Chamfer: BRep_API: command not done - on a bspline wall

Is there an existing issue for this?

• I have searched the existing issues

Problem description

I have reduce the problem on a simple geometry - i call it bspline wall (thinkness of the wall is 2mm). BSplineChamferBug.FCStd.zip

I need a chamfer on the upper inner edge.

If i create the chamfer on the outer edge, all works fine:

If i try to create the chamfer on the inner edge ... ... it fails with the error output: Chamfer: BRep_API: command not done

The problem seems not to be related to the relation between "wall thinkness" and the chamfer length. I have try the chamfer lenght of 0,1mm - 1,0mm and all produces the same error. The problem seems to be related to the base geometry of the "wall" (extrution), because in some cases the inner edge is posible and the outer edge chamfer fails - in some cases the inner edge chamfer is posible/working.

In the Freecad 0.21.2 it seems to work on the bspline-eight base geometry: BSplineChamfer0_21_2.FCStd.zip

The problem seems a litle bit related to the base bspline form, because in some cases the inner edge chamfer is working and the outer not - in other base-bsline geometries, the outer is working and the inner not.

I'm aware, the length of the chamfer is need to be shorter than the "wall" thinkness - but i can not see a rule, in witch cases the chamfer is not posible (and ends in the error BRep_API: command not done).

Full version info

OS: Debian GNU/Linux 12 (bookworm) (lightdm-xsession)
Word size of FreeCAD: 64-bit
Version: 1.0.0RC2.38806 (Git) AppImage
Build type: Release
Branch: (HEAD detached at 1.0rc2)
Hash: 3d63fc6c2f665a8d5e6468845a419bcac80756c7
Python 3.11.9, Qt 5.15.13, Coin 4.0.3, Vtk 9.2.6, OCC 7.7.2
Locale: German/Germany (de_DE)
Stylesheet/Theme/QtStyle: unset/unset/Qt default
Installed mods: 
  * Manipulator 1.4.9
  * 3D_Printing_Tools
  * fasteners 0.3.50
  * BOLTSFC
  * Assembly4 0.12.2

Subproject(s) affected?

None

Anything else?

I now also checked the problem at ...

OS: Debian GNU/Linux 12 (bookworm) (lightdm-xsession/xcb) Word size of FreeCAD: 64-bit Version: 1.1.0dev.39092 (Git) AppImage Build type: Release Branch: main Hash: a65d05c6e495038168eefcba6a1e43218fbb3a20 Python 3.11.9, Qt 5.15.13, Coin 4.0.3, Vtk 9.2.6, OCC 7.7.2 Locale: English/United Kingdom (en_GB) Stylesheet/Theme/QtStyle: unset/unset/Qt default Installed mods:

• Manipulator 1.4.9
• 3D_Printing_Tools
• fasteners 0.3.50
• BOLTSFC
• Assembly4 0.12.2

... and it still exists on the dev build.

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