I taught a couple of classes this last week-end which is something I love doing. It is an opportunity to see and hold yet another Featherweight. Some machines that come to class come with a problem, or two, and some problems are new to me. That's when it begins to be fun for me. When I find something new I love saying something like, "Gee, Ive never seen something like this before" and listen to the owner swallow their gum.When you are locked-up in a room working on sewing machines all week you have to find fun where you can get it. They don't let me out often.
The machine in question was not sewing so pretty good. It puckered the fabric between each and every stitch and the fabric was very hard to pull out of the machine at the end of a line of stitching. When you pulled the fabric out of the machine, or if you pulled on the bobbin thread as it came up through the needle plate it was much harder to pull on than it should have been. So I said to myself, I said, the bobbin tension is set much too high so I coughed the bobbin case out. I got out my trusty gauge to test the bobbin case tension and the gauge said it was spot-on at 2.5 grams. I put things all back together and it still did not sew correctly.
I had noted that the bobbin within the bobbin case was black which was unique and it was of a one-piece construction as having been turned on a lathe rather than made from separate parts pressed together into an assembly. When I put the bobbin back into the case the flange of the bobbin that closed off the opening of the bobbin case stood just a little tall and it was noted that when the bobbin case w/bobbin was put into the machine it took a bit more pressure than what seemed normal to get the bobbin case to snap into the hook assembly, yet still without having to use a hammer.
The bobbin we were working with turned out to be a bobbin made for an Elna sewing machine of the 1930's. If you lay a Featherweight bobbin case on a flat surface beside the Elna bobbin, the Elna was about a sixteenth of an inch taller which made the bobbin stand proud and drag within the bobbin carrier and resetting the tension wasn't the answer at all. If not laying side by side for comparison the two bobbins looked just alike.
I had looked at the bobbin within the case when I first took the bobbin case out and had commented to myself, "myself, that's odd" and just let it slide.
When you see something that doesn't seem just right, and you've got some little nag of a problem, look harder at what seemed "a little strange" and think the strange and the nag through together as if they may be related. It is interesting how many FW problems have been corrected by thinking through something "just because it initially didn't look quite right."
Source: Dave's Blog