If you've got a good machine shop near you, they can build up the spool and turn it down. They'll also need to bore out the hub and install a bushing. I've had it done on many occasions, and it works well. Make sure that they build up the spool with either millable hardface or just steel rod. One guy used bronze, and it was shot in a hundred hours. It's pretty expensive, as machine shop stuff goes, but it's cheaper than the new stuff. You also might want to check the balance on your pulleys. They get worn and out of balance. It makes them bounce and put a strain on the belts. You might want to have the faces cut back to flat, then balanced. It seems to help. Good luck!