Happy National Sewing month! All month long we are celebrating by sharing some of our favorite sewing projects right from our books!
The following information is from Sewing Machine Reference Tool by Bernie Tobisch.
Using the Right Bobbin
A common cause of problems is using the wrong bobbins for your type of sewing system. Many bobbins look the same or have very slight variations. However, using the wrong one can cause not only tension problems but breaking thread. A good policy is to buy the same bobbin that came with the machine originally.
In the example below, notice that the bobbin in the machine is slightly higher than the top edge of the bobbin case. As the top thread tries
to come over the top to form a knot, it catches under the bobbin and jams the machine. At a minimum, this is frustrating, but there is also a chance it will end up spinning the bobbin case around and damaging it.
TIP: Prewound Bobbins
Prewound bobbins work well, provided they match the size of the bobbin meant for the sewing machine. However, if the machine has a low bobbin warning, it will most likely not work when you use these bobbins.