The use of circular saws is especially common in construction. Most of the work requires cutting and changing the shapes and sizes of finished materials. The circular saw helps to cope with such tasks quickly and get a quality result. But the instrument is not able to serve forever, sooner or later it may become dull. For this, it is necessary to know exactly how to sharpen the teeth for a saw in a domestic environment.
How to determine wear?
Checking the saw blade for wear is an important issue that should be given special attention. Deep damage leads to the inability to sharpen the circle. There are three main characteristics by which you can understand that the saw needs to be sharpened or replaced:
- Strong heating of the protective cover and the formation of smoke. The circular saw has a special casing that signals that the saw has become dull by heating. In especially difficult situations, smoke may appear from it.
- Sometimes the saw device involves mechanical feed (if you need to manually adjust the force of pressure). In such a situation, wear can be noticed if the pressure has to be intensified.
- If, when sawing wood, carbon deposits and a strong unpleasant odor are formed on the workpiece.
All the situations described above tell the user that it is time to sharpen the device.
Types of cutting teeth
On the surface of the teeth are four planes. the front, rear and two side.
At the moment of intersection with each other, they create a single cutting edge, due to which the sawing of surfaces occurs.
There are several tooth shapes:
- Straight tooth. Most often it is used only for an early longitudinal cut. During such work, quality and accuracy are practically not important.
- Oblique tooth. The back plane of such a part is tilted to the right or left. On the saws, these teeth often alternate, which is why they are called "variable-cut". Such teeth are most often used in tools. The size of the corners can be different, this is due to the coating of the treated surface. wood, chipboard, plastic. They are used for longitudinal and transverse movements. A large angle of inclination on the tools is used when cutting plates with double-sided lamination. This helps to avoid chipping material. The larger the beveled angle, the easier the saw passes through the surface. But this greatly increases the likelihood of tooth breakage. On some products, the teeth are tilted not only in the back, but also in the front.
- Trapezoidal tooth. The main advantage of this type is that the edge is dull slowly. But they are rarely used alone, usually alternated with straight teeth. During operation of the device, the trapezoidal teeth are located above the straight ones, therefore they undertake the main (rough) sawing work. Straight teeth finish. This design of the saw is used for sawing plastic, chipboard and MDF.
- Conical tooth. This type of tooth is considered optional, since it only helps to incise the lower part of the material (most often the laminate). This design allows you to protect the surface from chips and cracks. Conical teeth usually have a straight front face, but it can also be concave. This type is used for finishing cutting.
Important! Each type of tooth requires thorough processing when sharpening. You can not sharpen them at one angle.
Instruments
Do-it-yourself sharpening the saw is allowed only when using special devices. To do this, there is a grinding machine that helps to carry out the process on the machine, rather than manually. Then the result becomes more accurate.
In addition, other improvised devices are used for sharpening:
- Mounting vice;
- File;
- A piece of wood.
Replace the listed devices will not work. If not even one of them is available, then sharpening will not work.
Grinding principles and angles
At the edges of the saw are four main sharpening angles. They, together with the shape of the tooth, can be the main operational characteristics of the tool. To describe each tooth are used:
- Front and back corner.
- Cutting angles of the front and rear surfaces.
These characteristics may depend on the type and weight of the circular saw, its purpose, and the density of the particular surface.
Sharpening angles on the scheme
Based on the parameters indicated above, all circulars can be divided into several types:
- For cutting longitudinal holes. When completing this task, you should use a front sharpening angle of 15 to 25 degrees.
- For transverse cutting. In this situation, the rake angle can vary from 5 to 10 degrees.
- Universal sharpening. To perform any operation, the saws are sharpened at an angle of 15 degrees.
The size of the sharpened angle is set not only from the direction of movement of the saw, it is also associated with the workpiece material. If you need to cut through very hard materials, you should choose the smallest angle. To work with softer products, the angle increases.
Important! If a carbide saw is used long enough, maximum wear can be seen on the upper cutting edge. A detailed examination of the tooth plane shows that the front surface of the material is most affected.
How to sharpen: basic methods
There are two available methods for sharpening circular saws. manual and with a machine. In order to sharpen the disc correctly at home, it is necessary to take into account some nuances.
