home Drugs Sharpening a rip saw blade. How to sharpen circular saws with your own hands. Sharpening a circular saw by hand

Sharpening a rip saw blade. How to sharpen circular saws with your own hands. Sharpening a circular saw by hand

Sharpening saw blades is necessary for any tool used for wood processing. It is carried out in the event of a decrease in the quality of the cut and requires compliance with basic rules, since the period of operation of the saw is also affected by the skill of sharpening.

Rules

Pliers can act as a bending tool, but in this case it is necessary to monitor the position of all teeth, otherwise the disc will be damaged and will not ensure proper processing of the wood.
During work, the holding bars must fit snugly against the disk, and the surface must remain in the same position.
In order for saw blades to be sharpened correctly, the position of the part must provide a clear view of all teeth.
As a rule, the main tool is a machine, but sometimes it becomes necessary to remove the disk and secure it in a vice.
Before changing the angle, a suitable tool is first prepared and marks are made.

Preparation

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 using special bars, which are placed on both sides of it. Marks are placed on the blade for all teeth, and equal forces and an identical number of tool movements are applied in the process. This way you can produce high-quality, uniform processing of the disc.

The part is installed back after reaching required type and checking sharpening angles. Next, you need to make a test cut on the machine and verify the quality of the work performed. It is important that all the teeth are placed on the same plane, otherwise the movement of the block will be uneven, and the operation of the machine will be accompanied by characteristic noise. This is also possible if some teeth require adjustment.

Wiring

If you sharpen saw blades yourself, it is worth remembering about the spread of the edges, 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 a routing; it ensures a uniform bend in the middle part of all elements. After this procedure, the saw will move more freely, and the width of the cut will become larger.

Taking into account the fact that the cut is made not by the disk itself, but by its edges, which gradually remove layers of wood, it becomes clear that with an increase in the spread of the teeth, the likelihood of jamming decreases, and the cut becomes wider. It is worth noting that in this case, more effort has to be applied to operate the tool. In the absence of special devices, many people use it to spread the teeth, 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 that will subsequently be processed. For example, to obtain an even cut without any imperfections or protrusions on soft rock, a large setting is required. It is desirable that the teeth deviate in the selected direction by 5-10 mm. Sharpening saw blades for wood is carried out only after setting, otherwise the teeth will be unsuitable for use due to the resulting deformation.

Angle selection

The purpose of the saw, that is, the type suitable materials, determines the required sharpening angles. Relatively large value is used for elements rip sawing(within 25 degrees), for cross cutting saws this parameter is 5-10 degrees. Saw blade sharpening angle universal type(used for longitudinal and cross cutting) is 15 degrees.

In addition to the cutting direction, the density of the material to be cut must also be taken into account. As the density decreases, the value of the front and back angle 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 do you need to sharpen saw blades?

To know when you need to start using a circular saw, you can choose a small part whose density and quality corresponds to the materials used for the work. Next you need to cut the block. The disc does not require processing if an even 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, if you don’t have a special tool, go to a workshop. It is worth noting that this process must be carried out in accordance with all rules and taking into account safety precautions. Before this, you need to decide on the required angle and shape of the teeth. There are also additional factors, indicating the need for sharpening:

during wood processing, a burning smell is felt and carbon deposits form on the cut itself;
the motor begins to overheat and contributes to the heating of the device casing;
Great effort is required to move the disk.

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 high-quality results. The problem is that this process requires equipment with expensive tools and knowledge of all aspects and features of such painstaking processing. Craftsmen must have experience in this field and comply with all the nuances and stages of work. For example, the sharpening angle is affected not only by the tool used, but also by the disc itself, in particular by the material used as a basis during production.

Must have an angle corresponding to the types of surfaces used for work. The equipment can operate with values within 45 degrees. A special role is played by compliance with the established grinding angle, suitable for processing a particular material. Only by taking into account all recommendations and work rules 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 advanced functionality. In particular, it must provide cooling of the treated area in the form of supply of a special composition and carry out work in automatic mode. Such equipment is usually equipped with a controller designed to detect the number of teeth and sharpen the disc itself with the selected number of cycles. The machines also have a magnet, which is necessary to secure the saw and prevent it from moving during processing. For sharpening, it is used on the surface of which diamond coating is applied. The machine for sharpening saw blades is, in addition, equipped with an electric motor to automatically move the saw and perform processing in the required area.

