Table with a saw. Sharpening circular saws on wood with your own hands: geometry of corners, machines. Sharpening a circular saw: the classic method

The construction of a private house will be difficult and time-consuming without the use of modern tools. A circular saw has gained great popularity among builders, surpassing other types of saws for wood with its accuracy and cleanliness of the cut.

Scheme of a machine for sharpening circular saws and knives.

Since this power tool is one of the actively used and therefore wears out devices quite quickly, sharpening circular saws with your own hands becomes very important.

Tools for sharpening circular saws

To properly sharpen a circular saw, you need tools such as:

• file;
• mounting vice;
• a block of wood;
• colored marker.

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What signs will tell you that you need to sharpen the saw?

Figure 1. Diagram of a saw tooth. Planes: a- front, b - back, c - two lateral. Edges for cutting metal: 1 - main, 2, 3 - additional.

Sharpen your saw blade only when necessary. And the fact that such a moment has come will be signaled by 2 clear signs. In particular, urgent sharpening of circular saws for wood is required if:

1. On the safety covers of the saws in the area of ​​\u200b\u200bthe electric motor, strong heating is felt. Sometimes such an increase in temperature is accompanied by the appearance of smoke from under the casing.
2. To get good work results, the saw blade has to be pressed harder than before.
3. As a result of the work of blunt teeth of saws on wood, the appearance of dark marks, traces of soot, is recorded on the cuts in the wood. The characteristic smell of burnt wood may spread.

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Types of cutting teeth

To better understand how the correct sharpening of circular saws is performed, you should understand the features and structure of the part of the disc that cuts the tree. This main part is the cutting teeth.

All teeth are made from hard metal. Each of them (Fig. 1) has 4 working flat surfaces: front (a), back (b), as well as two side planes (c). They play a supporting role. One main (1) and two additional (2 and 3) edges for cutting material are formed on the intersection lines of the specified work planes.

In accordance with the configuration, all cutting teeth of circular saws are divided into the following varieties:

Figure 2. Scheme of the sharpening angle.

1. Straight teeth. Most often used for accelerated longitudinal sawing. Not designed for perfect cut quality.
2. Beveled (oblique) teeth. They are characterized by the presence of an angular cut on the back flat surface of the tooth on the left or right side. Sometimes on the disk, teeth with different sides of the bevel alternate and then they are called alternately beveled. Such elements are used for cutting not only wood, but also chipboard, various plastics. With a large bevel angle, high-quality sawing without chips on the cutting edges is ensured.
3. Trapezoidal teeth. In cross section, the cutting surface has the form of a trapezoid. Thanks to this configuration, they do not get dull for a long time. Often on the disc alternate with straight teeth. In this case, the trapezoidal elements perform rough sawing, while the straight ones perform the finishing.
4. conical teeth. They have a conical shape. Usually perform auxiliary functions of preliminary notching of the laminate. These teeth process the specified flooring to prevent chipping when cutting laminate panels with the main saw.

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Principles and angles of sharpening circular saws

Figure 3. Scheme of grinding metal on saw teeth.

The working parts of circular saws are sharpened along 4 main sharpening angles. These angles (Fig. 2), like the shape cutting tooth, are the main technical parameters disk.

So, each circular tooth is characterized by the front (γ), back (α) angles, as well as the cutting angles of the front and rear surfaces (ε1 and ε2). The value of the specified angles depends on the purpose of the sawing device, the material being cut and the direction of sawing.

In particular, a saw for slitting sharpen at a relatively large rake angle (from 15° to 25°). The sharpening index of the rake angle for cross cutting is in the range from 5° to 10°. But the universal version, which processes the material in all directions, is traditionally sharpened at an angle of 15 °.

In addition, the specified angles are affected by the degree of hardness of the objects being cut. Their values ​​are strictly dependent: the harder the material of which this or that workpiece for sawing consists, the less sharpened the cutting teeth should be.

