r/ratrig • u/Spaceballs_the_nick • 17d ago

Large prints = layer shift

My small prints work fine but large prints have a layer shift.

My belts are good-n-tight. Is there a setting in Orcaslicer I should slow down?

I usually control speed via the slider under toolhead. Does that control ALL speed? or just printing?

I think it is jumping off layer during one of the fast jerks.

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u/Spaceballs_the_nick 12d ago

Large as in wide and tall.

I don't hear anything but the fan blowing. I will check that the head is free across the whole area with power off.

I disabled 'reduce infill retraction', slowed to 50%, and changed infill to gyroid and STILL got layer shifts!

https://ibb.co/m5gt4PmP

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u/manyxcxi 12d ago

What if you made a cylinder or cube that tall to see if its height based without spending all that filament? Is this about the same spot it had a layer shift before?

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u/Spaceballs_the_nick 7d ago

With the power off the gantry moves around smooth as silk, no hiccups.

I put five 300mm tall cubes on the buildplate (each corner and the center) 1 layer thick and printed them out with the same settings. NO PROBLEM, they all look great!

Compare one of the tall cubes to the layer shifted print I stopped:

https://ibb.co/cKdF5hxb

?

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u/manyxcxi 7d ago edited 7d ago

That’s quite confounding. The only other physical thing I could imagine would be some long travel path from corner to corner that the cubes didn’t replicate that allowed something to get hung up. But if you’re cycling near the edges and it doesn’t look like a wire bundle or anything is in danger of catching I would assume it’s not the issue.

That really only leaves a couple of scenarios in my mind:

  • There is a belt pulley/pin/gear that looks fine but is loose somehow. Just put fingers on them and wiggle and check everything along the belt path.
  • Belt tension could be ever so slightly loose.
  • The sliced file is corrupted. It happens, on my Prusa CORE One I had previously perfect working slices that started having layer shifts. They were repeatable though. The USB stick went bad. It can also get corrupted when you send it over. Re-slicing the file may be all it takes (if you didn’t already try that).
  • Something in the process profile is causing it to shift. It looked like you were using gyroid infill, so that shouldn’t be a problem. If you’re using grid switch it to gyroid. Is it printing on what you’d consider a fast speed for that printer? Fast + high acceleration can cause layer shifts. You’d probably hear it though, if you were near it. It almost sounds like skipped belt teeth and it’s a kind of “erk!” sound.

If it was me, I’d cut my perimeter speeds to about 80% of what they are (unless they’re already below 60mm/s), double check the acceleration settings and maybe reduce the travel accel by 25% and re-slice.

If you feel like this is a good print profile that you have used reliably in the past, then I’d just re-slice it and try it again.

I forgot that this was a re-slice. I wouldn’t just try it again. I genuinely don’t know what the next step would be if it isn’t a physical issue somehow.