q:
When modelling for 3D printing, can I distinguish somehow the type of infill in various areas of the model? Say there may be some areas in the model where I want 100% infill (maximum strength) but some areas where the infill can be less (maybe 25%).

I am new to 3D printing, doing my first model (enclosure for electronics - camera module). Using tinkercad.com only so far. Places where 100% infill is wanted are usually walls of the case and "threads" for the bolts but I want to make the enclosure as stiff as possible as a whole so I am thinking about using some sparse infill in the "free space" inside of the enclosure (so that it does not break so easily when it falls to the ground etc). I just do not know how to define this within the model.

[A]
I found out I misunderstood some principles of designing/modelling for 3D printing.
I designed my object for 100% infill which is not really necessary. It turned out that one does not mostly have to take care of the infill % and just model the object for example as solid 3D cube and the printing service will then take care of it to print well, hopefully slicing it well for printing and choosing the correct infill percentage.
So instead of designing a "hollow" cube with 3mm thick walls filled with 100% infill and free space inside, one can design a solid cube and the printing service will then print it "somehow" - they may make the walls only 1 mm thick but fill the inside of the cube with 10% infill which may work just fine for final object stiffness etc.


q:
How can I vary the infill percentage for different layer heights of my model?

Context: The bottom part of my model needs about 20% infill.  The geometry of the top part of the model (mostly cones of various sizes) prints well with 0% infill and is of course a lot faster to print if I can specify this.

[A]
Your question is very similar to
Different infill in the same part
and
Using multiple infill types within one model [duplicate]
. The difference is that you specifically ask for Slic3r and a variation in layer height infill percentage.
Actually
this answer
describes using "helper volumes" in Ultimaker Cura to set different properties for certain parts of the model
(
UPDATE
: that answer now includes also Slic3r instructions)
, but it appears that this answer is very much applicable to Slic3r also. Please read
this
posting. Quoting from the reference:
Finally, I fired Slic3r up and loaded the main part, then clicked on
  Settings... and then hit Load modifier... I loaded the new volume as a
  modifier mesh and I applied 100% solid infill...
Secondly,
this
answer where 2 different infill percentage sliced models are manually combined at a certain height may also work for you (this is a perfect valid solution for Slic3r, but requires some editing skills).
Basically, although you request for a solution for a slicer other than already described in other questions, boils down to a similar answer, the only difference is the implementation in Slic3r is called differently.
To do this in
Slic3r
see
this reference
.
The blog describes the use of a simple volume (the green volume loaded from an STL file). After loading:
Right-clicking on the main part brought up the object settings menu.
  From there, clicking "Load Modifier" and selecting the previously
  saved model adds it to the part as a modifier.
The green "+" was selected and "Fill Density" was added to modifier
  list and set to 100%.
This shows that the functionality in Slic3r is very similar to the functionality in Ultimaker Cura.

s: huggingface

c: devops

d: intermediate


q: I've seen a few print time-lapse videos lately which use gyroid infill: wavy lines, which deform across layers so that the waves end up alternating between the two axes. Other than making the time-lapse videos look much cooler, what are the benefits of this infill style compared to the more common hatching or cross-hatching?

[A]
From
this reference
you can read that:
A gyroid is a naturally occurring structure which be found in
  butterfly wings and even within membranes inside cells. In 2017, MIT
  researchers discovered that when graphene was shaped into a gyroid
  structure, it had exceptional strength properties at low densities.
  They then discovered however, that the crucial aspect of this was
  actually the gyroid structure itself, and that other materials such as
  plastic could benefit from this.
It is assumed that this type of infill has better properties against failure than the normal types of infill we know.
A test conducted by an author named Martin is found
here
. He printed test specimen and subjected them to bending to test the resistance against shear stress.
From the figure can be concluded that the gyroid infill has a better resistance against bending for a lower weight.
The advantages of gyroid infill over the tested infill types are:
high shear strength, and
low weight (so less filament needed).
On top of these advantages Gyroid infill prints relatively fast with respect to some other infill types and is close to
isotropic
(i.e. uniform in all orientations), meaning that is very suitable for flexible prints.


q:
When printing several objects, I recently encountered a problem that arises when the structure in itself is relatively thin or the support towers have a small surface: the printhead would in motion tend to knock one or more over as it traveled or catch at them and create layer shift.

How can I avoid collisions with the already printed parts of a layer?

[A]
The problem was twofold:
Lack of bed adhesion due to the small contact surface
motion into the already printed objects.
The
quick and dirty
way was to change two settings:
Print with a small (3 mm) brim to stick the supports to the print and provide more surface. Other materials than PLA may need considerably more brim!
Activate Z-Hop to force the nozzle to lift over the print when traveling
These tricks don't solve issues with very thin structures or in all cases. In those cases, it can be mandatory to increase the structure's (support) thickness or change the alignment.


q:
I have a concept that's roughly 18"x30" (about 457x762 mm), and I just realized that the Makerbot and similar printers only allow dimensions around the size of a piece of paper. What are other options? Are there large 3D printers I just don't know about? I looked up TMC injection mold, but couldn't find anything on size (most links go to PDFs with printer images).

Is injection even in the same "world" as 3D..? Sorry for confusing the two.

[A]
Yes
If you have the money
Either read
here
or look at the ones I plucked out of that list to show you:
First of all, 3D printers on FDM basis can become quite large, if you pay extra. And the price goes up really fast as the dimensions grow because the demands on stability grow exponentially.
Larger Printers?
One example of a "scaling" printer family is the CR-10: The baseline CR-10 is about 300x300x400 mm, so about 12x12x16 inch for 400\$. Not enough? 400x400x400 on the CR-10 S4 for ca 760\$. 500x500x500 on the CR-10 S5 for 900\$. That's 20 inch in all directions. But that's still not enough, isn't it? Well, if you need to go larger, you need to go professional...
Going Big!
Well, there are printers like the gCreate gMax 1.5 XT+ (406x406x533 mm) for a mere 3000\$. That's enough, isn't it? Well, we can even go
bigger
: 610x610x610 mm for a mere 3500\$ on the Modix Big 60.
Still not satisfied? Industrial machines can go even larger! A BigRep Studio for the
little
price of 50000\$ could achieve 500x1000x500 mm.
Even more? Go Parametric!
As amra mentioned, the
Hangpringer
project of printers has no "set" build size, but you will have to provide a build platform of fitting size and a room it can work in undisturbed and with filament supply ready... just... bring a ladder? And be wary of people tripping over wires... and somehow find a ginormous, evenly heated bed somewhere...
Ways around
Assembly
That is a little overkill, isn't it? Well, the first thing you need to remember when 3D printing is: unless you make a functional part that has to have certain dimensions, feel free to scale it down if it is just for visuals. Then, you can assemble prints. Like, take a smaller printer and print the object in halves or quarters. Then glue it back together.
Order
You don't want or can't assemble the part? Well, there are printing services out there that have these larger scale printers I mentioned (or at least similar ones) that offer to make your parts for you and then ship them to you. Usually, that is much more cost effective than buying one of these ginormous printers yourself.


q:
Other than the most obvious issue with the filament kinking in the tube, what other issues could arise when trying to print flexibles (i.e. TPU/TPE, Nylon, etc.) with a Bowden style extruder setup?

Can the kinking issue be alleviated by a well-constrained filament path (proper ID) in a properly sized Bowden tube?

[A]
As a user of an UM3E, which uses Bowden tubes and has TPU as an available material, I can tell you that the kinking issues can be alleviated or downright avoided.
I've printed quite a few things with the Ultimaker-brand TPU 95, and never had problems with kinking in the tube.
Ultimaker uses 2.85 mm filament, with Bowden tubes adapted for those and a rear motor, i.e. the motor is on the back on the printer and not right on top of the print head.
I personally wouldn't consider Nylon as one of the really flexible material, but that's my opinion. Never had kinking in the Bowden tube with Nylon either in my UM3E.


q:
When exporting an STL from Fusion 360, one must select an STL refinement level to use for calculating the maximum triangle count.

For FDM printing (0.05mm and above layer heights), where is the point of diminishing returns on STL refinement level when printing PLA and PETG on an Ender 3 with a 0.4mm nozzle? All mechanical components on the printer are stock.

[A]
I don't know that this can be definitively answered for a specific printer and all arbitrary designs.
The refinement level basically determines how smooth a curved surface will turn out.  The STL file format can only express an object in terms of triangular-shaped surfaces, so Fusion 360 will need to approximate a curved surface by breaking it up into triangles. Flat surfaces and straight edges can be represented perfectly, so they won't be affected. Low refinement will use a small number of relatively large triangles. On a part like your example, the cylindrical shaft will have noticeable facets. Higher refinement means a larger number of smaller triangles.
If you have "Preview Mesh" checked as shown, you will be able to see the triangle wireframe, and you can use your own judgment if it's "good enough".
Ultimately, higher refinement means longer processing times and larger file sizes. The final print time won't be affected much if any.
Personally, I always use high refinement. Even on my modest system, it only takes a few more seconds to prepare a multi-hour print, and maybe a few hundred kilobytes or a couple megabytes on my hard drive that I will barely notice. This is a small tradeoff to ensure the best possible STL definition.


q:
I am trying to create a mechanism with moving parts, and would like to see how it works (whether it even works) before printing it.

For example, there's a servo with a bracket, and I would like to see how far can the bracket move before colliding with other objects.

Unfortunately I cannot find any information on how to set pivot points and rotate objects around these points in FreeCAD. Is this even possible?

[A]
freeCad has a draft rotate function in
DRAFT workbench
:
Select an object;
Press the Draft Rotate button, then;
Click to set the rotating point and rotate.
You will get used to that after a few trails.
There is a
step by step guide
on freeCad site.
There is also a
short demo of the function here
.


q:
If I have an image like the one attached, what’s the best way to create an accurate depth map of it? I have photoshop CC and 3ds Max, but I don’t know what settings work best with Slic3r. There is a plethora of settings and combinations to choose from in either programs.

