Foot Speed Controller Troubleshooting
What to do when you press the foot control pedal but the sewing machine does not work. One of the reasons could be a foot speed controller failure.
Lets learn how to works the foot control pedal and its possible breakdowns.
But first I want to warn you that it's not recommended to disassemble the pedal yourself. It can do experts only. But if you look inside the foot pedal you can best understand how woks it and to troubleshoot.
Note: Before removing the bottom cover, it is necessary to disconnect the pedal from the socket.
The screws holding this cover are located under the gaskets which are glued to the base of the cover.
Note: Never open the electrical appliances themselves!
Now let's see what is inside the foot speed controller of the sewing machine.
When you press the pedal this plate pressed to both graphite details. As a result, the electrical circuit closes and the electric motor of sewing machine starts to work.
The surface of the copper plate contacting the graphite bushing must be clean. It should not have any burned-out areas or oxides.
If you need a great effort to make the sewing mashina work, check the gap size between the plate and graphite bushings.
Note: The copper plate must not touch the graphite bushings in a loose fit. In addition to it, it should evenly toach both bushings during the pressing.
The gap size between the plate and graphite bushings an be changed by loosening the screws. Then slide the rheostat case in the desired direction.
This photo shows the part of the foot speed controller that does not affect the operation of the pedal. This is an electric capacitor. It is necessary to extinguish electrical impulses.
Now let's consider the case when the sewing machine does not can to regulate its speed. And only if you press the pedal to the end, the sewing machine starts to work but at the highest speed.
Look at this photo. When you press the pedal to the end these contacts are closed. The copper bushing (with arrow) goes down to the petals and closes the electric circuit "to the straight line" (without resistor). The sewing motor starts to rotate at maximum speed.
Now let's see what is inside the ceramic case. If you remove these cooper plates, be prepared to find a lot of thin graphite washers.
Never do this because they are very fragile and can easily break. If the cause of the malfunction is inside this enclosure, it is better to buy a new pedal.
After years of work these plates are burned out or covered by a touch, which prevents good contact between them. In some circumstances you can repair the pedal if you can remove carbon deposits.
The above reasons do not happen often and they can not be fixed at home. You will need to contact the service center.
But there are problems that are easy to avoid if you know about them in advance.
Often the cause of the malfunction of the foot control pedal is electrical wiring. Inspect carefully all the contacts, starting from the resistor and to the plug located on the body of the sewing machine.
Note: The wire in the twisted and twisted sections of the wiring may break off.
Make sure that you do not have such segments on the wiring.
In addition, check that there are no with bare wires.
Occasionally, the wiring is disconnected from the electric outlet or from the plug on the body of the sewing machine.
If the wire near this plug constantly moves, a breakdown may occur into it. A sign of such a breakdown: the electric motor of the sewing machine works intermittently.
The surface of the metal parts of the electrical socket must be clean. They should not have rusty and oxidized areas.
Now you know how works the foot speed controller. But you should know, that there are other types of foot control pedals, having a different working principle.
English isn't my first language, so please excuse any mistakes and help correct them.
E-mail for sending is on the contact page.
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