Confused about bobbins
 

I have never gotten vintage bobbin sizes straight in my mind. I know which bobbin fits my 221 and 301, and which fits my 15-91 and 503, but don't know what names they are referred to. Class 66? Class 15? Neither?
I won a goodie bag at my guild and it had a bobbin that looks like it would fit my 15-91, but is shorter. It is the bobbin in the middle of the pics. What does that fit and what is it called? I need a class on vintage bobbins....
Can anyone help me get this straight in my mind (or what is left of it...)😳
[ATTACH=CONFIG]533431[/ATTACH]
[ATTACH=CONFIG]533432[/ATTACH]

I thought Singer 15's took class 15 bobbins but the 500 & 503 took class 66? I have a 500 and I'm almost positive it takes 66's. I don't think a 15 would fit(?)

I'm not sure what that middle bobbin is though, sorry. Maybe an L?

L-R: 15, 66 (if the top has a slight convex curve, it's hard to tell from the photo; if not, see *), 301

Singer 503 takes a 66

*What do you call the bobbins for the 306/319?

I just buy the ones that my machines call for. Singer 2662 and Singer 401. I go according to what my manual and charts suggest. I have photos of anything and everything regarding my sewing machines on my cell phone and in my computer files. If it isn't broke, I don't fix it.

The middle could be an L bobbin (my Juki uses these) or a 66 bobbin, which is slightly different. They are not interchangeable in spite of being very similar. Is there a difference from top to bottom on the bobbin? The L bobbin has a small slot neat the center to slide onto the winder, while the 66 has a small hole near the center for the same purpose.

Ok, so my 15-91 takes a class 15, as shown on the left. It has a flat top. The 503 takes a class 66 which has a slightly rounded top. The bobbin on the right only fits the 221, 222 and 301. Is that correct?

The middle bobbin is still not identified for sure. But I know I don't have a machine they will fit. If anyone wants them, you can have them - there are 4 of them.

Thanks for all the comments!

The middle one could be a rotary bobbin. My repairman looked at one of mine and said that's what I have.

I agree with Pat, having flat sides it looks like an L style rotary bobbin. My Pacesetter uses these.

Cari

Yes, 15 is 15, 503 is 66, 221,222,301 take the right one and that's all.
201 takes a 66. Some of the 600s take 66 and Touch and Sew takes the screw-apart clear, plastic ones. There was a lovely chart not long ago on QB. Try searching in the archive. It had pictures. I printed it out, put it in a notebook along with downloaded sewing machine manuals for future reference. I save stuff.

I've changed my mind. I don't think the middle one is an L bobbin so don't know what it is.

Cari