Thanks for the advice, kd 124. The back center of the frame wasn't meeting so the carriage would have to hop every time it hit center. I started taking it apart and found that the screw and screw hole don't match up. If you screw it in, it 's back to machine jumping, so it's out. I don't know if that's the reason for all the vibration, but it rides smoother now. Now that there's nothing on the frame, or anything about to go on the frame, I'll do your measuring and remeasuring trick.
Putting on the binding now...hoohoo, it's ALMOST done!!!!!!!!!
bev.