Filament tube of death
Sometimes the filament will go through the tube to the extruder, sometimes it doesn't. It gets held up right before going into the extruder assembly. I DONT UNDERSTAND!!!
And if it does go past it, it won't go down far enough to be picked up by the gears. I think this a a setting, but I can't find it! Tried calibrating the mmu2 and it keeps going into a mode flashing all leds red and the only way I can get out of it is by restarting the machine.
ABOUT TO PULL MY HAIR OUT!
RE: Filament tube of death
All LED flashing red normally means, that FINDA detects filament on powerup. So check your selector for filament (or strings of it) before powering up your printer. And make sure the FINDA probe (and IR sensor) is properly calibrated.
You can reset the MMU without restarting the printer: There is a reset button on the right side you can press using the small allen key.
If the problem only arises "sometimes" as you mentioned you might have a problem with too much friction somewhere in your filament path so if your filament is bend a bit too much or varying in diameter it gets to hard for the MMU to feed it to the extruder so the loading is aborted. You can check the friction by manually load filament all the way to the end of the PTFE at the extruder (leave the service door of the MMU open, so the gears in the MMU don't cause any friction) disconnect the PTFE at the extruder and try to pull out the filament. Does it move smoothly enough? If not try to install larger ID PTFEs and/or the MMU passthrough adapter for example...
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