MK4S Upgrade X & Y layer shifts by 20mm
Hi folks,
An issue has come up where the upgraded MK4S just decides to shift its origin mid print. This is the third time shit has occurred since the upgrade from MK4->MK4S and I'm at a loss. Each of the prints have successfully completed previous prints but for some reason the printer just decides to do this:
Its completely random. I have printed the above file successfully 2 times and then this happens on the third. Two other times were with two different prints that were also both successfully printed. MK4 printed hundreds of hours without issue, MK4S upgrade has dozens of hours and multiple failures.
Any ideas?
RE: MK4S Upgrade X & Y layer shifts by 20mm
FWIW, I am in the same boat - I just discovered this today.
Two things to try:
1) Ensure the printer is on a totally stable surface (this is NOT the case with mine, and I will need to adjust this in the morning)
2) Ensure the set screws are tightened on the x and y axis pullies. I suspect that mine have loosened due to 1) above (again, will try in the AM).
I am guessing that you pass x- and y- axis calibration, that the belt tension is correct, and there are no obstructions near the pullies. ( https://help.prusa3d.com/article/layer-shifting_2020)
Good luck!
Prusa is MK4S w/ MMU3 (formerly MK4 / MMU3, MK3S+/MMU2), 2 Prusa MINI+, Octoprint. PETG, PVB, (some) PLA.
RE: MK4S Upgrade X & Y layer shifts by 20mm
Are you using the speed profile? Try raising the nozzle temperature. I've found with the higher 4S speeds underextrusion is a problem. Raising the nozzle temperature can help.
Underextrusion can lead to crashes, causing the layer shift. Especially in areas of big infill where the sides are higher.
RE: MK4S Upgrade X & Y layer shifts by 20mm
I had this layer shifting problem on my factory-assembled MK4 when I started to use the IS profiles. After some time I checked and tightened all the screws on the printer and the problem went away. Check especially all the screws involved in the x and y axes, as @happykatz said. Screws on the printer tend to come loose(r) over time.
RE: MK4S Upgrade X & Y layer shifts by 20mm
Thanks for the feedback all! I'll give the machine a once over to ensure everything is tight, especially the pulleys (never thought about that). Yes it passes calibration but i'm going to give everything a once over today and try again. It is on a stable base and still seems to be contained between the bumpers of the Prusa enclosure so i'm guessing loose pulley or layer crash as suggested above.
This was a structural profile, i don't tend to use the speed profiles. You have ALL given me some good insight into other potential source of issues, MUCH APPRECIATED!
Will report back later after some maintenance!
RE:
Update on my end - pulley screws were reasonably tight, but the screws holding the motors and the extruder had loosened with the vibrating of the printer. After tightening these, I wanted to see if the problem persisted, especially if I could see evidence of underextrusion.
@brian-12, This appears to me to be what is happening: I am attaching pic below. Is this what you would expect to see ?
Prusa is MK4S w/ MMU3 (formerly MK4 / MMU3, MK3S+/MMU2), 2 Prusa MINI+, Octoprint. PETG, PVB, (some) PLA.
RE: MK4S Upgrade X & Y layer shifts by 20mm
It looks to me like the infill printed very poorly, which is what prints the fastest.
I'd try raising nozzle temperature 10C. What filament are you using?
The other thing I'd recommend is watching the print so you can see what's happening, especially when it starts the infill. If it starts to print poorly pause the print and take a picture.