Any tool during operation wear. Circular saws are no exception. With prolonged use, their teeth become blunt, productivity decreases, the quality of the cut deteriorates. In addition, the load on the motor increases, which can cause its combustion. Replacing the disk with a new one will fix the situation, but the old one can be reanimated.
Image 1. Diagram of the circular saw tooth device.
Sharpening a circular saw with your own hands is a common procedure for those who regularly cut wood, drywall and other materials. The fact that the tool needs to be serviced may be indicated by several factors: when working, it is necessary to apply increased effort, there is a smell of burnt wood, dark traces of the teeth of the disc remain on the kerf, the engine is overheated, and there is smoke from under the protective casing.
For the manufacture of discs, alloyed steels of increased strength 65G, 9HF, 50HFA or their foreign analogues are used. It provides rigidity and reliability. Cutting plates based on tungsten, cobalt and carbide alloy are soldered to the disk. The hardness of these plates is determined based on their percentage and the grain size of the carbide phase. Soldering of the working teeth to the disk is carried out at a high temperature with silver or copper-zinc solder.
Image 2. The shape of the teeth of the circular saw.
The circular saw blade has 4 working zones and 3 cutting edges at the junction of these zones (image 1). Depending on the purpose, the teeth may have a different shape (image 2). Discs with straight teeth are designed for quick cutting. Bevelled - allow you to work with the material in the longitudinal and transverse directions and prevent chipping. Often, the teeth on the saws that are beveled to the right and left alternate. Trapezoid teeth often set in combination with straight. They rise above the straight and perform the main cutting function. Saws with tapered teeth are used when cutting laminate to avoid chipping and cross-cutting.
The main load falls on the front side and the upper cutting edge, but the side faces also get blunt when working with massive materials. Do not allow the edges to blunt by more than 0.2 mm. Sharpening should be carried out in two planes: front and rear. In addition to honing, you need to pay attention to the divorce of teeth. If it is necessary to perform it, then use a special key - wiring, which has slots for the teeth and a fixture of the divorce value. A similar tool is used to divide the teeth of the hacksaws (image 3):
- A - slotted layout, B - layout with emphasis;
- 1 - a slit, 2 - a handle, 3 - an emphasis, 4 - a nut-lamb an emphasis, 5 - the screw of fixing of size divorce.
The correctness of the wiring is checked by a special template.Back to table of contents
Image 3. The scheme of the tool for the separation of the teeth of hacksaws.
Sharpening hacksaws, cutters on a chainsaw, circular discs can be made in artisanal workshops. In the absence of special equipment, this can be done manually. To sharpen the disk will need:
- wooden bars.
If the disk is installed on the machine, then it is not necessary to remove it. Fixation in a fixed position is carried out with wooden bars. In order to avoid accidental start of the installation, it must be disconnected from the mains. For sharpening outside the machine for fixing, the saw is clamped in a vice.
Before starting the disc is cleaned and degreased. Marker marks the first prong, after which it is sharpened. Subsequent teeth are sharpened with the same pressure as the first. Sharpening should be uniform. Divorced teeth are processed through one, after which the disk is turned over and sharpening of the incisors curved in the other direction is performed.
People who work a lot on circular saws often have to sharpen the tool regularly. To do this, they arrange in the workshops homemade devices. The grinding wheel is installed on the electric motor. This is either a CBN for sharpening high-speed steel, or a PCD diamond wheel for working with hard alloys. The latter requires periodic cooling, as the diamond begins to burn at a temperature of 900 ° C. To do this, use cutting fluid.
Sharpening must be done precisely butt-end, even a small error can lead to disc damage.
It is impossible to do this manually. Special equipment provides high accuracy and eliminates error. Craftsmen have to resort to various tricks. Equipped with a platform on which the drive is mounted. It can be made movable with an adjustable motion limiter. Such a platform can be made of fittings for sliding furniture. The limiter can serve as a bolt, the twisting or unscrewing of which provides the desired depth of feed. To fix the disc, you can use a washer mounted on the platform, selected according to its internal diameter. The displacement of the disk around the axis is regulated by the teeth clamps.
In the simplest version, these are screws screwed into the platform. After sharpening the first tooth, the disk turns, and the next one is honed. The device allows you to perform work quickly and efficiently.