Originally Posted by
Barb_MO
If bobbins are interchangeable why can't you wind different bobbin on a particular machine. I have three Janomes and one Bernina and I can use one machine to wind bobbins that I use in another machine.
Bobbins aren't interchangeable unless they're the same bobbin size. Bobbins are manufactured to specifications, and sometimes the differences in specifications are hard to see with the naked eye; the hole could be slightly smaller, or some other dimension different by just a couple of centimeters.
Makes a difference to the machine, though. I once "fixed" a machine that was brought to me because it jammed when it sewed. Owner said it worked fine until she ran out of thread and inserted a new (plastic) bobbin. Turned out the new bobbin was not quite the same as the old bobbin, even though they looked very similar. When I looked closely, I could see that one had slightly curved edges while the other was straight.