Greetings Joe, I have used DRAPs in the past on aluminum sheet up to .187" thick. I drove them with a Procunier tapping head. I ran the DRAP as fast as I could without having to slip the clutch too much when the tap started to cut. I always used cutting versions and didn't even know about the form versions until I read your post. When used in one of your units do you run it at two different speeds? Slower for the tapping? Thanks, Eric