layershift laayershift laayeershift
Hi there,
I just wanted to ask if somebody else is getting frustrated because of layer shift issues ?
this is absolutely annoying and to be honest, it is getting expensive as well. my last 5 prints are all destroyed by this issue. I made differnt try's with IS and without IS, of course all my calibrations worked without issues and it seems that this is not the issue. I also tried to reduce the speed down to 60% but without getting a better result.
sometimes it happen on a height of 5mm, sometimes much later on a height of 50mm or 70mm --> this is driving me crazy.
i start to hate myself because of the decision not to buy a another printer 🙁 i could cry.
i also made the experiance, that just sometimes if a print is finished and i want to start the next one, the z-height is lost. i mean if it ends on the 50mm height, it will be seen as 0mm for the next print and everything fails from the beginning. Then i have to turn off, move down the nozzle manually and have to re-calibrate again. this is not a big deal because i know it meanwhile, but to be honest, i cannot accept the layer shift issues, moreover i cannot believe that i am still the only one with that topic.
slowly i start to get a prusa hater .....
RE: layershift laayershift laayeershift
I had layer shifts when input shaping was in Beta, but they went away when I get belt tightness tuned properly. Have you tried their app for this?
Regarding the height issue at the start of the print, have you altered your start gcode? The printer should always home before it starts a print if using Prusa's standard start gcodes, so it should know where zero is regardless.
RE: layershift laayershift laayeershift
Thanks to your answer and questions
a) of course i have used the app to get the belt in the correct tightend - perfekt, also if i reuse the app again, absolutely no issue
b) the gcodes are unchanged (i never did that) --> export from fusion 360 --> gcode done by prusa slicer. this issue happen not that often (every 4-5 attempt). but it is annoyin.
i really do not know what to do. i have wasted more material than i new bambu would cost
RE: layershift laayershift laayeershift
I don't know how exactly the z-levelling routine works for the Mk4 but I wonder how it is possible for it to start at a random z-height. Does that mean the printer entirely skips bed-mesh levelling? In that case I would assume that there is either somethign severely messed up with your firmware or your print file has some flawed g-code. Check your profiles to be sure, especially the g-code parts (start g-code etc).
I would also check if all your grub screws on the steppermotors are really tight or slightly loose (tighten, maybe use loctite), and in the printer settings I would disable clash detection, at least on the Mk3 that detection causes more problems than it helps.
Mk3s MMU2s, Voron 0.1, Voron 2.4
RE:
hard to describe the issue, but i will try to explain:
1) former print has been completed
2) print-head (nozzle) moves away and goes slightly up, and the print is then always (after a print) in a different height (in my example ~150mm)
3) i start the next print, and by that the nozzle warms up to 195 degrees and starts the nozzle clean in that height instead of trying to home the print head.
4) is is clearly impossible that the nozzle will be cleaned - this can be done 100 times, it will not be changed.
This means i receive the error that the nozzle cleaning failed, and meshbed leveling will be skipped.
After that i have realized (with prusa connect) that the height of ~150 is set to 0 !!!
Then i have to turn off, move down the head manually and restart the printer -> then it works
of course i use the latest FW, and have it already replaced and flashed it again with the latest ... same issue
RE: layershift laayershift laayeershift
Check if there is a lot of resistance in the filament path from the spool to the extruder. This can trigger the load cell and give a false indication of having reached the print surface. Most of time the printer can distinguish this condition from really reaching the print surface (and you then eventually get an error that Z homing as failed), but not always, and I have rarely seen the printer reset Z=0 at some position high above the print surface, and then try to clean the nozzle there.
It helps to make sure that the filament is a bit loose at the beginning of a print. You can also try recalibrating the load cell. Another option is to switch to a reverse bowden tube setup, which is what I ended up doing. That way movements of the extruder do not pull filament from the spool. It can a bit be inconvenient in other ways though, e.g. for color changes.
The printer resetting all axis positions to 0 at the beginning of a print is, AFAIK normal, and part of homing. Someone could have manually moved the print head between prints. It is also needed as a precaution to prevent the nozzle from being driven into the print surface.