How do you adjust the bobbin tension??
 

I have a singer 66 and having problems with the bobbin tension. Does anyone know how to adjust it?

I think the bobbin tension is controled on the bobbin case. You can tighten or loosen the little screw that holds down the plate you slide your thread under. (I hope I explained that right).

Ann is right! :) Page eleven of this PDF explains it a bit more...

http://www.a1sewingmachine.com/manuals/66.pdf

ETA: Only turn the screw a 1/4 turn at most at a time and test it before adjusting it further. :)

Got it...Thanks!!! my new, old machine is all cleaned and running great. I can't wait to quilt with her.

Careful when adjusting the little tiny screw. I did that years ago on a machine I had at the time. The screw fell out and it was lots of fun to get it back into the tiny hole. Got it going again.

the tension can be a pain on the older machines...Just when I think I have it figured out and its working great it gives me troubles. I love the look of my treadle and someday I hope I will love the way it sews as much as I love the way it looks. I am off to use my Janome or I will never finish this quilt.

If it's the original bobbin case, under the spring may be packed with lint. You can carefully! remove the screws, take that spring off and wipe both it and the case down, then put everything back together again.

If you do this, do it over a white towel-if you drop a screw it won't bounce, and will be easy to spot. If you've got two screws, make sure you know which one came out of which hole-they're often different lengths. An eyeglasses screwdriver is the perfect size for this. After you've got it back together again, you're still going to have to readjust the tension. I find it easiest to go backwards-that is, screw it all the way in, try it, and then back off 1/4 turn at a time until you get it where you want it. Once you've got it there, you can mark the case with a fine tip permanent marker-I usually start the line in the screw slot so I can line it up again if I need to.