Filament stuck while unloading at the end of the print
Lately, when a print is complete the filament will get stuck in the extruder unit while trying to unload. This happens about 40% of the time. It will try to retract the filament for some time and then error out and say that the MMU is having issues and the extruder enters cooldown.
To get the filament out, pulling on it usually doesn't work, nor is the filament held by the extruder gears. I need to reheat the extruder and grab the filament with my fingers and push down while using the control panel to move the extruder motor. Once the extruder gears are in contact with the filament, I continue to drive the extruder motor until filament is coming out of the nozzle. At that point, I'm usually able to go back to the "Unload Filament" option and it unloads the filament correctly.
Any ideas why this could be happening? My theory is that the filament gets a bit of a mushroom at the end which makes it too large to be pulled through the hole.
RE: Filament stuck while unloading at the end of the print
Same thing is happening to me. The filament tip is clean and I can manually pull it through with no issue. It may be a firmware issue that needs to be resolved.
RE: Filament stuck while unloading at the end of the print
Looks like similar issue in the German forum (Chrome translating for me): https://forum.prusa3d.com/forum/original-prusa-i3-mk2.5-mk3-multi-material-2.0-hilfe-zur-hardware-firmware-und-software/fw-3-8-0-probeme-beim-entladen/