Hi everyone, I hope someone can help with this. I've got a MK3 with a MMU2 extruder. It has worked fine for several months, but this last week it has started doing something weird: the extrusion seems to stop and start intermittently (see the image below). The only other symptom I can describe is that the extruder occasionally makes a high-pitched sound like metal slipping against metal (but I've never seen the gears slip, even when trying to force them to slip by pulling on the filament). I have gone through every troubleshooting step I can find with similar issues, but none of them have worked. I have:
- Cleaned the nozzle
- Replaced the nozzle
- Tried different filament manufacturers
- Tried different filament types (ABS and PLA both had the same problem)
- Updated firmware of both MK3 and MMU2 (was already up-to-date, but tried anyway)
- Re-leveled bed
- Adjusted z-calibration
- Adjusted extruder tension
- Cleaned the extruder pulleys
- Greased the extruder gears
- Tightened the extruder pulley/gears to the motor shaft
One more note, at one point it started working again. I got several flawless prints, and the only thing I did was to power-cycle the unit. But then after a few days (and power-cycles) it went right back to intermittent extrusion, and power-cycling did not fix it this time.
Basically, I've done everything short of disassembling the extruder and rebuilding it. Before I take this drastic step, I was hoping someone here might have some ideas. Thank you!