Hi Michael,

>>>definitely a bug in the booleans there, I will put it on my list.

May I ask what that list is for?


>>>Sometimes saving and reloading can make a difference because when a sphere is first created it has a special mark on it that labels it as a surface of revolution.

Saving / reloading to make simple boolean is really quite a strange way of working. But as simple example that will not always work:-


Boolean union made after save/ exit progam/ reload.(test.3dm)
I do see that on such a simple boolean that it does depend on where the (what I call) the split line is located on the sphere and how this interacts (the position of it) with the top of the cylinder.



I did start to create a chess piece, but have dropped it, as I am having a number of problems with further booleans on the head.