Approximately 60 percent of the machines on the market are compatible with the standard L size prewound bobbin. The debate continues but the prewound users are winning. Although some machine manufactures warn against using prewound bobbins, it is a fact that many of the educators on their staff do use them. The risk of prewounds is in the thread quality. Make sure you use a good quality thread and clean the bobbin area regularly. The advantage is in saving time and not having to wind your own bobbins. Prewound bobbins hold up to three times more thread than self-wound bobbins.
Facts and FAQs (Frequently Asked Questions) about prewound bobbins.
Why should I use prewound bobbins when I can wind my own?
Good prewound bobbins are wound by high tech machines which provide a smooth, uniform wind. The result is much more thread on the bobbin than a self-wound bobbin. Whether you're in the middle of an embroidery design or a quilting or sewing project, having to stop to change the bobbin is always an inconvenience.
What does L style and M style mean?
These are the two most common sizes of prewound bobbins. Some longarm machines (A-1, Gammill, Handi Quilter, Homesteader, some Noltings) use the M size, which is the larger bobbin. Some longarm machines (APQS, some Noltings) use the L style bobbin. Approximately 75% of home machines use the L style. The trend is moving toward more compatibility as most home machine manufacturers are making their machines compatible with the L style bobbin.
Should I tear off the cardboard sides?
If the bobbin fit is too snug to accommodate free rotation, take off the cardboard sides. This will not affect the function of the bobbin. If your machine has an automatic bobbin sensor, leaving on the cardboard sides will make the sensor think the bobbin is always full and will therefore not provide a low bobbin warning. The solution is to either tear off the cardboard sides and use the sensor or to leave the sides on and sew until the bobbin thread runs out.
Is there a difference between plastic sided and cardboard sided bobbins?
Either type is fine. Plastic bobbins are reusable; cardboard bobbins are disposable. Because the plastic-sided bobbins are so smooth, they may continue to spin even after your machine stops and cause backlash. Some machines seem to work better with the cardboard-sided bobbins because the cardboard sides provide more friction and backlash is usually not a problem. If it is, the bobbin tension may need to be tightened.
Should I use a polyester or a cotton bobbin thread?
It's a matter of personal preference. Polyester has very little or no lint. Cotton prewound bobbins will throw off lint and will require more frequent machine cleaning.
My dealer told me not to use prewound bobbins. I've even heard they will void my warranty.
That's a myth. Today, almost all major machine companies sell prewound bobbins.