Rectangular 1st layer defect on part of the build plate

Bambu Lab X1 Series Troubleshooting
1

My last few prints have a very strange 1st layer defect, almost perfectly rectangular, covering a small area on the right rear side of the build plate (see pictures).

The first few prints I noticed it didn’t cover the whole area, so I thought the rather old textured sheet had become bad and replaced it with a completely new sheet. Yesterday I printed a large sign and noticed how uniform the defect is, which is quite puzzling tbh.

I have since replaced the complete hotend assembly and run the full calibration, just to make sure. I’ve printed a small test square, same problem.

So to sum it up:

  • Did exchange the textured sheet for a new one
  • Replaced the hotend
  • Run calibration
  • Tried Polylite PETG and Bambu HF PETG

Does anyone have an idea what might be causing this?

IMG_3682
IMG_36821676×1568 331 KB

IMG_3683
IMG_36831920×2050 557 KB

2

Factory reset didn’t help either.

3

Can you provide the .3mf file you are using? It’s a very odd problem. Does the gcode preview give you any idea of what it going on?

4

It happens with every model. For testing before/after factory reset I’ve just created a primitive, in both Orcas Slicer and Bambu Studio.

5

Does it do it with the prints that come preloaded on the printer?

6

Thanks for the suggestion, I’ll have to check. But it happens only on a small part of the rear right corner, not sure if any of the pre-installed prints covers that area.

7

deextrussion

8

Yea, whatever.

I think this is some strange firmware bug, where the bed leveling reports wrong values for that quadrant and subsequently causes the toolhead to print in the air on that specific part of the plate :man_shrugging:

9

but to me it seems like a deextrusion

10

Why would that happen on a specific part of the build plate, with every model and even primitives like a small cube? And did you notice the shape?

11

on specific part of the build plate go check gcode

12

As I said, it happens wirh any model. I even generated primitives in different slicers.

13

idk neither