The "low profile" holder eliminates the need to remove the compound. The turning head is recessed enough so that the cutter is aligned with the center line. Using the flat head socket screws also helps provide clearance for the handle, which is also bent up at a slight angle. The photo on the left shows the graduated rule, and the scribed line at the center of rotation. The sliding tool holder is adjusted for the desired radius for the ball being turned. The assembly is rigid enough so no flexing occurs when turning. Since light cuts must be taken anyway, flexing is no problem.
