Jam in filament sensor chamber in extruder body
I've recently got the MMU2 upgrade, but haven't had a lot of luck with multi-material prints. Now I'm having issues just doing single filament.
I've managed to get a jam / twisted PLA filament in the "sensor chamber" in the extruder. After clearing it once, and happening again, I noticed the PTFE tube above the chamber (going into the Filament Sensor Cover) got warped and jammed into the Cover (it no longer protrudes into the extruder).
So I'll replace this with fresh PTFE tube. Also the Filament Sensor broke and gives a connection error now (no big deal, as it was disabled anyway).
I suspect it could be heat creep making the PLA too soft (snaps when I tried to pull it out), or excess friction downstream in the extruder body (so jams up when doing a load filament) , or the new MMU2 getting stuck and causing a jam during filament unload, as the extruder pushes the filament up., ruining the PTFE above.
Thoughts?
Re: Jam in filament sensor chamber in extruder body
I just finished upgrade my MK3 extruder and assembling the MMU 2 and I think I'm having the same or similar issue with the PTFE tube (new one) with the new sensor cover that has the brass coupling inserted. For me even manually pushing filament into the new cover sensor brass coupler would not work it would get stuck before getting to the idler area. When I looked at it from above while a light shinned brightly it seemed a piece of the new extruder printed part was blocking the filament. Sometimes it would go thru if the PTFE tube moved a bit, but that is only when the cover was off and the tube could actually be moved around a bit.
I haven't completely resolved this yet but I did use a 2mm drill bit to remove the offending bit of black plastic and it is working better now.