P1P Filament Run Out/Resume to Layer Shift

Bambu Lab P Series
21

I think you need to be completely Bambu Lab stock hardware, no modifications, no 3rd party parts, no 3D printed parts.
The problem, like mine, seems to only occur during a color change so what’s that tell you?

  • there is some hard obstruction in the tool head path
  • uniqueness during the change color routine only
  • no hard obstruction over the hotbed

could it be the filament wiper? I dont think so because it’s quite flexible.

go back to stock.
turn off the printer and manually move the prinhead around and see if you can feel any change in the movement.
look closely around the back left corner X/Y belts and cabinet back plate.
I think the problem is in that area and the only thing I dont like is the non-stock printhead front cover, at least the bottom cooling part.

Show the video with a stock cover

22

The problem was related to too high belt tension, the rezonance measured with the Prusa belt tuner shows that above 75 Hz problems begin, I have now set 65-70 Hz and it is ok

23

the problem is caused by non standard accessories, usually something around the parked print head. The printer will do a layer shift only after the first color change, regardless of the layer #. Mine was caused by a motor cover in the back left corner for X/Y. As soon as I removed it the problem never came back. Manually moving the print head around never gave me an indication there was an obstruction. Lesson learned - very few non standard accessories are good else Bambu Lab would have included them.