#I was fixated on the fact that a bobbin case isn't metal if it's a top load

[allisonreader]

Time to talk sewing machines again!

Today's topic is the difference between how you put your bobbin (the bottom thread) into the sewing machine.

There's two main types of ways to put the bobbin into the machine. Top load/drop in or front/side load.

Which is exactly as they sound.

Now a drop in/horizontal hook/top load machine will never have a metal bobbin case, it will be a plastic one with some metal pieces. A good or at least better machine will have a metal hook which goes around the bobbin case. The hook is the part that actually catches the top thread to interlock the top and bottom thread. (If a machine has a plastic hook, run the other direction. It's a cheap machine and either not fixable or not worth fixing.)

A front load/vertical hook generally has a metal bobbin case. With this one there are some exceptions (mainly newer Bernina machines that have large bobbins, they have bobbin cases that are plastic in places and are front load) but for the most part if the bobbin goes in the front or the side of the machine, the bobbin case is metal. As should the hook be again.

There is nothing wrong with a plastic bobbin case. The biggest thing with them is that metal bobbin will wear them out quicker. So it's not recommended to use metal bobbins with them. Some new machines won't even sew with a metal bobbin in them if they have a low bobbin indicator/sensor built into the machine. So for most new machines only use plastic bobbins. And you do have to make sure that you use the correct bobbin. All bobbins are not the same and not all machines take the same kind. Using the wrong bobbin can cause tension issues.