Question to all those with the gear driven, potted motor 15-91's. WHICH is the correct bobbin to use?
Hurray! I just picked up my 2nd vintage machine, a 15-91.
But... with the machine came two different types of class 15 bobbins.... one set was def. a class 15, straight sides, NO holes other than the thread out hole. The other handful, are the class 15s that have evenly spaced larger holes all around, on both sides.
I've heard that the old Singers tend to sew better with vintage bobbins specific to the machine... which ones do I use? want? Or are they both okay? What's the difference? Well, I guess the ones with all the holes are lighter, of course. Since the 15-91 is a vertical bobbin... which one is better for it?