How Does A Sewing Machine Work?

You are aware of how to operate a sewing machine, but do you understand how a sewing machine functions? A sewing machine’s sole function is to sew, whether it’s for a quick stitch or a more involved project. Sewing machines are available in a wide range of styles, from straightforward ones to more complex ones. Sewing machine operation requires a more advanced level of mechanical and electrical design knowledge. Nonetheless, for your convenience, we have attempted to explain in the simplest terms possible.
Let’s wait no further and look into the in-depth details of a sewing machine’s working mechanism.

Types of sewing machines

The three main types of sewing machines are manual, electronic and computerized sewing machines. (Read detailed post about the types and history of sewing machines here)

Sewing machine parts and their functions

Before we can understand how a sewing machine works, we need to know how it is put together.

(Source of image: https://encrypted-tbn0.gstatic.com)

• Handwheel: The sewing machine’s handwheel is a spherical component in the upper right corner. The handwheel is used to manually advance the sewing machine. The stitching speed can be changed with its help. To avoid messing up your machine’s timing, it should always be facing you.

• Bobbin holder: An item for sewing that stores sewing machine bobbins is known as a bobbin holder. If you don’t store bobbins correctly, the thread starts to come off, resulting in a tangle of knotted thread. In this case, the main purpose of bobbin holders is to keep a group of bobbins together and in order.

• Bobbin winder: A bobbin winder is found on almost all sewing machines. The type of bobbin winder will differ depending on the machine. The thread will be wound onto a small, circular bobbin using a bobbin winder from a bigger spool. This tiny spool will fit into the sewing machine’s bobbin case.

• Stitches: The basic stitches are provided by sewing machines with corresponding symbols and numbers. These representations help explain the stitch’s appearance and intended use. Each stitch is different and has a different needle movement that is programmed into it. It also needs a different sewing foot and a different setting for the tension or breadth.

• Stitch length: The stitch length of a sewing machine is the separation between two successive needle punches made in a single motion. The length of each stitch is measured in millimeters or by counting the number of stitches per inch (SPI).
  On your sewing machine, check for the dial with the graphic that resembles a dashed line to determine the stitch length. Small dashes appear at first, and then they gradually get bigger.

• Stitch width: The stitch width determines the width of each stitch, which ranges from a thin stitch to a large stitch. The machine may switch from a straight line stitch to a zigzag stitch using the stitch width adjustment. How far the stitch extends from side to side depends on the stitch width. On your sewing machine, look for a dial with mountains and peaks that begin flat and progressively rise in height to indicate the stitch width.

• Spool holder: The tool that correctly aligns the thread is known as a spool holder. The thread is positioned by the spool holder in such a way that it will move through the machine without breaking, knotting, or tangling.

• Thread tension: A dial on the machine’s thread path is used to control the thread tension. The amount of thread that can fit through the machine to make a stitch is known as the thread tension. The more thread there is in the stitch, the looser it becomes. The less thread used, the tighter the stitch.

• Thread cutter: A blade used to cut threads is known as a “thread cutter.” The thread cutter can be found on some sewing machines along the left side, close to the back. On some devices, it can be on the device’s back.

• Reverse lever: Reverse stitching is possible with the reverse lever. Reverse stitching is used to keep the stitches in place at the beginning and end of seams. This feature is very important because it lets you make stitches and seams that are stronger and more durable.

• Thread take up lever: The thread system of the sewing machine is made up of the thread take-up lever, which is right above the presser foot. After a stitch has been made, the thread is lifted back up out of the fabric by the thread take-up lever.

• Presser foot: A presser foot is a part of a sewing machine that keeps the fabric under the needle in place while stitching. With the help of the presser foot, your sewing machine can do more than just straight stitching.

• Needle: The main component of a sewing machine is the needle. The needle must be heavy enough to pierce the fabric without being too large to make an ugly hole since it brings the upper thread down to meet the lower thread.

• Needle position: By using the needle position option and the presser foot guides, you may position the sewing machine needle precisely where you want it to be when stitching.

• Feed dogs: The feed dogs dispense the fabric under the presser foot. So that you may stitch in a straight line, they draw the cloth in between the throat plate and the presser foot. The feed dogs also control how much fabric passes through at once, regulating the stitch length.

• Foot controller: You may regulate the speed of your stitches by using the foot controller to start and stop the machine.

Sewing machine working mechanism

The needle mechanism, bobbin and shuttle mechanism, bobbin thread mechanism, feed-dog mechanism, and stitch mechanism are the main mechanisms that will help you comprehend how the sewing machine works.
We can’t show you a sewing machine schematic for the components we just specified. But we’ll do our best to describe how these sewing machines’ interior components work together to create the sewing. Let’s go into more depth about each of them:

• The needle mechanism

The needle system is the first mechanism you’ll encounter. The take-up lever operates the needle mechanism, which is in charge of raising and lowering the needle. The needle mechanism consists of a lower shaft that pushes the needle up and down and an upper shaft that turns a wheel. These shafts convert the motor motion into downward and upward motion.
The upper shaft holds and turns a wheel, and the motor powers a mechanism that makes the wheel round. The lower crankshaft is then attached to that wheel, which makes the action move back and forth. The needle can then rise and fall at that point. Indeed, a thread is required for the needle. This thread, which enters the needle eye, is taken right off the bobbin.

