1. Straight-Shank Drill Chuck Arbors These Arbors are compatible with straight spindles, which are most often found on manual lathes and CNC machines.

2. It is essential that only a variable speed drill with a 3/8" chuck be used and that the Castrating instrument be tight and secure in the drill chuck

3. To get started, place the Crowning ball (round-head brass screw) in the electric drill chuck and apply a liberal amount of the abrasive material both to the screw head and at the mouth of the bore