Consider the Coca-cola formula. It's been a secret for over a hundred years, despite a number of competing cola-ish brands. Consider also that the label you buy is the label of the supplier, and there's no guarantee that a given supplier won't change the manufacturer they use for bulk material at any time (raw colored plastic, just not drawn into filament).
As to doing analysis on your own, I fear the cost of a good gas chromatograph, mass spectrometer, etc. is staggeringly high.
---
Tags: filament, print-material, color
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thread-10347 | https://3dprinting.stackexchange.com/questions/10347 | Prusa i3 MK3S 3D printer PETG printing problems | 2019-06-22T19:50:22.753 | # Question
Title: Prusa i3 MK3S 3D printer PETG printing problems
I am using a new Prusa i3 MK3S 3D printer kit. I print lots of things using PLA and PETG.
After a week of great performance I noticed that when printing some objects with PETG filament I often encountered a problem when there's **intense stringing, infill gaps, artifacts, the object sometimes detaches from the plate.** I use the Prusa Slicer and Cura and print with the temperature 230/90 °C, speed max. 300 %.This problem occurs rather regardless of which infill methods I choose. I see this problem more often when printing models sliced with Cura. Sometimes everything goes fine, but most of the time I need to stop the print due to the model collapsing, detaching from the surface, its parts collapsing due to infill gaps. The printer sometimes makes some 'clicking, cracking' sounds when printing with PETG. *My filaments come from Fiberology*.
Surprisingly, I have run the selftest, XYZ, Z calibrations and all the other ones without any errors. The wizard told me that the axes are perpendicular and it gave me congratulations. All the other tests went nearly perfect as well.
I do not encounter any problems using PLA, just with PETG. I try to maintain the filament properly (keep it away from moisture, in a closed box). Sometimes (rarely) **I get crashes. The filament often builds up on the hotend and I remove it.**
I do not know what to do, the build went very well and there are no errors, even though I am a new user and this is my very first 3D printer. I have searched the web and I haven't found people reporting this exact same thing.
Could You help me? What can I do to improve the quality of the prints, perhaps maintain PETG better **(maybe I'm doing something wrong) and most importantly, solve the problem**?
# Answer
> 3 votes
230 °C is way too cool for PETG and will result in underextrusion unless you print really slow, and poor bonding. Underextrusion in turn leads to stringing because of pressure build-up. I print PETG at 250 °C.
# Answer
> 2 votes
You might try printing with Prusa's recommended settings. They tend to be hotter and slower than I expected.
I have made several pet-G prints with the same machine you have.
---
Tags: print-quality, prusa-i3, 3d-models, petg
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thread-10352 | https://3dprinting.stackexchange.com/questions/10352 | Find OpenSCAD code from image | 2019-06-23T10:44:49.803 | # Question
Title: Find OpenSCAD code from image
I have an OpenSCAD model which I am looking at in the application, code to the left and the rendering to the right.
Am trying to modify a certain piece, and have commented out all the commands that I believed were related to that piece, but there is still one subtracted cube left, i.e. somewhere in the code there is a `difference` block with this `cube` command somewhere in the 2nd part (I believe, as I cannot see any other possibility).
It would be very nice if I could just click on the image and get the software to display the corresponding commands in the code.
Is anything like that available in any tool?
# Answer
> 2 votes
To my knowledge, OpenSCAD does not have any such feature. However, a related feature might help you: the debugging aid modifier characters. By inserting `%`, `#`, `!`, or `*` before an object (including aggregate objects), you can control how it renders in relation to the whole file; this makes it possible to do "binary search" type operations to figure out where the object you're seeing is.
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Tags: openscad
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thread-147 | https://3dprinting.stackexchange.com/questions/147 | Which are the food-safe materials and how do I recognize them? | 2016-01-13T05:44:21.367 | # Question
Title: Which are the food-safe materials and how do I recognize them?
What materials which are commonly used in 3D printing, are food-safe?
Are there any certifications/grading process for such materials, which can help me with my cross-checking and selection?
---
I have been using an FDM printer.
# Answer
> 23 votes
Food safety is a property of both the process and the material. You can't stick food-safe material in a printer that has previously been used to print something food-dangerous and expect the result to be food safe.
The only way to know if a given material is food-safe is to ask your supplier, but a lot depends on how you then process it. For instance, FDM printers often have brass nozzles, which contain lead. To print food-safe materials, you need to use a stainless steel nozzle.