Equipment for processing saw blades coated with diamond chips

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 particular strength. They also have a latch with high level tilt The base is supplemented with special rubber elements that reduce vibrations, which can impair the quality of the work performed. Thanks to this addition, the noise level generated during processing is reduced. Adjustment on the equipment is made manually, while diamond-coated discs used for sharpening saws increase the quality of the result obtained and extend the life of the tool.

What to consider when processing

The operating principle of the sharpening disc has its own characteristics, as well as its structural design. The materials for its manufacture are based on nitrogen and boron compounds, which increase not only the accuracy of processing, but also the resistance to high temperatures that characterize the process itself. It must be taken into account that the circles have different diameters and are suitable for different instruments and types of materials, so you need to carefully select the required model in accordance with the available tool to be processed.

Peculiarities

Sharpening of saw blades in Moscow is carried out using various equipment. Processing can be carried out semi-automatically, that is, without human intervention; the task of the craftsmen is only to install parts on the machine and remove them. The most common type of equipment on which sharpening is done manually. It is easy to adjust thanks to the locking levers, and precise observance of the required sharpening angle is achieved using special clamps. main feature lies in the linear delivery method. This ensures high-quality processing of both rear and front teeth. Thanks to the additional function of the machines, which consists in diagonal sharpening of 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 take into account the degree of grain. Fine-grain products provide minimal processing of the chains, while coarse-grain 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.

During long-term use, carbide-tipped circular saws may lose their original qualities. But this does not mean that you should purchase a new cutting tool. In most cases, sharpening can be done at home using any suitable machine.

The need to sharpen the saw

Carbide-tipped disc

First you need to decide whether you need to sharpen or not. There are several obvious signs indicating the relevance of this procedure. If you ignore them, then in the future the disk may become unrepairable and cause the failure of an expensive machine.

The advantage of using a tipped saw blade is that it will last longer. It is also designed for processing hard wood. Surfacing is made from steel 9ХФ, 50 ХВА, 65Г and similar compositions. They are characterized by high hardness, but at the same time, with significant use, the likelihood of their breakage will increase.

Timely sharpening of circular saws using a machine with your own hands is carried out with the following obvious signs:

increased load on the engine. The reason for this is the deterioration of sharpening and, as a result, the power unit needs more power to cut wood. If the engine design does not provide protective relays, it may fail;
deterioration in cut quality. The first sign is an increase in the width of the cut, as well as the formation of chips and irregularities along its edges;
increase in workpiece processing time. The cut takes longer than usual to form.

The best way is to periodically check the condition of the wood soldering disc. To do this, you will need to temporarily leave the machine and dismantle the cutting tool. If its geometric parameters do not coincide with the original ones, sharpening is necessary.

How to determine the sharpening angle of a circular saw

Geometry of carbide tips

The best option would be to have an initial template according to which you can correct the geometry of the cutting edge. Often it is made of thin-walled stainless metal, less often - of thick cardboard.

Carbide teeth are manufactured in accordance with GOST 9769-79. But their geometry and geometric dimensions are determined by the manufacturer based on the purpose of the saw. If there is no template, you need to independently determine the required sharpening angles. To do this, it is recommended to use a pendulum inclinometer.

Do-it-yourself template making technology.

Take a new disc with soldering, which is completely identical to the dull one.
Draw precise outlines on a hard sheet of cardboard.
Using a pendulum goniometer, determine the initial geometry of the carbide tips.
Enter the data on the template.

In the future, it can be used for self-sharpening on a machine or provided as a sample for companies providing similar services.

Additionally, it is recommended to compare the obtained data with the reference ones. In rip saws, the rake angle is usually 15°-25°. For transverse models, this figure ranges from 5° to 10°. In universal models, the rake angle is 15°.

It is important to remember that the rake angle can be negative. Similar models are used for cutting plastic sheets and non-ferrous metals.

Methods for sharpening circular saws

Machine for sharpening tipped circular saws

Any sharpening machine can be used to form a new cutting edge. It is important to initially choose the right sanding wheel and use it to sharpen the edge. To do this, it is necessary to use corundum or diamond models.

