Faulty gcode generation with hex grid

strayr commented 3 years ago

Version

2.3.0+win64

Operating system type + version

Win 10 Home 20H2 build 19042.804

3D printer brand / version + firmware version (if known)

Not relevant, is g-coge generation bug, verified it's NOT a gcode display bug by printing on an Ender3 4.2.2Melzi board, Vanilla MArlin 2.0.6.1 bugfix

Behavior

Incorrect Gcode generation Attatched STL generates incorrect gcode on one side of hex grid. STL producing faulty G-code does not appear to be of inconsistent shape, looks fine in F360 and converting to BREP and exporting as a new mesh generates the same issue.
Steps needed to reproduce the problem Slice model, have tried Prusa MK3S & MK3S+ and Ender3v2 printers likely printer independent, appears independent of filament, reproducible on all system presets, and pn MK3 and Ender 3 quality presets from 0.24 and finer. Assuming only dependency here is sufficient layer height resolution.

BIT_bio_genesis.stl_03.stl.zip

Expected Results Uniform layer count for hex grid, Cura generates consistent thickness. hex grid so I doubt it is the STL is at fault. Should look like this at every edge.
Actual Results

Note the hex grid is only one layer thick on one edge. prusa slicing

Is this a new feature request? NO

Project File (.3MF) where problem occurs

Reproduced here using only system presets BIT_bio_genesis.stl_03-bugreport.3mf.zip

strayr commented 3 years ago

An update: I have redrawn the original mesh in F360 with a deeper grid because i felt the original was flimsy anyway. I'm still getting the slicer failure in prusaslicer. I'm wondering if it's a quirk of the geometry.

It's not happening in superslicer 2.3.55.

03 Thick Mesh Top.zip

rtyr commented 3 years ago

The missing parts of the model are too thin for default extrusion width. If you look closely, you can see that the walls are visibly thinner in that problematic area (I guess it was not intentional). Most of the default profiles use smaller extrusion width for first layer.

You can either fix the model or just use smaller extrusion width for this print.

thi

rtyr commented 3 years ago

BTW it would be probably better to make the bottom of the box solid and then slice it with 0 top/bottom layers + honeycomb infill :-).

strayr commented 3 years ago

The missing parts of the model are too thin for default extrusion width. If you look closely, you can see that the walls are visibly thinner in that problematic area (I guess it was not intentional). Most of the default profiles use smaller extrusion width for first layer.

I couldn't even see that trying to figure it out in F360. It's not my model, and was originally OpenScad. I've rebuilt it, but I was looking at it for Z thickness being wrong and it didn't occour to me that it was a X-Y thickness. Thanks for the help and sorry for wasting your time with what wasn't a prusaslicer bug.

rtyr commented 3 years ago

No problem. Closing.

prusa3d / PrusaSlicer