Did anyone do this before? If so, can you share your technique?

[A]
From a single image from this perspective (front view) you cannot map the coin surface in detail. There is reported limited success in estimating the depth of single images, but, this is for images with a clear perspective (e.g. like a picture of a room showing the walls and floor at an angle). In order to map the surface you will need to have multiple images and preferably know the direction of lighting on that object.
People with one eye cannot estimate depth very well, you need two eyes and a trained brain to understand the differences in depth.


q:
Assume somebody has a Monoprice Maker Select and has changed from the original brass extruder gear to a D4 Plus one, which is slightly smaller (10.6 vs 10.9 mm outer diameter).

This person might be wondering if he/she needs to compensate for this difference, and which setting that would be in Cura IIIP.

(Have never calibrated the extruder and am still not sure it is absolutely necessary, since the difference in the gear size is only 3%.)

[A]
If you change the extruder wheel for a different sized wheel, you need to calibrate the extruder to make sure that if you ask to extrude 100 mm it actually extrudes 100 mm.
This answer
on the question "
How do I calibrate the extruder of my printer?
" describes how to do that.
It is not required to flash your firmware. The G-code command
```
M92
```
can be used to set the new amount of steps for the extruder. The Monoprice Maker Select has a Melzi control board that is running Repetier firmware. This G-code command is supported by Repetier firmware.
You need to be able to connect a so-called terminal to your printer. Applications as Repetier-Host, Pronterface, OctoPrint, and probably many more have so-called terminals where you can interface with the printer by sending command to it when the printer is connected through USB (please mind the communication speed of the board, called Baud rate, these are not the same for all boards).
Sending
```
M503
```
will report the current settings for
```
M92
```
, e.g.:
```
```
M92 X100.00 Y100.00 Z400.00 E100.00
```
```
Extrude 100 mm without the hotend attached so you can measure the amount that is extruded. If that is 80 mm you need more steps
$ \frac{100\ mm}{80\ mm} \times 100\ steps/mm = 125\ steps/mm $
You now need to send
```
M92 E125
```
and the new steps are set. Use
```
M500
```
to store the setting.
You could also change the flow extrusion parameter in your slicer, but it generally not good practice, it is better to fix the printer rather than adjusting in the slicer. However, if you do want to fix it in the slicer, as mentioned in the comments, you can also add steps setting in the start G-code script:
"To get around flashing the new values to the ROM, you can add this to the machine settings in Cura under "Start Gcode" this way it will append your values at the start of every print."
. Note that other slicers have similar functionality.


q:
My Anet A8 was working and printing great until my hotbed connector snapped and shorted out my motherboard. After replacing the connections to my hotbed and my motherboard I can't print anything because the filament flow is very inconsistent. It often laying down nothing. See my included picture.

I've tried a bunch of suggested calibration settings but none of them worked:

increased extruder temp,

decreased speed,

increased flow,

Any ideas or thoughts would be great.

[A]
Please note that the problems you faced are typical for the Anet A8, the connectors are underrated for the application. Also, do note that the stock firmware does not have thermal runaway protection, which is considered to be very unsafe and could potentially lead to burning down your house! Please flash a firmware that supports thermal runaway protection, like e.g. Marlin Firmware.
Basically you just tried to change some parameters to see if they have an effect. This is generally a good idea to get an idea of the problem, but a more technical approach would be to start from the beginning and exclude things you have tested. As for now you cannot conclude why the print looks as shown in the image, e.g. it also looks as if the nozzle to bed distance is too large.
The question remains if your 3D printer board did survive the shorting of the hotbed leads!
To troubleshoot this particular problem it is advised to check whether the extrusion process still does what it is asked to do. Disconnecting the hotend from the extruder and measuring how much filament is extruded would be the first thing to check. Please look into
How do I calibrate the extruder of my printer?
. It seems odd that the extrusion is off if the firmware has not changed, or alternative settings stored, but to be sure it would be the first thing to check. From this exercise you'll learn whether the firmware is set correctly and the extruder working properly. It can still be that the extruder gear slips, e.g. because the filament does not have a lot of friction when disconnected from the hotend.
When the extrusion process works and the commanded length is extruded, you can update the question with what you have done. After this, and if the problem persists, you can look into nozzle clogging and filament resistance for instance.


q: I just assembled a Prusa i3 MK3 and went through the calibration process, but when I print the first layer doesn't look good and my prints come unstuck from the bed. I think it might be Z height but this was as high as I could put the probe without the paper moving on the calibration test. The layers after the first few look good but then the print either warps or comes unstuck and moves.

[A]
Judging by the images you posted in your question, the first layer distance is too far away from the bed for the current filament flow.
This could either be related to:
having an offset on the first layer like a height correction in the slicer,
an incorrectly levelled (read height adjusted) bed, (you did the paper test correctly, so this is probably not your problem, it is mentioned for completeness)
under-extrusion
slicer setting not correct, e.g. filament diameter or flow modifier not 100 %
incorrectly calibrated extruder
Your most likely problem is under-extrusion. It would be advised to calibrate the extruder:
How do I calibrate the extruder of my printer?
and check the slicer settings.


q:
How can I achieve keeping the motors active during pause to avoid moving their position during filament changes?  I have changed the filament during some prints to change the color or to change the a newer spool, but sometimes the X axis is moved during the change. I'm now using some cloth clips to prevent moving during this change.

To pause the 3D printer I'm using the LCD menu ->pause, then I go to Move axis X, then I move close to 0. This change is manually and random since I don't know when the old filament reel is going to finish. The printer use Marlin as firmware with Ramps 1.4

[A]
I have not tried this, but you could use the
```
M84 S0
```
command, this prevents the motors to go into an idle state.
From the
```
M84
```
G-code wiki
(firmware specific!):
On
Marlin
, Repetier and RepRapFirmware, M84 can also be used to
  configure or disable the idle timeout. For example,
```
M84 S10
```
will
  idle the stepper motors after 10 seconds of inactivity.
```
M84 S0
```
will
  disable idle timeout; steppers will remain powered up regardless of
  activity.
What rests is to implement this command into your G-code file to be executed during pause. Depending on the pause method you could introduce this command. I have not tried this, but you could put the command in your start G-code and test if the motors keep powered!
Furthermore,
a specific filament change command is available for specific firmware applications
. This code,
```
M600
```
, can be used to change filament. From the
Marlin documentation
you can read (since you are using Marlin Firmware, you could use this G-code command):
The
```
M600
```
command initiates the filament change procedure. The basic
  procedure will move the print head away from the print, eject the
  filament, wait for new filament to be inserted and the user to
  confirm, load and prime the filament, and continue with the print.
```
M600
```
may be initiated automatically if a filament runout sensor is
  installed.
Please do note that in Marlin Firmware the
```
M600
```
command is only available when the comments before
```
//#define ADVANCED_PAUSE_FEATURE
```
in the advanced configuration options file
Configuration_adv.h
are removed, hereby activating the command.


q:
I have a long print that keeps aborting. At some random point mid-print the printer says "Click to resume...". There is nothing in the G-code that asks for user confirmation. What could it be that triggers this? I noticed that sometimes (not every time) there is a blob of plastic in the way that should not be there.

On one occasion, after the "Click to resume...", the LCD showed the message FY178.N16466 and again waited for a click.

The printer is an Anet A8 with Marlin 1.1.9. Slicer is Cura. I am printing via USB from Cura directly.

This is the error message:

[A]
This is not an answer/explanation per se, but it might help you track down the cause.
It
might
be worth
enabling logging
```
M928
```
to the SD card (ensure that the R/W tab on the SD card is set appropriately), so that (after this has happened a few times) then you can look through the log to see what the command preceding the abort was, and if it is consistently the same (sequence of) commands that cause this to happen.
```
```
M928 filename
```
```
If that doesn't throw up anything obvious, then, in conjunction with logging, you could enable debugging, see
```
M111
```
Debug level
. For example:
```
```
M111 S7 ; ECHO, ERRORS, INFO
```
```
Then run through the long print again. As before, after a few of the
click to resume print
messages, then go back and check the log for anything that might indicate why this is happening.
To subsequently disable the debugging:
```
```
M111 S0
```
```


q:
I'm at a location where I don't have easy access to toothed belts for my printer (a RepRap Wallace). While trying to look for some solution, I saw some talk of using fishing line as a belt, along with a log of admonitions of Don't.

However, as I have easy access to fishing line, but almost no access to a toothed belt, I was thinking of using multiple strands of fishing line with regularly spaced knots to simulate a toothed belt. However, Google didn't help much with either usage or possible Gotchas.

Is there any possible issues that I may face with this solution?

[A]
I’m going to recommend not using a fishing line with knots.  Probably the biggest problem you’ll have using the fishing line with knots is if the knots are not perfectly spaced,  movement along the X or Y axis is not going to be consistent. This could result in weird deformations in your print.
Depending on how you tie the knots they may not grip the teeth of the gears quite well enough to prevent slippage.
Both of these issues will mean that you will not get very good quality prints assuming the print doesn’t outright fail.
You would be better off waiting to get the correct belt then attempting to use fishing line.


q:
I have what I thought would be a simple question.

I don't have an auto leveling probe, I do my leveling manually with 4 screws and a piece of paper (I measured the thickness to 0.1 mm).

For the longest time I would have trouble with the first layer, sometimes having to give the bed screws a quarter turn to bring the bed up a bit. I would see that the nozzle seemed quite far away from the bed. This went on for the longest time and I just chalked it up to the quality of my printer.

I realized recently that when I level the bed, I am inserting a piece of paper in between the nozzle and the bed. Obviously, I should be taking the thickness into account as a 0.1mm thick piece of paper accounts for 50 % higher than the nozzle should be for a 0.2 mm first layer height.

