This is an 'air pass' to demonstrate how the Circle Segment tool works in one of my applications. The radius of the part where it's being finished is smaller than the radius of the outboard arms, yet 'in-line' with them, making this a very difficult surface to obtain a very smooth finish like the one I attained here, using only conventional cutter geometry. This is programmed with GibbsCam, using the Morph Between Two Curves strategy.