Howdy;
I have a National brand model 306N (Made in Japan) walking foot machine used to sew vinyl and leather. It came with one M size black bobbin case. I usually pre-wind a bunch of bobbins with whatever thread I am going to use on a job and would like to obtain some extra proper bobbin cases for this machine. The bobbins are large M style (1" x 3/8"). The machine has some parts stamped Seiko and is made in Japan. It looks sort of like a Consew 206 series machine. I bought some M bobbin cases on eBay, supposedly compatible with my machine, but they had to be ground down at the upper-left opening, to allow the cases to fit into the shuttle. Also, the thread comes out of the springs in a jerky flow and causes the stitch knots to move up and down.
Apparently, this machine uses a non-standard bobbin case, with a much wider opening on top. This is because the case has to clear two tiny screws on top of the shuttle assembly, about 1/4" apart. The cases I bought do not clear the left screw head and cause the case to jam, unless it's left tab is ground off at the opening on top (which I did, with limited success).
I have posted a group of pictures below to show what the OEM bobbin case and the machine looks like.
Hopefully, somebody here has a similar machine and/or knows where I can get the proper bobbin cases for this machine. If you have some you don't need I'll be happy to buy them from you.
Thanks in advance, Wiz
