Hi Michael,

Now we're getting somewhere. The washer works if it's exported with analytic surfaces:

WriteAnalyticCurves=n
WriteAnalyticSurfaces=n
- fail

WriteAnalyticCurves=y
WriteAnalyticSurfaces=y
- success

WriteAnalyticCurves=y
WriteAnalyticSurfaces=n
- fail

WriteAnalyticCurves=n
WriteAnalyticSurfaces=y
- success

But, going back to the bent part we started with, .stp files of your "119 R063 sendcutsend3.3dm" and "119 R063 sendcutsend2.3dm" exported from MoI with WriteAnalyticCurves=y and WriteAnalyticSurfaces=y fail with the same error when uploaded to SendCutSend.

If I try uploading a .stp exported from "119 R063 sendcutsend.3dm" that I originally posted with the non-analytic planes generated by Sweep, but now exported with WriteAnalyticCurves=y and WriteAnalyticSurfaces=y, I get a new error "This STEP/STP file has an inconsistent thickness and cannot be manufactured."

Re:
> Does "good.stp" come from sheet metal mode in SolidWorks?

I downloaded it from McMaster-Carr. No idea of the software origin beyond what's in the header.

- Peer