My question is, how do I set (either in Cura or directly in Marlin config) the z home offset to account for the 0.1 mm thickness of my calibration paper?

[A]
It is preferred to get the distance correct by hardware changes (leveling screws). But it is possible to do it with software. You can not only change the Z offset in the slicer or in the configuration of Marlin, but also with G-code commands.
The "paper drag" method is perfect for determining the correct Z level. Once you leveled with the paper, you do not need to create an offset to account for the paper thickness, however, there are purists that do that. So basically, what we call Z=0 is in fact Z="paper thickness", unless you are a purist. But a slightly larger gap makes printing much easier. Too small heights cause e.g. rippling effects or too much pressure build-up in the nozzle. In order to change your offset after leveling, you could try one of the following methods. This is sometimes a useful method for creating a little extra offset for printing PETG, but personally I do not do that.
In Ultimaker Cura
:
Open the plugin manager ("Toolbox"->"Browse packages...") and install "Z Offset Setting", a new parameter will be available in the "Build Plate Adhesion" settings menu called "Z Offset". (See also
this older, not up-to-date answer
)
In Marlin configuration file
, modify the MANUAL_Z_HOME_POS constant:
```
```
//#define MANUAL_Z_HOME_POS 0
```
```
In G-code
:
By adding the following lines to your start G-code (see e.g.
this answer
) using the
```
G92
```
G-code command:
```
```
G0 Z0.2 ; Move the head to 0.2 mm (so now 0.3 on your machine)
G92 Z0  ; Call this Z = 0
```
```
or when you are able to connect to the printer over USB using a printer terminal (e.g. Pronterface, Repetier or OctoPrint) using the
```
M206
```
G-code command:
```
```
M206 Z-0.2 ; Will raise the Z height by 0.2 mm
M500       ; Stores the offset in memory
```
```
Alternatively, when you cannot connect through a terminal, putting the last 2 lines in a text file and saving that as a
```
.gcode
```
file on an SD card and "printing" the file will also store the new offset (if
```
M500
```
is enabled in the configuration file:
```
#define EEPROM_SETTINGS // Enable for M500 and M501 commands
```
)


q:
I'm 3D printing almost 2 years, and I expected to have better result after changing to complete smooth rods with new bearings.

I have a problem with my Z axis giving me inconsistent prints; I already replaced the leadscrews, E3D clone with Bowden tube, I decided to replace all smooth rods on all axis and also the bearings. After I replaced all this, my prints are still bad, also I'm very dissapointed with the results after the replacements. I have checked all I could think of; PID tuning, belts, ....) but I'm running out of ideas.

Printing settings:

print speed is 40mm/s,

retraction is 3mm at 30mm/s,

extruder 205°C for the first layer, then 200°C

[A]
From the pictures can be seen that you have good lead screws as there is no cyclic anomaly/wobble present at the side. It appears as though the lines at the sides of the print are more or less random X/Y positional inaccurate.
These lines can be caused by various reasons. From what is read you tried to improve the mechanical system by upgrading the hardware. It could still be the case that there is still some backlash or play left in the system (e.g. I had once had too much tolerance on the holes of the linear shafts in the printed X-Z mounts causing similar problems). Vibration should be looked into also, e.g. do you have a binding bearing or a large mass on the printer that interacts with the carriage movement like a spool holder on top of your frame. Or maybe the micro-stepping does not work optimally, so check the stepper driver currents.
If it is no mechanical issue, it could be that you are facing inconsistent extrusion caused by variation in filament thickness or gear slipping or too much tension on the filament by friction in unspooling. Or else a hotend temperature variation. Maybe insulation on the hotend helps.


q: 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?

[A]
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."


q:
After building a Delta printer, I noticed that my whole prints are slightly tilted around the Z-axis in comparison to the slicer (e.g. Cura). There is no twist layer wise. This means, the prints themself look actually perfect.

I just don't know what could be the reason of the rotation. I do not believe it is a build issue of the printer, because I tried to keep the printer frame pretty stiff and symmetric.
Could it be, that the Auto-Calibrate Feature of Marlin can add such a rotation?

The picture below illustrates the problem. I expect the black alignment of the print and get the orange one. Note that the print is still a rectangle with ~90° corners.

[A]
If I am reading this correctly, your prints are being either stretched or your prints are shifting / leaning on more complicated prints.
In this case, given that you are on a Delta printer, my answer is the same for all. I usually do Cartesian based 3d printing but the concept is the same for any drifting or leaning. You simply need to recalibrate your steps per MM for each motor, and tighten your belts. You will have the complication of the interaction of the 3 arms, that others will be able to answer better. But in the end, if each arm moves as it should, the belts are not slipping, and you do not have issues with moving too fast (jerking can cause the belt to shift, and a loose belt can cause whiplash / and other print artifacts). My bet is your steps per MM is off on one of the motors, or you could have an overheating issue (not likely).
There are many
guides
to help with Delta specific calibration.
I can provide a better answer with photos. See
Stackoverflows guide on asking questions
.
Edit with the diagram (not a photo), you issue might be caused by stepper over voltage and you will need to adjust your pololus. If you hear a repeating Thud noise, you have your voltage too high.


q: I am modifying some Slic3r config parameters and comparing the results.  How can I have two instances (or equivalent: I would like to see two model windows with their associated configuration screens) of Slic3r at the same time?  I'm on OS X, but if there is a generic (e.g. within Slic3r) solution that will be preferrable.

[A]
From a terminal window, run the command
```
```
open -n -a slic3r
```
```
Each time the command is executed, a new instance of Slic3r is created.
As per Carl's note, keep in mind that both instances of Slic3r will be sharing the same configuration files, so it will be safest not to save configuration changes while both are open.


q:
I'm new to 3D printing and I recently got my first 3D printer, an Ender 3 Pro by Creality.

I've tried to find information about the type of nozzles should I look for. I'm trying to find stainless steel nozzles but there are so many models (M7, M8, etc.) and I have no idea what nozzle type I should get.

I've tried searching on Google but the only info I could find is that the extruder is an MK-10.

I am also looking for a heating cartridge for the hot end, but I still cannot find no information about the size that I need (15 mm/20 mm/30 mm). Also looked for info about the heated bed so I know what kind of thermistor I need (I found two types and no clue which one to get).

Where can I find some technical information about these?

[A]
There is no such thing as a single MK10 hotend design. The Chinese aftermarket has mingled the designations.
If it has a
MK10 like Makerbot
hotend, then the nozzles you are looking for are M7 threads. It appears (see
this answer
) that your hotend is a cloned MK10 and has different dimensions, you have the M6 version.
Quote from link above: (this is about the Makerbot MK10)
MK10 was a complete change of the hotend. MK10 uses smooth OD thermal
  barriers with a larger 4mm OD 2mm ID PTFE liner. MK10 also uses M7
  threads, vs the M6 of all previous models. This is because a 4mm PTFE
  liner is barely enough metal to make the outer tube with m6 threads.
  MK10 is completely incompatible with all previous hotend parts. Every
  part is different. Mk10 still uses MK9 feeder parts.
You could measure your current heat block (the width of the Aluminium block); if you look at the MK10 drawings  of a proper M7 MK10 Makerbot (or derivative) hotend (below) you see that the width of the block is about 19 mm (which would be the length of the heater cartridge).
The CEO of ToyBuilder labs explains the difference between an "MK10" and an MK8 in
this video
:
As can be seen, your nozzle clearly is not an MK10.


q:
I started using rafts more often, to get better results with complex or fragile parts, but my Ender 3 consistently under-extrudes the initial outside line of the raft (for the first inch or two, where extrusion starts).

It is often very thin and does not adhere. This often leads to problems with the following pattern of raft layer 1 curling up (ABS) as it does not meet the edge line (due to the 1-2 inch gap in the perimeter).

Skirts avoid this problem by getting the flow going, but rafts only print a single outer line.

Is it possible to specify more than one outer line on a raft in Ultimaker Cura?

Is it possible to add a skirt to a print that has a raft (or at least some initial printing to get the flow going)?

Is it possible to add some initial G-code that will extrude a line, say from near the start position to the start of the print?

[A]
It's not necessarily the case that the apparent underextrusion of a small portion of your raft is the root cause.  ABS is notorious for shrinkage and peeling.  As a start, you should have a full enclosure so as to maintain a warm environment while printing.
It's also quite possible that your bed is slightly off-level or a few microns low for the first layer, either of which can cause adhesion problems.
Yes, it's pretty much trivial to add a few lines of gcode to extrude prior to the "official" raft -- or you could just toss a fake small object into your slicer to extend the raft over both the real and the fake parts.
FWIW, with a little care I've found a wide brim outperforms a raft for almost anything I print


q:
I'm getting some slight pooling on the end of straight lines on my Ender-3

Is this due to over extruding? Or some other issue?


q: What are the most common 3D printing file formats, and which one is more effective or used more than others?

[A]
STL
is the standard for pretty much everything out there.
EDIT: This is for models to be sliced and printed. Gcode is what would actually be executed, after slicing, to create the print.


q:
I want to print a piece of fruit modeled in Blender. It is an STL file.
Please note that I am an absolute beginner at 3D printing models.

What do these red zones mean? What is wrong about the mesh in each case?

The fruit has some low-poly seeds. These used to be a particle system but I then changed them into individual objects.

This view shows the base of the fruit, why is it colored red?

[A]
3D printers cannot print in the air without a prior layer or a support structure supporting the new printed layer. For the picture showing the bottom of the fruit, the red area is the calculated area that requires support for printing, so please enable that in the slicer application.
For the top picture please post a detail or a zoomed in part. It is currently difficult to see what is the matter. It looks as though the STL model is incorrect and Ultimaker Cura thinks that the seeds are upside down, hence the red coloring also. This means that you need to fix the normals of the faces in the STL model. Please look into
this answer
and
this answer
for some hints.


q:
Is it a good idea or do I need to calibrate my E steps after I switch to a new filament due to the different types I use (to make my prints accurate)?

