sorry for this late reply. i know of no way to make figures collide with each other. honestly, i don't even know why that is in the menu. there has often been grousing about that with this program. sadly, you must simply be careful how you place things. working with magnets, you can make one part of something displace another part of something. but that is pretty complex in itself. as far as i know, it simply comes down to very tedious placement of objects. best to have mutliple views open upons placement. so sorry. if i am wrong i certainly hope someone will speak up, but i don't think that is the case.