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MMU2s Idler position lost during print  

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MMU2s Idler position lost during print

So last Thursday my mmu2 unit arrived and since then I had the worst weekend in my 3d printing life...

Been using the mk3s for quite some time (and before that for 2 years a Chinese Prusa i3 clone) and was changing to Mosquito hot-end due to heat creeping issues a while ago. since then the printer was working perfectly.

After assembly of the mmu2, I simply could not get a successful filament change until the 4th go, when the selector blade kicked in. The tips for simply too thick (although perfect to Prusa manual and the fact I also changed the mosquito heat break with v2 which is wider). After mmu2 cut the filament it mostly loaded ok but jammed after sone 10 cuts because of waste filament ends got stuck somewhere in the selector.

So I tried a complete Hotend downgrade back to the original E3D V6 with the original Prusa MK3s Heat break. After that, it seemed all work well.  The only issue seems again to be my mood going from filament buffer to auto rewind spools and it happed sometimes the filament was pulled out of the mmu when extracting the filament and rewinder was to strong.

recognized the issue eliminated autorewind spools and got real confident it will work... multi-color print about 30 tool changes in all good when the idler lost position.

 the selector was ok, filament tip perfect, only the idler bearing was not lined up with the correct filament input. After some searching online I could solve the print by resetting only the mmu which homed position and continued printing. soon the problem repeated. Again reset solved the issue.

But I do not want to babysit my printer through 15+ hour prints.

As read on the web this is a known issue, only solution found is reset of the mmu. Hope Prusa Team will do some modification to the firmware in the future.

But if not/till then can somebody help me with a temporary fix, like adding mmu2 home command to every 5x or 10x tool change?

That would most likely solve the issue I have an not cause any new ones...

any advice on how to do this?


Thank you


Posted : 23/11/2020 9:07 pm