E.g. calibrate when switching from PLA to ABS/PETG?

[A]
No that will not be necessary.
However, you could use calipers to measure the diameter of the filaments (e.g. at 5 positions over a few meters) and calculate the mean diameter, if there is a significant difference between the new and the currently used filament you could change the diameter in the slicer (or the flow modifier), you do not need to calibrate the steps per millimeter every time you change filament.
You only need to calibrate the steps per millimeter if you change something in the extruder hardware setup, e.g. different extruder, different stepper driver, a new gear, etc. As long as the hardware is not changed a calibrated extruder setup will move a certain amount of filament regardless of the diameter variation (per rotation of the extruder gear an amount of
$2 \times \pi \times (gear\ radius)$
mm of filament.


q:
Given the Marlin Firmware what is the difference between the following lines of code:

G4 S20

and

G4 P2000

[A]
The code
```
G4
```
refers to
dwell
. (From what I'm seeing, it can be written as either
```
G4
```
or
```
G04
```
).
```
P
```
is the length of dwell time, usually in milliseconds. The parameter
```
S
```
seems to be invalid, because the only inputs are
```
X
```
(seconds),
```
P
```
(milliseconds), or
```
U
```
(undefined). If you have
```
S20
```
in your code, it is invalid, whereas
```
P2000
```
will cause all axes to remain unmoving for 2 seconds before moving on.
(Note: Not all machines will accept
```
X
```
or
```
U
```
.)
EDIT:
This answer is specific to
non-specific
g-code, taken from this
Source
, since the OP did not state any specifics about their firmware type or equipment used.


q:
Given a Marlin firmware and a line of G-code such as the following:

G1 F100 X50 Y50 Z0 E-10

What defines the speed at which the stepper motor associated with the E-value is retracting? It is my understanding that the Feed Rate defines the speed of the movement (in this case 100mm/m) but I am not clear how I could accelerate a retraction?

The reason I am asking is that I am not seeing a swift removal of material as i retract. Could the slow feed rate be the issue? I am using a pellet printer (WASP 3MT) and generating G-code from polylines on Silkworm.

[A]
You instruct the printer to move from a certain X-Y position instructed by the previous move, to X=50 and Y=50. While moving at a feedrate of 100 mm/min, it will also retract 10 mm of filament (if the previous extruder distance was 0) during that move. If the movement distance is large, the retraction is slow. If you started from X,Y = 49.99,49.99 it would be very fast.
If you want a fast retraction, first move to a position, and than retract fast, so in separate commands. Do note that we usually do it the other way around: first retract fast and then move, this way there is less oozing of the nozzle.
To sum up, in your G-code command, the speed of retraction depends on the path of travel (the length and speed defined by the feed rate
```
F
```
). If it is fast retraction you are after, you should split the command into two separate commands.


q:
I'm looking for the specific density of the GEL-LAY and LAYWOO 3D materials by manufacturer CC Products.

It isn't noted on their website or on the spool or the box the spools came in. I've looked for hours on Google and various websites, from resellers to people who tested it, without being able to find it.

[A]
I can't provide the end answer, but if you already have the material, you should be able to measure this yourself quite simply.
Measure and cut a sample of filament, and weigh it. For example, a 10 meter length with a 1.75 mm diameter will have a volume of:
v = pi * r
2
* l
v = pi * (0.175 cm/2)
2
* 1000 cm
v = 24.05 cm
3
Density is mass divided by volume. If your sample weighs 18 g, this would be
d = m / v
d = 18.0 g / 24.05 cm
3
d = 0.748 g/cm
3
Note that the accuracy of this measurement will depend on the accuracy and precision of your measurements. A household kitchen scale might not be good enough for such small weights. In order to get a good weight measurement, you may need to use a much longer (and heavier) sample of filament.


q: Is there a difference between 3D printing and additive manufacturing if any then explain?

[A]
Origin
3D printing and additive manufacturing (AM) both refer to a
range of processes
where, opposed to subtractive manufacturing methodologies, materials are joined to create products. E.g.
FFF
,
SLS
, etc.
From
this reference
you see a reference to 3D printing:
Additive manufacturing is the official industry standard term (ASTM
F2792) for all applications of the technology. It is defined as the
process of joining materials to make objects from 3D model data,
usually layer upon layer, as opposed to subtractive manufacturing
methodologies.
From e.g.
this reference
one reads that there is no difference:
Between the terms 3D printing and additive manufacturing, there is no
difference. 3D printing and additive manufacturing are synonyms for
the same process.
Useage now
However, as the AM processes and applications grew in time, 3D printing has become a subset of AM. As worded by
Peter Zelinski
in August 2017:
To be sure, the terms overlap. They can be used in ways that make them
sound like synonyms. But the relationship between them and the
difference between them is this:
3D printing is the operation at the
heart of additive manufacturing
, just as “turning” or “molding” might
be the operation at the heart of a conventional manufacturing process.
In short,
additive manufacturing requires and includes 3D printing,
but it also entails more than 3D printing, and it refers to something
more rigorous
.


q:
I have a new Prusa i3 MK3 and I have noticed that my prints consistently turn out worse on 0.05 mm layer heights than on 0.10 mm. The edges of the 0.05 mm prints turn out rough and sometimes stringy.

Seems similar to a retraction problem but I never have this issue on 0.10 mm prints with the same retraction settings.

What might be causing this issue?

[A]
When printing at small layer heights (high resolution), you probably need to do some test prints first to see if your normal settings work for the lower layer height. You are most probably experiencing an increased pressure build-up in the nozzle due to the nozzle being closer to the bed. A test that might be useful for you is spacing several objects at different distances to see if the retraction, which you already suspect, may be not working optimally or that the nozzle leaks/oozes an excess amount of filament due to pressure build-up. This shows an example of such a test where the nozzle shows oozing.
Tuning the extruder to alleviate the pressure could be:
an increased retraction length, and/or
retraction speed, or
looking into the option called coasting where you stop extruding before the printer reaches the end of the deposition path while it still prints material caused by the pressure build-up.
When printing at 0.05 mm on my home-build CoreXY I experience much smoother prints opposed to printing in higher layer heights (less resolution), but I also get some very fine stringing, noticeable when printing multiple objects or objects with voids.


q:
I have a WiFi module that only needs two wires connection to work. These are RX and TX pins connected to Arduino or the CR-10S printer board but I don't know if there is any physical or software UARTs TX and RX pins. My goal is to add a Wifi support to the CR-10S printer. Since this is not Arduino and the pins are not labeled, it's hard to tell which TX and RX pins are not being used.

In the image of my motherboard below, any port or pin with line pointing to is considered as being used by the printing software so I can't used them.

There are still ports or pins that are not used. Can any one tell if there is a  TX and RX pin that is not being used from the image above? I need them to communicate with the printer wirelessly.

[A]
You are looking for a capacitor that must be connected to Pin 4 of the LM2596.
Maybe you could provide a better picture of that area so we could see the different tracks on the board.
The LM2596 is in the center of the right side of the board (it is also labeled  with LM2596D). The pins should be counted from top to bottom (in your picture)
My guess is, the Elko you are looking for is connected to C31, and you must look for the positive pin.
In this wiring diagram Cout is the capacitor you are looking for. The SMD Parts R1, R2 and CFF should be R31, R32 and C31 in your picture.
With the corresponging measurements I would say you do not need to replace the capacitors.
In comparison to the old board your board already has the "fix" implemented.


q:
I am currently encountering a problem where under certain circumstances, the extruder stutters when it starts a new layer. I am printing on an Anycubic i3 Mega and am slicing with Cura 3.6.0. The problem seems to occur in the main part of prints, as well as in supports. However it seems to only occur after a retraction has taken place. I have taken a video of the stuttering which can be found here: https://photos.app.goo.gl/G3TLKveMsLNRQmgv7
When a print is done the stuttering results in walls looking like this:

Can anyone help me figure out what is causing the stuttering?
Thank you very much!

[A]
You retraction settings may be too high. Direct drive extruders require less retraction than Bowden style extruders. Typical retraction settings for direct drive are 1.5mm at 50mm/s and for Bowden, 4mm at 50mm/s. The speed usually makes more of a difference than distance beyond a certain point.
You can get away with smaller retraction settings if you increase travel speed because there will be less time to ooze. You could also try using Coasting as well.
Anyway, try reducing your retraction settings if they're higher than what I stated above. Another alternative is to set an extra prime distance so that extra filament is extruded after the retraction.


q:
I have designed a bread mark and printed it on the Prusa i3 MK3.

I wanted it to have as sharp edges as possible, so I used a triangle:

However, it seems that the print cut off layers that are too thin (x-y-wise) and instead of a 1 cm high bread mark, I only have 0.5 cm.

What is the X-Y-resolution of the Prusa i3 MK3? In Slic3r, can I make sure that any wall is made as thick as needed for it to be printed?

I have the default 0.4 mm nozzle.

[A]
This is dependent on the slicer and the nozzle diameter. Typically, you cannot print a wall smaller than twice the nozzle diameter because walls need an inner and outer line. Therefore, your slicer will make some cutoff and won't print walls below a certain threshold, in order to try to faithfully replicate your model.
Slic3r, I believe, will automatically go down to single line walls, but if you turn on "Detect thin walls" in Slic3r's Print Settings, more of the thin walls will be printed. Slic3r will actually reduce the plastic extruded to attempt to make even thinner walls, but there's still a limit.
With a 0.4 mm nozzle, you should design walls no smaller than 0.8 mm, or 0.4 mm at the very smallest.


q:
I have a small problem where plastic comes out of the nozzle while the printer is at a standstill (normally towards the end of heating the nozzle for a print), and whilst it moves from the line for clearing the nozzle on the left of the bed (Cura) before the actual print starts. This causes a slight problem where the first few millimetres of the printed line curls upwards when the nozzle comes back around again it goes over it but it causes a slight bump that makes a very small (but noticeable) skip or bump in the print on the bottom layer.

