How to make a circular saw with your own hands from a washing machine engine?

A circular saw is always useful on the farm: in the country or in a private house. But not everyone can afford a good expensive tool, and a cheap analogue quickly breaks down. The way out of the situation is to make a circular saw with your own hands. For example, you can make it from an engine from an old automatic washing machine, which is a pity to throw away, and takes up space. Such a homemade tool is able to cope with a board up to 5 centimeters thick. The advantage of this design is its weight, which is about 20 kilograms. The saw turns out to be mobile and you can carry it with you in the car.

The question arises whether any washing machine will work. Of course, the more engine power, the more powerful the saw will turn out and cope with large tasks. But a low-power tool will always come in handy on the farm. It does not need a stationary table, a regular box will do, which will be both a support and a place for chips. The main aspect is to connect the motor correctly, otherwise the assembled circular saw will not work. But this is not the only difficulty.

In order for the tool to work properly and cope with various tasks, without spoiling the material, you need to adjust the engine speed. In the washing machine, a tachometer is responsible for regulating the speed, which is controlled by an electronic system. In a homemade tool without electronics, a different solution is required. The collector motor has several leads. In order to determine which one to connect to, you need to "ring out" with an ohmmeter all the leads in pairs. We find where the greatest resistance is.

We also check other connections at the collector and brush outputs. We also carry out measurements and mark the wires of the speed sensor. If in the model they are inside the case, it must be disassembled. We connect one output from the coil to the first outlet of the collector. The remaining contact of the coil with the second collector outlet must be connected to the mains. We are conducting a test run. Since there is a high risk of injury from moving parts and electricity, extreme care must be taken.

During the operation of the tool, it becomes necessary to work with materials of different dimensions, therefore, it is necessary to be able to adjust the speed up or down. To do this, you can use a dimmer or trigger from a hand-held electrical device, because they allow you to adjust the voltage supply and, accordingly, the speed of rotation of the disk. We connect one of the terminals of the coil to the output of the armature, and the second is powered from the mains. We connect the second armature output through the dimmer in the same way. We check the circuit and run it.

A more complicated way to regulate speed is to use a tachometer. With it, you can adjust the speed of rotation without losing engine power. Attention, you need to connect the tachometer using a microcircuit. It evens out the power when the load on the shaft increases. You can buy the necessary microcircuit or make it yourself. This will help the circuit board TDA 1085. The list of necessary parts is extensive, but having a list at hand, it is easily assembled in specialized stores.

There is nothing complicated in assembling a circular saw, but there are some nuances. The circular saw motion module includes the following elements:

• motor shaft;
• shaft for disc attachment;
• belt that transmits movement;
• motor and saw pulley.

The build process includes the following steps:

1. a drive belt is put on the smaller pulley: rotation is transmitted to the saw blade from the shaft; to avoid slipping the belt, notches are needed on the pulley, if they are not there, we make 3-4 transverse grooves ourselves;
2. for better adhesion, bitumen can be applied to the surface;
3. the belt can be used not only from a washing machine, but also from any equipment; it must be jagged and strong enough;
4. in order to avoid slipping of the drive loop from the large pulley, a small protrusion is welded on its end; you can weld a disc with a larger diameter than a pulley;
5. For safety reasons, the disc on the shaft should be fastened very well so that it does not jump off during operation, which can lead to serious injuries;
6. to adjust the belt tension, the engine fixing hole must be bored.

To start a homemade circular saw, you can install a switch from an old household appliance. A push-button switch, which was used on Soviet models of washing machines, will do. At the entrance, it must be powered by two contacts, and inside one wire must be bifurcated. Thus, we get three outputs: one will be a phase, the second will be zero, and the third will give a displaced phase through a capacitor. This circuit breaker will provide a start, but after it you need to disconnect the capacitor.

For the convenience of work, the circular saw must be placed on a frame with a bed. It can be made from a 20 mm rectangular profile. The frame is connected by welding, since during operation, vibration is transmitted to the joints, and they must be securely fastened. Bolted connection is acceptable, but less reliable. It will need to be periodically inspected and bolts tightened. It is also better to weld the bed to the frame. The engine is fixed at the bottom, a working platform is obtained at the top. You can also adapt the table from an old foot-operated sewing machine.

Consider the following tips from professionals:

• homemade circular saw is intended for domestic use; it is capable of processing small volumes of lumber with periodic interruptions in work;
• if the tool is often in demand and the amount of work is large, in this case it is worth considering the option of purchasing professional equipment;
• no need to cut forcibly if the material does not go; for a more powerful tool, a more powerful engine is accordingly needed.

How to make a circular saw from a washing machine engine, see the video below.