Originally Posted by
JJBlaine
Not sure if this applies to your machine, but I found that with my 99K, I had to track down original vintage bobbins. The new size 15's I bought did not fit on the winder at all, and caused all kinds of issues with the stitches. Once I found the vintage bobbins, she sews like a dream!
The 66, 66K, 99 and 99K machines take a class 66 bobbins.
Janey - Neat people never make the exciting discoveries I do.