I have a Square taper BB on 2 of my bikes. Tried getting the cranks off with the puller, but after a couple revolutions it comes to a stop and can't be budged, even after hitting it with a hammer. (YES, I know I shouldn't do that, but it wouldn't budge.) This happens on both bikes. Does this sound like something I'm doing wrong? (I did it the way I saw on a video.) Could it be the puller not working properly? Or, a problem with the cranks/BB? Any other way of getting them off (without destroying the cranks, BB, or frame)?