The process of building private houses and various buildings will be quite complicated without the use of a circular saw. It is much better than many saws for wood, because it surpasses them in accuracy and cleanliness of the cut.
Due to the fact that this tool is actively used, it wears out quite quickly, and therefore sharpening circular saws with your own hands becomes extremely necessary.
What you need to sharpen circular saw blades
First of all, you need to prepare the appropriate components that will allow you to properly sharpen the saw blade for wood. It is important to provide the following tools:
- file;
- mounting vice;
- wooden bar;
- colored marker.
How to know when it's time to sharpen your saw blade
sharpening circular saw should only be carried out when the need arises. You can recognize the onset of such a moment by two clear signs. In particular, an urgent sharpening of a circular saw on wood is necessary:
- If strong heat regularly occurs on the saw guard in the area of the electric motor. In some cases, with such an increase in temperature, smoke is released under the casing.
- With strong pressure on the tool to obtain a good cut in the process of processing the material.
- If dark marks appear, traces of soot on the wood and a characteristic smell of burnt wood. This is due to the fact that the saw teeth are blunt.
Varieties of sharpening cutting teeth
For a better understanding of how circular saw blades are sharpened, it is necessary to study the features and structure of those parts of the tool through which material is sawn. Cutting teeth are the main element involved in sawing wood.
They are made of hard metal. The cutting teeth consist of 4 working flat surfaces: front (a), back (b) and two side planes (c), which have an auxiliary role. By means of one main (1) and two additional (2 and 3) cutting edges, intersection lines are formed for each specified working plane.
Depending on its configuration, a circular saw may have different kinds cutting teeth:
- Straight tooth type. Often used for accelerated longitudinal sawing. They do not have the ideal cut quality.
- Beveled (oblique) type of teeth. They have a characteristic angular edge on the right and left rear surfaces. In some cases, the blades have teeth with different sides of the bevel, which alternate around the entire circumference of the saw. Using such discs, you can cut wood, chipboard and various plastics. A large bevel angle ensures a high-quality cut without chipping on the cutting edge.
- Trapezoidal teeth. The cross section of the cutting surfaces have a trapezoidal shape. This configuration allows you to work without blunting for a long period of time. Often the disc has straight teeth, which alternate with trapezoidal. In such cases, the trapezoidal element plays the main role in rough sawing, while with the help of a straight type of teeth, finishing is performed.
- Conical tooth type. They have a conical shape. As a rule, they perform an auxiliary function for preliminary cuts on the laminate. The conical type of teeth is used to process the specified floor covering. Such a saw allows you to prevent chips on the material, as often happens when using the main saw.
Video "Sharpening disks for a circular saw"
The process of sharpening a circular saw blade.
The principle and angle of sharpening discs for a circular saw
The working part of the circular saw is sharpened at 4 main sharpening angles. They refer to the main technical parameters of the cutting disc, as well as the type of shape of the cutting teeth.
It is worth noting that all the teeth of a circular saw are characterized by front (γ), back (α) angles, as well as the cutting angle of the front and back surfaces (ε1 and ε2). The value of each specified angle must correspond to the purpose of the sawing devices, the materials to be sawn and the direction of sawing.
In particular, a rip saw is sharpened at fairly large rake angles (15° - 25°).
The indicators of sharpening the front angles for transverse types of cut are in the range of 5 ° - 10 °. Universal options used for processing materials in all types of directions are standardly sharpened at 15 °.
In this case, the value of the specified angle is also influenced by the fact that the cut objects have hardness. Their value has a strict dependence: with a greater hardness of the material that is being cut, the cutting teeth should be less sharpened.
According to the main principle of sharpening teeth on a carbide saw blade, it is important to consider that when long-term operation the most significant wear processes occur on the upper cutting edges. As a result, with intensive use, their lines can be rounded up to 0.3 mm or more. Regarding the planes of the teeth, it is worth noting that the greatest wear occurs on the front surfaces.
With proper sharpening of the cutting element, such shapes of the cutting edges should be provided in which the radius of their rounding will not exceed 0.2 mm. In this regard, it is recommended to perform parallel grinding of metal on the front and rear planes of the teeth. The use of this method is considered the most appropriate. It is possible to sharpen only one front plane, but in such cases, this operation requires more time. In addition, the teeth will wear off faster as more metal needs to be ground off the rake surfaces.