The main principle of sharpening the teeth of carbide saws is based on the fact that during long-term operation, the most significant wear occurs on the upper cutting edge. As a result of intensive use, its line can be rounded to 0.3 mm or more. As for the planes of the tooth, the most wear is fixed on the front surface.

Proper sharpening of the cutting elements should provide such a type of edges, in which the radius of their rounding does not exceed 0.2 mm. To do this, it is recommended to grind the metal in parallel on the front and back planes of the tooth (Fig. 3). This method can be considered optimal. It is possible to sharpen only one front plane, however, in this case, such an operation will take more time, besides, the tooth itself grinds faster due to the need to remove more metal from the front surface.

The standard layer of metal to be ground off is 0.05-0.15 mm.

The use of disk elements has found distribution in many areas of industry, so the machine for sharpening circular saws has become widespread. The main requirement for such a tool is the high quality of cutting materials. Sharpening is not such a simple task as it might seem at first glance. In this case, you can not do without special equipment. The following indicators affect how difficult the operation will be:

What material is the item made of?

Saw diameter size;

Angle of inclination and shape of the tooth.

Machine

A sharpening machine is not just one device. So you can call large group equipment and tools for special purposes. According to the method of production, they are divided into two groups:

Automatic. The whole process of sharpening is completely mechanized and there is no need for human participation. Such devices are used for industrial purposes.

Manual. It can be any fixtures and tools for sharpening by hand. The performance of such equipment is much lower than automatic machines. This type has found application in handicraft workshops for domestic needs.

Equipment of this kind is on sale in a wide range, the devices may differ in functions, power and price. Manual machine for sharpening circular saws, the price of which will be much lower (about 20 thousand rubles), you can make it yourself. The equipment consists of dense and hard alloy plates that serve as cutters.

Plates for them are made of alloys different composition.

They have different tooth configurations. The strength will depend on which alloy is used. Not the last role is played by the grain size of the alloy. It should be smaller to give strength and hardness to the product. Usually such hard alloys are obtained from cemented cobalt. Therefore, it is so important that the equipment is exactly the machine for sharpening carbide saw blades.

Differences in insert teeth

The tooth of hard alloys has four main planes for work: front, back and side (auxiliary). When the planes intersect with each other, cutting edges are formed: the main and a pair of auxiliary ones.

The shape of the teeth is as follows:

Straight. The use of this form will be justified when a longitudinal cut is required, fast in time and not mandatory in terms of quality.

Oblique or oblique. The angle of inclination of the back form in this case can be right or left, they alternate with each other. This configuration is the most common. Sharpenings of various sizes serve to work with different materials in any direction.

By changing the size of the bevel angle in the direction of increasing, you can increase the cutting and reduce the likelihood of chipping, but this will lead to a decrease in the strength and durability of the tooth itself. It is also possible to tilt the front part of the plane of the element.

Trapezoidal. This tooth dulls the edges more slowly than the beveled one. Alternate it with a straight line. At the same time, the rough cut was made with a longer trapezoidal cut, and the finishing cut was made with a short straight cut.

Conical. This form of teeth performs a rough cut of the lower edge of the boards, while the upper one is protected from chipping. Basically, the front face of such an element is flat. But if you make it concave, then it is possible to use this device for cross cutting in the final version.

Sharpening angles

The basic angles are those determined by the shape of the teeth. This is the front and rear, as well as the bevel along the front and rear planes.

The size of the angle is also determined by the hardness of the cutting material.

With high hardness, it is made less. The front cutting angle is available in a negative design. This finds application in non-ferrous metals and plastics.

Prices

You can buy a machine for sharpening carbide saw blades at a cost of 15,000 rubles. You can fork out for more expensive devices. For example, PP-480Z will cost its owner 280,000 rubles. Prices vary and depend on the purpose of the device, its functions, power and performance. For a small workshop or home use, you can purchase a JMY8-70 circular saw sharpening machine. Its cost is within 18,000 rubles.