Food safe materials can be identified by mean of an universal symbol.
Moreover, to ensure food-safety of a 3D printed model you may need to further process it (for instance, by vapor smoothing or coating with a food-safe lacquer). Some claims circulate on the internet that 3D printed models may have surface porosity in which bacteria can grow, but I've not been able to find a reliable source for this claim. Still, you need to be cautious.
# Answer
> 9 votes
There are 3 things that might affect food safety of 3D printed objects:
1. The filament - it's food safe only if it says so on the package (even if the plastic is not toxic you don't know about the color and other additives)
2. The hotend - the hotend and nozzle may leak metals into the filament, you need something like a full stainless steel hothead.
3. And finally, 3D printed objects contain little holes that bacteria can get into - so nothing printed on an FDM printer is food safe unless coated with some food safe sealing material (except for single use)
# Answer
> 9 votes
### Food Contact Substances
There are regulatory agencies in most developed countries that regulate food containers. In the USA, the Food and Drug Administration (FDA) regulates Food Contact Substances (FCS) which are materials that come into contact with food during production, manufacturing, storage, packing, and use.
They have many lists of FCS which are either approved for use, generally recognized as safe, regulated, restricted, or otherwise already evaluated and for which they have recommendations.
It is up to the manufacturer to ensure that FCS are safe, so the liability rests with the person making the 3D prints. If you make something that looks like a cup and could be confused with a cup, you may be responsible for following these guidelines.
### US FDA regulation for ABS and PLA
The FDA has an online resource to help guide manufacturers through these lists, Determining the Regulatory Status of Components of a Food Contact Material.
Within this, for instance, you will find the list for materials that are appropriately regulated indirect additive, under which you'll find where polymers are listed, 21 CFR 177.
Part 177, INDIRECT FOOD ADDITIVES: POLYMERS
Notably, PLA is not present in this section, or any other list that I've searched (but a more thorough search may prove productive).
ABS is included here, in section 1020, which I've quoted below. Whether your filament manufacturer is following this ABS formula or not is something you will have to determine for each ABS supplier you use, though. Additives, colorants, and other ingredients may make a specific ABS non food safe, according to the FDA.
> §177.1020 Acrylonitrile/butadiene/styrene co-polymer. Acrylonitrile/butadiene/styrene copolymer identified in this section may be safely used as an article or component of articles intended for use with all foods, except those containing alcohol, under conditions of use E, F, and G described in table 2 of §176.170(c) of this chapter.
>
> (a) Identity. For the purpose of this section, the acrylonitrile/butadiene/styrene copolymer consists of:
>
> (1) Eighty-four to eighty-nine parts by weight of a matrix polymer containing 73 to 78 parts by weight of acrylonitrile and 22 to 27 parts by weight of styrene; and
>
> (2) Eleven to sixteen parts by weight of a grafted rubber consisting of (i) 8 to 13 parts of butadiene/styrene elastomer containing 72 to 77 parts by weight of butadiene and 23 to 28 parts by weight of styrene and (ii) 3 to 8 parts by weight of a graft polymer having the same composition range as the matrix polymer.
>
> (b) Adjuvants. The copolymer identified in paragraph (a) of this section may contain adjuvant substances required in its production. Such adjuvants may include substances generally recognized as safe in food, substances used in accordance with prior sanction, substances permitted in this part, and the following:
>
> Substance Limitations 2-Mercapto- ethanol The finished copolymer shall contain not more than 100 ppm 2-mercaptoethanol acrylonitrile adduct as determined by a method titled “Analysis of Cycopac Resin for Residual β-(2-Hydroxyethylmercapto) propionitrile,” which is incorporated by reference. Copies are available from the Bureau of Foods (HFS-200), Food and Drug Administration, 5100 Paint Branch Pkwy., College Park, MD 20740, or available for inspection at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal\_register/code\_of\_federal\_regulations/ibr\_locations.html. (c) Specifications. (1) Nitrogen content of the copolymer is in the range of 16 to 18.5 percent as determined by Micro-Kjeldahl analysis.
