How a Sewing Machine Works

A tour of the mechanics of the sewing machine and an understanding of how it works might keep you from breaking down on the needlework highway. This fine-tuned piece of equipment comes with a manual. Refer to it. Each machine is different, and the manufacturer knows best.

It Has a Heart

A needle, with its eye just above its point, is fastened to a bar and driven up and down by a motor. As the point partially enters the fabric, it pulls through a small loop of thread, which is grabbed and wrapped around another loop, creating a chain stitch, the simplest function of the machine's loop-stitching system. This motion creates the basic seam; the quality of the machine determines variation of stitches that lock, stretch, zig and zag.

Walking the Dog

The presser foot holds the fabric in place. As the motor powers the drive wheel, belts and upper drive shaft to turn the crank, the needle bar is put into motion. After the needle passes from the fabric, the feed dog inches the fabric forward.

On Pins and Needles

Thread winds on a path and feeds through the machine's tension. Adjusting the tension to accommodate fabrics and threads controls gapping stitches and puckering fabric, while assisting with sewing speed. A threaded bobbin encased in a shuttle is rotated to the beat of the needle, assisting in the looping process. Improper tension and accelerated speed leads to thread tie-ups in the shuttle and bobbin assembly.

The Pedal to the Metal?

A foot pedal controls the motor and varies speed of the sewing machine. A controlled foot pressure puts parts of the machine into the proper motion. High-end machines allow a computer to command various motors, move the needle bar and feed dog, and control the tension. Remember that a sewing project is a construction zone. Speeding through it can leave you with some hefty fines.

It Ain't Broke, But Fix It

Keep your machine covered when you are not using it. Oil it as the manufacturer recommends, using oil that both lubricates and eliminates rust. Use compressed air and a brush to clean areas of dust and fabric debris. Change the needle with each project.