Why is my bobbin not winding?
If your bobbin does not wind quickly and smoothly when you press on your foot pedal, your bobbin winder might not be fully engaged. This can cause uneven winding. Make sure you push your bobbin pin all the way over or loosen your bobbin wheel completely to engage your bobbin winding mechanism.
Where do you insert the bobbin after threading?
Place the bobbin case in the palm of your hand with the front facing down and the open end facing up. The thread direction of the new bobbin should be winding clockwise as you drop the bobbin into the case. Insert the bobbin into the case. Route the thread through the thin slot opening and under the tension spring.