Sharpening rules

The main wear of the saw teeth occurs on the upper edge, which is directly involved in cutting. Its rounding can be 0.3 mm. The center face changes first.

The wear of the saw should not be allowed to be significant. The edge can be rounded no higher than 0.2 mm. A saw that is duller than this value is harder to sharpen. This will take longer than normal wear tools. The degree of wear is determined either by the type of cut or by the teeth.

We must not forget how many sharpenings are produced as much as possible. This value is located within 30-35 times. To achieve this result, both surfaces are processed at once.

The machine for sharpening circular saws allows you to work in only one plane. And then it will be reduced by about 2 times.

Before starting work, clean the working disk from dirt, and also measure the angles of inclination. Preparation for sharpening is carried out from the front of the tooth. The metal layer that can be removed is 0.20 mm.

If abrasives are used for sharpening, they must be cooled with liquid. special composition(SOZH). For best quality and reducing the specific gravity, it is better to choose a circle of high grain size.

No nicks or irregularities should be allowed, even if it homemade machine for sharpening circular saws. They can lead to untimely exit from work and crumbling of the metal.

Artisanal

It will not be difficult to sharpen yourself. Especially if you have the necessary equipment. And if not, then you can make it yourself. It is possible to make a machine for sharpening circular saws, the price of which will only please, from simple parts. To do this, you will need the following basic elements:

Engine;

Caliper;

Tilt mechanism;

Stop screws.

The circle is fixed on the engine, the disk blade - on the support, while the screws will ensure the movement of the workpiece along the axis of the circle, which will provide the desired angle.

The main task for such an element as a machine for sharpening circular saws is to fix them in the required position relative to the circle. This is necessary for the exact observance of angles, this can be ensured by a stand mounted on the frame of the machine in the same plane with the circle.

When the disc is placed on a stand, the teeth must be perpendicular to the plane of the saw machine.

The stand does not have to be made stationary, if necessary, you can make it floating, for this, screw the hinge on one side, and hook the second part to the frame rigidly with bolts. On a structure of this type, you can easily turn the disk of the apparatus to the desired angle and carry out work in a given plane.

Difficulties at work

When using circular saws for sharpening, you may encounter the difficulty associated with the formation of incorrect angles. To eliminate such a defect, it is necessary to fix the center of the saw in the required position relative to the circle. A groove made on a stand can solve such a problem. It will help straighten the saw. There are also easier solution- make stops in the working surface that can fix the device in the correct position.

Exploitation

Before the beginning self-manufacturing this unit, you need to consider the drawings of the machine for sharpening circular saws. You can calculate them on your own, or you can turn to a professional. In any case, in order to understand all the subtleties of the future device, one cannot do without a preliminary paper version. If you have the necessary knowledge, then you can cope without contacting the master.

After the implementation of the future machine on paper, it will become clear what tools and materials will be needed in the process, what is already there, and what needs to be purchased.

A do-it-yourself circular saw sharpening machine has a great advantage in terms of price over the factory unit. It also does not require any special skills to work.

Sharpening without a machine

You can sharpen a saw at home without the help of a machine. But at the same time, you should not hold it manually, while sharpening it. For the correct operation, the efforts of the hands will not be enough, and the eye will not be able to align the desired angle. To simplify the task, you can use some kind of fixation device; for this purpose, a regular flat delivery is useful. In this case, the axis of the grinding disk must coincide with the surface of the stand. And the circle, in turn, should be placed perpendicular to the saw. If necessary, to make corners, the structure is made movable with the help of hinges. But here there is a difficulty in maintaining the same angle of front and rear sharpening. To avoid this, rigid fixation of the saw wheel in relation to the abrasive disc will help. This can be done by using a mandrel groove or attaching stops to the stand, which will allow you to secure the corner.

Conclusion

Like any tool, a circular saw needs proper use and care. Compliance with the technology will increase the service life of the product.

So, we figured out how to make a machine for sharpening carbide saw blades. To do this, you will need quite a few materials, as well as some skills and a desire to make a useful thing with your own hands.