The standard layer for grinding metal is a value of 0.05-0.15 mm.
How to sharpen a circular saw with your own hands
You can sharpen the saw at home completely on your own. For these purposes, there is no need to visit a workshop to use a specialized grinder or purchase it. It is quite expensive, and is used for sharpening in rare cases, unless of course you plan to use it for large-scale production purposes.
But holding saw blades in your hands while sharpening teeth with a grinding wheel is not the most the best solution. A circular disk is not a drill, it is much larger. No hardness of the hands and an excellent eye will not allow sharpening so that the cutting elements are sharp enough and suitable for effective use. To do this, you need to provide the simplest fixing device.
To hold the gear circular circle in the desired position relative to the plane of the grinding tool, you can use the most ordinary flat stand.
The position of its surface must correspond to the level of the axles on the rear disk. The toothed circle is placed on a stand so that the tooth plane to be sharpened is perpendicular to the blades of the saw blade. To sharpen beveled teeth along the front and rear surfaces, it is necessary to provide movable hinges in this device.
But in such cases it is quite difficult to maintain the same values of the front and rear angles of tool sharpening. To eliminate this problem, it is necessary to perform a rigid fixation of the center of the saw according to the desired position in relation to the grinding wheel. This is done using grooves for the mandrel, which is mounted on a stand with sharpening saws placed on it, or by installing a special stop on the stand, which will fix the saw blade according to the required angle to the abrasive stone.
If you follow all the requirements that apply to sharpening a carbide circular saw, then this tool will work as efficiently as possible over a long period of time.
Video "How to sharpen a saw blade with your own hands"
Demonstrative video on the implementation of self-sharpening of the cutting saw blade.
The complexity of sharpening saw blades with carbide teeth is due to the use of sintered tungsten-cobalt alloys for the manufacture of cutting inserts, which are subsequently attached to the disk by high-temperature soldering. But the main difficulty is caused by their geometry and the need to provide a certain angle when sharpening.
Tooth shape and sharpening angles
According to GOST 9769, a carbide tooth in its design has 4 planes - back, front and 2 auxiliary. According to the geometry of the cutting inserts are straight, beveled, trapezoidal and conical.
The front angle of sharpening determines not only the characteristics of the saw blade, but also its purpose:
- 15-25° - for longitudinal sawing;
- 5-10° - for transverse;
- within 15° - universal application.
Also, the size of the angles is also determined by the hardness of the material being cut - the higher it is, the smaller the sharpening should be.
Basic sharpening rules
Basically, the main cutting edge is subject to wear - it is rounded up to 0.3 mm. Carbide teeth should not be allowed to wear beyond this value. This leads to a decrease in productivity and an increase in the time for subsequent sharpening. Dullness is determined by the teeth and the cut (the quality of the cut worsens).
- With the correct performance of the work, the maximum operational resource of the saw blade with soldering is ensured - up to 30 sharpenings. Therefore, sharpening should be done along the front and back plane of the tooth.
- First of all, the front plane is sharpened.
- Soldering during sharpening should be in full contact with the surface abrasive wheel.
- It is recommended to sharpen the teeth in short strokes (within 3-5 seconds), which will prevent them from overheating. Since with increasing temperature, the microhardness of the abrasive decreases, and hence the effectiveness of sharpening.
- The thickness of the removed metal should not exceed 0.15 mm.
Materials and tools
To sharpen discs with carbide teeth, you can use diamond wheels and silicon carbide. To obtain a smooth surface without nicks, it is recommended to use abrasive with the highest grit. Otherwise, the notches will crumble during operation, which will lead to a rapid blunting of the soldering.
It is best to sharpen on specialized machines with the ability to adjust the angles of the saw blade. To regulate its position in the horizontal plane (in the case of teeth with a bevelled front plane), special devices with pendulum goniometers are used.
But the purchase of special equipment for home use, when the need for it arises no more than once every few months, is not advisable. And holding the saw blade with your hands in exact accordance with the required angle is something from the realm of fantasy.
