My problem is similar to my boolean modifier isn't cutting into my shape properly. I am trying to insert an M3 thread into the inside wall of a cylinder. I have part A an M3 bolt from the Bolt Factory, and part B a solidified Cylinder. I think that I need a difference operation. I think that I need Part B as the target to have the Modifier, and part A the bit providing the modification required.
If I juxtapose part A and B, and have the bolt as the target, I correctly lose the bottom threads of the bolt.
But if I try to operate on the cylinder B, nothing happens.
The answer to the similar question involved a prior Mirror Modifier but this does not seem to be necessary or if so why?
I am an 80-year old git, and really struggling! I can supply my shapes, but it is pretty basic in the scheme of things.