These 306s have a bobbin case that is secured with a position finger. It is tricky, but you have to get the position finger just so to allow the thread to"escape" At first I thought that was the problem with my bottom tension being too tight. It wasn't. It was just gooey in there and flushing it out with the alcohol and the tri flow must have been the magic cure. That is all I can figure.
I spent some time cleaning her up. The crinkle finish is a challenge and after a bit I could not decide if I was removing dirt or paint. Y ou know, that beige finish is deceiving. I quit. She needed a dust cover so I ripped an old sheet up intending to sew together a drawstring bag.
What the heck, try the 3 stitch ZZ cam. And it worked. For a while. Then the fabric would not track and the presser bar got lazy. AGAIN. All this happened while I was talking to my sister on speaker phone. Gotta go, Alice, got a machine in crisis.
I took the whole presser bar assembly apart. I don't recommend it if avoidable. The culprit was some goo on the part that rests in the groove in the back of the machine where the lever rises and falls.
I also realized that the feed dogs were not fastened tightly. I had tightened them once, but having never removed them in the first place I did not know how tight they should be. They were VERY loose. Thank Rain for encouraging me to get the Brownell bits (http://vssmb.blogspot.com/) Itightened them up and got the machine all back together again, and VOILA.
NEXT, the 301A in progress.