Art, how new is this big Powermatic? I'm asking because if you aren't the original owner, someone could have done something to it earlier in it's life that wouldn't be detected. I had the same problem before with a Delta Homecraft I bought used in '83. It was complete with a Delta motor and step pulley. All I did was mount it to a bench, and turn it on. I had this one spot that always left tearout, was never completely balanced, and I couldn't figure it out. It wasn't until 2009 that I just happened to be looking at the motor pulley as it was winding down and saw the pulley was out of round. It turns out that the motor has a 1/2" arbor, the pulley has a 5/8" hole, and the bushing was about 1/2" x 9/16". There were no problems after I corrected things.... Jerry (in Tucson)