There is only one way out - to build a stand, the surface of which will be located on the same level with the axis of the abrasive wheel. This will ensure that the position of the back and front plane of the tooth is perpendicular to the grinding material. And if you show your imagination and fix one side of the device pivotally, and on the other make supports in the form of bolts with the possibility of screwing in and out, you can also control the angle of inclination relative to the horizontal plane. And the accuracy is verified by a pendulum goniometer.
To ensure the angle required for sharpening the front and rear planes of the soldered teeth, stops can be equipped on the stand that will fix the saw blade in the desired position.
Saw blade sharpening is essential for any tool used for woodworking. It is carried out in case of a decrease in the quality of the cut and requires compliance with the basic rules, since the literacy of sharpening also affects the period of operation of the saw.
rules
- Pliers can act as a bending tool, but in this case it is necessary to monitor the position of all the teeth, otherwise the disc will be damaged and will not provide proper processing of the wood.
- During work, the retaining bars should fit snugly against the disc, and the surface should remain in the same position.
- In order for saw blades to be sharpened correctly, the position of the workpiece must allow free viewing of all teeth.
- As a rule, the machine tool acts as the main tool, but sometimes it becomes necessary to remove the disk and secure it in a vice.
- Before changing the angle, a suitable tool is preliminarily prepared and marks are made.
Training
Before starting work, it is necessary to de-energize the tool, the part of which has lost its previous characteristics. The disk is tightly fixed with the help of special bars, which are placed on both sides of it. All teeth are marked on the blade, with equal forces and an identical number of tool movements being applied in the process. So you can produce high-quality, uniform processing of the disk.
The part is installed back after reaching the required appearance and checking the sharpening angles. Next, you need to make a trial cut on the machine and make sure the quality of the work performed. It is important that all the teeth are placed on the same plane, otherwise the movement of the bar will be uneven, and the operation of the machine will be accompanied by a characteristic noise. It is also possible if some teeth require adjustment.
Wiring
If the saw blades are sharpened independently, it is worth remembering about the edge setting, in which all the teeth gradually bend in different directions, but the distance between them remains the same. These actions can be performed using a special tool called wiring, it provides a uniform bend in the middle of all elements. After carrying out such a procedure, the saw will acquire a freer stroke, and the width of the cut will become larger.
Taking into account the fact that the cut is made not by the disc itself, but by its edges, which gradually remove layers of wood, it becomes clear that with an increase in tooth separation, the likelihood of jamming decreases, and the cut becomes wider. It is worth noting that in this case, more effort has to be applied for the tool to work. In the absence of special devices, many use teeth for breeding, but this technique has many limitations and is not suitable for all saws.
The type of wiring is primarily influenced by the type of wood, which will subsequently be processed. For example, to obtain a smooth cut without any flaws and protrusions on soft rock, a large wiring is required. It is desirable that the teeth deviate in the selected direction by 5-10 mm. Sharpening of saw blades on wood is carried out only after the wiring has been carried out, otherwise the teeth will be unusable due to the resulting deformation.
Angle selection
The purpose of the saw, that is, the type of suitable materials, determines the required sharpening angles. A relatively large value is used for rip sawing elements (within 25 degrees), for cross cutting saws this parameter is 5-10 degrees. The angle of sharpening saw blades of a universal type (used for longitudinal and transverse sawing) is 15 degrees.
In addition to the cutting direction, the density of the material to be sawn must also be taken into account. With a decrease in density, the value of the anterior and posterior angles increases, that is, the tooth becomes more pointed. The rake angle parameter can also be negative, this is necessary for working with plastic and non-ferrous metal.
When to sharpen saw blades
To find out when you need to take up a circular saw, you can pick up a small part, the density and quality of which corresponds to the materials used for the job. Next, you need to cut the bar. The disc does not require processing if a smooth cut is formed, the saw moves easily and does not make noise during operation. In the opposite situation, you need to sharpen the disc at home or, in the absence of a special tool, contact the workshop. It is worth noting that this process must be carried out in accordance with all the rules and taking into account safety precautions. Before that, you need to decide on the required angle and shape of the teeth. There are also additional factors that indicate the need for sharpening:
- in the process of processing wood, the smell of burning is felt and soot is formed on the cut itself;
- the motor starts to overheat and contributes to the heating of the casing of the device;
- it takes a lot of effort to move the disc.
