Print rotates around its axis

Hi friends, I’m stumped. I’m printing 4 of these fidgets at a time. In the middle of the print the slices rotate. I have good prints with 2 fidgets, fails with 4. I have good bed adhesion, other prints work perfectly. I’m pretty sure it’s the file, but I need help figuring out what setting might cause this. Thanks!

Could you please send a link to the STL? I love this kind of problem :slight_smile:

me 2, please. Would try it on a bunch of different printers to unearth it’s secrets :slight_smile:

This is the STL used

I printed a single design worked fine. I deleted a few outer layers and printed a single design just fine. When I copied the design to print 4 at a time is when it failed. I checked belts, same issue. I drastically increased the z-hop to make sure I didn’t bump, same issue.

Thank you! My printer is busy now but it will be the next job. Were you using regular PLA?

It’s a 2 tone PLA, nothing special

Thanks again. Sorry for delay. Running it now. Only ~15 layers into 103. The slicer gave a warning about some empty layers … I took a screenshot just in case it’s relevant later.

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Alrighty. Tried that experiment myself, with attention to all the leveling and meshing and making the adhesion correct. Printed with 3 layers raft. I was in a different room and heard the nozzle knocking the print, ran back and stopped it, and took a picture.

The heart in the lower right of the print bed is most interesting because it was an inner ring that got knocked out. And it hit hard enough to detach it from the raft.

Went back today to run a different kind of experiment: bed temp consistency. Heated it up to PLA standards (50C bed), let it sit there for 10 minutes to warm up, then measured the temps at different parts of the PEI build plate. Results are as shown:

This sort of indicates that perhaps an enclosure would help for prints that use up more of the bed.

Ok, it’s not just me :smile: you’re awesome for experimenting! Any thoughts if this is due to the STL or configuration?

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Interesting, I’ll have to get my IR gun out and map my bed too. Looks like I’m building an enclosure next

Re-running the same job again (same objects & placement, same filament etc) but with some altered settings. I unplugged the big parts fan (on the X crossbar) to eliminate the possible differential-cooling aspect of it. Subsequent layer height (after the first) went from 0.20 to 0.22mm … nozzle temp moved into the higher end of what the filament manufacturer recommends … level bed to low single digits … remesh at 50C … watching it now with the speed set to 50% via fine-tuning. That spiral prime turned out perfectly this time, which is a good sign. Will post results here later.

A possible error condition from before is that one of the 6 groove wheels for Z travel (lower outside right) was slightly loose, and X & Y belts definitely needed retightening.

Pretty sure it’s not the STL. Slicer gave no warnings. But we shall see. Your print actually got a lot further than mine did. It’s rainy here this weekend anyway so I won’t be far from the printer.

Whoa! Glad it’s running slow and I can watch it … but … it looks as if the internal walls of the object are almost too thin to properly self-support. Paused the print and took a few closeups:

Leaning now towards the notion that the STL itself may be a bad design.

Was running the job first at 50% speed then 70%, but it’s turning out well enough that it seems OK to go to 100% of CV’s 150mms speed. None of that knocking I sometimes heard on other wide prints.

This makes sense, some of my “straight” prints also had jammed material that did not allow the hearts to slide past each other

Just for kicks I took the speed as high as 140% of CV’s 150mms preset … and then a very faint knocking began to be audible … guessing this was the prior layer that had just not yet cooled adequately. Backed down to 120% and the print is running fine so far. 32 of 93 layers.

Printed successfully. 6:51 for the set of four.

After the bed had been heating for hours running this job, the corners measured more like 45-46C, which was better. A moving target, the printer was in motion at the time.

You did it!

Did you change anything besides the print speed?

Also, I see you used a raft, were you able to disconnect it cleanly? I just went straight on the bed.

I have almost always printed on a raft. It disconnected cleanly. I did let the print cool for an hour before touching it.

Lots of mode changes …
Raised the extruder temp range from 190-210 to 210-220 and saved it as the PLA profile.
Ran the raft layers at 50% speed (the fine control menu) then rode the speed control % listening for any knocking in the print head hitting the model. Kept notes. Ran it as fast as 140%.
Changed the layer height from 0.20 to 0.22.
Disconnected the big parts fan on the X crossbar … working on an alternate solution for that.

Without knowing more, the operable idea is that the not-yet-cooled-enough filament needs time to shrink properly before the next layer can be deposited on it. Ran a similar test this morning to learn more about that.

You removed the fan completely? Was it bumping the print or just too much cooling?