Replace the needle, re-thread the machine. Make sure no inconsistent motions.
So, at speed, I bet your thread isn’t running smooth. If it’s not the needle then, the looper isn’t catching it under, your knee lift is partially released, or your bobbin carrier isn’t set right.
Replace the needle, re-thread the machine. Make sure no inconsistent motions.
So, at speed, I bet your thread isn’t running smooth. If it’s not the needle then, the looper isn’t catching it under, your knee lift is partially released, or your bobbin carrier isn’t set right.
Or, you need to test multiple materials.