Originally Posted by BellaBoo
Do the drop test. Put a fresh bobbin in the bobbincase, thread the bobbincase correctly except for the "pigtail". Hold the bobbincase up by the thread (leave a hand underneath so it doesn't hit the floor!), let it dangle and jerk the thread to test the tension. If the bobbincase drops a few inches and stops you are in the ballpark. If it doesn't drop at all it's too tight. If it hits the floor it's too loose and you forgot to put your other hand under it.
What is the pigtail referring to?
The TOWA gauge takes the guesswork out of the drop test. It's also helpful if you are trying to get some help from someone over the phone. The first question I ask when I get a phone call for help is "What tension are you using on your bobbin". I need a number.
Some bobbin cases have a twisty thing that looks like a pig's tail. Not to be confused with the finger, the pointy thing that fits into the grove on your hook assembly.