• The bobbin and shuttle mechanism

The bobbin and shuttle mechanism is the sewing machine’s next critical component. The shuttle mechanism is responsible for transferring the thread from the bobbin to the needle and then to the fabric. Stitches cannot be made without a shuttle and a hook. Gears enable the mechanism to rotate a little bit more quickly than the needle. The bobbin, which rotates to deliver the thread to the needle, is where it all begins.
An arm or hook is used to remove this thread from the bobbin from underneath the sewing plate. A shaft is moved by a set of gears or pulleys that are located beneath the needle. When the needle drops, this shaft is connected to the hook that seizes the thread.

• The bobbin thread mechanism

A machine-sewn stitch cannot be created without the bobbin thread mechanism. A secure stitch known as a “lockstitch” employs two threads: a lower thread and an upper thread. A spool is used to feed the upper thread, which is then threaded through the needle. The bobbin is used to feed the bottom thread. The top thread can hook onto a loop created by the bobbin thread. The stitch is finished when the bobbin thread loops into the top thread.

• The feed dog mechanism

The feed dogs make sure that the fabric moves through the machine at the same speed, which is necessary for even stitching. The fabric is pushed through between the throat plate and the presser foot by the feed dogs, which look a lot like tiny teeth. The feed dog mechanism is used to feed the fabric into the machine so that threading can take place. It is actually the most complicated mechanism, despite the fact that it sounds simpler than the others.
This system moves forward and up with the help of two mechanisms that move around a central shaft. The center of the shaft is occupied by an egg-shaped wheel. This wheel is in contact with a lever that oscillates. The other portion of the shaft is moved by the crank that is connected to the lever. The egg-shaped wheel touches the lever once more when this section of the shaft moves. By doing this, the lever is guaranteed to go back and forth steadily.
The shaft goes up and down as the lever oscillates back and forth. A set of teeth can move the fabric thanks to the two crank mechanisms. To move the material on top, it travels forward and upward.

• The stitch mechanism

All of the parts inside the sewing machine that were described above work together to make even, perfect stitches. In order for the bobbin hook to capture the thread and create a loop that passes around the bobbin, the take-up lever pulls the needle up and down, releasing the tension on the thread and puncturing through the cloth and the region beneath it.
The cloth is then advanced along the throat plate by the needle after it has been pierced by the feed dogs. As the needle penetrates the cloth to release the tension on the thread, the take-up lever keeps functioning by pulling the thread downward. For the bobbin and shuttle hook to grip it and create a loop that wraps around the bobbin thread, this is necessary.
The take-up lever moves upward when the needle rises after making a full rotation, tightening the bobbin thread underneath the fabric to finish a single stitch.

Thread tension settings for a sewing machine

I thought about putting thread tension here because it is an important part of making stitches. The amount of thread that can fit through the machine to make a stitch is known as the thread tension. When threading your machine, the thread must properly rest between the tension discs. The machine won’t be able to sew properly if it doesn’t.
The machine needs a bottom and top thread to create a well-formed stitch. To perfectly interlink at the center of the cloth, these threads must cooperate with one another. One will drag the other through to the other side of the fabric if there is an imbalance. This will result in a stitch of poor quality that might not hold.
Most of the time, you can’t change the bobbin thread tension because it is set at the factory. Usually, the modifications can be made at the top of the thread tension. The default setting for typical straight-stitch stitching is usually at position 4.5. Most textiles should work fine with this.
You might notice that the bobbin thread is dragged through to the top if you are using a wider stitch instead of a straight stitch. The stitching may be seen at the stitch’s sides, and the fabric may be somewhat elevated or bunched.
If you see this, ease up a little on the pressure, perhaps to a level between 3 and 4. The fabric will then lay flatter. If you are topstitching and want the stitches to stand out more, it also helps to slightly release the top tension.

How does a sewing machine work – Summary

Older sewing machines used a stitch called a “chain stitch,” which is very weak and makes it easy for stitches to come out. Modern sewing machines use the lock stitch, which is much stronger and is made when two separate threads cross each other through a layer of cloth. For this reason, you need to thread the top needle of the machine and thread the bobbin below the surface.
Understanding how sewing machines operate is helpful for more than simply feeling knowledgeable; it also helps you understand why your sewing machine can break down, which does happen to all of us occasionally. This article should assist you in improving your problem-solving skills and help you solve some of the typical sewing issues that may arise.

If you are a beginner sewist, review our best sewing books for beginners and best sewing machines under $200 to get started. If you are an advanced sewist, have a look at our best sewing books and best sewing magazines posts and if you are looking to get a basic, heavy duty or industrial sewing machine, have a look at some of our great articles. Happy Stitching.

Similar posts you will enjoy

Frequently Asked Questions