Manual way
Special machines for sharpening the edges of the saw are rarely used in domestic conditions, because their cost is high. Therefore, in the absence of such a device, it is possible to cope with sharpening with improvised devices, such as an angle grinder. At the same time, it is forbidden to hold a circle in your hands without fixing it. Otherwise, it will not be possible to achieve a sufficient cutting angle for further work with the material.
To securely lock the circle in the correct position, use a flat stand.
- the surface of the stand coincides with the level of the axis of the grinding wheel;
- a gear wheel is placed on it so that the sharpening plane becomes perpendicular to the saw blade;
- the design of the device is complemented by a swivel joint.
The stand will help to comfortably position the saw blade for processing relative to abrasive material. Before starting work, a clear marking is carried out. For this, a color marker is used. They draw lines that will sharpen the element at the desired angle. A vise will help to securely fix the disk to the surface.
Video of grinding a disc for a circular saw angle grinder:
Using a machine
When the master has access to a special grinding machine, the processing of elements occurs quickly and efficiently. This device is small, so it’s comfortable for a beginner to work with it. There will be no problems even when used in a domestic environment.
When buying such a device, they look at the abrasive wheel. For its selection, individual nuances are taken into account:
- It’s best to buy a wheel made of diamond-coated elbor or green silicon carbide;
- If a carbide blade is sharpened, problems may arise even when using the machine.
The very process of using the machine for sharpening is extremely simple. The operator should conveniently place the disk on the device and clamp it using a special lock. Before starting work, it is recommended to mark the first tooth with a marker. This will help not to get confused during grinding, and not to check the teeth that have already been processed. To select a sharpening angle, a special meter is provided on the device. The necessary angle should be set on it, after which the device will perform the task on its own.
A circular saw is a useful tool that can not be avoided during construction. It helps to make cuts in surfaces, as well as change their shape and size. For grinding discs use special machines or improvised materials. Doing it yourself is not so difficult, you must adhere to the recommendations listed and not be afraid.
Sharpening a disk with victorious soldering:
Sharpening of circular saws is an obligatory measure during the operation of this equipment. Woodworking requires the master to have tools with appropriate cutting properties. Like sharpening chainsaw chains, circular saws require increased attention. If the shortcomings are not eliminated in time, over time, the tool will begin to blunt much faster.
Signs of wear
Sharpening saws is a common event, as well as do-it-yourself chainsaw chain turning. You can entrust the device with carbide, victorious brazing to specialists. This is due to the fact that the victorious solders have increased hardness, which is why it is impossible to grind with a regular file. This will require an expensive diamond grinding tool.
Video: Diamond Saw Sharpening
The first thing you need to do is determine the current state of the saw wheels. Chainsaws and chains have certain signs of wear. If you know about them, you will easily find out that the sharpness of the circular saw has deteriorated significantly.
- On the casing of the engine of your circular saw, the temperature began to rise significantly.
- To cut the workpiece, you have to apply more physical effort with your own hands. A similar phenomenon is characteristic of blunt chains of chainsaws.
- From time to time smoke may come from the engine.
- When processing workpieces, an unpleasant burning odor is formed.
- Darkening forms at the edges of the saw wheel. This is soot. It can also appear on the surface of chainsaws.
- The wooden workpiece begins to move jerkily around the machine, although during normal sharpening the movements should be smooth.
- When the machine is operating, extraneous noise is observed.
- The tooth geometry of the saw blades of your circular saw is broken.
General sharpening rules
Photo of ways to sharpen circular saws
As in the case of sharpening chains of chainsaws, self-sharpening requires adherence to certain recommendations.
- Carefully follow the uniform removal of metal along the profile of the teeth of the saw wheel;
- Never press the saw blade firmly against the grinding wheel. If the machine for sharpening circular saws will be in close contact with the grinding wheel, this will lead to overheating and further deformation of the material;
- Watch for maintaining the height and profile of the sharpening upon completion of processing operations;
- When sharpening discs, use coolant. This is also recommended for those who carry out chainsaw chains;
- Avoid burr when turning the saw blade;
- When sharpening your face, rely on an important rule. It is necessary to sharpen only the front, or front and back side of the tooth. Although in practice, many do-it-yourselfers prefer to sharpen from the back of the saw wheels, considering this method more convenient;
- Products with victorious soldering are sharpened with diamond tool-grinding devices. Only such tools can truly effectively restore the cutting properties of this tool. You can use a regular file, but in fact it will not give the desired effect.
Sharpening methods
You can use the tool-grinding machine for saws or improvised devices.
There are three main sharpening techniques where a specific tool is used, and the rules for processing discs are followed. Which one is the most correct is hard to say. Having tested each technique, you can draw certain conclusions for yourself.
- Classical
- Full profile;
- Sharpening the edges of the teeth.
We will tell about each of them separately.
Classic
This sharpening technique has been used for a long time, which is why it got its name.
- Sharpening starts from the back of the disc.
- The front part running onto the material during cutting remains in its unchanged position.
- Processing can be carried out directly on a circular saw or to remove a saw circle, having established it in a vice.
- If you grind on a circular, be sure to disconnect the machine from power.
- To fix the disk, use a pair of bars that will fix the circle like wedges. The bars should be firmly pressed to the product to prevent it from moving when turning.
- With a felt-tip pen, mark the first tooth with which you will begin.
- Perform a certain number of movements on the first tooth with a grinder. Remember their number.
- For all subsequent teeth, repeat the same in quantity and intensity of movement.
- Upon completion of sharpening, be sure to check the performance of the updated saw. If there is no extraneous noise, vibration and the disk machine behaves stably, you have managed to do the job correctly.
Alternative solutions
Alternative sharpening methods include those two methods that we described above. They are quite effective, therefore they are often used by masters.
- Full profile saw blade machining. Among all turning methods, this method can be considered the most accurate and high quality. This is due to the fact that specialized grinding machines are used for full-profile sharpening. A special circle is selected in size and in one approach passes the entire cavity between the teeth of the disc, while capturing the surface of the adjacent cutting edge. Such a technique for turning saw blades avoids the likelihood of tooth deformation circle. The only drawback of the sharpening method is that for the processing of saws of different profiles, it will be necessary to use the corresponding different circles.
- Turning the edges of the teeth. The popularity of this method of turning circular saws is explained by the fact that it can be used on a professional level and in ordinary home conditions. If sharpening is carried out using a machine, you will need to purchase the appropriate abrasive wheels that match the parameters of your saw blades. But it is optimal for most owners of circular saws to use the home processing method. This is due to the fact that often it is not necessary to carry out a large amount of work, and all processing of cutting edges is carried out by a file. To effectively sharpen a product, sometimes it’s enough to carry out 4-5 movements with a high-quality file. So the teeth will acquire the necessary degree of sharpness.
Expert Advice
Experience is a useful thing, thanks to which you can avoid a number of mistakes typical for beginners. Therefore, paying attention to the advice of specialists is very useful if you want to achieve a positive result for yourself when turning a circular saw.
- Always use safety glasses. For some reason, many ignore this rule, because of which the masters themselves then suffer. Therefore, before starting sharpening, be sure to wear all the necessary protective equipment;
- Do not attempt to remove more metal than is required. Remove as much as possible to remove all existing cracks, burrs and bumps;
- Be sure to hold the disc steady while turning;
- If the disc has not been sharpened for a long time, you will have to remove a larger layer of metal;
- Observe the identity of all teeth in shape and height.
Initially, grinding seems to be a technologically complex process. But with a little experience, you can easily sharpen the circles of circular saws.
In order to sharpen the saw blade with victorious soldering, it is necessary to take into account some features of this product and select the tool as carefully as possible.
Material and shape of the teeth
Saw blades are steel blades, the tips of which are cutters welded by high temperature welding.
As a rule, these parts of the tool are made of sintered tungsten-cobalt alloy (VK, VK6, VK15 grades, etc.). Hard alloys are also used. But it should be borne in mind that strength depends on the grain size of the carbide phase.
The soldering itself (tooth) has the following planes:
- Front;
- Back;
- Two side (auxiliary).
That is, intersecting, they form two cutting edges:
Measuring the degree of sharpening a circular saw
In most cases, band saws with victorious soldering are rarely used, but for significant amounts of material and for a long time. Therefore, it is normal that the incisors begin to grind over time. Sharpen this product as necessary. Determining the degree of sharpening is quite simple:
- When sawing the material, irregularities, chipping, chipping begin to appear, and when cutting wooden objects. a characteristic smell and black marks on the material;
- Work on the machine is complicated, as more effort is needed, as a result of which there is a strong load on the engine.
Important! Lack of observation of the sharpness of the disc cutters can lead to the fact that the product can no longer be sharpened or repaired. Therefore, it is worth carefully monitoring the status of the tool.
It should be noted that, as a rule, protective relays are provided in these machines. But if there are none, the device can crash faster if the sharpening is done incorrectly or not on time.
Materials used and the grinding process for the victory tooth of a circular saw
When working with a circular saw, the main edge is most often blunted. During the cutting process, the main emphasis is placed on it, so it is necessary to ensure that it does not round out by more than 0.3 mm, since difficulties may arise during subsequent sharpening of the cutters, not to mention a decrease in productivity.
Auxiliary planes are also subject to wear (although to a lesser extent), especially when working with massive products.
High-strength materials such as diamond wheels, silicon carbide (green) wheels, etc. are used to sharpen the teeth of circular saws with victorious teeth.
Important! Before starting the process, it is necessary to verify the cleanliness of the device, that is, make sure that there are no dirt or water on the planed surfaces. It will also be useful to treat the diamond wheel with a cutting fluid, since there is a high probability of rust when cooling with plain water.
When choosing an abrasive wheel, you should pay attention to the fact that its surface is a little grainy, because this is how the desired cleanliness of the surface of the sharpened tooth is achieved. Otherwise, when working on the material will remain chips, nicks and other defects.
To process win-win soldering, the grinding wheel rotation speed should be at least 15 m / s, that is, with a diameter of 120 to 125 mm the rotation speed should be at least 1500 rpm.
There are special devices for sharpening solders. machines for sharpening, the advantage of which is:
- Variability of movement of both the machine and the abrasive wheel;
- Ensuring a smooth sharpening angle.
Further actions are performed manually. turning the saw in a circle (per tooth), subsequent grinding, checking the volume of metal to be removed. Such mechanisms are excellent for processing solders at home.
Types of sharpening
The process itself is divided into three types:
1. Sharpening the front surface of the straight tooth
The tooth and the abrasive wheel are installed perpendicular to each other, given that the saw itself must have a horizontal position. In the event that the machine does not provide an angle scale, you can use the pendulum protractor. Next, you need to firmly fix the tools.
The process itself is a contact of the abrasive wheel and the grinding surface back and forth by means of a mechanism in the machine, while pressing the tooth against the wheel in manual mode. This process is repeated with each tooth of the saw.
For convenience, you can make a mark on the tooth from which sharpening began.
2. Sharpening the tooth beveled on the front surface
This type of sharpening provides for the execution of the same actions as before, with the difference that the angle of inclination must be changed in accordance with the location of the teeth. You can measure the slope with a pendulum goniometer. First, the positive angles of the tooth are ground through the tooth.
Next is the process itself:
- Sharpened every second soldering;
- Then the angle changes to negative;
- The remaining teeth are machined.
- Back grinding
This process provides for the possibility of changing the position of the disk so that the back plane of the solder is in contact with the abrasive wheel.
If there is no sharpening machine, you can make it yourself. How to sharpen a disk with your own hands:
- Make a support for the saw, which will fix the saw. This device should hold the saw tight, otherwise the process will be dangerous for the contractor;
- Adjust the stand on which the disk itself will be located (if necessary, the angle of inclination can be changed to support);
Important! The abrasive saw and saw blade should be perpendicular to each other.
- Fasten the circular saw in its center so that it is in contact with the circle in the desired position (to maintain the same rear and front sharpening angles).
It should be remembered that after sharpening on the winning teeth there should not be chips, cracks, gaps and other defects. If glare is not visible on the cutter, then the work is done correctly.
It should also be noted that the sharpened tooth plane and subsequently processed material are dependent on each other. if the workpiece material is solid, then the soldering should not be too pointed.