What you need to know
Sharpening of saw blades (St. Petersburg) today is carried out by many companies, but not all are able to provide a quality result. The problem is that this process requires equipment with expensive tools and knowledge of all aspects and features of such painstaking processing. Masters must have experience in this field and observe all the nuances and stages of work. For example, the sharpening angle is affected not only by the tool used, but also by the disk itself, in particular the material taken as the basis for production.
Should have an angle appropriate for the types of surfaces used for the work. The equipment can work with values within 45 degrees. special role has compliance with the set angle of sharpening, suitable for processing a particular material. Only when all the recommendations and rules of work are taken into account can the service life of the cutting element be increased.
Sharpening carbide saw blades
The processing of such elements has several complex stages and is carried out on special equipment, which is a grinding machine with extended functionality. In particular, it must provide cooling of the treated area in the form of supplying a special composition and carrying out work in automatic mode. Such equipment, as a rule, is equipped with a controller designed to detect the number of teeth and sharpen the disc itself with a selected number of cycles. Also on the machines there is a magnet necessary to secure the saw and prevent it from moving during processing. For sharpening, it is used on the surface of which a diamond coating is applied. The machine for sharpening saw blades, in addition, is equipped with an electric motor for automated movement of the saw and processing in the required area.
Processing equipment for saws coated with diamond dust
Such machines must have a design, complemented by a cast reliable base. This ensures high precision processing of discs, which are made of materials with special strength. They also have a high-angle lock. The base is supplemented with special rubber elements that reduce vibrations that can impair the quality of work performed. Thanks to this addition, the level of noise that occurs during processing is reduced. Adjustment on the equipment is made manually, while the diamond-coated discs used for sharpening saws increase the quality of the result and extend the life of the tool.
What to consider when processing
The principle of operation of the grinding disc has its own characteristics, as well as its structural design. The materials for its manufacture are based on compounds of nitrogen and boron, which increase not only the accuracy of processing, but also the resistance to high temperatures that characterize the process itself. Please note that circles are various diameters and are suitable for different tools and types of materials, so you need to carefully select the right model in accordance with the available tool to be processed.
Peculiarities
Sharpening of saw blades in Moscow is carried out on various equipment. Processing can be carried out semi-automatically, that is, without human intervention, the task of the masters is only to install parts on the machine and remove them. Most often there is a type of equipment on which sharpening is done manually. It is easy to adjust thanks to the equipment in the form of locking levers, and the exact observance of the required sharpening angle is carried out using special clamps. The main feature is the linear feed method. This achieves high-quality processing of both rear and front teeth. Thanks to the additional function of the machines, which consists in the diagonal sharpening of the edges, the operation of the saw is simplified and the quality of the resulting cut is improved. When choosing a disc for, first of all, you need to consider the degree of graininess. Fine grit products provide minimal processing of the chains, while coarse grit products remove a sufficient layer of material. The cost of such discs is directly affected by the popularity of the manufacturer, the quality of the base and the type of product.
A circular is a device on which work is carried out with building material. As a rule, a tree is processed. A toothed disk is used as a cutting tool. Over time, he dulls. Sharpening a circular saw blade is carried out both on a special machine and with your own hands at home.
Sharpening circular saw blades is required when work becomes impossible. This can be understood by three signals:
- Protective cover heating. Smoke appears from under it, exits the cutting zone.
- The need for additional effort when feeding the workpiece at the time of cutting.
- When wood comes into contact with cutting metal there is a burning and smell.
Types of teeth
The main cutting element of the disc are the teeth. They are made from hard metal. The tooth consists of four sides: anterior, posterior and two lateral. Also from the main cutting edge and two additional ones.
Teeth requiring sharpening are divided into:
- Direct. Are applied to longitudinal sawing of a cloth.
- Beveled. They have an angle cut on the back plane of the tooth. They can cut not only wood, but also plastics or chipboard.
- Trapezoidal. In cross section, the cutting plane has the shape of a trapezoid. Thanks to this, they can be sharpened less often.
