“CIRCULAR SAW” IN THE CASE

Circular saw— a very useful thing in any household. On the usefulness of it, perhaps, is in second place after the drill. About design systems: easy-peasy. The basis of it —motor type TAO-AND from the washing machine. The electric motor is not necessary to purchase especially for the time it can be removed from the available machines (it is quite easy to dismantle), simultaneously lubricated bearings. Notice that the margin of safety and durability, this unit is very significant, so it is a temporary use of the saw will not lead to a noticeable reduction in resource most of the washing machine.

To the motor the factory installed pinch bolts pulled the corners of the 50×50 mm and a length of 140 mm. thereto by bolts M6 flat head screws attached from bottom to the base of chipboard size 600x300x20 mm, and the top — the same size Desk, made of plywood thickness of 15 mm (from the PCB, vinyl plastic and duralumin). The M6 bolts with countersunk head to the table from the bottom attached the bearing to the shaft on which you installed the blade and the pulley belt transmission. For disc saw blades in the table there is a corresponding slot width of 10 mm. Console table part and Foundation of a joint stand, made of metal rod with a diameter of 20 mm with axial threaded holes M6 in the ends.

 

On the table parallel to the saw blade guide installed length 450 mm from the dural area 40×40 mm For its fastening and adjustment of the distance to the disk (in small limits) to the bottom shelf of the area is cut in two transverse groove 30×6 mm For wider adjustment of this distance in the table on the grooves with an interval of 25 mm drilled several pairs of holes from a kit of furniture parts and mounted the threaded sleeve kit of furniture parts to which the M6 screws and fixed guideway.

The manufacture of the body of the bearing unit, the shaft and the clamping sleeves mounting the saw blade was entrusted to a qualified Turner because of the quality of these components largely depend on the security and reliability of the machine is in operation. Housing for bearings 60203 machined from steel 20, rest detail is steel 45.

 

Arrangement of circular saws:

 

1 — Foundation (EAF s20); 2 — electric motor DAO-A (from washing machines); 3 — brackets (aluminium angle 50×50,4 pieces); 4 — Desk (plywood s15); 5 — circular saw blade (d200, 81,6, g = 48); 6 — bearing; 7 — a bolt, IB (4 pieces); 8 — guide rail (40×40 aluminium angle); 9 — (STZ, rod d20); 10 — stand-case (Board “25); 11 — belt; 12 — bearing boss (block 40x40x40, 4 PCs.)

 

Bearing housing welded to steel plate 6 mm thick with dimensions 120×80 mm. to avoid spraying of metal, bearing housings before welding was carefully polished with chalk. Threaded holes can be cut directly into the plate and fasten the Assembly using the screws, but in our case it is made of longitudinal grooves, and the bearing is drawn using nuts and bolts. This provides adjustment of belt tension. (In the first embodiment, such adjustment could be made by installing shims of appropriate thickness between the Desk and the surface on which it is based.) Fasteners used finish. The driven pulley from an old washing machine, but if you are not, then it may be carved from aluminum alloy. Strap has a length of 550 mm, for shorter the use of saw blades with diameter 200 mm will be problematic. All the holes in mating parts are drilled together in the process of pre-Assembly. Before pressing into the housing bearings are filled with grease of “Li-tol-24”. When using bearings other numbers should be correct dimensional chain case.

 

Sawdust from the motor covers easily removable flap. For getting sawdust in a storage bin (stand-case) in the base there is a slot size 150×70 mm.

 

The machine is provided with a switch that allows you to instantly disconnect the engine on completion of the work or in emergency situations. The wiring diagram has a starting relay of the type RTK-s, which disables the motor in case of overload (when mounting the relay should be borne in mind that the arrow on its housing during operation must be oriented up).

 

In the absence of the starting relay it is possible to apply the capacitor starting system, to ensure the operation of which is convenient modernized series switch. One key placed elastic element is a piece of foam or sponge rubber size 20x10x5 mm, which ensures that it returns to its original position upon termination of pressing and disconnecting the start capacitor. The motor is started by pressing START during the time required for the output of the motor to the operating speed. The box is mounted on this key enables the second key feed power to the engine. Released the run key returns the elastic element to the initial position, and the contact pads of the capacitor opens. In this case the STOP key is enabled, ensuring operation of the engine. Stop the saw after clicking on the bottom edge of the keys STOP. When using a capacitor system start-up circuit required fuse on current of about 6 A.

 

 

Staff electrical circuit with the starting relay

 

Electric circuit with capacitor starting system

 

 

It is seen that the engine torque in the presence of the operating capacitor much more. Therefore, when using the regular system, the starting relay, it is advisable to connect the capacitor to terminals relay “O” and “P”.

 

Special attention is paid to the selection of the saw blade. The optimal disc diameter 200 thickness 1,6 mm with 48 teeth for longitudinal cutting of boards with a thickness up to 40 mm. Generally the engine power does not allow the use of disks of large diameter and thickness. Does not make sense to buy the disks for cross-cutting—saw longitudinal and transverse is quite satisfactory. When cutting chipboard teeth of conventional steel drive very quickly, “sit down” due to the presence in the material of the solid binder. So to cut a significant amount of DSP it is necessary to get a disk with teeth, equipped with carbide inserts.

Before working the power saw mounted on the stand box, made of birch planks with a thickness of 25 mm. Inside the corners of the box attached to the wooden pillars with dimensions 40x40x40 mm, on which rests the base of the machine. The stand serves as a hopper for collecting chips, but in working condition — case, when the saw is inverted and the base of the reverse side is located on the same bosses.

 

For the sample quarters made the plate of the required thickness with a groove for the saw blade, which is placed on the Desk and secured it with screws. Guide in this case also screws bolted to the plate.

 

Circular saw (left and right)

 

During operation, it does not exclude a stop of the engine due to overload. In this case, the motor should switch off immediately, remove the load, wait a bit and re-insert. In case of sticking of the relay contacts may be lightly knock on his hull. The cause of frequent stops without overload is usually blunting of cutting edges of saw teeth, especially if they are made of tool steel. Regrind them without removing the disk from the machine, personal or velvet rasp, semi-circular or diamond-shaped cross-section. Very important and divorce saw teeth 0.6—0.8 mm.

 

For the dissolution of the long boards made auxiliary bearing with roller, taken from a squeezing device of a washing machine. The support is mounted on a stand of appropriate height at the right distance from the machine.

 

When working on the saw, it is important to observe safety rules: wear protective glasses and gloves, for feeding short workpieces use the pushers. Protective covers easy to do, but necessary.

A. NIZOVTSEV