Slicer acts differently for .6 vs .4 nozzle?

Bambu Lab X Series Bambu Lab X2D
1

Trying to print some Fiberon PA612 on my X2D. I almost never use .6 nozzles but with the simplicity of swapping I thought I’d give it a go.

I’m struggling with curling on a mild overhang (30*). I noticed while going over everything that the slicer only detects the overhang on one axis and not the other (it’s a two sided sloped overhang with identical angles). This made it only activate overhang fan for one side and not the other.

I also noticed it was giving me 10% aux fan on both sides despite no aux fan enabled (it didn’t show it in the slicer preview either). I do have chamber temp set to 0 as Fiberon requires no heated chamber and seems to discourage it but I don’t know why it would activate at all.

I swapped back to the .4 nozzle and the slicer now recognizes both overhangs identically and does not turn on aux fan at all. Why would this happened just based on changing the nozzle size? Makes trouble shooting a complete nightmare when the slices does random unexpected behaviour like this.

Appreciate any thoughts.

2

Sounds like bug.

Do you see the same behavior with different sizes like 0.2 or 0.8?

Also on different files? If you try to recreate it with some primitives? Some things to troubleshoot.

3

Some screenshots or the 3mf/stl in question could really help understand the nature of it

4

The slicer really only does random things when the 3D model is corrupted. That’s why it’s almost essential that you upload the 3MF file to the forum.

I remember a case where a user had a similar problem, and it turned out that the model got messed up during export, which then caused issues with overhangs and supports - completely by chance.

5

Sorry I should have taken screenshots for sure. The corrupt model theory is interesting so I will check that. I noticed with the .4 nozzle that aux fan still comes on, so that’s not nozzle specific but the overhang detection certainly was. I will reattach the .6 and see if I can re-create once this prints done.