Erroneous fillet during STEP file import

Rhino Rhino for Mac
1

Importing the below STEP file into rhino leads to a wrong fillet. Basically it rounds an outer edge what should in fact be a rounded inner edge. The STEP file was created in FreeCAD-1.0.0. Importing the STEP file into FreeCAD itself or Autodesk Fusion gives the correct results.

erroneous_fillet_during_step_import
erroneous_fillet_during_step_import1518×1374 64.7 KB

erroneous_fillet_during_step_import.step (22.5 KB)
erroneous_fillet_during_step_import.3dm (3.2 MB)

2

Thank you for you feedback, but I also get the same result after imported it to OnShape,

StepIssue
StepIssue1090×717 83.7 KB

StepIssue2
StepIssue21551×1041 126 KB

3

Look for an option when you export from FreeCAD to “Split closed surfaces”, “Split periodic faces” or something similar.

You might try IGES instead of STEP.

4

It turned out that this is in fact a regression defect in the CAD kernel (OCCT) used by FreeCAD. It will be fixed within their next release.