Here is a neat hobby that can turn into a real job or even a business. I am talking about sewing machine repair. There is a special thrill when a broken down sewing machine springs back to life almost like new " right in your hands. While there are challenges, it can also be loads of fun.
At first, fixing sewing machines can be an overwhelming task. There are so many different makes, models, and designs to learn. When you look at sewing machines, they may all look alike. As soon as you start taking off the covers, you discover just how different they really are. The hook assembly is one of the things that every sewing machine user should and every technician must understand.
When you look at a sewing machine, one of the first things you need to identify is if the machine has an oscillating or a rotary hook assembly. They do much the same task on your sewing machine, but they do it very differently.
Find the bobbin on the sewing machine. Look under, around, or behind it to find the hook. Rotate the hand wheel forward and watch the hook move. How does it move? If it moves in a complete circle around the bobbin it is a rotary hook assembly. If you look closely, you can see that as the needle comes down and starts back up, the point of the hook slides behind the needle just above the eye. It picks up the thread and pulls it around the bobbin.
Where do you put the bobbin on this machine? I could be inserted in front, or top under the needle plate, or on the left end of the machine. If it is a top loading bobbin, the machine is usually a rotary hook machine.
Both the front loading and side loading machines can have either hook system. A good example of the side loading machine is the popular Singer Featherweight. Bernina is famous for their front loading CB oscillating hook system, but they also produce front loading rotary systems.
A rotary hook moves around in a continuous circular motion. An oscillating hook moves back and forth. How can you tell which type of sewing machine hook assembly you have?
If you have any question, answer this. Does the hook move back and forth (Oscillating Hook) or in a complete circle (Rotary Hook)?
An oscillating hook starts out with its point up and just to the left of the needle as the needle moves down. When the needle starts up again, the hook slides behind the needle to pick up the thread from the needle. The scarf is a cut out area of the needle just above the eye which helps the thread form a loop making it easy for the point of the hook to grab the thread. The needle continues moving up while the point of hook continues moving in a half circle to the bottom. At the bottom the thread slides off the hook, and the hook makes its swing back to its starting point for the next stitch.
Oscillating and Rotary hook systems do the same job. That job is pulling the thread from the needle around the bobbin carrier. The point of the hook slides behind and through the scarf of the needle to get the thread. Then it carries it to its destination.
The movement and positioning of the hook and needle must coordinate exactly. Slight variations result in skipped stitches, poorly formed stitches, or no stitches at all. The hook and needle travel through a finite pattern. For each stitch the hook and needle must align perfectly. As the needle rises, the loop must form on the back of the needle. The point of the hook must travel to precisely the right position and at the right moment for the hook to snag the upper thread. This is called Hook Needle Timing.
There are several ways to adjust the hook needle timing depending on the sewing machine. Some adjust the position of two interlocking gears immediately below the hook. Some must be adjusted at the right side of the lower shaft where the lower shaft joins the vertical shaft. Some must be adjusted by adjusting a timing belt. In all cases, the key is to cause the needle and hook to meet at the right time in the right way and form stitches.
The more you learn about how sewing machines work and how to repair them, the more sewing machine repair you can do. Just think there are millions of sewing machines just waiting to be serviced by somebody. You could be that somebody.
At first, fixing sewing machines can be an overwhelming task. There are so many different makes, models, and designs to learn. When you look at sewing machines, they may all look alike. As soon as you start taking off the covers, you discover just how different they really are. The hook assembly is one of the things that every sewing machine user should and every technician must understand.
When you look at a sewing machine, one of the first things you need to identify is if the machine has an oscillating or a rotary hook assembly. They do much the same task on your sewing machine, but they do it very differently.
Find the bobbin on the sewing machine. Look under, around, or behind it to find the hook. Rotate the hand wheel forward and watch the hook move. How does it move? If it moves in a complete circle around the bobbin it is a rotary hook assembly. If you look closely, you can see that as the needle comes down and starts back up, the point of the hook slides behind the needle just above the eye. It picks up the thread and pulls it around the bobbin.
Where do you put the bobbin on this machine? I could be inserted in front, or top under the needle plate, or on the left end of the machine. If it is a top loading bobbin, the machine is usually a rotary hook machine.
Both the front loading and side loading machines can have either hook system. A good example of the side loading machine is the popular Singer Featherweight. Bernina is famous for their front loading CB oscillating hook system, but they also produce front loading rotary systems.
A rotary hook moves around in a continuous circular motion. An oscillating hook moves back and forth. How can you tell which type of sewing machine hook assembly you have?
If you have any question, answer this. Does the hook move back and forth (Oscillating Hook) or in a complete circle (Rotary Hook)?
An oscillating hook starts out with its point up and just to the left of the needle as the needle moves down. When the needle starts up again, the hook slides behind the needle to pick up the thread from the needle. The scarf is a cut out area of the needle just above the eye which helps the thread form a loop making it easy for the point of the hook to grab the thread. The needle continues moving up while the point of hook continues moving in a half circle to the bottom. At the bottom the thread slides off the hook, and the hook makes its swing back to its starting point for the next stitch.
Oscillating and Rotary hook systems do the same job. That job is pulling the thread from the needle around the bobbin carrier. The point of the hook slides behind and through the scarf of the needle to get the thread. Then it carries it to its destination.
The movement and positioning of the hook and needle must coordinate exactly. Slight variations result in skipped stitches, poorly formed stitches, or no stitches at all. The hook and needle travel through a finite pattern. For each stitch the hook and needle must align perfectly. As the needle rises, the loop must form on the back of the needle. The point of the hook must travel to precisely the right position and at the right moment for the hook to snag the upper thread. This is called Hook Needle Timing.
There are several ways to adjust the hook needle timing depending on the sewing machine. Some adjust the position of two interlocking gears immediately below the hook. Some must be adjusted at the right side of the lower shaft where the lower shaft joins the vertical shaft. Some must be adjusted by adjusting a timing belt. In all cases, the key is to cause the needle and hook to meet at the right time in the right way and form stitches.
The more you learn about how sewing machines work and how to repair them, the more sewing machine repair you can do. Just think there are millions of sewing machines just waiting to be serviced by somebody. You could be that somebody.
About the Author:
Get more detials on repairing sewing machines Dr. David Trumble. Explore his extensive curriculum of sewing machine repair courses. Pick up your own free copy of his beginning course 7 Steps To Peak Performance For Your Sewing Machine.
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