Research on bobbins within sewing machines

[mariannesews]

Dear Janice,
i assume that you are looking at machinal machines, as those of use with computer machines have a machine that warns us when the bobbin is running low or stops when it runs out.
I have this feature in 3 machines, because they are embroidery machines its almost impossible to go back to where you run out of bobbin once you hace unhooped your item, so all my machines ( janome 8000 from about 17 years ago) stop. In other words, they have a sensor that tells the computer to stop the machine, and also measure the bobbin thread to warn you when its getting low.

The clear cover drop in bobbins work well for being able to see the colour and amount of thread in the bobbin. they generally go with a teflon bobbin case, so they also dont require oiling and there are probably a heap of noise and machanical advantages i havent thought of.
Hoi; I have not read all the preplies so i know i'm repeating these clever people in all likelyhood.
If you are using an old machanical machine at school perhaps you could think of some clever way to warn that person they are about to run out, like tying a little bit of coloured thread to the start of the bobbin thread before the real colour you want to use. That way when you are sewing you will have a visual warning that you are on the last of your thread. I'm thinking of if you were sewing a white cloth with white thread, a little bit of red or black at the end might be noticeable from the top. The knot might also catch which would prevent you from going on. of course this might also be a pain if it makes the top stitch messy for a few stitches.

If i were you i would experiment with getting a warning on the machines ypu are using at school, so you can experiment and also so its something you can use.