Impossible Print - Repeated Print Failures - Arctos Robot X Pulley
I am pretty tired and discouraged with this printer. I have had to put in (near) the same amount of effort as my old Ender 3. Any help would be greatly appreciated.
I have tried printing this part MANY times and lost almost an entire roll of filament to print failures. Very disappointed.
Here is what I have checked:
0. Checked the X & Y belts - Check. They appear tuned and properly tightened.
1. Printed different Test Prints (to same hight, cubes/cylinders around edges/corners of print bed) - No issue
2. Different orientations - issue persists
3. Different infill types - issue persists
4. Slowed acceleration down from 4000m/s^2 to 2500 - issue persists
5. Slowed down overall print speed to 70 or 80% on printer (manually) - issue persists.
6. Sliced the part in different orientations - issue persists
Do you all have any idea of what is going on here? I have tried reaching out to Prusa Support - but I have not heard back yet. Furthermore, when I did talk with Prusa Support, they were not able to provide a solution (and I did not receive emails, as requested). If you look at the photos, you will see that the layer shift only happens once the print starts the "gear" / "tooth" portion of the pulley gear. In each case, it was a slightly different shift and at slightly different z heights - so there is nothing wrong with the z axis, from what I can tell. It seems the issue is happening along the Y axis, but yet when check the belts & I try other print files - they look & print fine.
Thank you for your help!!! - Luke
RE: Impossible Print - Repeated Print Failures - Arctos Robot X Pulley
You mentioned a layer shift but not sure where it's happening? Best thing to get good advice here is to upload your 3mf project file here using the Attach file button. Make sure it's zip compressed or the forum software will reject it. That way we can see the model topology but also all your settings. Many things can cause layer shifts, and without seeing model and settings it's just a crap shoot.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Impossible Print - Repeated Print Failures - Arctos Robot X Pulley
Can you explain to me how do that? When clicking "Add Media" it says that 3mf files are "not an allowed file type" which I found bizarre. I tried uploading 3mf originally but was forced to use photos since "add Media" button would not allow me to. Regarding "where" the layer shift is happening - if you see the photos below, it always happens in the geared/toothed section of the print.
RE: Impossible Print - Repeated Print Failures - Arctos Robot X Pulley
@foxrun3d clearly told you that the *.3mf file needs to be zipped. The forum will not accept any other format than *.ZIP. Next time, read other people's posts more carefully.
RE: Impossible Print - Repeated Print Failures - Arctos Robot X Pulley
Sorry about that @foxrun3d & @miroslav.h4 . Somehow I missed your comment about zipping the 3mf file. Please see the attached. I attached the regular file and the two test files. Both "gear" files failed, but the boarder cubes/cylinders test print worked fine enough.
See Zip file below. Thanks again - Luke
RE: Impossible Print - Repeated Print Failures - Arctos Robot X Pulley
Now that's interesting. I printed the test file on one of my Mk4S's and ended up with the same layer shifts. I did change the infill to cubic but don't think that makes a difference. So I would exclude stuff like belts, warping, etc. because I know I don't have usually layer shift issues on my machine and couldn't see any warping at all. It seems something related to the geometry of the model. The layer shifts seem to start around 8 mm or so, around where the top layers of those two inner protrusions begin. I don't see anything obviously suspicious though. Wish I had the time to drill into this more but at this point this is as far as I can take it.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Impossible Print - Repeated Print Failures - Arctos Robot X Pulley
@FoxRun3D thanks for the reply! Very interesting to hear you got the same result. Do you know how I can elevate / raise this to Prusa, formally?
My hope is that this is something that either firmware, software, or slicing can solve - and not a fundamental limitation of the printer’s hardware. Crazy situation. This part has been successfully printed on many other printers (it’s part of a big open source project)… so I am surprised the MK4S has such a hard time with it.
RE: Impossible Print - Repeated Print Failures - Arctos Robot X Pulley
Maybe the best way is to open a ticket on their Prusaslicer GitHub page.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Impossible Print - Repeated Print Failures - Arctos Robot X Pulley
Are you using classic or arachnine perimeter generator?
RE: Impossible Print - Repeated Print Failures - Arctos Robot X Pulley
Nevermind, I looked at the 3mf and nothing jumps out at me.
