Ok. I was trying to apply my CAM softwares thinking when it is parsing arc and such. The post processor has several setting for various machines and software outputs.

Break arcs into quadrants. Combine more than 180 degrees. Etc… etc… something about signed arcs and the processing into xyz coords that the machines controller reads. There are tons of controllers. Not all created equal.

Was taking a guess at what “lock tangents” is actually doing or setting in the step file with regard to arcs. Was trying to figure out if yyspipebender is actually trying to post process the geometry and needed one of these specific settings

Maybe if we can see the 2 stp files we can figure that out…