Review on Diameter Mandrels for Plywood, Drywall, and Plastic by Brian Cruz

I purchased this and a personal emergency arose which delayed my ability to use it until last weekend, March 29th. So this package was with me until the 29th. I drilled 4 holes and when I drilled the 5th the drill bit broke. It took over 2 days of drilling and not in one sitting. Drilled 3 one day, 1.5 the next. So since I ordered before I could use it, I can't return it (and haven't tried it, it's not their fault - life happens). Really mad at myself for not trying it out before my commitment to see if it works or not. He was very upset that he couldn't manage at least a few boards. Do not buy.