I am using the Ender 3 running Marling 1.1.9 with a Bltouch and a glass bed, I didn't seem to have this problem before I upgraded to the glass bed and Marlin for the Bltouch.

Any help will be greatly appreciated.

[A]
This effect is called oozing. At the end of heating up the hot end, left filament becomes so liquid that it oozes out of the nozzle. This left filament could be a left over from the previous print where an insufficient retract prior to the last print finish causes this (you could retract the filament a little further in your "end G-code" script, first reset the E to zero
```
G92 E0
```
and then retract
```
G1 E-3 F1500
```
, be sure that the priming length in your "start G-code" takes care of this distance).


q: I was noticing on a print I had just done that the quality was not up to typical snuff. I had just started using a roll of PLA filament that I had been keeping on a shelf without a wrapper for a couple months. How long can you store filament before it gets too hydrated from the air to print? I expected more than a couple months but perhaps I am wrong?

[A]
In
theory
, most filaments don't go bad within a year. However, praxis shows, that averse conditions can impact the filaments over time and age them to unusability.
Among the damaging factors is heat, but most filaments also are hygroscopic and absorb water to some small degree, or even heavily like Nylon.
As a result, it always a good idea to at least try to store filament dry. To enforce this, some use racks in a well-heated room, others are blessed with very dry weather overall. And on some locations, like the coast, you might even be forced to use dryboxes for each and every filament to try to slow the degradation of steady hot humid air leaching out the additions from the filament.
Dryboxes can keep the filament reasonably isolated from the surrounding air and so prevent moisture interacting with them to some degree. It is also a good idea to store them out of direct sunlight, as UV light might destroy color and/or the plastic. More information on why to use them is for example at
this question
A couple construction videos using an IKEA box and a bit of foam were offered by
Tom (Thomas Sanladerer)
and
CNC Kitchen (Stefan Hermann)
in 2017.
But fear not: most filaments - PLA included - can be freshened up again if the damage is not to prolonged! Baking them at a low temperature or storing them in a dehumidifier has worked in some climates. For PLA, keep the temperature at below 80°C. A couple of hours should get some the moisture that has seeped in out again. The Quality might not get back to that of fresh filament in all cases, but you might at least regain reasonable to good printability.
Also note, that different filaments are differently affected.
ABS for example is a little less hygroscopic than PLA, while HIPS is one of the least hygroscopic filaments available.


q:
I bought a few new nozzles expecting them to come with that little tube that comes out of the nozzle. They didn't come with them after all, so I tried to reuse the tube I originally had in the printer. Turns out my old tube is 4mm OD and 2mm ID, but the new nozzles have 2mm holes for the tube to go in. I use 1.75mm filament, so it seems like to be able to fit the filament through the tube would be impossible barring a tube with an 0.125mm wall.

My question is, can I put the tube outside of the nozzle? That is, not stuck in the hole for the nozzle. In theory, the tube would still direct the filament into the right place. It looks like that might be the point of these new nozzles, since it seems so unlikely that someone would be able to stick a filament tube in the nozzle.

If not, where can I find the tubes I need? I've looked in a few different places and I can't find it. Or are the nozzles useless, and should I return them? Thanks for the help.

[A]
Let me clean up a little nomenclature
The PTFE tube is either a Bowden Style Setup delivering the filament from the extruder down through the cool-end and to the heatbreak or just a liner in the cool-end and heatbreak for direct drive. In both cases they are to prevent clogs. In most setups it is
not
pushed into the nozzle which is in the heater block (they exist, see below).
The liner/Bowden tube guides the filament through the heatsink and into the proper Hotend/Meltzone. In the better designs intended for higher temperature like ABS (see left half), it ends in the heatbreak. This also has the added benefit of having less chance to leak if the tube slips a little bit.
Simple setups (see right half) butt it against the nozzle and thus limit the temperature range. This kind of butted setup can lead to leakage if the tube slips up. In either case, it is no problem to reuse the PTFE tube when changing nozzles, it is even advisable in the case of a Bowden setup as it might change the length of the path.
The nozzle is usually screwed into the heater block from below, and for best use, one screws it against the heatbreak in a heated state - this is called hot-tightening.
If you somehow end up destroying your PTFE Tube, you can get them under the keyword PTFE tube, Bowden tube or Pneumatic PTFE tube on the internet.
PTFE inside the nozzle?
Yes, these exist, OP has them, they look like this, and are not what has become the industry standard.
I can think of no good reason to put an PTFE Sleeve
into
the nozzle, but someone did it, and it sis a valid approach. However, I see several problems with it:
the PTFE tube degrades if pushed deep into the melt zone and can lead to clogs.
the added PTFE is not a very good at transmitting heat, thus reducing the effectiveness of the melt zone. This can lead to needing either much lower printing speeds or a much higher printing temperature to achieve good prints
It should be of no issue to convert from this style into the butted-style (right) just by using a short length of PTFE in the heatbreak. I would prefer though to combine it with a heatbreak where the PTFE ends and making this what is commonly referred to as an "all metal hotend" (left).


q:
I want to extend all my CR-10S wires. I have two long wire types: 22 and 18 AWG wires. I've done some research and found the following:

Extruder heating element:  22 AWG or lower.

Extruder thermistor sensor:  22 AWG or lower (Doesn't really need much amp).

Fans:  24 AWG or lower (Doesn't really need much amp).

Limit switch/filament sensor: 24 AWG or lower (Doesn't really need
much amp).

Here is where I've problems determining which wire gauge to use:

Stepper motor wires: ?

Bed heater wires: ?

What's the wire gauge needed for the stepper motor and bed heater wires? Obviously, the bed heater needs more amp so I expect lower wire gauge. Is my 18 gauge wire enough for this?

On the Reprap site, it says that 18 AWG or lower is fine for the heating bed.


q:
Here is the sequence of my Gcode, printed in mid-air:

Print (E20)
Retract (E-20)
Dwell (G4 10,000)
Move away (E0)
Print (E20)

See the path on the printscreen below:

When the printer dwells it oozes. How can i stop that?

I am using a WASP 3MT, pellet extrustion, 3mm nozzle, Marlin firmware, Gcode done on Silkworm for Grasshopper.

Gcode around the dwell:

G1 F300 X-25 Y-25 Z30 E15.96
G92 E0
G1  F0 X-25 Y-25 Z30
G1 F1000 X-25 Y-25 Z36 E-89.42
G92 E0
G4 P10000
G1  F0 X-25 Y-25 Z36
G1 F1000 X-25 Y-25 Z32 E0
G92 E0

[A]
Since you retracted the filament (very far), but stay at elevated temperature for almost 2 minutes, this must be left-over residue inside the nozzle/throat that is stuck to the wall that becomes liquid and oozes out of the nozzle because gravity pulls it downwards.
This answer
on the question
"Ender 3 extrudes plastic whilst at standstill, and while moving to start of print"
explains the oozing problem in detail.


q:
So I just got a Da-Vinci 3-in-1 Junior Pro 3D Printer, and was excited to start printing my first model.

When I open my .STL File in the XYZWare that comes with the printer, and click print, it says that the cartridge inserted into my printer in not genuine, and that it won't print until I order a genuine cartridge. What is interesting is that the cartridge loaded into this printer came with the printer itself, so it is genuine.

Is there something I am doing wrong? Here is a picture of the cartridge in my printer -->

A Google search about this issue doesn't come up with any results that are of any use to me.

[A]
A
quick search on the internet
showed that your experiences are shared by others.
Apparently, it has something to do with a faulty chip or the software.
From
this thread
:
I had the same thing, the cop on the underside of the cartridge wasn’t
programmed properly, if you have the latest firmware update and it
still doesn’t work contact the seller and they should send you a
replacement chip
I had this happen 2x. It ended up being that I had xyzware open.
Xyzware needs to restart in order to detect the new serial number of
the filament.
You could ask for support from your supplier or restart the XYZ software.
You could also
hack
the NFC chip that is inside the spool. (
DISCLAIMER
:
Do it at your own risk
!)


q:
I thought as a fun project to make my own 3D printer out of a normal printer parts + some parts out of old CD-ROM drives that are lying around. The printer of my choice is an HP PSC 1315 one.

But I have these questions:

Does this printer users stepper motors or is using a combination of DC ones and some sort of position sensor?

What kind of electronics and firmware I can use for this type of builds?

[A]
No, Printers are not good sources
Common printers contain at best one stepper motor
in the scanner
, and it is usually too weak for use as an X or Y stepper, but for a very slow printer they might be useable, especially if you could source 2 or 4 of the same type.
The main motors in the printer are almost universally DC motors that get their turning signal as a voltage from the main board, which again uses positional information from an encoder strip/disk. Using both of these to make a 3D printer is usually not feasible.
However, they usually have good rails (sadly often of non-standard diameter) and might be salvaged for a decent optical sensor. See also
Thomas Sanladerer's video
about this.


q:
I've recently purchased an Ender 3 and have had great success with some Cura settings found on a YouTube Tutorial at 0.2 mm resolution.

So then I noticed that there were default settings in Cura for the Ender 3. Except printing at 0.2 mm it selects a 20 % infill, and when choosing 0.1 mm it changed the infill to 10 %.

I changed infill to 20 % and attempted to print this but there were gaps in the bottom layer and it won't stick to the bed. Is there anything else I need to change in the process?

The shape is essentially a cube with a circular hole in the middle, sliced in half.

