I don't know if the manuals would help or not. I've only tried on a couple of machines. The bobbin case on a 620 was all messed up and I was able to get it set and was able to sew a cover for the manual and foot controller bag. The Pfaff 1222 I tried at least a half dozen times and thought I got it so that it would stitch properly. I put it away and when I got it out again it was off again. It is still in "time out"
Janey - Neat people never make the exciting discoveries I do.