Extruder teeth eating away filament

Bambu Lab A Series Troubleshooting
1

I have been using my A1

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for about 5-6 months now and this problem startin 2 months ago. Randomly it eats away the end of my filament like shown in the picture and just stops extruding. It happens randomly. I can finish 60 hour prints without problem but then it just does this after 10 min. What could I do?

2

This will often happen when there is too much nozzle pressure which is normally cause by trying to print too fast, the nozzle temp being too low or a partial/full clog. The filament can’t be pushed through the nozzle at the rate that the printer is trying to and thus the extruder chews through the filament. Another problem could be the filament width being over the spec in that section.

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3

Any chance you lost the bearing that supports the long side of the extruder shaft?

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4

Nope, I still have that, took the extruder apart and cleaned it but no result

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5

could the problem be that one time the print let go of the plate and the filament built up on it? A lot of filament was in the heating part but I mostly cleaned it. There’s still some residue but it’s usable. Can this cause heat problems?

6

I would say that this is caused by too much force on the filament, making it eat away at the gear. Causes my include:

  • ambient temperature too high, making the filament too soft and easier to “eat away”
  • nozzle a bit clogged, still letting the filament to go through but requiring more force
  • filament path causing too much resistance (worn PTFE tubes, for instance)

You can try:

  • replace the nozzle, if you have other to spare
  • replace the PTFE tubes (or try to print with only one filament, without the tubes)
    Any of these will reduce the force required to push the filament and (hopefully) stop “eating away” the filament at the gear.
    Just my two cents.