- Conical. They have the shape of a cone.
Sharpening angles
A circular saw has four corners which, after blunting, must be sharpened. These are the front and back corners. Also the cutting angles formed by the front and back surfaces.
Depending on the direction of sawing, they are needed. In longitudinal cutting, the value of the front angle is in the range of 15−25 degrees. In the case of cross cutting, the grinding angle is reduced to 5-10 degrees. If universal cuts are required, then the tooth is sharpened at an angle of 15 degrees.
An important influence on the value of the angle is the density of the material. The lower it is, the sharper the tooth is required. If the material being processed is plastic, then the angle can be negative.
Sharpening circular saws with pobedite soldering
The sharpening angles of carbide-tipped saw blades are not easy to maintain because the tooth is applied to win. This alloy is attached by soldering. The geometry of the cutting part is complex, and the sharpening parameters require precise exposure.
The work is carried out when the cutting edge is smoothed to a radius of 0.3 mm. Greater value should not be allowed.
- Sharpening is carried out on the front and back planes of the tooth. If the work is carried out correctly, then the total number of sharpenings until the blade is completely worn out will be 30 times.
- Start work from the front plane.
- The part of the tooth that is soldered should fit snugly against.
- Turning time is 3 to 5 seconds. It can't be longer. This leads to excessive heating of the metal. It is reheated and tempered with a decrease in hardness.
- The thickness of the material to be ground is around 0.15 m.
Machine Application
The simplest machine for working at home is is an abrasive motor. Wheels can be diamond, elbor or silicon carbide.
It is difficult to keep the canvas in a certain position relative to the abrasive. You need to use the tools. This may be a horizontal stand or a fixing device, where the upper plane must coincide with the axis of the abrasive.
The tooth to be sharpened is positioned on a plane so as to be perpendicular to the blade. After turning on the engine, the canvas is brought to the circle and pressed against it with a tooth. The layer of the removed metal is regulated by pressing force. Having finished work with one tooth, the next one is brought up in the same way. And so on in a circle to the end.
For the purpose of universalization, the stand is modernized. The front part is made movable, and a pair of bolts is screwed into the back. With their help, you can adjust the inclination of the canvas. It becomes possible to sharpen the front and back plane of the oblique tooth.
There remains the problem of maintaining the same angles of front and rear sharpening. To do this, it is necessary to fix the canvas relative to the center of the abrasive wheel. To do this, the disk is inserted into a special mandrel, and a groove is made under it in the stand. The necessary is maintained by moving the mandrel along the groove. If the diameter of the discs is different, then it must be possible to move the engine or stand with a groove.
Another way is to install stops that will fix the desired position of the disk.
Sharpening by hand
In the absence of a machine, sharpening can be done with a file. To do this, it is important to clearly fix the disk. This is done with a vice. If the canvas is not removed from the circular, then you can do without them. Bars are inserted between the teeth, and the tool rests against a vertical plane.
A mark is made at any point of the circle with a marker. This will make it clear when the work is completed. Processing is carried out with a flat file, which fits well between the teeth. The upper edge of the tooth and its front face are subjected to the greatest wear.
First, work is carried out with the back surfaces of the teeth around the entire circle. At the second stage, they begin to sharpen the front edges. It is important to remember that the applied force must be the same, then all the teeth will be evenly sharpened.
It is really possible to sharpen a circular disc at home. To do this, it is better to purchase a simple machine. In his absence, you can use a vice or homemade stops. At the end of the work, check the tool. In the process of cutting, his work should be smooth and quiet.
Regardless of the tool used in the work, it is always subject to wear, but in some cases temporary restoration is possible. So sharpening a circular saw with your own hands is a natural process that anyone can perform.
An inside look at a circular saw
The disk itself is made of very strong alloys 50XFA, 9HF and 65G, and foreign companies use their own versions with similar properties. The material has increased reliability and rigidity, due to which incidents occur extremely rarely.
But the working part (cutting inserts) is usually made on the basis of tungsten, carbide and cobalt, which makes it possible to achieve high strength indicators. The characteristics of alloys are formed at the initial stage, because depend not only on the proportion, but also on the grain size of the carbide phase (with a decrease in grain size, strength increases).