[A]
Basically you have 2 issues, first, an adhesion in combination with layer thickness problem, second, an infill problem.
Starting with the infill issue, when you lower the layer height, without increasing the amount of layers for the "Top/Bottom Thickness", you get a very thin shell (unless the top bottom thickness is expressed in mm). A lower layer height should, because of the lesser amount of filament being extruded over the infill, should be accompanied with a higher infill value, but that is necessary for the top layers, your issue is with the bottom layer and adhesion. As said, a lower layer height also implies lower filament flow, for the first layer this lower flow causes an inconsistent flow to adhere the filament to the bed (probably caused by the gap between the nozzle and bed from leveling with a piece of paper). Most slicers will add some extra features to increase the change to get the filament to stick to the bed; one of those is an increased first layer height (e.g. in Ultimaker Cura, the first default layer height for Ultimaker 3 printers is laarger than the rest of the layers), others include modifying the flow by e.g. over-extruding for the first layer.
You could try to increase your first layer height to the value you create successful prints with, specify the thickness of the bottom and top (or increase the amount of layers for printing these) and increase the infill percentage.


q:
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

[A]
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
.


q:
I am trying to print my first test but my Creality Ender 3 starts printing near the front edge and within 10 seconds is printing in front of the tray (off onto my table).  I really think it should be starting the print in the middle and then never going so close to the edge and even over it

What can I do?

[A]
When a print is not printing on the build platform, you either:
Have the incorrect settings in the slicer (e.g. Ultimaker Cura,
a common mistake is that the "origin at center" option is active
), or
Have the center of the bed incorrectly stored in your firmware. (See:
How to center my prints on the build platform? (Re-calibrate homing offset)
or
Recalibrating Home-position
).
Note that the most simple change (after you verified the slicer settings and confirmed that it still does not print in the center) is adjusting the settings in the slicer (bed settings, of start G-code script), this way you do not need to compile and upload new firmware (e.g. if you are uncomfortable or inexperienced in doing so), but, fixing it in the firmware is the best solution. Why? If you change the offset in the slicer you force the bed dimensions to a new position that
you know
where it is, while if changed in the firmware, the printer "
knows
" the actual size and the limits.
To fully answer your question, we need a little more information what slicer you use and what the current settings are. From your question it sounds as if the offset is more than a few millimeters. Usually this hints to an incorrect slicer setting (frequently Ultimaker Cura).


q:
I keep hearing about vase mode, but I have some problem figuring out how to set it up in my slicer; I use Cura slicer.

So, I'd like to get some settings to do it in Ultimaker Cura, using PLA if the material is important, plus any advice on how to properly do it and ensure that the print retains it's shape on print.

[A]
Vase Mode changed the name in some version before 3.5. Now you can achieve this with 2 modes: "Surface Mode" and "Spiralize Outer Contour". To turn it on do this:
Choose the Custom setting menu on the right
click a gear to set up what settings you want to see
Under the header "Special Modes" you find both Surface Mode and Spiralize Outer Contour
set the checkmarks on both
Turning on the Surface mode to
```
Surface
```
and checking
```
Spiralize Outer Contour
```
gets the "classic" Vase Mode.
Turning on
```
Surface
```
without
```
Spiralize Outer Contour
```
gets an infill-less outer perimeter
Now, the
classic
Vase mode will only print the
single most outer perimeter
of a print, so your model will have to be very limited with angles and contain no bridges - with one perimeter, you will only be able to print at best 45° angles!


q:
We're printing on a WASP 3MT pellet extruder with PLA. To save time, we're leaving the hotend at 160 °C between prints but realized that the print quality varies, from one print to the another, when using the same G-code file.

Could it be that leaving the temperature at 160 °C constantly creates more fluid PLA and therefore affects the following print?

[A]
PLA starts to change its properties at above its glass transition temperature of 60-65 °C, if stored there too long. Keeping it at 160°C, close to the melting temperature (173-178 °C) can degrade the material relatively rapidly. During an extrusion, this is usually mitigated by filling fresh material into the melt while the older material gets extruded, but keeping the machine stagnant at the high temperature has not only creep the heat up from the designated melt zone (thus preheating material that should not be preheated yet) but also can damage the material deep in the melt zone. Together with this possible material degradation, the preheated material melts faster and might overshoot the aimed at print temperature until the normal temperature is reached again. Both effects can lead to reduced print quality in the lower layers.
The time saving from keeping the filament heated up for an extended period of time is,
in my opinion
, not worth the quality reduction that can come from using non-uniform material. You pay
more
in lost prints than you save in time for heating up the head.
If it is impossible to not keep the hotend heated between prints, it might be advisable try these:
Starting every print with a larger purging operation might get rid of degraded material. It would be as simple as extruding some quantity of material before starting the actual print at the edge of the build plate.
Aside from purging, it might be a good idea to reduce the hold temperature from 160 °C to a lower temperature, allowing the melt to partly solidify and keep the heat creep in check.


q:
Is a home 3D printer capable of printing a good bicycle air pump?

I've searched the Internet and there is very limited info on it. Things need to be rigid and very minutious in the valve part of the pump. I could give an example of what I thought in the image

[A]
depends
You certainly can print
parts
of
a
bicycle pump, for example, the outer case and maybe the inner piston, maybe even the housing for the connection valves.
However, you cant print the buffer spring or the valves itself. You will have trouble printing the adapters. And you will have to print in ABS to smooth the inside of your pump with acetone vapor, so you have a smooth surface that forms an air seal under operation.
It would be cheaper and more durable to just print just the fittings and use a PVC Pipe as the cylinder itself.
As in all things, if this is a
good
pump depends a lot on design and your machine.


q:
I've just printed my very first part and it did not want to come loose from the build plate, it fact, it just broke instead.

I can heat the bed up again and work it off, but I wondered if a release agent would be better?

I have a silicon release spray (like those use with molds).  Could I spray the base with that before starting printing?

[A]
PLA should not be printed at 235 °C. If your printer requires such high temperatures to make the filament very fluid, you have too much friction in your system, e.g. this can be caused by clogs or too low layer height printing the first few layers. Note that such high temperatures are also a cause for obstructions as the filament can carbonise creating clogs. On the other side, too low temperatures also cause too much friction or resistance.
The sound you are hearing is often referred to as "clicking" and can be caused by steps being missed or the extruder hobbed gear to skip back as a result of the friction/resistance.
Now that clicking is introduced, please look into
this answer
and
this answer
to answer your problem.


q:
While printing a simple model, my printer starts to layer-shift the build in a direction suddenly. I used the default setting for ultimaker Cura 3.4.1. It has done this same thing for multiple different prints. I would guess it is the software.

How do I fix the issue?

[A]
You have a case of layer shift. Layer shifts happened to me in 3 ways:
The movement of the axis is hindered. Check if all cables run freely and without any chance to catch! improper cable chains can cause binding and stop the printhead or bed in movement and thus induce a shift.
The acceleration might be too fast. Shift the acceleration of the printer movements down a notch. Don't print faster than ~60 to keep the acceleration in check, as the printer will try to reach the top speed as fast as possible, thus limiting top speed also limits acceleration.
The model might be broken. Re-slice the model
just in case
.


q:
Some prints take a long time and, as I'm not in a workshop, I need to pause the print sometimes.

Are there any special considerations I should take when pausing, or can I literally just click pause, leave it for twelve hours or so, and it'll continue without any ill effects?

I'm using PLA at present.

[A]
If you keep the head hot during the pause, and over the print, you will melt the material already deposited.
If you move to X0 Y0 (like on a layer change) and pause there, you can cool off the head (or not), but will want to prime (advance) some material before resuming your print - or risk an initial void, as the heated material will expand and drip to some extent.
If you move to X0 Y0, retract, and cool off for your pause, you should be able to heat up, advance, and resume with few issues. You will probably still need to some manual cleaning where the resume was, as there is likely to be some buildup.
Also, if you let the bed cool during your pause, your print may become unstuck from the bed.


q:
Why is it that if I execute a gcode command that causes the stepper motor to turn in reverse (any negative move on the X axis), after the step it will emit a high pitched whine until it gets another command to rotate in its forward direction?

Executing multiple reverse commands will cause the tone to vary in frequency each step, and always it goes away after another step in the opposite (forward) direction.

Sometimes.

And other times it does it in both directions, but only on every other step. One step +X its there, next step its gone, next step its back, and so on...

Then they also make a different noise when idle, before I disable them with the "disable steppers" command.

What are these noises?

And is it bad to leave the motors in this state? Will it burn them out?

[A] this is normalISH for stepper motors. they have a fair ammount of current pulsing through them at relatively high frequencies, coils and other parts that will vibrate. if it quite loud you can look into the boards that drive them, depending on your printer they are replaceable, and better 'drivers' send cleaner signals that make less noise. however: if your motors get hot or start making clicking noises, or stop randomly, or acting up more significantly, you should look adjusting how much current they are getting. search for stepper motor calibration, basically you need to adjust the ammount of current the motors are getting, but if the machine prints normally, then this is not something you want to play with. you can also probably find the data sheet for your motor, they are usually rated to operate up to about 50C


q:
The first layer is very patchy indeed.  I've calibrated the build plate pretty accurately but even if it was a badly calibrated build plate I don't think it would have this effect.

It doesn't seem to have a negative effect on the print.

Should I be concerned about this?

Is this due to a the build plate fault?

