That is how I do it too. Get the shaft pretty straight before you spin it up. The belt sander will take out minor imperfections and keep the shaft round. I second what DC said. I once had one come out of the drill, and get shot at high velocity (that happens fairly often). This one hid the door, bounced back, and hit the underside of the belt, and get shot back in the opposite direction. Couldn't do it again if I tried, but it was a big surprise.