Sewing machine companies began using plastic or nylon gears in their machines sometime after World War II. I've seen pictures of machines that the one area that got the most wear, the gears, were the weakest part of an otherwise all metal machine. I can only guess that this is when the idea of "planned obsolescence" came into being, because it would be difficult or impossible to repair those broken plastic gears. For these used machines I wouldn't spend the money either unless or until I could look inside to see what the gears looked like, if it in fact had gears. Any purchase of a used machine should have a good inspection first, unless you are buying it on someplace like e-bay, and then like anything there you take a chance of it not being what you thought it was.
This use of weak plastic parts hasn't happened in just sewing machines either. I've bought many different things new and found that plastic was in place on whatever part was the most likely to break, like hinges on a lunch box, or small gears on a kitchen appliance. Frequent use guarantees it will break in a few months.
These old metal machines have been brought back to life with just cleaning and oiling, and they are still running strong. They have simple but very strong engineering that has lasted, in many examples, more than a century, as machines that were manufactured in the late 1800's and forward are still doing their job with no problems. The most common Singer class 66 machine, and the class 15 machine use bobbins that are still sold in fabric stores today. The 66 uses a common needle, the 15x1, as do many other household sewing machines. Care has to be taken in inspecting the wiring on the older machines, if it looks in good shape with no bare wires anywhere and it runs good too, then the machine will do the job. If in doubt about the wiring, have it inspected by a qualified person.
Edey
Officially Recognized Stretchpert in Hobbies and Crafts Edey's Vintage and Current Needlework BlogLife is like a quilt - it is made beautiful from all the little pieces stitched together.
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