Rodney

My experience is the new Singer branded bobbins are narrower at the edge than the vintage ones. New bobbins didn't fit the bobbin winder on my 1948 66. The guide was wider than the bobbin. I ended up filing the guide down so the bobbins would work on it. The new metal Singer bobbins are garbage. The plastic ones are far more consistent in size.
You might try a different brand and buy from a quilt shop or actual sewing store. Chain stores like Joann's and Walmart only carry the crappy ones.
Vintage bobbins are like gold to me. I get them whenever I see them now that I've learned there is a difference.
Rodney

ArchaicArcane

Yeah, I agree, I've had tons of plastic bobbins with worn edges and I throw them out.
With a lot of the bobbins - metal and plastic - there are several levels of quality you can buy. Guess which level most people stock?

I've never bought the cheap ones and haven't had any trouble with the metal or plastic. Now, that's me as a "dealer" (i.e buying wholesale) and I can see the different levels and choose accordingly. The consumer has a hard time doing the same because they have to buy what's offered. All I can say is looking for the best price will bite you in the rear as far as bobbins.

This comes back to the consumer though. We've demanded a less costly solution and manufacturers have responded with a cheaper product. Manufacturers have told the factories that the lower quality level was acceptable for their client (us) in order to supply product at the price we're willing to pay. The only way to change that is to stop buying the lower quality and demand the higher quality products.

J Miller

Another thing about modern made 66 and 15 bobbins is there is little consistency. In the same package some will be narrow at the rims like Rodney said, some will be rough, some will wobble on the shaft (I've had some that were so out of speck you couldn't wind them on the machine).

I've got to the point I go for all the old vintage bobbins I can get. The only place I get new bobbins at is Sew-Classic.

Joe

ArchaicArcane

Again though, those will be the low quality bobbins. Apparently the quality control is the first thing to go on the low quality stuff. I don't buy anything labeled Singer if I can help it because all they seem to stock is the lower quality bobbins. I think Jenny's doing the same thing that I do - order only the higher quality so you don't get the come backs. I ordered a bunch of 66 bobbins from her before I set up with that distributor in Canada and never had a problem with hers. They're also heavier than the cheaper ones and feel closer to a vintage bobbin.

I did this when I was in computers as well. I always told people I didn't build the cheap machines. If they wanted cheaper than my machines, they could pick it out - get the extended warranty - and I'd configure it but I wasn't going to be their warranty source for a cheap machine. I still have machines that I built more than 10 years ago that are running and only got retired because XP is no longer supported and the machine didn't have the ooomph to run the latest operating systems.

J Miller

All my best new Class 66 bobbins have come from Sew-Classic. I buy them 50 at a time. And then they seem to get spread out amongst my machines that use that style and I can't find any when I need one .

Joe

ArchaicArcane

I had that problem too. Then I ordered another batch of bobbins from Jenny and bought a 503 while I was waiting for the order. It came with a ton of bobbins as well if I remember right. I've been "set" ever since. I have an abundance of the plastic bobbins too from other machines I've bought. I dump the garbage ones and save the ones that are well made.

mom-6

I much prefer the good metal bobbins. They seem to perform consistently better than the plastic ones. I got a bunch if the metal ones from sew classic and they have been great.

purplefiend

I prefer to use vintage metal bobbins in my old machines, I've had too many problems with the new ones. The center hole to fit onto the bobbin winder is either too big or too small. I don't have these issues with original bobbins.
Sharon in Texas