When I purchased my Bernina (new) many years ago, it would sew through 5 layers of denim. Today I tried to sew through 4 layers of cotton fabric and it would not go. The machine bogged down and the bobbin thread knotted badly. I have noticed it seems to be getting weaker. I have a Superior Needle in it and the thread is new on a cone.
Any ideas what the problem is or what I can do to fix it?
I also tried to sew a new zipper onto a fleece jacket and what a mess that was.
Thanks for your ideas and help.
