Originally Posted by
friquant
So far I'm thinking maybe shim that whole piece to ride a little higher (washers) so the bobbin case won't climb over the stud when the hook moves in reverse.
For the curious minded: After some experimentation I discovered that
on this machine the bobbin case only climbs over the stud when turned QUICKLY in reverse. For example turning the handwheel 180 degrees in the course of a third of a second, the bobbin case will bind against the inner face of the hook body.
But if I move the handwheel
slow and smooth in reverse (like a quarter turn per second), the bobbin case stays planted at the bottom and the hook is able to keep moving. (Meaning the bobbin does not bind mechanically (ratchet) against the body of the hook).
On this machine (your mileage may vary), even with the machine threaded (with or without fabric under the presser foot) I can move the handwheel in reverse for several revolutions SLOWLY without any problems. The hook never picks up the thread, no stitches are formed. The bobbin case never binds against the hook, the thread never binds into a mess. And afterward I can go back to stitching in forward and the forward stitches are well-formed.