[A]
First things first:
Don't Panic
Your heated bed is made from metal with some sort of Build-Tak-Clone surface. It is not broken from what I can see. Your print is
not failed
, however, the quality does suffer a little bit.
Your bed does warp a little under heating. That is perfectly
normal
, and you should actually calibrate your layer thickness against a hot heatbed, not a cold one as metal that is heatbed extends - especially over the heating elements. The main heating element is usually in the center, so it "bulges" a little there, and if the heat has not equalized everywhere, it can show a dimple around it. So it warps slightly. The extent of the warping is determined by a couple factors, but from what your print looks like, it is not in a worrisome amount - the second and third layers will even it out.
I can't tell how much time passed between reaching the print temperature of the bed and the start of the print, but you might want to make sure  the heating behavior heats the bed
first
and the hotend
second
, allowing the heat energy in the bed to spread more evenly. A tiny
```
G4 P20000 ; wait 20 seconds
```
(see here)
` in the pre-print code, before
cleaning & priming
the nozzle might also help.
You can try to get more even first layers by positioning the parts in areas that do not suffer from warping.
As
Tom
mentioned, you might get better base layers if you increase the first layer thickness. I usually print with about 0.15 to 0.2 mm for the first layer,
regardless
of the following layer thickness to even out small miscalibrations and unevenness in the heating.


q:
I have a 3D printer at home, the Colido Compact, and for some reason when I 3D print big flat surfaces a really weird thing happens. I'm using some PLA from Colido too I think

It almost seems as if the bottom layer does perfectly but when it starts printing out the top surface this happens, because the one on the bottom left is in two parts because the upper part is the bottom one and that one is perfectly flat, then I took them apart and the weird thing just stayed with the top part... and also on the weird warps there are bits of brown goo or something? I don't know it looks as if the filament was burned...
It only appears on pretty big surfaces because smaller ones don't seem to have the problem.

Anyone knows what is happening?

[A]
The oozing is due to hot-end getting hot before the bed leveling procedure: if you move the hot-end warm up command
after
the
```
G29
```
line you avoid that oozing
```
```
; Ender 3 Custom Start G-code
M104 S{material_print_temperature_layer_0} ; Set Extruder temperature
M140 S{material_bed_temperature_layer_0} ; Set Heat Bed temperature
G28 ; Home all axes
G29 ; BLTOUCH Mesh Generation
M190 S{material_bed_temperature_layer_0} ; Wait for Heat Bed temperature
M109 S{material_print_temperature_layer_0} ; Wait for Extruder temperature
G1 F1800 E-3 ; Retract filament 3 mm to prevent oozing
G92 E0 ; Reset Extruder
G1 Z5.0 F3000 ; Move Z Axis up little to prevent scratching of Heat Bed
G1 X0.1 Y20 Z0.3 F5000.0 ; Move to start position
G1 X0.1 Y200.0 Z0.3 F1500.0 E15 ; Draw the first line
G1 X0.4 Y200.0 Z0.3 F5000.0 ; Move to side a little
G1 X0.4 Y20 Z0.3 F1500.0 E30 ; Draw the second line
G92 E0 ; Reset Extruder
G1 Z5.0 F3000 ; Move Z Axis up little to prevent scratching of Heat Bed
```
```
The above code will activate the heating elements but starts homing and leveling procedure without waiting for the elements to get up to temperature. Only after the bed leveling is finished the printer will pause and wait for the heating elements reach the desired temperature.
This will prevent oozing on a cold start, but you will still be affected if you start a print right after another print, when the hot-end is still close to  melting temperature.
If you prefer to avoid that condition you might want to also move the
```
M104
```
and
```
M140
```
commands after the
```
G29
```
bed leveling command.


q:
I printed out this calibration shape from Thingiverse with an unexpectedly catastrophic failure.  It looks like there are a lot of things wrong here.

I used the Normal profile in Ultimaker Cura.

There's so much bad in this print that I'm not sure where to start.

It appears that walls weren't printed at all.

Resolution is way below par.

Overhangs are collapsing (not sure if that would be expected at those angles)

The in-filling is inconsistent and "blobby".


q:
My Anet A8 suddenly had issues with being unable to heat the bed. After ruling out software issues, I disconnected the connector and found this (sorry for the terrible quality):

The left most pin on the male connector (bed) is also charred. How could I best repair this?

[A]
New Bed (Connection)
You will at least need a new female connector, but as the connector burnt, you have some underlying problem that made the connector burn in the first place: either the board is sending bad signals to the bed, or the bed is not rated for the board or you
just
had a faulty connector (the most usual culprit). Honestly? Replace the whole connector for a properly rated and intact pair - these pin connectors are not rated for 12 V at all but for 5 V!
If you don't use a beefier connector, solder the wires
directly
to the bed.
Safety first!
Anet isn't known for good firmware implementation of safety, so make twice sure that you
run a firmware that has Thermal Runaway Protection enabled!


q:
I printed a test cube with ABS on my Ender 3 and after some tuning, I still have a problem I cannot solve. Two of the vertical edges (I believe they are the ones on the X+ side) are slightly squished in. Could this be due to warping or something else? I printed it at 0.1 mm layer height, 235/110 °C hotend/bed temperatures.

Here is a picture:

[A]
I think this is caused by the shape of the hole. The shape is parabolic or circular, this means that if you slice it as in the green part, the slicer determines the placing of the layers along the curvature. If it has a shallow curvature, and slicing layer height is relatively thick, the curvature of the object cannot be followed. But, if you have more than 1 top layer, this usually should not be visible. I don't think that you have a single layer, so this is a pretty odd anomaly that I have not seen yet (that you look at the infill without top layers).
You could get past this by using a local different infill, e.g. 100 % infill. You can look at
this answer
of
the question: "Different infill in the same part"
. This should help you out printing in your preferred orientation.


q:
Can I Print models from Sources like Thingiverse and sell them ?
I will be only charging the print costs and will provide full credits and attributes to the original creator of the model (with links to their profiles) in my web-page.

There are websites like 3dhubs where the seller will print any file the user uploads. Similarly I want to charge only for the printing services.

[A]
I've informed myself a bit about this and found out the following:
It is good that you state the Name/Website or any Reference about original creator
Creative Commons absolutely requires this, even if you don't charge anything for your prints.
So, whether you are trying selling your print or not, you should still always do this.
You are not allowed to sell your prints
Creative Commons License dictates that you are not allowed to commercialize products that are based on any of their sources. This means, even if you are only charging the printing costs, you are not allowed to sell them, as you are profiting of their sources because you did not design the prints yourself.
For further information on this, you should probably check out the official page for this,
https://creativecommons.org/licenses/by-nc-sa/3.0/
I hope this helps, Max


q:
I started a print on my Monoprice Select v2 and let it run.
I'm printing with Dikale PLA at 200 °C extruder and 60 °C build plate temperatures. My initial layer speed is 30mm/s then 60mm/s after that.
Although the Monoprice comes with an aluminum build plate, I put on a FYSETC magnetic bed plate which says it's suitable for PLA printing between 50 °C - 80 °C.

When I returned home, the print had been lifted off the build plate. I used a brim and even applied magigoo gluestick to help it stick but that didn't do the trick.

I also noticed it's charred at one corner. Any idea of what this might be a symptom of?

Here's what was printed

[A]
You have more than one problem going on. As for the print lifting up, that could be for a multitude of reasons. Clearly better bed adhesion is required. It also appears the printer stopped printing at one layer. Now for the charred part, I think it could've been caused by the nozzle staying in one area for too long (possibly when the printer stopped printing.). This causes the plastic touching the nozzle to overheat and burn up. The charred section can usually be pulled off pretty easily. However, since it definitely appears you have more than one issue here you should pursue some research (perhaps other questions on the site) on the matter.
Hope this helps!


q: I recently got a Dremel 3D20, and I understand it only takes PLA filament according to the Dremel site.  However, I was wondering if anyone has successfully used TPU filament or knows it will work fine.  I’m more than happy to use other software to change the temperature, I just don’t want to gunk up or otherwise ruin my printer.

[A]
TPU wants in general two things of your printer:
A Printing Temperature of (over many makers) 195-230 °C
A Direct Drive (extruder on the printhead)
Bowden extruders are not ideal for printing flexible filaments such as NinjaFlex due to the excessive
  distance between the stepper motor and the extruder head. However, some users have generated
  successful prints using reduced speeds.
ninjaflex handout
Check the temperature you can reach, and you are lucky, as some of the smaller Dremels use Bowden but the 3d20 is apparently direct drive.
If you want to try to run a Bowden with flexible filaments, dial down speed down really low (20-30 mm/s at most) and pray.


q:
Recently got an Anycubic I3 Mega Printer and I've been playing with what it can do, but after a model is done it leaves residue on the build plate behind that is bugging me. Do I NEED to remove it? If so, how? Thanks! (I'm using PLA if that matters)

My Problem:

[A]
You should remove it because it can and will affect the quality of future prints. Residue can mix up with new filament and create a ugly of colors and also prevent adhesion in places, thus potentially ruining your next print.
You have several solutions to clean up the bed:
Scrape it off: usually works, but you risk chipping the surface if you're not careful or if you stumble upon a bit of residue that is stubborn and you need to apply strength to get rid of it. I think a scraper is included with the printer.
Sponge and soap: Since the bed cannot be removed, as far as I can tell, you'll need to make sure that the sponge isn't dripping or put towel paper around to avoid damaging the components below, including the heating unit. Rub it gently on the residue until it soften and detaches. It might take a bit to work.
Yellow glass cleaner from Karcher
: my favourite, the one I use on my printer and it never failed me. Spray it on a cloth or something, and rub it on the bed until the residue softens and detaches. It might take a bit to work, but you don't run the risk of dripping liquid on any component, and it works way better than soap and without the risk of chipping the bed like when you use a scraper.


q:
I bought a 32 GB SDHC (Sandisk) I'd like to use for my Monoprice 3D printer.

I have downloaded Partition Wizard and partitioned a 2GB primary partition formatted as FAT and it still does not show any files.

What am I doing wrong?

