Hello everyone!
I have been experiencing a persistent issue for quite some time now. Whenever I print larger designs, the quality significantly deteriorates the higher it is printed. As you can observe in the picture, the top part appears distorted and it seems like the printhead fails to align properly with the underlying layers. Interestingly, when I print a single item, the quality is perfectly fine.
I have already examined and ensured proper tension in all the belts. I have also checked the hotend and cooling system, which are functioning correctly. Additionally, the spindles appear to be in good condition as well.
Any help is appreciated!
Sounds like heat creep.
Do you have Z hop turned off?
Since you can print one item fine, I’m thinking nozzle hit print when traveling, turning on z hop should help
Z hop is turned on. It is not only with multiple prints but larger single once as well https://imgur.com/a/9NC6ilE here is a other great example. strangly though it is most of the time only partially that it happends to the print
edit2: Yeah, the more I have thought about it, the more convinced I am that it is related to travelling settings/travelling speed. I would enable every retraction setting that promises to decrease stringing, enable any setting that helps avoiding printed parts when travelling, decrease significantly the travelling speed… But I’m leaving the original comment below just in case.
First of all I would confirm that the printing speed is consistent between the multi piece project and the single one. I get that kind of aligning issue in tall thin pieces in my miniatures if I set the speed too fast… the nozzle scratches the piece slightly and makes it wobble by going too fast, resulting in that effect.
Once you have checked that, I would try to print the single piece but offsetting it to the position of the one in the bottom right of the images, just to discard bed leveling, because that one seems to come out slightly worse than the others.
If the single piece still comes out ok even after being offset to other positions, then my last theory would be that by printing multiple pieces, they are having enough time to cool off individually until each layer gets to them, and the material is not fusing properly. And to test that I would try to print groups that slowly increment in size, first a pair, then 3, then 4… Until you find the amount that doesn’t come up right.
I think those are all the theories I can come up with for this issue, but if I come up with something else I’ll update.
edit: Now that I think about it, another difference is that the single piece wouldn’t have travelling moves… Maybe they are the ones causing this if they are too fast.
Hi Kylian, Are all these printed in the same orientation? What happens if you print one rotated 90 (and 45) degrees on the vertical axis?
I find it curious how the artifacts are more pronounced on one side than on the other (last image).
The problem occurring with tall prints make me think this could be inertia from the bed slinging. How badly does the printer shake? Do you print using the spool on top of the printer? If so try with the spool to the side. I’m fond of this spool holder https://www.printables.com/model/120198-spool-holder
Feel free to follow up with more questions. Don’t hesitate to reach out to Prusa support either, they’re great.
Rotating the part does not change the artifacts sides. I initially though that because the artifacts are more on one side. it would have something to do with the belt tension. But i checked this and tightened them up without any effect.
the spool does not sit on top of the printer. its sits next to the printer with a ptfe tube going in. Wouldnt the inertia artifacts be visible in the single on that got printed just fine?
I have posted this before on the Prusa forums some months ago without much luck. Me and the people could not find what was causing the issue. I set the printer aside for a while because i was a bit done with it for the moment. Just picked it up again to look in to the issue once more.
No change with rotation is weird. Do you mean the artifacts are on the same side relative to the parts, or relative to the printer?
Is this a modified MK3S/S+? I see the extra screen, but what about the PTFE tube, is that from an MMU?
If the inertia is from the relatively fast movements between parts, no. Printing moves are more gentle than movement-only moves.
Edit: It may be worth trying to print at 50% speed (knob anti-clockwise during printing) just to see if that changes anything.
Rotating the part on the printbed results in the same artifacts relative to the printer. always the backside the most. Hence i thought belts being the culprit before.
It is a slightly modified MK3S With MMU2S. It has a display with octoprint. I rule out octoprint being the culprit as printing from the SD card directly results in the same. The entire print assembly is fully stock.
I will give printing it at 50% a try to see if it improves things. thanks for the suggestion!
I’ve seen similar issues happen if the edges curl up from too little cooling and the nozzle catches on that when travelling from part to part, but it would be rather obvious if that is happening.