The best option is to use special equipment designed to perform this work. But because of him high cost in many cases its acquisition is impractical. Alternative way is to use a grinding machine with the ability to change the angle of the corundum disk.

Under no circumstances should you sharpen by hand yourself. Firstly, it will take a lot of time. Secondly, the result obtained will not meet the standards. If it is not possible to sharpen a saw blade for wood yourself, it is recommended to use the services of specialized companies.

Do-it-yourself professional sharpening of circular saws is performed according to the following rules:

the main deformation occurs at the upper edge of the tooth. The edges are rounded from 0.1 to 0.3 mm. It is from this place that processing must begin;
sharpening is carried out along the leading and trailing edges. This will ensure the possibility of repeating the procedure up to 25 times;
the removal amount should not exceed 0.05-0.15 mm;
The level of processing of the front and rear edges should be the same.

After sharpening the discs for wood is completed, it is recommended to finish it with fine-grained sandpaper. This can be done manually or using a special machine.

Experts advise using special corundum discs, the end surface of which has a groove special form. It will make the procedure easier.

Ways to increase the service life of saw blades

Tooth angles for sharpening

The process of forming a new cutting edge is labor-intensive and time-consuming. Therefore, it is recommended to fulfill a number of conditions to increase the service life of the disk.

Hard solders have long term operation. However, they are more likely to chip and break off. Alternative soft is practically not susceptible to such defects. But its service life is shorter than that of a solid one.

The appearance of roughness on the cutting surface is not allowed. In the future, they can lead to chips and cracks.

The video shows an example of a do-it-yourself disc sharpening machine:

Drawings and tooth geometry

Sharpening of circular saws must be carried out strictly in compliance with the standards and requirements for the geometry of the teeth of each individual disk. To properly sharpen a circular saw with your own hands, you need to know the shape of the tooth and its geometry.

Straight tooth Oblique (beveled) tooth at the back Oblique (beveled) tooth at the front
Trapezoidal tooth Conical tooth Concave tooth

Circular saw sharpening machines, review and comparison

How is a circular saw sharpened?

A circular saw is a steel disk with cutters on its edge and spaces between them - sinuses. They may look like soldering from an alloy harder than the substrate, or cut from the shape of the body itself. The entire row of saw cutters is called the ring gear, and the disk is called the blade. The front surface of each tooth is the front edge, and the back is called the back. The distance between adjacent vertices of the incisors is called the pitch. In standard saws, the entire ring of teeth consists of the same pitch and height. As a result of the work, a hand-held circular saw leaves a cut in the wood - a gap limited by three edges.

Sharpening a circular saw, as well as fine-tuning its carbide-tipped teeth, is carried out using abrasive (carborundum) wheels. The method can be combined: the first (rough) procedure is performed with abrasives, and the finishing procedure with diamond tools. To preserve the carbide of the cutters and the properties of the grinding wheels, pre-treatment is carried out due to the length of the blade - along the rear edge, and the thin one - along the front edge.

Sharpening a circular saw according to back side consists of grinding the steel part of the cutter at an angle α+69deg;. A fine procedure for a carbide plate uses an angle of α+29deg;, finishing the part of the plate that is adjacent to the blade is an angle of α. The front edge is processed by preliminary sharpening along the entire length of the soldered plate, and the final edge is processed along the front side (subject to the use of a finishing method, which should be carried out with the participation of continuous cooling). However, for diamond sharpening wheels based on bakelite bond, sharpening a circular saw in normal mode may be acceptable.

On modern machines that use combined type tools (two fractions of grains - diamonds with abrasives), sharpening is carried out with continuous cooling in one pass with an allowance of 0.25 mm removed. There are carbide saws that use plates with double-sided processing. Rearranging, they work on both sides, then they are recycled to make new canvases. Such sharpening of a circular saw significantly simplifies the management of tool management due to the centralization and consolidation of the enterprises used.

If the back edge of a tooth is made flat on a disk, and sharpening is carried out along it in parallel layers, as the cutter wears out, its back angle sharpens, and with a certain number of sharpenings, it risks becoming unacceptably small. Of course, you can process the tooth along the plane of the back strip, which will maintain its slope. But such a measure will lead to a decrease in the sharpening angle with a deliberate loss of cutter accuracy. To ensure a constant slope, the back face is processed according to one of three options for laying out curves: the Archimedean spiral method, through a logarithmic spiral, or along a circular arc emanating from a displaced center. The widely used Interskol circular saw is sharpened using the latter method.

