Boolean Difference cuts wrong part

Hi, despite carefully clicking on the corner part then selecting my curved cutting surface, Boolean Difference removes the larger part of the base.

I wanted a 5mm radiused corner, failed with a sweep surface, those pesky feathered surfaces again. then tried fillet, and decided to use the failure there to act as a cutting surface, at least it cuts, but the wrong part.

Just how does one create a surface which is bound to be coincident as it goes tangent, for cutting away such parts, especially if I wanted an elipse section. there is no elipse fillet, wish there was.

BooleanDifferenceCutsWrongPart.3dm (96.3 KB)


You have an open surface so you have to manage the surface normal direction.
Use the Dir command to Flip the normal of the curved surface.
Then your Boolean Difference will work as expected.

Then read this FAQ: