When I first started sewing, I always think how the sewing machine is working. I was always curious about the mechanism of the sewing machine. Sometimes I open and disassemble the sewing machine and try to see how it is working. How it is making the stitch.
Later I came to know that, sewing machine consists of many parts which work together to get the stitch done. The machine works through a mechanism called sewing machine feed mechanism.
In this post, we will discuss more about the sewing machine feed. We will understand how it works. As it is important to know your machine very well. Because, when it will give any problem, you can solve it by your own.
Sewing Machine Feed Mechanism
Sewing machine feed mechanism is basically the motion of three components that is needle, looper and bobbin. While sewing the two threads the upper thread and the inner thread both combine together to create the stitch.
The upper thread goes through the needle and the inner thread comes from the bobbin. Both the threads make a loop because of which stitch is performed.
Function of the feed mechanism is to advance the fabric to the feed of the sewing machine and also decide the length of the stitch. Correct feed mechanism also helps to avoid sewing faults.
Sewing machine feed mechanism ensure correct, uniform and well balanced stitch length. It also ensures the fabric to remain flat and don’t gather.
Types Of Sewing Machine Feed Mechanism
There are mainly 6 types of feed mechanism to maintain the speed of the sewing machine.
- Drop Feed Mechanism
- Differential Bottom feed
- Adjustable Top Feed System
- Needle Feed mechanism
- Walking Foot Mechanism
- Unison Feed Mechanism
- Puller Feed Mechanism
1.Drop Feed Mechanism
Drop feed mechanism is the most common feed mechanism found mostly in home sewing machines and some industrial machines. It is the most simple feed mechanism also known as regular feed.
Main components of drop feed mechanism are throat plate, feed dog and presser foot.
In this mechanism the feed dog advance the fabric through the machine. When the needle pierced into the fabric and when the needle is up after creating a stitch, at that time the feed dogs present in the bottom of the sewing machine grab the fabric and move it along the sewing machine.
In drop feed mechanism, fabric is grabbed by only the lower feed dog. So, it will be difficult to sew multiple layers of fabric and thick fabrics. As the bottom feed dog only grab the fabric, so the lower ply is fed more than the upper ply. As a result shifting of ply occurs in case of thick and multi layered fabrics. For thick materials it is not good, because it is difficult to maintain uniform stitch length in thick materials. So, it is very good for thinner and few layered fabrics.
2. Differential Bottom feed Mechanism
Differential bottom feed mechanism the modified version of drop feed. It consists of two feed dogs, one in the back and one at the front of the needle. This also works same like the drop feed but the speed of each part can be adjusted separately.
This type of feed mechanism is used for stretchy materials. This is mostly found in sergers and overlockers. Stretching and gathering of fabric is done by this technique.
You can adjust the speed of each feed dog according to your need. When the speed of the front feed dog is higher than the back feed dog, which results in moving more fabric than the back feed dog. This removes the stretched out wave that is caused by sewing some type of fabric.
When the speed of the back feed dog is higher than the front feed dog. then the back feed dog will pull more fabric than the front. In this case, we get lacy effect.
3. Adjustable Top Feed System
In this feed system, two sections of presser feet are used. One presser foot holds the fabric when the needle penetrates the fabric and the lower presser foot moves and presses the fabric. It gives speed to the top layer of fabric and feed it.
This type of feed mechanism can be used in both drop and differential bottom feed system. When the adjusteble top feed is combined with differential bottom feed in a sewing machine then gathering of top ply or bottom ply may occur.
4. Needle Feed mechanism
The needle feed sewing machine is also known as compound feed machine. It is a type of mechanism that consists of combination of feed dog and an inner presser foot. In this type of mechanism the needle moves backward and forward. Both the needle and the feed dog move together to move the fabric.
Needle pierces the fabric through the feed dog to make one stitch. Then fabric and needle move simultaneously. Both feed dog and needle also move at the same time. Then the needle rise up again and move to form next stitch.
This type of feed mechanism is useful for multi layer fabric like wadding and slapping. The stitch length can be changed by changing the feed dog.
5. Walking Foot Sewing Machine
A walking foot sewing machine is also called as top feed machine. This mechanism has 2 feed dogs. Theses feed dogs are mounted onto the preeser foot. These move with lower feed dogs and needle. THe feed dogs pull the fabric to move it. After the presser foot islowered the feed dogs grip the fabric and move it forward. All these are done while making sure that the upper and lower layers of fabric advance evenly. This prevents shifting of fabric. As you loo carefully while the maching sews you can see the foot walks over the fabric while sewing. So, it is called walking foot.
These machines are best suitable for sewing heavy and multiple layers of fabric as well as quilting and working with materials that are prone to shift.
These machines are not useful in sewing lighter fabrics. The preeser feet is bulky, so it is also difficult to stitch designs.
5. Unison Feed mechanism
The unison feed mechanism is also called as tripple feed mechanism. It is a three feed mechanism. In this the feed dog comes up to meet the needle and the presser foot. Feed dog, presser foot and needle, all the three move to make the stitch happen.
There are two presser feets in this. one is holding and other is feeding feet. One move with the needle and the other holds the fabric from below.That is why it is called three feed or tripple feed mechanism. Three types of feeding mechanisms working here. These are drop feed, needle feed and walking foot. That is why it is called triple feed mechanism.
This is useful in sewing bulk, heavy and difficult to sew materials like leather upholstery etc.
It has used only in special cases. Shifting of ply is not possible in this.
These are not good for lighter materials. These are also little complex in design and usually larger than standard sewing machine.
7. Puller Feed Mechanism
The puller feed mechanism is a modification of drop feed mechanism that use additional rollers. These rollers are called puller. These pullers grip the fabric and move it forward. These rollers work along with the feed dog.
The rollers grip the fabric and pull it through the machine while rotating and at the same time feed the fabric evenly. This puller feed mechanism is good for heavy and stubborn material because it is exceptionally well in cotrolling fabric movement
These type of sewing feed mechanism is useful in sewing hevay-duty fabrics like canvas and PVC. These type of machine also need regular maintainance, little noisy.
Conclusion
We have done a deep analysis on different types sewing feed mechanisms here. There are many feed mechanisms. But, I tried to put all those that I know. Go and read about them all. Check in your own sewing machine and tell which type of feeding mechanism your machine has.
