After I cleaned the bobbing case, I went to put it back together and now it wont work at all. The bobbin keeps flying out and it wont sew even one stitch. It was working just fine up until I took it apart.
Euro-Pro Shark model 9110, it's only a few months old

Ryan Peters, December 2006

I have noticed that when the bobbin is not the right fit it will jump out of the casing.

joann cronin, March 2014

To keep the bobbin case from bouncing about in the hook race, There is a small circular indentation on the outside of the case which belongs in the right hand bottom corner of the race {5:00}, fitting snuggly Around the upper left hand corner of the stopper on your machine {small metal rectangular device also at the 5:00 location}.
This ought keep your bobbin case in check & nicely balanced in operation while the race is whizzing around it! Never give up, much sewing trouble is caused by simple mechanical operations gone awry.

Holly Lucination, September 2007

Make sure you put it back together the right way . Also check the bobbin and make sure that it is not bent or anything and that you have the right one and that it is put back into the bobbin case the way it should go and that it is threaded right way . If you put the bobbin into the case backwards the machine will not work .

Nancy Salisbury, February 2007