Originally Posted by patdesign
Lately I have found that many of the new metal bobbins both for my 401 and my 15-91 DO NOT FIT or operate properly in the machine. Only the old ones work. Lots of the new ones especially the 401 bobbins just build up birdnests, and I do know which way to insert the bobbin, the 15 91 bobbins are so poorly machined you can see the little slot is not straight, and that little slot is what makes it fit downon the bobbin winder post.:)
I bought class 66 bobbins from WM and from Joann. They do not work. The class 66 bobbins I bought from sewclassic work just fine. My sister and I got a price break when we ordered 100.