Tried quite a few things before gritting my teeth and buying this. Used Bob's cnc 4 machine to cut holes in PVC for RGB lighting. I can't believe people still use step shank drill bits to cut holes. This attachment reduces the stress on your machine and reduces the torque applied to the workpiece. For an exact cut, you do not have to constantly readjust the workpiece. Cut 50 holes in 14 minutes. Will switch to channel J next year. With this bit, the process will be several orders of magnitudeβ¦