In the attached file I have three surfaces (Gray, Purple, Red). Red started out as Purple with the ends cut down.
If I do a boolean difference of Gray - Purple it works.
But, if I do Gray - Red it fails. In fact I cannot do any split between
If I do a intersection the cap is here:
But it is not clear to me why there is a gap here at all.
I have to doubt it has to do with tolerance because I have changed that up and down with no effect and it works with the purple.
What is preventing the difference? Or Split?