MMU3/extruder makes odd clicking sounds and fails to load the filament in one slot
I have noticed that sometimes, when I try to load a new filament into a slot in the MMU3, it starts clicking, and the filament (typically PETG) won't load. I usually have to pull it out and cut it at least a few times and just try again to eventually get it to work, but I don't understand exactly what is happening despite having built this MK4 and MMU3 from the kits.
Video of the problem occurring (with audio)
The filament can be passed all the way through Bowden tubes just fine, right up to the extruder. However, when I pull the filament back out, I notice it has some pretty deep grooves. I suspect that the little "gears" that pull the filament forward aren't working in this case, and maybe that is causing the clicking (but I don't believe this is the root issue). Any thoughts or help understanding what is going on would be greatly appreciated.
Thanks.
Sean
RE:
I had a similar problem and eventually figured out that it was the filament which had got hard and was holding the curve it picked up whilst on the reel. Then when it tried to feed through to the bowden tube it missed and hit the surround, it also occasionally missed by so much that the filament came out the side. This also got worse the further into the reel I got. Trying to sort this out I also ended up getting some broken bits of filament stuck in various places in the MMU which were a pain to remove.
As I wanted to get the job finished I swapped out the reel and picked out the broken bits from the MMU and that fixed it. I suspect the hard, brittle filament was caused by it being damp but as I've not need that colour since I've not bothered drying it and retrying but I will some time.
RE: MMU3/extruder makes odd clicking sounds and fails to load the filament in one slot
OK, had the same thing a couple of days ago. Stuck the filament in the dryer overnight and now it is switching in and out on the MMU just fine