Take a look at the bottom of page 62. It has instructions for cleaning your bobbin basket (it holds the bobbin case), as well as how to get the case back in. There is a projection on your case on the lower right; that projection MUST rest against what is called (and pictured there in the bottom drawing) the cushion spring. The top of the bobbin case that goes under the needle is the only flat part. When putting in the bobbin case (mine are very similar), I have found it helpful to insert it slightly counterclockwise of the spring, making sure the case is flat in the basket, then twist it counter clockwise so that the projection is against that spring. While your case is out, be sure to CLEAN that area thoroughly with a q-tip (I put a drop of sewing machine oil on the two ends of the swab to help pick up lint), taking care to get under the lip of the bobbin basket, where a lot of lint can accumulate, and then put ONLY one drop of sewing machine oil in the hook race and the center where it is indicated in the manual. After you have replaced the bobbin case but before you have put a bobbin in it, turn your hand wheel TOWARDS YOU (ALWAYS towards you, for anything) several times to distribute the drop of oil. The race is between the outside of the basket, and the metal hook surrounding the basket, and the indicated place is the only place (with the needle all the way up) where you can get a drop between them. It's also possible that lint or other debris--like pieces of threads--are preventing the case from seating correctly.
on Nov 20, 2014