For support normal conditions sharpening those areas along the contour of the tooth blade that are in the plane of rotation of the blade or located close to it, arrange a side clearance angle through an oblique side turning of the rear wall of the cutter (like a conventional planer saw).

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Features of using a machine for sharpening a circular saw

Types of machines for sharpening circular saws

Speaking about equipment for sharpening circular saws, it should be noted that it covers quite a few types of machines, which include models of the simplest design, capable of performing the necessary operations manually, as well as automatic machine lines that can sharpen circular saws without human assistance.

The machines offered today can be classified into two large classes:

machines for household use;
machines for professionals.

Such a division is conditional. Moreover, the difference between these equipment lies only in productivity, which refers only to the time during which the sharpening equipment can operate in continuous mode. For models designed for home use, this figure is no more than 15-20 minutes. After this period of time, the user must give the machine time to rest. Professional models significantly superior to similar machines according to the parameter under consideration, since they are able to work for 8 hours, and to ensure efficient work they need the same pause, which is enough to arrange only twice per work shift.

Today, each manufacturer has its own approach to the division of this equipment, on the basis of which the assortment is formed. Some focus on the design, others on the reliability margin, and there are those for whom the most important parameter is the demand for a certain brand of equipment.

The equipment in question also deserves special attention. Based on this parameter, machines can be classified into two groups:

having abrasive grinding wheels;
equipped with sanding belt.

The equipment with circles is most often used. As for the models that provide a sanding belt, then they are most widespread V industrial production. They allow not only to give circular saws the necessary cutting ability, but also to ensure the final grinding of saw blades.

Saw sharpening procedure

A variety of alloys can be used to create the serrated blades found on circular saws. All of them may differ from each other in characteristics, which are determined by the properties of the alloy, as well as its degree of grain size. Moreover, as the grain size decreases, the strength and hardness of the material used increases.

Also, circular saws may differ from each other in tooth sizes. Based on this feature, the following tooth shapes can be distinguished.

Straight teeth

Most often it can be found on saws that used for fast rip cutting. where special attention is not paid to the quality of the cut.

Beveled teeth

These are the teeth that are most often found on circular saws. Located on the saw, these teeth can differ from each other in the type of sharpening, which can be right or left. Working with such circular saws eliminates the formation of chips, the risk of which is especially high at the edges of the coating being cut.

Trapezoidal teeth

A tool equipped with such teeth demonstrates a long service life and does not require sharpening for a long time. These saws are characterized by the fact that trapezoidal teeth are used in conjunction with straight ones. Their location creates the opportunity for rough sawing with the help of trapezoidal teeth, and thanks to the presence of straight teeth, conditions arise for finishing cuts.

Bevel teeth

Saws that are equipped with cutters of this type can, in addition to performing their main task, also be used to cut the bottom layer of the board, as a result of which it is possible to prevent chipping on the top layer.

Homemade saw sharpening machine

Anyone can cope with the task of sharpening circular saws, for which they do not need to have special skills. The lack of special equipment will not be a serious obstacle, since if desired you can make such a machine with your own hands. The first thing you should know about when manufacturing such equipment is what elements it will consist of:

A do-it-yourself sharpening machine must have a device that would allow you to fix the saw in the required position in relation to the emery wheel. Due to this, it is possible to maintain the required tooth sharpening angles with high accuracy. This can be done using a stand, which will have to be installed on the machine frame in the same plane as the grinding wheel.

When placed on the stand saw blade, its tooth with its plane forms a right angle with the saw blade. In some cases, it is possible to manufacture this stand in a movable version. With this task you can easy enough to handle. To install one side of the surface, a hinge is used, and the other part must be made in such a way that it is rigidly fixed at the edges, using bolts for this purpose. By creating a sharpening machine in this version, the user will have the opportunity to position circular saws at any angle and sharpen in any plane.

However, in the process of using such a sharpening device the user may face serious difficulty- he will have to make an effort to ensure that the sharpening angles are the same. To do this, the center of the saw must be secured in the required position relative to the grinding wheel. You can simplify the solution to this problem if you create a special groove on the stand, which will make it easier to adjust the saw.

