How Does A Sewing Machine Work: 3 Mechanisms Explained

The answer to how does a sewing machine work will be easier to understand if we go through the three specific mechanisms for each part. Do not worry because we’ll use simple terms. You will also know more about the functions of each component.

Do you also happen to own a Singer sewing machine? Then, consider giving this tutorial on how to thread a Singer sewing machine a quick read. 

how does a sewing machine work


How Does A Sewing Machine Work Step By Step


How the needle mechanism of the sewing machine works

A shaft drives a wheel, while a crankshaft is responsible for the upward and downward movement of the needle.


How the bobbin and shuttle mechanism of the sewing machine works

The shaft uses gears to turn the shuttle and hook, which are responsible for making the stitches. This way, it will work faster than the needle mechanism. The hook is also what contains the bobbin.

Speaking of stitches, you might benefit from knowing how to thread a Brother sewing machine if you have this specific brand. We have written different tutorials for various models and sewing machine brands, so please browse our blog. 


How the feed-dog mechanism of the sewing machine works

There are synchronized mechanisms on the main shaft responsible for moving the fabric through the sewing machine. This so-called feed-dog mechanism ensures that the stitches made by the sewing machine are of equal length. One of the mechanisms pulls the feed dog from right to left via a lever being rocked by a wheel, while the other is a crank that moves the feed dog up and down. 


Hand Sewing Vs Machine Sewing

You will understand how a sewing machine works much more quickly if you compare it with hand-sewing. However, these are two different actions because you make running stitches when sewing manually, while a machine sews using lock stitches.  


Sewing by hand

To make a running stitch, you’ll push the threaded needle through two pieces of fabric together. Then, you’ll push the needle through the material in the opposite direction. Therefore, only a single thread is needed since the stitches are alternating on the upper and lower sides of the joined fabric. 


Sewing with a machine

A sewing machine works unlike hand sewing since it uses two threads instead of one, and the stitch is a lock stitch instead of running stitch. The needle feeds a thread above, while a bobbin feeds the other below. If you still can’t imagine it, the loop formed by the thread on the needle catches a hook on the shuttle that contains the bobbin thread. 


Why Does A Sewing Machine Have Two Threads?

A sewing machine needs two threads because its needle is only there to prick the fabric, allow one thread through, and create a knot with the other thread. This is how a sewing machine makes stitches compared to sewing by hand and pushing the threaded needle through the fabric. The bottom thread is also fed from the bobbin that’s inside the shuttle, which is a rotating case with a hook. 


How a sewing machine makes stitches with two threads

  1. The needle from the top goes down into the fabric to allow the upper thread through the fabric
  2. As this is happening, the shuttle rotates, and its hook approaches the needle thread
  3. The needle goes up and leaves a loop of the upper thread, and the hook on the shuttle will go through it
  4. The shuttle hook locks it around the bobbin thread by dragging it around
  5. The needle tightens the upper thread by going upward and then pulling it off the hook

What Is The Purpose Of Bobbin?

The main purpose of the bobbin is to support the bottom thread similar to cylinders that hold the yarn when weaving. Do not confuse it with the bobbin thread, which is a thread typically used for basting or embroidery.  Back to the bobbin of the sewing machine, it is composed of the following:

Bobbin case

The bobbin case holds the bobbin to keep the thread neat during unraveling. 

Bobbin tension system

The user can also reset the tension system of the bobbin.

Bobbin winding system

The bobbin finding system is what loads the thread to the bobbin smoothly. 


Can A Sewing Machine Work Without A Bobbin?

You can’t use a sewing machine without a bobbin because its stitching mechanism uses two threads. However, there are exceptions to this since some machines only use a needle thread. Nonetheless, making lock stitches will always be impossible without the bobbin on a sewing machine. 

How to sew without a bobbin?

You can sew without a bobbin if you’re using other machines instead of a sewing machine. They include sergers, overlocker machines, and chain stitching machines. You can also expect that using an embroidery machine will be impossible if you don’t have a bobbin.


And that’s it! To recap how does a sewing machine work, you need to understand three mechanisms. They are the needle, bobbin and shuttle, and feed-dog mechanisms. 

It’s also crucial that you understand that sewing machines make lock stitches using two threads. So it won’t work without a bobbin because the bobbin holds the bottom thread. We hope this was a helpful read; leave us a comment if you have any questions. 

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