Newly installed MMU3, prints look good but crashes on wipe tower
So I just got my MMU3 assembled and installed on my MK4S yesterday and so far on 2 test prints, it has printed the object just fine but the wipe tower looks like a mess with gaps and places with filament sticking up so the nozzle hits it. Those ones finished, but then we tried the 2 color Benchy and it didn't finish because of the wipe tower issues. The strange thing is that the object itself prints just fine. We're running Overture PETG with the test models Prusa has on Printables (obviously changing the filament type to be correct in the slicer because it seems like every multi color model and file is set for PLA). The photos show it really well but they're big so I had to zip them. Anyone have this issue in the past? I couldn't find anything with the search function so sorry if this has already been addressed and solved.
RE: Newly installed MMU3, prints look good but crashes on wipe tower
FWIW, the MK4S is on firmware version 6.2.6+8948 (to fix an issue where it would stall out and never load in the filament, as suggested on another post) and the MMU3 is on version 3.0.3.
RE:
I consider it a bug, the nozzle spends too much time too close to the wipe tower surface while the MMU swaps filaments:
- the nozzle melts into the wipe tower
- any dripping filament builds blobs that eventually catch the head
My solution is a custom tool change G code e.g. G1 X10 Y10 F5000 that moves the head to an empty spot on the print bed while the MMU is busy. For small prints also G1 Z10 F5000 works but this will crash once the wipe tower exceeds 10 mm in height (adjust number as needed but it gets slow).