>
> (2) Residual acrylonitrile monomer content of the finished copolymer articles is not more than 11 parts per million as determined by a gas chromatographic method titled “Determination of Residual Acrylonitrile and Styrene Monomers-Gas Chromatographic Internal Standard Method,” which is incorporated by reference. Copies are available from the Center for Food Safety and Applied Nutrition (HFS-200), Food and Drug Administration, 5100 Paint Branch Pkwy., College Park, MD 20740, or available for inspection at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal\_register/code\_of\_federal\_regulations/ibr\_locations.html.
>
> (d) Extractive limitations. (1) Total nonvolatile extractives not to exceed 0.0005 milligram per square inch surface area when the finished food contact article is exposed to distilled water, 3 percent acetic acid, or n-heptane for 8 days at 120 °F.
>
> (2) The finished food-contact article shall yield not more than 0.0015 milligram per square inch of acrylonitrile monomer when exposed to distilled water and 3 percent acetic acid at 150 °F for 15 days when analyzed by a polarographic method titled “Extracted Acrylonitrile by Differential Pulse Polarography,” which is incorporated by reference. Copies are available from the Center for Food Safety and Applied Nutrition (HFS-200), Food and Drug Administration, 5100 Paint Branch Pkwy., College Park, MD 20740, or available for inspection at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal\_register/code\_of\_federal\_regulations/ibr\_locations.html.
>
> (e) Acrylonitrile copolymers identified in this section shall comply with the provisions of §180.22 of this chapter.
>
> (f) Acrylonitrile copolymers identified in this section are not authorized to be used to fabricate beverage containers.
>
> \[42 FR 14572, Mar. 15, 1977, as amended at 42 FR 48543, Sept. 23, 1977; 47 FR 11841, Mar. 19, 1982; 54 FR 24897, June 12, 1989\]
### Regulation globally
The EU has a database for this, though without some industry specific experience it appears difficult to search. For instance, rather than listing ABS as an item, it lists the three monomers that constitute ABS seperately, so you have to read through the Acrylonitrile section, the butadiene section, and the styrene sections seperately to understand the food safety aspects of ABS.
Of course someone has gone to the trouble of parsing all these different regulations in different countries and created a book that summarizes much of what you can glean from individual databases, Global Legislation for Food Contact Materials J S Baughan but it's not an inexpensive resource, and needs constant update so may need to be repurchased each year to keep up with the latest legislation worldwide. It would, however, be a handy reference and starting point for a hack space or library for makers.
### Conclusion
Keep in mind that these are regulations formulated by government bodies. They may have a scientific basis (and hopefully they all do) but they do not replace your own testing and common sense. Even if you follow these regulations, you may still be liable for any unsafe objects you create.
# Answer
> 3 votes
I have looked at this a lot, both from the standpoint of my own use, and of selling items on Etsy.
As far as I can determine, PLA and ABS are both generally safe.
The FDA lists ABS and PLA as safe plastics for food contact, although some pigments and additives can bring their own problems. ABS is nit generally safe (per the FDA) for contact with alcohol. I don't know why.
So, for my use, I make wine, beer, and cocktail containers from PLA, and coffee mugs from ABS.
PETG softens too much with boiling water and does not work for coffee and tea mugs. I've tried. It fails.
Be careful if you use acetone smoothing on ABS. The acetone enters the ABS, and even after a few days of ambient conditions, the plastic may contain enough acetone to create bubbles in the plastic when the acetone boils off in response to hot water. I had heavily smoothed this particular teacup. Perhaps if it was less exposed to acetone vapors, it may have let the disolved acetone escape faster.
I have used non-smoothed ABS coffee mugs for months without problems.
You will read about brass nozzles contaminating the print with lead. You will read about the ridges being bacterial breading grounds. This may be true.
ABS still makes a fine coffee mug for personal use.
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Tags: material, safety, food
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thread-10356 | https://3dprinting.stackexchange.com/questions/10356 | Is there an easy way to split models in OpenSCAD? | 2019-06-23T16:59:33.190 | # Question
Title: Is there an easy way to split models in OpenSCAD?
I'm wondering if I can take one OpenSCAD object, and cut/splice/split it into two different objects that can then be manipulated independently?
One approach is to duplicate the object, difference it along the cut border with a 3rd object, and then difference the result with itself. This seems overly complex and I suspect I'm missing something
PS - the point of this is that I have a nicely designed part where I need to create an interlock. I want to first cut the part in half, and then create some interlock mechanism
# Answer
> 8 votes
Rather than differencing a copy of the object from itself, which is subject to numerical instability, choose a box ("cube" in OpenSCAD terminology), and intersect it with one copy of the object, then difference it from the other copy of the object. This is all easy if you use modules to encapsulate your parts, and it also works with imported STL files.
