Here’s an odd one I encountered:
In the attached, if I try to do a boolean difference subtracting the vertical shape on the right from the ring shape:
I get this:
I cannot find anything wrong with it. SelBadObjects does not get it. Zoomnonmanifold does not get it. Rhino says it is closed but every display mode showing surfaces displays an open object.
Problem Subtract.zip (560.2 KB)
Problem Subtract_pc.3dm (946.7 KB)
You might try breaking your cutting volume into smaller chunks, or mirror the other side if it is symmetrical. Tried it on a PC and Rhino thinks the problem is here:
My own guess is that there is something wrong with the Ring shape before you attempt the Booleen difference. I do a fair amount of Booleen differencing in my work, and that’s usually the source of problems.
I assume you are trying to get full thickness “grill” lines vs. just the top surface in your image given the two gaps in the subtracting solids.
