Anyone who ever gets a chance should attend a Ray White machine repair seminar. His web site has a listing of sites. We had him come to our town and it is not hard to do. You find a place, perhaps a LQS, for as cheap as you can and play host. You used to get a discount if so many came to the seminar. He also holds classes in MO, where he lives. He also brings lots of supplies and parts and sells them cheaper to students. Ray used to have a CD with lots of manuals on it. I don't know if he sells it on his website or not. Whitesewingmachine.com, I think.