Specifically, it should look something like this:
```
module mycut() {
translate([x,y,z]) cube([w,l,h]);
}
difference() {
myobject();
mycut();
}
translate([u,v,w])
intersection() {
myobject();
mycut();
}
```
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Tags: openscad
--- |
thread-258 | https://3dprinting.stackexchange.com/questions/258 | How to minimize damage when removing an ABS print from a heated glass print bed? | 2016-01-15T00:47:30.323 | # Question
Title: How to minimize damage when removing an ABS print from a heated glass print bed?
Usually it will either will rip the tape, or break the print somehow. Currently using ABS on a taped glass bed with a layer of hairspray for adhesion.
# Answer
> 6 votes
I moved to a plain glass heated bed with a brush applied acetone and ABS mixture. Using an old emptied nail polish bottle with brush, I added some acetone and then threw in ABS pieces until it reached a brush-able consistency. I then brush it on the glass build plate where I believe the print will occur, and it works very well. On removal of the part the coating comes with it.
I just found previously that ABS would adhere to my kapton taped heated bed too strongly to use, and so while this involves a little work before each print, it's overall better than kapton for me.
I did experiment with sheet metal beds coated with kapton, but they curl during printing due to the ABS thermal stress, allowing my parts to be concave on the bottom side. Easy to remove from the plate, though, since it flexed. There may be a good middle ground material but I didn't experiment further.
# Answer
> 2 votes
I have had best results with ABS on a heated printbed (untaped) with a thin coat of UHU Stic. It can be a little tricky to remove but minimizes damage.
# Answer
> 2 votes
Glass has a very peculiar effect under heating, that can be used to remove extremely delicate parts from the surface of it:
Glass expands and shrinks differently to the ABS under temperature. Letting the glass bed cool down has it shrink, creating tension on the interface layer which can be exploited with a thin scraper. Putting the bed with the print into the fridge increases the tension to a point at which the bonding breaks. This results in the part popping free in several areas (sometimes everywhere) and easing the removal.
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Tags: heated-bed, abs, desktop-printer
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thread-10349 | https://3dprinting.stackexchange.com/questions/10349 | Do 3D printers really reach 50 micron (0.05 mm) accuracy? | 2019-06-22T22:06:22.017 | # Question
Title: Do 3D printers really reach 50 micron (0.05 mm) accuracy?
I've always been wondering about the actual accuracy of 3D printing devices. When looking for the perfect machine to buy, I looked at the speed, price, filaments supported etc, but also accuracy. I once asked somebody who could give me some advice on what to look at.
One of the things I was told about was that many printers don't necessarily have that crazy precision of 0.05 mm (50 micron). Another person told me something different - he said most of those printers actually were capable of putting out 50 micron layer height. How is it really?
Another thing is that the official slicers for those machines also claim that this precision is real, for instance the PrusaSlicer v2.0.
There are many high-end, very expensive machines and even they sometimes claim their resolution is worse than 50 microns.
# Answer
There's not a simple answer to this question, or if there is, it's "no". However the situation is a lot more complicated. When printer specs cite accuracy like this, they're usually basing the claim on the nominal size of the smallest movements on each axis by one "microstep" of the stepper motors. There's a great article on Hackaday explaining the how this affects accuracy: How Accurate is Microstepping Really.
At the mechanical positioning level - putting the print head where it needs to be to extrude the material with the desired accuracy - you have at least these factors limiting your accuracy:
* Microsteps are generally spaced roughly monotonically between whole steps, but do not necessarily divide the whole step into even portions. How well they do is a matter of the stepper drivers your printer's controller board uses. Generally, microsteps are 1/16 of a step (although there are drivers with 1/8, 1/32, or even 1/256, maybe others too), so if you see a rated accuracy of 0.05 mm, a whole step, which might be the minimum you can get reliable accuracy from, is likely 0.8 mm.
* Stepper motors are deflected slightly - up to 2 whole steps but less than one step is more likely if they're not overloaded - under load. So are belts. How much this affects you depends on the design of the printer and how much mass each axis is moving. Direct drive extruders are much worse in this regard. Delta printers are probably best in it.
