Joe,
Many class 15 machine don't care which way the bobbin unwinds, but many will not sew well if the bobbin is put in the case the wrong direction. The correct direction of unwinding helps prevent backlash/back-spinning of the bobbin as it gets emptier and lighter weight.
The easiest way to figure the correct direction is to remember that the thread has to reverse direction as it leaves the bobbin and goes under the bobbin case tension spring. Or visually it makes a 'V' path. Put a threaded bobbin in the case and thread it both ways, you will see the path differences.
The 15-90 series (11:00 finger as viewed from the solid side) of cases thread so the the bobbin is unwinding counterclockwise. The other series (1:00 finger) unwind with the bobbin spinning clockwise.
Here are a few pictures of the case differences.
[ATTACH=CONFIG]463799[/ATTACH] [ATTACH=CONFIG]463800[/ATTACH] [ATTACH=CONFIG]463801[/ATTACH]
I hope this helps,
Cathy
Originally Posted by
J Miller
minibarn,
I will re-read the manual on the bobbin issue. I do know I put my bobbin in the 15-91 case the same way I do all the other machines that use class 15 bobbins and it works well.
Joe