Hi ..
I have been working all day on an old large model created in Rhino and decided to stay in Rhino rather than take a chance on losing my layers and material assignments.

But ... I had to do what I thought was a rather simple boolean subtraction. It failed a number of times even when I rebuilt the objects from scratch a couple of times.

So I saved the couple of objects that failed in a new file and opened them in MoI and performed the boolean difference.

Immediate success!

Bravo Michael.

thanks
eric