Print dramatically failed, never seen before

[Engineer]

Alright. First, this is not a hardware bug, definitely not. I just put the model in Bambu Studio, printed again – same result:

What happens if I cut the piece? Nothing, it prints as expected:

I measured at which height the problem occurs: 6.25 mm. That means, the error happens at about layer 31 because the layer height is 0.2 mm.

First, have a look at layer 30:

But now, look at layer 31 :

And when I go deeper, I finally confirm that this is a critical slicer bug which is able to destroy your printer if you leave the printer printing over night:

I suspect “FEATURE: Gap infill” is where it starts. I can confirm that from the preview it is as slow as in real:

The feature is found at Quality > Precision > Arc fitting.

See the difference when enabled and disabled:

I made a bug report now here: Critical Slicer Bug: Quality > Precision > Arc fitting · Issue #3886 · bambulab/BambuStudio · GitHub

[RocketSled]

Your conclusion seems right to me. Slicer bug. Repeatability is a data point I didn’t get before.

I’ve run in to funny slicer things myself. Like supports that aren’t needed, or that are square shaped. Moving or rotating the part slightly corrects the problem.

[Kalvin]

This is definitely an issue with the slicer where it puts in lots of bad gap infill. Sometimes it does this in mid-air, causing the ‘blob’ to fall to bed or the print below.
I’ve had this issue for over 6 months and it shows mostly where there is a very fine curve in the model and there is a gap in between the inner and outer walls. This has been reported as a bug and there have been several changes in BS over that time that don’t actually fix the problem, but rather just moves it to another location.
The only work-around that I have at the moment is to set the ‘resolution’ for arc fitting to ‘0.001’ OR by turning off arc fitting.
The model that has given me the most problems with this issue is Wheelie bin - Trash or storage by Every Day Counts - MakerWorld

[salt.wei]