Bobbin Thread Breaking
I am quilting on a Little Gracie Frame with a Janome 1600 PDB. I think it's a B, lol. It quilted fine to do the one border. Ran out of bobbin thread. Replaced it, now it will only quilt for a few seconds and the bobbin thread breaks. Changed bobbins, same thing. Oiled, cleaned etc. same thing. So I adjusted my tension on the bobbin case, it became really loose. As I was pulling while it was loose, the thread tightened up and broke. Tried again, it was supper loose, pulled about a yard out and it got real tight and broke. What causes this? Do these cases go bad?