How does the bobbin work on this sewing machine?
Hopefully you have reached a positive conclusion to this problem by now. For future reference, the thing in the middle or as referenced above as the “part-that-is-not-the-bobbin-case” is called the “hook”. The thing all the way to the left that clips into place is called the “race”. I find it easier to seat the hook in place without the bobbin case attached to it. It moves in a very specific way within its’ housing. Because of this it will only go in one way and it’s very easy to tell when it’s in there correctly. Once you have it seated, replace the race and clip it in place. Then thread the bobbin correctly in the bobbin case and replace it on the spool of the hook. Make sure it’s all the way in there–bobbin cases are notorious for not fully seating on the hook. I always listen for a click and even then double check with my fingers, but then I cannot visually inspect my bobbin area unless i lift up my 100 pound industrial machine head. Here
