Hi All Using a ball nose end mill, I need to make some radial cuts in a hemisphere. Think of the slots as the five arms of a star. They eminate from the top of the hemisphere and then go down the outter edge to the bottom of the hemisphere. The ball nose is a 1/8" CD and the depth of cut will be 1/8". What I am making is a guitar knob to be afixed to a solid shaft. So I'll start by drilling a shaft hole in the brass rod, cutting off the 3/4" brass to be rounded, placing this brass "slug" on a shaft in the lathe, cutting the hemisphere and then drilling a side hole into the shaft hole for a set screw. With all that I should be able to take this hemisphere knob and afix it to my rotary table. How do I cut my grooves from there?