The cutting inserts are soldered to the disc by means of high temperatures, and silver (optimal) or copper-zinc (worse) is used as solder. For seasonal homework, the copper-zinc version is ideal, while sawmills and professional workshops need better silver counterparts.
Now you need to carefully consider 1 tooth of the circular saw (Fig. 1). It will be very unusual that there are 4 working zones:
Figure 1. Scheme of the device of the tooth of a circular saw.
- A. Front;
- B. Back;
- B. 2 auxiliary.
These zones intersect with each other, due to which 3 cutting edges are formed:
- 1. Main;
- 2 and 3. Auxiliary.
It is thanks to such a complex system that a high-quality cut occurs without errors and nuances. In addition, there are 4 more types of such teeth:
- Straight. Longitudinal fast cut, where you can sacrifice a little quality.
- Beveled. The main option that allows you to work with most materials in all directions (longitudinal and transverse). The bevel is left and right, and most often both options alternate on the saws, thereby increasing the quality. With a large bevel, it can be used as scoring, because. they don't chip.
- Trapezoidal. Slowly dull, but they show themselves perfectly in work. Often used in combination with a direct one, due to which it is possible to achieve the most accurate effect. The trapezoidal one rises above the straight one, therefore it does the rough work, and the straight one, in turn, does the finishing work.
- Conical. Such saws are used as auxiliary saws to prevent chips from cutting the lower layers of the laminate, as well as for cross cutting.
How should the tool be sharpened?
The main wear occurs at the top cutting edge and front edge, so it is on them that the main activity is directed during sharpening. But do not forget about the side faces, because. when working with massive workpieces, they also get their own considerable load.
When working, do not allow blunting more than 0.2 mm, because. otherwise, sharpening will take much more time and effort. This factor is determined visually by the cut or by the tooth itself.
Tooth sharpening should be carried out along 2 planes - front and back, which will significantly extend the service life. Sharpening only the front part will reduce these terms by at least 2 times. Before starting work, the metal is cleaned of all third-party materials, and then degreased.
Only 2 types of circles are used for work:
- CBN (elbor) is used for sharpening high-speed steel with an increased strength factor;
- PCD (diamond and silicon) are used for sharpening hard alloys. During long-term operation, cooling of the coolant is required (water cannot be used), because when reaching 900 C, the diamond burns out.
When sharpening, the tooth is perfectly butt to the working surface, otherwise you can lose the entire disc, or not achieve the desired result. Due to the fact that each disk takes a considerable amount of time, you need to mark the starting point with a marker.
Special machines are equipped with everything necessary to ensure comfortable operation, so it is almost impossible to make a mistake on them, while in artisanal conditions you will have to show a little ingenuity. You will need the following tools and materials:
- stand;
- electric motor;
- nozzle-adapter;
- sheet steel;
- Bulgarian;
- screws.
To begin with, you need a small electric motor, which is qualitatively fixed to the surface at a height of 5 cm or higher. An adapter for grinding discs is put on the shaft, after which the main structure is ready.
But it is inconvenient to hold sharpened objects in your hands, so for them 3 cm below the shaft, another plane of sheet steel is formed at a distance of 2 cm. 3 longitudinal slots are made in it with a step of 1 cm and a diameter of 0.3 cm, into which the locking screws.
As a panel for fixing, you can come up with a lot of things, up to a frame made of reinforcement for each individual diameter. The result is important - a strictly perpendicular position, which allows you to influence the entire exploited edge.
Sharpening teeth on a chainsaw and hacksaws is done in a similar way, but in the latter case, you can use sharpening stones, because. the material is very malleable, and a small error in the result will give a very imperceptible effect. When sharpening such saws, another complication often arises - the teeth are bent, which makes future operation very difficult.
Summarizing
Despite the many nuances, sharpening circular saws is quite simple and fast. It is important to carry out this process with great accuracy, so that the final result can be achieved in the shortest possible time.
In the absence of a professional saw sharpening tool at hand, you can build it from improvised materials.
For a complete assembly, it usually takes up to 3 hours, and the service life is limited only by the capabilities of the electric motor itself.
