Bobbin problems
This happened this past week. My Juki 600 is making an awful noise. Sounds as if the bobbin is spinning & jumping around. It sews but the bottom stitches aren't quite straight. I've cleaned quite a lot changed needles a couple times , tried different brand threads & new bobbins using different threads. Tried different dials, seems a little worse using higher numbers. Don't know what to try next. When I bought the machine I also bought extra bobbins. These are the ones I'm using. I have two machines so my first thought was maybe I had mixed up the bobbins. The bobbins look evenly threaded.