Ensure the bobbin has the proper tension by following these steps:
1. Holding the bobbin spool in your left hand, pull 2-3 inches of bobbin thread off the spool with your right hand, ensuring the bobbin thread is coming off the spool in a clockwise
2. Place the bobbin spool into the bobbin case; again, ensuring the bobbin thread is coming off the spool in a clockwise rotation.
3. Place the bobbin case (now with the bobbin spool in it) in your left hand. Pull the excess bobbin thread clockwise around the inside of the bobbin case until you reach the slot in the bobbin case.
4. Now, pull the bobbin thread under the tension spring (looks like a flap) and into the tension guide. Make sure the thread pulls smoothly from the bobbin.
5. Drop Test: To ensure the tension is correct, simply hold on to the excess bobbin thread and motion downwards. The bobbin should come out of the bobbin case and the case should drop about 2 inches and then stop.
Move on to the next step if this occurs, if not, you will need to adjust the bobbin case following these steps:
a. Did not fall 2 inches: If the bobbin case does not drop approximately 2 inches, then the tension is too tight. Using a flat head screw that was provided to you (labeled “Minus Driver Small”) loosen the adjusting screw one to two minutes to the left.
b. Fell more than 2 inches: If the bobbin case falls much more than 2 inches, then the tension is too loose. Using a flat head screw that was provided to you (labeled “Minus Driver Small”) tighten the adjusting screw one to two minutes1 to the right.
7. Trim the thread to 3-4 cm before inserting the bobbin and case into the hook assembly. Long tails can cause the bobbin thread to tangle when the machine begins to stitch.