While sewing machines may vary a little from model to model, the working principle is the same for all of them. Wondering how does a sewing machine work? We have prepared a guide that will get you familiar with the process and the inner working of this essential product. We’ve also included some extra information if you want to learn even more.
How does a sewing machine stitch?
For the average person, sewing involves using a needle and a length of cotton thread. This is the technique that is used for simple hand repair, and it is known as running stitch. To use this basic technique, you need to join two pieces of flat fabric together, thread the needle with a length of cotton, and push it through the two pieces of material.
You then have to pull the needle through and move it along the material so that you can form a stitch. Then you will need to push the needle back through the material in the opposite direction. This basic sewing technique is easy to understand.
If that is all you’re familiar with, then the way that a sewing machine works can appear overly complicated since it only uses one needle that keeps raising and lowering. How can the one needle pass the thread back and forth without getting the length of cotton tangled up?
Unlike a handheld needle, the eye of a sewing machine needle is located on the pointy end that goes through the fabric. The secret to the way that a sewing machine works lies in the fact that it uses two separate threads of cotton, one that’s fed from above through the eye of the needle and another one fed from below by a reel mounted in a rotating carrier.
The reel is called a bobbin, and the rotating carrier is called a shuttle. The process can be difficult to visualize, but it is, in fact, very simple. The needle goes through the fabric, it stops for a moment to give the shuttle time to lower and connect with the needle. It then rises a little, but it leaves behind a loop of the thread. The hook of the shuttle will now pass through the loop and catch it.
While the needle will continue to rise now, for the time being, the main action will take place under the material at the base of the sewing machine.
The shuttle hook drags the thread and rotates it in a circle so that it can lock around the other thread fed by the shuttle. Once the thread from the needle locks around the shuttle thread, the hook releases it, and the two threads are tightened into a stitch by the force of the needle pulling upwards.
Now that the stitch is tight, the process is ready to be repeated so that the machine can make the next stitch. All of this happens in a second, and the needle doesn’t do the stitching alone, as it may appear to an observer. It inserts the thread down through the material, and the shuttle takes that thread and uses it to form successive stitches.
The needle is used again at the end of the process to pull the stitch tight. This type of stitching that uses two threads instead of just one is called lock stitch.
Manual vs. electric sewing machine
There is a rich selection of models on the market that operate in slightly different ways. However, the working principle is the same no matter what type of sewing machine you get, be it electric or manual.
An electric sewing machine uses electric power to move the gears and coordinate them so that the needle moves up and down and puts the thread into the fabric correctly. There are two main types of manual sewing machines: foot-powered and handwheel.
Foot-powered style machines use a treadle and belt to move the various gears that put the needle, shuttle hook, and all the other vital parts in motion. A handheld machine works using the same principle, but it doesn’t have a treadle, which means that all parts are moved by hand.
Manual machines are, however, hard to find nowadays, and they’re mostly limited to the vintage category. They’re not as efficient or easy to use as an electric alternative, which is why many owners of manual sewing machines fit them with electric motors so that they can keep the vintage design and enjoy the fast and efficient work of modern machines.
What is inside a sewing machine?
A modern sewing machine is quite voluminous, so one has to wonder what kinds of secrets lie under the cover. If you were to take the cover off, the first thing that you will notice is a labyrinth of gears, cranks, belts, and pulleys. All of these parts are needed to put the needle, bobbin, and shuttle in motion.
All the aforementioned parts are run by an electric motor that is attached to a drive belt. The belt moves the drive wheel, which then rotates the upper drive shaft. From here, things can get more complicated since the upper drive shaft has plenty of mechanical parts attached to it.
One of the most important moving parts is the crank, whose job is to move the needle up and down in quick succession. The upper drive shaft is connected with the lower drive shaft that operates the shuttle. Because the driveshafts are connected, this means that the shuttle and the needle move in unison.
This is exactly the reason why sewing machines are so reliable since the unison movement of the two drive shafts make it difficult for the machines to deliver an improper stitch.
How do you start a sewing machine?
The following guide will describe the step-by-step operation of an electric sewing machine, but the same principle can be used to operate both foot and handwheel models. The instructions should work for all models, though there may be some modifications depending on the product you have. Make sure to check the machine’s manual before operating it.
Before you can power it on, you will need to make sure that the machine is placed on a stable, strong, and sturdy table or cabinet. The table or cabinet should give you good legroom so that you can find it comfortable spending long minutes or hours operating the machine.
The first step is to find the power switch, which is usually located on the right side of the machine. With some models, the location may be different, so in this case, you will either have to check all sides of the machine or check the user manual that came with the product.
The next thing to do is to place your preferred spool of thread on the spool pin. You should then bring the thread from the spool pin through the thread guide. The thread guide is the small part that is found on top of the machine, close to the spool pin.
Now you will need to go to the right of the spool pin where you will find the bobbin winder and stopper. You will need to ensure that the bobbin is in place and that the thread attaches to it.
Some models may be capable of doing more than one type of stitch. If you have such a machine, then you will need to locate the stitch adjustment dial and choose the stitch type you want to do.
On the left side of the machine, you should be able to find the thread take-up lever. You will need to take the thread through this lever. The next step is to adjust the thread tension dial until you get the tension that you need. If the thread is not tensioned properly, the machine won’t work well.
The next step is to thread the needle, and to do it, you will need to bring the thread down and then insert it through the eye of the needle. Once you have inserted it, pull it until it gets taut. It is recommended to leave at least a few inches of thread to help the lower and top thread connect with each other.
You will also need to replace the needle after going through 2-3 bobbins since otherwise, it can get too dull to puncture the material properly, and this can make your stitches look messy.
The last step is to catch the thread. To do this, you need to turn the knob on the side of your machine a few times. As you do it, you will see that the bottom thread will come up through the base of the machine.
Get a ruler or other flat object to push the thread strand to the back of the sewing machine. Your machine will now be threaded, and you can turn it on and start sewing.