When moving the mandrel with the wheel along the groove, there will be no serious problems with maintaining the required angle at which sharpening should be done. This problem can also be solved by another method. It is more attractive due to its less complexity. To do this, you need to create supports on the working surface with which the saw will be secured in the required position.

Basic rules for sharpening

In order to achieve desired result, when performing this work, you should adhere to certain rules:

Having at your disposal a homemade sharpening machine, you will be able to perform high-quality processing of the tool if you follow all the rules of this procedure. At the same time, your expenses will be much less than if you had decided to opt for factory devices. In addition to this, in order to use such a machine, you don't need any professional skills manual.

To sharpen a circular saw, you do not need to have a highly qualified specialist. There are no particular difficulties when caring for the machine. The main thing is to pay attention to the condition of the grinding wheel and regularly clean its surfaces from various contaminants. which may occur during work.

To ensure that you are satisfied with the result of saw sharpening, you must adhere to the following simple rules:

make sure that the disk being sharpened is positioned in a certain way in relation to the grinding wheel: the optimal position is when the disk interacts with the wheel with its entire plane;
It is also important to prevent the blade from overheating to critical temperatures. This can be achieved by setting the appropriate rotation speed of the wheel, and it would be a good idea to pour water on the wheel before sharpening;
You can determine that sharpening helped achieve the desired result by the presence of a uniform burr on the entire edge. The procedure is completed to give the saw blade the necessary cutting ability by processing it with a grinding wheel.

Conclusion

A circular saw, like any other cutting tool, at a certain point begins to perform its task worse. In such cases, it becomes necessary to sharpen the tool. This problem can be solved most effectively using a sharpening machine. If you do not have such a device, then you can purchase it in a store or make it yourself.

However, regardless of the option you choose, you must remember that it is the tool sharpening technology that determines how well the circular saw will subsequently cut. Therefore, before you start processing using a circular saw sharpening machine, you should familiarize yourself with the rules of sharpening. This will help you avoid damaging the saw blade and achieve the desired result with less effort.

Sharpening circular saws yourself is a task that is quite feasible for a home craftsman.

Do-it-yourself sharpening of circular saws - cost and reliability

A circular saw (the modern name is a circular saw) is much more effective tool in comparison with saber, longitudinal and chain. The quality of the cut and ease of use are beyond doubt. Using a circular saw, you can perfectly evenly cut a large workpiece, make cuts at different angles and work with a variety of materials.

A circular saw allows you to cut material both along and across the fibers with the same accuracy and quality. Of course, you can get a clean cut only with properly sharpened teeth. Circular saws are divided into three categories:

All metal
All-metal with spraying hard materials in the work area
Saws with tipped teeth made of hard alloys

The presence of technological grooves on saw blades is very important

Any disc must be sharpened with high quality, and the teeth must be correctly set. Dull teeth impair the quality of the cut, increase the load on the drive and make work unsafe. In addition, disks intended for working with hard materials must have technological grooves. Otherwise, when heated, the sheet may become deformed due to the expansion of the metal. This will lead to dangerous vibrations and poor cutting quality.

Differences in working teeth by geometric shape

The tooth has several working planes. The front plane “A” together with the rear “B” at the intersection form the main cutting edge “1”. At the intersection of the plane's thin lines with the side "B" auxiliary edges "2" and "3" are formed.

Schematic representation of a blade cutting edge

Designed to work effectively with materials different kinds cutting teeth.

Basic shape – straight tooth

Designed for rough and fast cutting. The cut quality is low, so it is not suitable for fine work and jointing of hard materials.

This shape of the cutting edge allows you to make smooth, precise cuts and is well suited for composite materials, for example, chipboard with double-sided lamination. There are practically no chips left on hard surfaces. Beveled teeth back surface They cut hard workpieces perfectly, but at the same time they become dull faster. The slope alternates, so a canvas with this shape is called alternately beveled. Both the trailing and leading edges can be beveled.

The main advantage is slow dulling. Such working teeth alternate with straight ones, working in a complex manner. The trapezoid is slightly higher than the main tooth, and, as it were, cuts through the material “roughly,” making it easier for the straight edge to work. Used for cutting plastics and materials with durable double-sided laminate.