RE: Impossible Print - Repeated Print Failures - Arctos Robot X Pulley
Update: When I tried some of the "normal" (non-geared parts) they printed just fine. However, when I tried some of the other geared parts for this project, they also failed due to layer shifting. My new hypothesis is that something due to the shape/type/size of these gears is causing the layer shift on my MK4S. Perhaps a slicer or software issue? I also posted the issue on the Prusa GitHub: https://github.com/prusa3d/PrusaSlicer/issues/14116
I am open to any ideas! As communicated above - my printer is not the only printer that is struggling to print these...
Attached are some photos and the 3mf file of the parts that failed this morning (same layer shift issue due to geared parts):
RE: Impossible Print - Repeated Print Failures - Arctos Robot X Pulley
First of all, turn off the supports. Slicer will tell you in blue where the supports would be appropriate. In this case, they are only placed in small screw holes. As for the layer shifts, they are caused by the toothed circuit. I thought of trying a total slowdown of the print and I took the settings from the good old MK2S as a basis. And it worked, the shifts are gone. However, at the cost of a long print time, the largest pulley prints for about 10 hours. But that would probably be bearable, the quality of the pulleys is good. With this setting, print only the pulleys with the small teeth, print the other parts on the MK4S settings. The note about the supports applies to all parts, in most cases in the photos it seems like a waste of filament to me. Attached is a test wreath, do whatever you want with the settings, maybe the printing could be accelerated on the printer to about 120-130% but I haven't tested that, I prefer quality over speed. Oh, and one more thing: Print larger parts separately, if something happens you will only lose one part.I posted this here yesterday, but it disappeared by morning, just like many others.
RE: Impossible Print - Repeated Print Failures - Arctos Robot X Pulley
Hi @miroslav.h4 ! Thanks for your response. I will check out your test file you attached. That is appreciated. I am still baffled as I recently met someone who was able to print this on the MK4S with the default settings (full speed, 4 walls, 30 percent infill, gyroid, etc.), however, that's only 1 person in 3 or 4 that I have talked with.
I think what I am after is why MY printer (or MK4S printers in general) are having such a hard time with this. This print has not caused other builders in the community any issues who use other printers by Bambu lab, creality, etc.. Ideally, I would like to get my printer running/fixed/tuned so that it is able to print this part appropriately without any issues as it should. That is part of why I posted it on here - and have also opened a ticket on GitHub. Hoping Prusa can print a test print and see what is up. Someone at Prusa told me they would - but then I never heard back.
RE: Impossible Print - Repeated Print Failures - Arctos Robot X Pulley
This *may* also be related to a bug in fw 6.2: https://github.com/prusa3d/Prusa-Firmware-Buddy/issues/4465
which causes layer shifts in certain models
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Impossible Print - Repeated Print Failures - Arctos Robot X Pulley
I had problems printing the several gear for the ARCTOS robot with 6.2 and after rolling back to 6.1.3 I've successfully reprinted two of them YP and XP. I'm waiting for more material (I'm using PA for the gears) then I'll retry printing XP (the large one) with 6.1.3 and I'll report back. 
RE: Impossible Print - Repeated Print Failures - Arctos Robot X Pulley
That @bryars. I confirm your findings. Wheel X (Large) is being printed. On FW 6.2.0, it's a complete disaster right from the first layer with gyroid padding. It seems to me as if when moving from perimeters to infill, the nozzle sinks into the already finished layer and only then moves to the infill. At that moment, there is a sound of banging from the printer, as if the nozzle has hit something and the layer shifts. The same file printed under FW 6.1.3 runs perfectly fine without any problems. The print setting is 0.2 SPEED 4 perimeters gyroid padding 30%. There is still a Z-hop set to 1 mm, which is left over from previous attempts. Setting the mass Generic PETG. So this leads to a recommendation for @luke2123: Downgrade FW to 6.1.3 and you shouldn't have any problems printing those damn bikes. And I saw that you also asked a question on github for developers. There you could expand the question to ask why the same file that fails on FW 6.2.0 can be printed under FW 6.1.3 without any problems, and therefore what the developers messed up!