Why does my sewing machine keep jamming underneath?
However certain you are that the problem with the machine is most likely due to a huge tangled mess of thread in the bobbin underneath the fabric, the most common reason for the jamming is usually the lack of sufficient tension in the upper thread.
Why does my bobbin keep locking up?
Sewing Machine: Machine locks up. Thread bunched up in the shuttle race often causes the sewing machine to lock up. … Clean lint and debris out of the shuttle race; they can prevent the needle from hooking the thread, resulting in thread bunching up in the shuttle race and jamming the needle.
Why wont my needle go up and down?
A disengaged clutch, broken drive belt or internal drive gear failure can prevent the needle from moving. Engage the hand wheel clutch if you have it disengaged for bobbin winding. … You’ll typically need to have a service technician examine the sewing machine and fix a drive gear failure.
If the thread has knots, is not smooth, is uneven, or is loose on the bobbin, then it has not been threaded correctly. If your machine uses a bobbin case, follow your sewing machine’s instructions to remove the bobbin from the case and re-thread it.