Latest recommendations for "failed to pull out the filament"?

Bambu Lab X Series Bambu Lab X1C
1

I’ve had my X1+AMS for a year but never used it to print multi-colors until a couple of weeks ago. The one and only print I tried worked flawlessly. Fast forward to this weekend, every single multi-color print fails with “failed to pull out the filament from the extruder…” when switching from one color to the next From this forum and Reddit, this seems to be a common error, but not one solution. Of the things I’ve tried, it hasn’t made a difference.

Additional Info:

  • If I click retry 2-4 times then I can usually get it to release
  • If I wait and let the printer cool down and click retry, then it works (only test a few times)
  • If I press the PFTE collar down at the hotend and yank out the PFTE tube, I can get it to “release” and then it retracts just fine. When I do this the PFTE comes out with some of the filament exposed. The end has a thin little “tail” which I think means it was still in the “throat/heat break”.
  • I also found if I tap/bump the PTFE Extruder Bracket while it’s trying to pull back that will “release it”.
  • There’s never a clog, but it does feel like it’s “stuck” in the extruder and not upstream toward the AMS
  • I removed my Y-splitter, but no change
  • I printed the Bambu X1 PTFE Extruder Bracket but no change
  • It happens with BambuLab brand PLA (plastic spool) and Overture (cardboard spool) and happens in all four slots.
  • I’m printing with the glass off and the door wide open.

So, what else should I try? I really don’t want to deal with BambuLab support so hoping you guys have some wisdom.

2

Have you checked out the extruder? Especially the filament sensor. Make sure all your ptfe tubing is cut square and fully seated.

3

Besides a square end on the PTFE tube what should I be looking for in the filament sensor?

4

Check if the PTFE tubes need replacement: PTFE Tube Wear in AMS and Maintenance Recommendations | Bambu Lab Wiki

5

Lots of dust, maybe a very small piece of filament. The switch is moving free and not hanging up on one side or the other.

6

I have 5 X1C’s running and was getting this non-stop. I tried a whole bunch of fixes and after doing these: AMS Fix Failed To Pull Back Filament Error by SPStudio - MakerWorld I don’t think I have had a single issue in the past 3 months. I put the update design in the bottom of each AMS to align to tubes plus I put the plastic bracket before and after the buffer to hold the tubes straight in. There are a few versions, I printer one that also holds the AMS cable neatly as well. Highly recomended.