Massive layer shift after ~24 hrs of flawless printing
I've never had a layer shift like this. The angled direction makes me believe it's one of the XY motors. I fixed a loose pulley and corrected belt tension before starting this print. After the print, both motor pulleys look good and tension measured correctly. I'm stumped.
RE: Massive layer shift after ~24 hrs of flawless printing
Did you check if the build plate is really free to move on the low end? Could be one or both of the Z motors skipped due to high resistance, causing a collision.
Such problems are more likely to occur close to the motors, because the threaded rods cannot flex enough to compensate. For such high prints I made it a habit to drive the Z axis to the extremes before starting, listening to weird noises. On the XL specifically, you can look at the tops of the rods / bearing mounts. They should not move while driving over the whole range.
RE: Massive layer shift after ~24 hrs of flawless printing
Thanks for the help! I messaged Prusa, Andres and I did some diagnostics and over several prints noticed a reliable failure: the small diameter rods which extend at an angle will break off. I even tried the XL version of the rocket engine. This print was originally intended for 0.6 mm nozzles. When I printed it I tried 0.4 mm, 3 perimeters, and 20% infill. This seemed to provide a substantial amount of material through that cross section, but it seems it's not enough. Andres attempted the same print and it failed in the same way.
As a Prusa test print, I'd like to arrive at a reliable method to manufacture this, but it seems it won't without a substantial amount of trial and error, which is expensive.
RE:
Seems weird to me. They are showing off this print, so it should print, right?
I'd rather think it's a slicing issue, or an issue with the newer firmwares, or his printer has the same problem as yours 😉
RE: Massive layer shift after ~24 hrs of flawless printing
Having similar issue and not even a 24 hour print, this was a ~7 hour print and repeated. Latest firmware and slicer. After 1st failure, resliced the model and sent to print and same thing....
RE: Massive layer shift after ~24 hrs of flawless printing
Having similar problems on my XL. Massive shift, seems to happen every so often. Anyone have any solutions?
RE: Massive layer shift after ~24 hrs of flawless printing
I've had similar shifts, always in X and Y at the same time.
I found that if I reduce the maximum acceleration from 5000mm/s^2 to 3000mm/s^2, they all went away.
I've never had a layer shift like this. The angled direction makes me believe it's one of the XY motors. I fixed a loose pulley and corrected belt tension before starting this print. After the print, both motor pulleys look good and tension measured correctly. I'm stumped.
RE: Massive layer shift after ~24 hrs of flawless printing
In my printing 99% of the layer shifts are caused by a bridge/overhang bending up into the nozzle. When it catches in the right direction the nozzle hangs and doesn't finish the move. There is no feedback mechinism to validate the X or Y move. The system always thinks it moved. The amount it didn't move becomes the "layer shift" amount. Running slower alows more torque on the servo to resist the shift, but may still happen.
It often repeats since the problem is the material cooling and bending. Not the exact same spot, but usually the same area within a few layers.
Sometimes it can be overcome with slicing options or changing part orientation.
There is software that will predict the problems and adjust the code, but the last time I saw it, the cost was $65,0000 U.S. Dollars and up. For Professional 3d Printing.
RE: Massive layer shift after ~24 hrs of flawless printing
after 2 weeks of support with prusa going absolutely nowhere. i checked the last place. this turns out to be quality issue at prusa as I'm finding out more and more. The issue was prusa assembled tech failed to tighten the xy belt clamps. mind you this was not the printer had printed thousands of hours and worked it way loose. This is a brand new printer and the belt clamp screws were barely installed. overall this XL is my worst $5000 investment. Output success rate is maybe 5% at best. I'm still dealing with multiple other issues. moving on and far away from prusa printers.
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Hi,
I suffered from the same issue several times and IMO it is caused by introduction of ramping in printer/extruder travel lift configuration - for example one print failed with layer shift (when phase stepping was enabled) or detected crash (when phase stepping was disabled) on 7th hour (out of 9) on the same spot, some failed on the 1st layer,...
I tried several things (filament check, temp change, .....) and finally resolved it by enabling printer/extruder "Steeper ramp before obstacles" - since that there are no mystery crashes anymore.
I reported it as feature request https://github.com/prusa3d/PrusaSlicer/issues/13235
regards, rp