Originally Posted by Rodney

I just went thru the same thing on our machines. Both use a Class 66 bobbin. Until a few weeks ago I'd never used a sewing machine and was pretty clueless about them. Still clueless, just not as bad now.
I bought Singer bobbins at Walmart. There seems to be a quality control issue with the metal ones in the 4 packs. Some are larger than others in the packs. I ended up throwing a few out because they didn't fit in our machines. I think out of 8 total I was able to use 5 of them. At 4/$1 it's not a huge deal, just annoying.
Rodney