Why even getting new shuttles that are supposed to be for a VS machine may not work, and how to address this issue: This may be because the arm that swings the shuttle can move slightly over time more toward the bobbin run (The curved metal wall where the bobbin swings against) in the machine. The shuttle then may slowly wear its edge against the run over time. If you try to put in a new shuttle that is supposed to be for the machine, then you may find that it does not quite fit — it it because of this slow wear over time has drawn the arm that holds the bobbin closer to the run. You will need to unscrew the small screw, connecting the area that holds the bobbin and the arm that swings it. When unscrewing this, you should only loosen it so that you can move the bobbin-holder back a few centimeters. Keep moving this back until the new bobbin fits snugly, and then screw into place and test.
Sewing With Nick 