Sewing Machine "Theory of Operation"

A picture is worth a thousand words. The following diagram shows how a machine like the ones I have produces a lock stitch.

My hat is off to whoever put together the following GIF file: If I could just add a button to stop and start it, it would be perfect!

There are numerous fine points of course. The upper and lower threads need to be properly tensioned and handled. The needle has a groove on one side and not the other.

Another type of machine generated stitch is the chain stitch, which does not require a second thread on a bobbin.

Have any comments? Questions? Drop me a line!

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