Butterflyblue

thanks! I’m pretty sure it isn’t from the tension unit, as that set screw is in place and I have an photo of the hand wheel lying on the workbench and this screw is in the background, which was a few days before I did anything with the tension unit.

I did take things apart again yesterday but couldn’t find any where to put it. It’sa lesson for next time about keeping better track of where things came from, for sure.

JoeJr

The little nub on the inside end makes me think it works as some kind of stop for another part, meaning when screwed in that nub will set into something.

Joe Ayres

When I looked at the picture, I thought it looks just like the pin that holds the plastic hand wheel in a Bernina. This pin keeps the plastic hand wheel from turning on the end of the shaft. It fits into a hole in the back of the wheel..
Another thought is a locating pin that properly positions something like the top cover. There would be a hole in the cover that that pin fits over. It wouldn't be used to secure something, just position it.
Screws like that are also used to secure the end of a big coil spring that has an eye in the end.
Just thoughts. Good luck finding it. I keep reminding myself to take pictures now that I have a camera in my pocket. but I forget that phones do this.... and I don't think of it when I am taking something apart!

Butterflyblue

I am still looking for where that screw goes, but I’m happy to report that I found and fixed the problem with the zig-zag. I hope it stays fixed. The reason I knew there would be trouble with it was the partially stripped screws that let me know it had been worked on before.

now the thing is to find out why the belt is slipping. I tightened it a bit but it only helped marginally. It doesn’t slip all the time, just sometimes when I (try to) start sewing. If I start it by hand it goes. That will be a real problem with free motion quilting, I expect.