How to Replace Bobbin Case Spring
How to replace the bobbin case brake spring
After the post a few days ago on how to check for proper tension on the bobbin brake spring (also called bobbin tension spring or bobbin anti-backlash spring) I have had several inquiries about how to replace one that has flattened out.
Pic 1 shows a small probe (in this case a ball point pen - but could be toothpick, small screwdriver, hair pin or similar instrument) inserted between the bobbin spring and the bobbin case - pry the spring gently up and it will pop out of the slots it is secured into.
Pic 2 shows the new bobbin spring oriented with the bobbin case, and the arrows show the tabs on the bobbin spring and the slots in the bobbin case where the tabs will be inserted.
Carefully place the new bobbin spring in the bobbin case (make sure the center of the spring is higher than the outer section) - gently push the tabs of the spring into the slots of the bobbin case with a small probe (pic 3).
Pic 4 - the center circle of the new spring (the pictures are from a new Cerliani M-class bobbin case) should be around 5mm (3/16") above the floor of the bobbin case - see arrows.
Last - use a probe to check to ensure that 1: the spring is thoroughly inserted into the slots, and 2: the spring center is higher than the outer edges – this video will show you how to test.
Quilt on!
Do you have questions on this topic or a suggestion for another one you are interested in?