Rich, I am talking of a off center weight wobble when the bobbin is spun to twist/untwist the thread when the bobbin is hanging. I bet that is Hans' wobble too but I'll let him speak to that. In any case a slight off center "wobble" is tollerable.

# of bobbins on the bench which are actually used = 3 Nor Bobbins. Uaually one loaded with white and two black.

Happy Trails!
Ronn