I have a 1950s Singer and the bobbin winder on it doesn't work. I love my side winder. I have other machines that I could use but the side winder is small and convenient to keep on the shelf by my Singer. I fill 30 bobbins at a time and don't have to mess with stopping to fill bobbins in between. I hate running out of filled bobbins when in the middle of a project. The side winder is easy to pull forward and plug in. Then just fill bobbins. It takes just minutes to fill all of mine. It is alot faster and easier to thread than my other sewing machines. I wouldn't be without it even if my Singer was fixed. To fill bobbins on my Singer I have to disconnect the needle. The side winder is just quicker and easier all the way around.