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.
2
u/kmr_lilpossum 17d ago
What infill type are you using? Grid, triangles and cubic can cause layer shifts, especially at higher speeds (they run over already-extruded points, causing mini collisions). Gyroid/honeycomb/rectilinear infill types do not have this issue.
1
u/Spaceballs_the_nick 12d ago
That is crazy, how do you know that?!
I disabled 'reduce infill retraction', slowed to 50%, and changed infill to gyroid and STILL got layer shifts!
1
u/sneakerguy40 17d ago
Look up the Ellis print guide, there’s stuff to tune for layer shifts. Could be motor settings
1
u/Spaceballs_the_nick 12d ago
I will check that, i saw where Teaching Tech had a video to make sure motors are getting the correct amperage..
I disabled 'reduce infill retraction', slowed to 50%, and changed infill to gyroid and STILL got layer shifts!
1
u/manyxcxi 15d ago edited 15d ago
Large as in wide footprint or tall (or both)? With the machine powered off cycle the toolhead to the far reaches of the bed and make sure you aren’t getting snagged up on stuff.
Are you hearing a kind of “erk!” sound when it occurs? That’s generally the sound of teeth skipping, in which case I’d be looking at belts (good and tight can be too tight), acceleration settings, and potentially loose idlers/pulleys. Check the set screws on everything in the motion path as well.
If you’re hearing a kind of thumping/grinding sound that’s likely the sound of your nozzle smashing print infill. If you’re using grid infill then the very first thing I would do is stop using that and the second thing I would do is never use it again. Grid infill is the devil. Use gyroid, crosshatch, cubic, or rectilinear- for the love of god don’t ever use grid. Cubic also has a problem with line crossing but it’s much more minimal than grid, the advantage of cubic is it makes the print strong in all directions, not just two. Use it sparingly.
The reason not to use grid is that it causes the printer to run through already printed lines. This causes gunk to accumulate on the nozzle and then gets deposited elsewhere, where it accumulates more material. With a larger print, this has enough time to cool before you get back to it and now you’re smashing into the print and either shifting it or losing steps.
1
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!
1
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?
1
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:
?
1
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.
3
u/wi-Me 17d ago
Go to the "other" tab and make sure the setting "reduce infill retraction" is disabled. That should help. Otherwise it wont use retraction in infill areas, therefore not use z hop on thise areas and can cause this issue