Working of a Sewing Machine

On average, a simple T-Shirt consists of nearly 1000 individual stitches. Now, think of all those stylized clothing we use on a daily basis. Stitches, stitches, and more stitches! What if we had to sew all these clothes by hand?

Well, sometimes it takes a blog like this one to discuss and appreciate the science behind simple concepts, as old as the “sewing machine”. What makes it so much better is the efficiency and a convenient design. Now, you see how this saying suddenly started making sense:

A stitch in time, saves nine.

Let’s quickly dive into the details of how a sewing machine works. There are two sources of thread.

  • The needle drives the top spool thread through the fabric. A rotating shuttle hook beneath the table hooks this thread and pulls it around the hook until it completes one rotation.
  • The second, bobbin thread is already attached to the hook but stays still till the top thread loops over it.

The further up and down motion of the needle forms a series of stitches as described in the following animation:

The motion of a threads in a Sewing Machine
Source: HBR/WIKIMEDIA COMMONS

Sewing machines, nowadays, have the ability to make a wide variety of stitches, including Chainstitch, Lockstitch, and Overlock. The speed ranges from 10 to 20 stitches per second, depending on the power, which is absolutely remarkable when compared to that of human effort. The foot-powered machine uses a combination of belts and lever to cause the motion of the needle, while a handwheel machine uses rotary motion by hand to move the gears. The recent electric-powered machines perform the same task using electricity.

Evolving for the past so many years, sewing machines have come a long way in improving their size, portability as well as efficiency. And we cannot deny the fact that sewing machines indeed make our lives so much easier. So next time when picking up your perfect-sized clothes, do take a second to appreciate the contribution of science in making all those neat stitches!

References:

  1. HobbyCouture — How does a sewing machine work?
  2. Wikipedia — Sewing Machine
  3. Interesting Engineering — How does a sewing machine work?