[A]
For an SD card to work with the printer firmware
Monoprice suggests to format the SD card to FAT32
.
However, the Monoprice Select Mini V2 is not able to read SDHC memory cards, it is advised to use an SD card (smaller than 4 GB) instead.
According to the
Monoprice support website
:
"Why is my printer not reading my SD card?"
:
If the SD card is not recognized on the printer or if the files are
  not reading, it could be an issue with the actual card itself. The
  first thing we recommend checking is that none of the print files on
  the SD card contain a space in their name. This shows in the printer
  as an unidentified character and can cause issues. If none of your
  prints contain spaces, we recommend reformatting your SD card.
Note:  If you choose to purchase an SD card,
please make sure that it
  is not labeled HC (High Capacity)
as it
may not be compatible with the
  printer
. This means that
the card must be smaller than 4GB in size
.
The last part of the support page is probably applicable to your card.
Some further information can be found in
What is the largest microSD card that a Monoprice Select Mini can read?
, specifically
this answer
. From this latter answer, I quote:
Cards between 2 GB and 32 GB
might
work, depending on the specifics of
  the card
Basically there are no guarantees when using large cards.


q:
I dont want the part cooling fan on during preheat, especially when I'm only heating the bed, it is just unnecessarily loud and serves no purpose at that time.

However when I set PREHEAT_1_FAN_SPEED to 0 it has no effect, the fan still spins at full speed as soon as I preheat either the hotend or the bed.

So why is this setting not working and how do I fix this?

I am using the latest version of Marlin.

The only one that is defined is the one that I am editing and it is the one that appears on line ~1260 of the stock configuration.h

#define PREHEAT_1_FAN_SPEED 0 // Value from 0 to 255

And this is the grep result of searching the entire firmware folder:

[A]
This answer is now obsolete now that the OP has updated the question with additional information. It is left here as a possible solution for those who have tinkered with there firmware.
Part cooling fan speed during preheat (from menu) is controlled by the setting
```
```
#define PREHEAT_1_FAN_SPEED     0 // Value from 0 to 255
```
```
in
Configuration.h
where a value of
```
0
```
implies no rotation, or 0 % and
```
255
```
implies 100 %.
If changing this value in your configuration does not result in a reduced fan speed, you could have this constant be defined somewhere else overriding this value.


q:
I managed to tear my build plate trying to get some very stubborn plastic off it.

I'll need to buy a new one, what characteristics are important for me to ensure it's compatable with my printer?

I can think of:

Dimensions

Power requirements

Connector types

That my printer moves the plate in the z axis (?)

NB  I'm so new at this I didn't realise that this was just a sticker on the plate, so I just need to replace this sticker.  However, as a question, I'm still curious as there's a good chance I will break it at some point.

[A]
If your printer's heated bed still works, but the sticker has been ripped in some places:
You can try and remove the rest of the sticker, clean the metal plate under the sticker (perhaps with isopropyl alcohol) and then apply a new sticker once there is no adhesive remaining on the heated bed.
You can remove the sticker with the method above, but instead of replacing it with a new sticker, you can buy a PEI sheet and cut it to size if required (read more about PEI
here
) and then stick it to the metal plate.
Personally, I would recommend the latter option, since PEI is low maintenance and the prints automatically pop off the sheet once it cools down, however just make sure not to print PETG on it, since it sticks too much.
On the other hand, if your entire heated bed is broken, the best-case scenario is to look for a heated bed that was designed specifically for your printer. Especially since your printer's heated bed has 3 mounting screws instead of 4.
If you somehow have a solution for mounting a heated bed with 4 mounting screws on a printer that uses 3, the things you need to watch out for are the heated bed's operating voltage (it should be 24v) and the dimensions must be the same. If the wires are not provided with the heated bed, make sure to get wires that have high enough gauge so that it is able to handle the high currents that the heated bed will need.


q:
I have a set of 2D pictures from a CT scan.

How can I convert them into a 3D model for 3D printing? An example looks like this:

[A]
Using the terms "convert CT scan to 3D model," I found a number of links of tutorials. One of them is described as free, with registration and appears to be web based. The link,
Embodi3D
, appears to have a relatively comprehensive set of instructions to accomplish your goal.
Instructables
also has a similar tutorial. Should neither of these prove suitable, the search terms above may be of value.
Image below via Instructables:


q:
When choosing a layer height, I know that often you go as fine as your printer will do for better precision, but sometimes you go a little thicker, for speed, for example.

I also see 0.1 mm and 0.2 mm as common thicknesses.

What are my options here? When I'm working on a part where I want to print a draft piece, and the quality matters less, can I set it to 0.15 mm? 0.11 mm? The Ultimaker Cura slicer I normally use will let me put in almost anything, but what can it really do? If I can use values in between simple 0.1 mm increments, are there reasons I might want to do so?

For reference, I have a Monoprice Maker Select Plus with a 0.4 mm nozzle and, again, Ultimaker Cura as the slicer. But more general answers for other printer types and slicers are also encouraged. I want to know about this generally, and not just for one printer.

[A] You decide which layer height you want based on the quality you desire, but never go over about 75 % of your nozzle diameter, so with your 0.4 mm nozzle never choose layer heights larger than 0.3 mm. The rationale of this rule of thumb is that the filament leaves the nozzle as a tube and needs to be flattened to make it adhere to the previous layer.


q:
In the context of a personal project I would like to reproduce the appearance of a commercial product of which I send you a cropped image.

I would also like to point out that I do not have the object in question, but it would seem that it is made from a polymer.

The product is a case with an embedded electronical card, so heat dissipation is important.

I'm interested by what kind of plastic is really used here. I plan to have the part manufactured by a company, so I think the method used will be SLS

I therefore rely on your expertise in the field of 3D printing to try to identify the material used.

Thanks

[A]
Is there anything else about this object, but its picture? Softening temperature, biodegradability, is it stiff of flexible, hard or soft, anything could help identifying its material.
Also, post-processing (sanding down or chemicals like acetone bath) greatly enhances the range of filaments that can be used.
Just from the picture, my first guess would be: it looks very much like what ceramic powder added filaments can yield with when you sand them down afterwards. Take a look at pictures of prints with LayBrick, CERAMO, etc.
On second thought,
the answer is: Polyamide/Nylon
. It must be either a polyamide case or polyamide coating of some other material. For home projects, MJF polyamide prints can easily be ordered online. Ordering polyamide coating of plastic parts can be trickier depending on your location, although definitely doable.
Going with Nylon at home prints may require a non-basic 3D printer and some expertise.


q:
After a brownout a print failed and it got the whole hotend covered in PLA. I am now in the process of replacing some parts on the hotend (one of the thermistor legs broke of) and also wanted to take the heater cartridge out. The problem is that the bolt that locks the heater cartridge is stuck and I am now afraid to strip the head.

Is there a trick to remove the bolt with the smallest probability of stripping the head? Is it better to apply heat or not? Should I soak it in Acetone or some other solvent? etc.

[A]
Acetone will not dissolve PLA, there are other nasty solvents that do that, but it is not recommended to go that way.
You could apply 12 V (if the cartridge is 12 V that is) directly. As the thermistor does not work, you cannot use the printer board. You should take caution not to heat it too far or too hot, but from your experience with your own machine you should know approximately how long it takes to heat up the hotend to working temperature. E.g. start with a minute and try to pry off the lump of plastic with pliers. If you can reach the bolt/worm screw, try heating until you are able to insert the hex key or screw driver.
This video
from Josef Prusa shows exactly what you need to do what is described above. The only difference is that you need to connect the heater element directly to the power supply as your thermistor is broken. So don't leave it on too long or you will bake the filament to carbonization, which is much harder to remove. Try to cycle it on/off.


q:
I have been working on a printer project that basically is a 2D printer (dot matrix type). We are using solenoids as actuators to make impressions on the paper. We are now in the process of designing custom software. But a problem that we have encountered is that we have no idea how to design software as we are a bunch of beginners in this field.

An idea we are working on is based on position-acknowledge technique. In this technique the computer sends G-code to the controller. The controller after reaching the position defined in code sends an acknowledgement and the computer then sends the next signal. This is the model we are currently working on.

Can anyone suggest any other ideas to make this work?

Is Our approach right?

Do 3D printers work using same technique?

[A]
3D printer firmware use gcode that is derived from CNC and no acknowledgment. They send movement commands to the stepper motors like
```
G1 X10 Y10
```
to move the printhead 10 mm along the X and Y.
You could use a ready 3D printer firmware like Marlin on a 3d printer board and use the X-axis or extruder output to couple to your solenoid, sending a
```
G1 Z0.1
```
or
```
G1 E0.1
```
, which will actuate it for a short time. You might even use E and Z on different solenoids.


q:
My ender3 came with a BuildTak-clone surface, and as I was a little too vigorous in getting the print off the bed (I had failed to level right and printed a bit too tight to the bed, resulting in SUPER strong adhesion), I needed to replace it.

Peeling off the black was easy. The plastic sheet that held the glue was easy too... but how to clean up the bed to get the residue glue off and prepare for the new 3M sticker?

[A]
Cleaning up the aluminium build platform was rather easy in a three step process as I figured out:
Preparation
Get the old bed-surface off and any film layers that stick to the original glue. Don't bother to try to scrape off the glue, it is wasted time.
Solvent
To remove the sticker's residue, I first tried heat and 70% isopropyl alcohol (aka isopropanol, 2-propanol), which was not very effective.
What did prove effective was nail-polish remover on the base of
acetone
. It worked like a charm to turn the sticky film into easily removable, goopy clumps. With small doses and a lot of rubbing/massaging it into the residue and careful use of the scraper, all the glue was gone after about half to three-quarters of an hour of work.
In subsequent replacement, I used
paint thinner
, which is more effective in goopifying the glue and allowing to scrape it off much faster. 10 minutes max.
Cleanup
After applying the generous amounts of nail polish remover, I thought that it might be best to get any of the additives that were meant to protect the skin off the bed - as well as the slight blue coloring - before applying the new tape. So I gave the aluminium a good wipe down with isopropanol.
In subsequent replacements I used ethanol 98 % to clean the bed before applying, just to make sure no fingerprints or glue residue creates bumps.
Applying the new bed surface was easy afterwards, and after a quick bed leveling, the printer runs like a charm again.