This one was based on an earlier study I did (NG623) where I was machining away the outside circumference of a circular hole pattern to create an interesting detail. In this case it is a internal and external hole pattern. And the two halves that sandwich the orange center ring use a large diameter but very fine threaded flange to thread into the ring. It was a first for me to use that kind arrangement but It was a problematic shape to assemble and was a great problem to have to solve.
