Whether you enjoy repairing sewing machines as a hobby, a job, or your own business, it can be both exciting and challenging. There are so many different models and designs, it can be difficult to keep up.
When you decide to learn about sewing machine repair, there is a lot to learn. One of those things is understanding sewing machine hook systems.
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.
If your machine has a rotary hook system, it will continuously turn around. Turn the hand wheel and see it rotate. The way it works, is simple. As the needle starts back up, the hooks point catches the thread in the scarf (just above the back of the eye). It then draws the thread 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.
Each part must work in perfect timing and coordination. The hook assembly and needle must reach their exact connection point on every stitch precisely when as where they are suppose to. This is called hook-needle timing. When they are out of synch or time, you will see skipped or potentially no stitches formed at all.
Adjusting the hook-needle timing is a very common adjustment. If the user breaks a needle, sews on excessively thick material, or debris builds up in the gears; the timing often gets jolted out of adjustment. The specifics of making this adjustment vary considerably from one model to another. Some adjust on gears located directly below the hook. Some adjust at the side or at the end of the lower shaft. Some use timing belts. The essential adjustment is always the same, however, in that the point of the needle must reach the scarf at precisely the right time and in the right way. Check the specific service manual for details on adjusting the hook-needle timing until you gain enough experience and knowledge to adjust it on the fly.
As long as there are millions of people using sewing machines, people will need sewing machine repair. You may just be the person to meet their needs either as a hobbyist or as you own business.
When you decide to learn about sewing machine repair, there is a lot to learn. One of those things is understanding sewing machine hook systems.
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.
If your machine has a rotary hook system, it will continuously turn around. Turn the hand wheel and see it rotate. The way it works, is simple. As the needle starts back up, the hooks point catches the thread in the scarf (just above the back of the eye). It then draws the thread 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.
Each part must work in perfect timing and coordination. The hook assembly and needle must reach their exact connection point on every stitch precisely when as where they are suppose to. This is called hook-needle timing. When they are out of synch or time, you will see skipped or potentially no stitches formed at all.
Adjusting the hook-needle timing is a very common adjustment. If the user breaks a needle, sews on excessively thick material, or debris builds up in the gears; the timing often gets jolted out of adjustment. The specifics of making this adjustment vary considerably from one model to another. Some adjust on gears located directly below the hook. Some adjust at the side or at the end of the lower shaft. Some use timing belts. The essential adjustment is always the same, however, in that the point of the needle must reach the scarf at precisely the right time and in the right way. Check the specific service manual for details on adjusting the hook-needle timing until you gain enough experience and knowledge to adjust it on the fly.
As long as there are millions of people using sewing machines, people will need sewing machine repair. You may just be the person to meet their needs either as a hobbyist or as you own business.
About the Author:
Get more detials on repairing sewing machines Dr. David Trumble. See 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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