Boolean Difference

For some reason I cannot subtract the red surface from the black. Ive checked direction. I moved the oval curve out a bit so that the center is off the black surface. Ive also tried boolean 2 objects. Ive also checked and unchecked the refit rail option in the 1 sweep. I’ve tried 2 sweep. What am I missing here?

CheersBoolean Issue.3dm (14.1 MB)

Hello - there is an extra, degenerate - super skinny -surfaces in each object -

Explode the objects, delete these skinnies and on the red surfaces and the outer black one, run MakePeriodic to close up the seam there where these surfaces are removed. Then Join and Booleans should work.

image

-Pascal

Thanks Pascal

How did these get there in the first place?
I extruded the black object from two circles and the red object was a seep from an oval curve.
Where did I go wrong?

Hello - the outer black surface is not from a circle, it’s from a more or less circular curve, originating… someplace…

-Pascal

I see that now. What about the red object? It is a single curve with no apparent artifacts.

Hello - I don’t know how you got there… but two circles and one ellipse is all you need to get the thing you want here.

Boolean Issue_PG.3dm (115.9 KB)

-Pascal