These can be mitigated somewhat, with tradeoffs, by using stepper motors with more steps per rotation, better stepper driver chips, reduction with gears, etc.
On top of that, you also have extrusion and properties of the print material limiting your accuracy:
* The extruder motor is subject to the same accuracy issues as the positioning ones. If you extrude too much or too little material anywhere, you'll necessarily have accuracy issues. You can compute them based on the cross-sectional area of filament, size of extruder gear, extruder motor step and microstep size, etc.
* If the filament diameter is not perfectly consistent, you'll also extrude too much or too little material.
* If material is not cooled or kept warm appropriately as it's extruded (this varies by material), it will sag, warp, or curl, ending up in a different place from where you wanted it.
* The more you vary the ratio between nozzle/extrusion width and layer height from an ideal ratio, the more the shape of the extruded material paths will differ from the model you're trying to print. With thick layers especially they'll become rounded rather than near-flat along the walls.
In theory, a lot of these issues probably could be mitigated a lot better than they are now just by better *slicing* \- the logic that happens on a computer to convert the original 3D model into instructions for where to extrude material.
With all that said, you can get pretty amazing accuracy still, especially with a good or well-tuned so-so printer. On my cheap Ender 3, after dealing with some issues now and then that made glaringly obvious problems, I can get dimensional accuracy within 0.1 mm in the X and Y directions, at least for some models. So I think it's very plausible that a better, or better-tuned, printer could get 0.05 mm accuracy.
> 12 votes
# Answer
> One of the things I was told about was that many printers don't necessarily have that crazy precision of 0.05 mm (50 micron). Another person told me something different - he said most of those printers actually were capable of putting out 50 micron layer height. How is it really?
Both things you've read are completely correct.
Most printers are capable of 50 micron layer heights. However, layer height does not equal "accuracy" or "precision". The layer height specification is a useless marketing term that you should ignore; layer height is to 3D printers what dynamic contrast is to monitors.
All FDM printers are inherently quite bad at producing parts with tight tolerances. The filament extrusion process introduces lots of variables that are hard to control: the diameter of the filament may vary, there is a delay between feeding filament into to the extruder and it coming out, and the gooey filament that comes out of the extruder behaves in unpredictable ways.
Nobody has figured out how to quantify "accuracy" for 3D printers in a way that correlates with the quality of the finished parts. It is impossible to tell which printer produces "better" or more accurate parts from the specification sheet of a printer.
> 9 votes
# Answer
A **resolution** (sometimes called "accuracy" for marketing purposes) of 0.05 mm means that if you produce a bunch of 10 mm dice and a bunch of 10.05 mm dice, then the 10.05 mm ones will be statistically larger. Note that dice don't have to actually be anywhere near 10 mm, nor does a random die from the 10.05 mm pile have to be larger than a random die from the 10 mm pile.
A **repeatability** (aka "repeat accuracy") of 0.05 mm means that in the experiment above every die from the 10.05 mm pile have to be larger than every die from the 10 mm pile. Note that your dice still don't have to be anywhere near actual 10 mm.
A **precision** (aka trueness) of 0.05 mm means that in the experiment above the average size of a 10 mm die should be within 9.975..10.025 mm. Note that individual dice don't have to be within that interval.
Finally, the **general accuracy** (as defined in ISO 5725) of 0.05 mm means that every 10 mm die should be within 9.975..10.025 mm.
To sum it up, the statement from your question is true for the "commercial accuracy", but not for the general definition of accuracy. For example here is an article comparing accuracy of 3D printers in dental applications (so we're talking high-end machines), with *average* accuracy ranging from 0,05 to 0,1 mm and *absolute* accuracy in range of 0,11 to 0,17 mm.
> 7 votes
# Answer
Tom's answer is correct, most printers will operate properly with a layer height *resolution* of 50 micron, using a 0.4mm nozzle. The resulting surface finish will probably be better than at a coarser layer setting, and at finer layer heights the print quality is likely to deteriorate.
Layer height is also likely to be fairly well defined (except for the first layers, overhangs, warping, etc), but this depends on the printer geometry.
The detail which is not so well controlled (or measured) is the squish/stretch of the molten plastic as it is extruded. This can have a significant impact on the localised surface finish (as well as dimensions of things like internal diameters).
Accuracy is maybe best assessed by the results of printing various types of test part than by a simple numeric parameter.
> 2 votes
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Tags: 3d-models, 3d-design, fdm
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