Incorrect print during infill

Bambu Lab X Series Troubleshooting
1

Hello forum,
I hope someone can help me with my problem.

My X1C Carbon does not print the first layer of the infill correctly.
The first layer is perfect, the second layer is also perfect.
I have tried several types of infill in the slicer.
I use standard slicer settings for PETG.
I have installed a new nozzle (0.4mm) and also tried a new roll of PETG Basic.
The layer height is 0.16mm Optimal @BBL X1C on a Textured PEI Plate.

It looks like some of the extruded fillament is not sticking to the bottom layer.

20241010_093104
20241010_0931041920×1081 268 KB

I am grateful for any advice
thanks

2

Could you please share the .3mf file used?

It is recommended to double-check that you are using the PETG Basic profile and not the PETG-HF filament profile.

The PETG-HF filament profile has faster settings and could cause this problem with regular PETG Basic.

it is also recommended to check the volumetric speed limitation in your filament profile, which would be 9 for PETG Basic.

3

Thank you for your quick reply.

unfortunately I no longer have the .3mf file that belongs to the photo as I have already changed it.

But I have looked at the setting for the Bambu PETG-Basic.
There is a max. volumetric speed of 13.
I think this is the setting for PETG-HF.
I have now changed the value to 9.

I have just carried out a test print.
Everything is fine with the new value of 9.

However, I can’t explain why it was set to 13