I haven't seen real many worn out bobbin cases - I've seen human destruction and rust...

That's what I don't get. .... what part's wearing out? Two different quilters have told me that though. She test sewed the machine a friend was buying for her daughter well,... but using it doesn't mean understanding it I guess... Perhaps that's what a technician was telling her and selling her parts?

or a plastic wonder sewing machine???

Could be. So what would wear out? The bobbin falls through the bottom? too much play on the sides? I suppose it depends too on which hook system. Most of the cheapies use the class 15 system... but that's a metal case... so this would be horizontal, I guess? The Singer CE-100 I had on my desk looked like it might be able to wear parts,... but it was a suspect quality machine anyway (as far as the under bits) Timing it was terrible.

Maybe the plastic wonders wear out bobbin cases? I have class 15 - metal bobbin cases - where somebody went a little nuts with the spring or lost a screw or let it rust or soaked it in 3 in 1 oil or just plain old MISSING but not ever seen one 'worn out'. Even then it is a very small percent of the machines I have seen or worked on. Now I have seen messed up Touch and Sew bobbin cases but we won't go there.

The metal bobbins can contribute to wear at the bottom of the plastic cases .... or so I've read.

The plastic bobbin cases in the Singers we have all show roughness at the bottom from wear. They vary a bit, but none of them are worn out. It is conceivable that if metal bobbins with pealing plating, rust, or other wear were used exclusively they could wear out the bobbin case. But as I said, none of ours, we have three now, had five, show excessive wear.

Joe

Does anyone know where I can buy metal bobbins? I only use plastic in my newer Janome but I like metal in my older machines.

Sew-Classic.com :)

better keep using plastic in the Janome.

Because I sew with these machines everyday: the 66 bobbins from WM DO NOT FIT! The plastic ones will. I bought 20 from sew_classic after she assured me they work and she was right. Maybe I will make earrings with the four from WM. They do fit the plastic junk machines WM also sells.