Needle hitting bobbin case model 750

On the right side you have two knobs to make adjustments. The lower knob will move the needle left or right so it won't hit the bobbin holder.

Sounds like your needle is hitting the needle plate instead of going through the tiny hole down to the bobbin. Try using the handwheel slowly and watch. Or perhaps the needle is hitting the bobbin case. Something has been knocked off the straight I think. Has your machine been dropped or dmamaged?

have you tried turning the bobbin the opposite way in the bobbin case?
it's also possible that the sewing machine may need some type of adjustment, it would be a good idea to have it check at a sewing machine repair shop.

Take it to a local sewing machine repair and sales business for repair.

try changing the needle--make sure it's the right needle for the
fabric being sewed
rethread the machine top and bobbin
make sure the bobbin is inserted into the bobbin case
it's also possible that the machine could have a timing problem
and needs to be checked

Try a new needle first failing that you may need to retime the machine, you can email me for an attachment of instructions [email protected]

Perhaps you have bent the needle. Or perhaps you have shifted the bobbin somewhat while removing jammed fabric.

On the right of the black bobbin case there are two screws, you can slacken those screws off and move the bobbin case nearer to the guard leaving enough room for the thread to pass through, if the needle is hitting the bottom you may need to retime the machine.

hook drive gear

With the needle hitting the bobbin case , it sounds like it might be out of time. Which I am sorry to say is not an easy at-home fix.