Discs with conical teeth are auxiliary. With their help, a preliminary cut is made in the laminate to prevent the formation of chips when cutting. Not used as a stand-alone tool.

In addition, the front plane of the teeth may have a concave shape. These saws are designed for cross cuts. The concave plane and sharp edge cut the transverse fibers of the material like a sickle.
There are discs with alternating active and passive teeth. Passive ones have a negative sharpening angle.

How to determine the wear of a circular saw?

All the qualities of a circular saw are available only with timely sharpening of the teeth. A dull blade spoils the material, increases wear on the saw’s drive mechanisms, and increases the risk of injury during operation. There are signs of dullness, when they appear, it is necessary to urgently sharpen circular saws:

To advance the workpiece during cutting, a lot of force is required
Chips and cracks appear on the cut
The drive motor gets very hot during operation
There is a smell of burnt material
Dark marks from overheating are visible on the edge of the cut

In addition, the sharpness of the teeth can be checked tactilely and using a magnifying glass. The rounding radius of the cutting edge should be within 0.1-0.2 mm. When sawing thick workpieces, not only the main working edge is subject to wear, but also the side ones.

IMPORTANT! When carrying out work, always use a disc suitable for the material. Otherwise, you will mistakenly send a working disc for sharpening.

General rules for sharpening a circular saw

Discs are sharpened a limited number of times. With each procedure, the size of the tooth decreases. Sooner or later, the tooth is ground down to a critical value, after which the use of the disc becomes impossible.

IMPORTANT! It is unacceptable to work on a dull disk. In addition to deteriorating the quality of the cut, to sharpen excessively dull teeth, you will need to remove large quantity metal

In order to extend the service life, sharpening is carried out on two working surfaces of the cutting edge. In this case, the thickness of the removed surface is halved.

Schematic illustration of proper tooth sharpening

If you do not violate the processing rules, sharpening can be done up to 25 times. Before sharpening, the disc must be cleaned of dirt. Mechanical restoration undesirable, it is better to use washing liquids containing solvents. The standard amount of tooth surface removal is 0.05-0.15 mm.
Sharpening angles are individual for each disc, and are indicated in the passport or directly on the sidewall.

Marking of the saw blade indicating sharpening angles

There are special machines for sharpening discs. which mechanically control the selected angles for each tooth. Depending on the intensity of use, the sharpening machine can have an automatic or manual drive. At home, as a rule, inexpensive models are used in which turning the disk to next tooth and control of the thickness of the metal being ground is carried out manually.

In such devices, the disk is fixed perpendicular to the grindstone, and the angle and pitch of the tooth are set. The master passes the sharpened surface over the whetstone a fixed number of times and moves on to the next tooth.

Sharpening discs are made of CBN, silicon carbide or use diamond sputtering. It makes no sense to talk about the fundamental advantage of one material over another. There are only specifics of application. For example, diamond sharpening stones can cut more hard teeth, but are sensitive to overheating.

You can sharpen it manually using a high-quality file. It is better to leave the disk in the machine. The first tooth is marked with a marker, the disc is fixed using wooden blocks, a clamp or a vice. A fixed number of file passes must be made on each tooth surface. Then rotate the disc by one tooth and repeat the procedure.

Sharpening carbide-tipped discs

Many home craftsmen are faced with the problem of sharpening discs with pobedit tips. If you sharpen with standard abrasives, you have to carry out the procedure longer, and the material may “release” from overheating. Diamond sharpening discs do a much better job, but they are too expensive. Sometimes it is more profitable to buy a new Victory disk.

The choice is up to the saw owner, but the general advice is as follows:

When sharpening disks with pobedite tips, you will have to use a machine in any case, regardless of its technical level. If you have such a machine, purchase diamond abrasive and sharpening discs of any hardness will not be a problem. If you don’t have a machine, it’s better to go to a specialized workshop to sharpen discs with pobedit tips.

You can spend money on purchasing equipment of any complexity, the main thing is that it does not stand idle and is in demand. For large volumes of work, it is more profitable to have your own sharpening machine for circular saws. If you only perform periodic repair work, it is cheaper to contact a workshop.

Sharpening circular saws

Circular saws are used throughout construction. Many works require changing the dimensions of the building materials used, making cuts, and much more. A circular saw allows you to quickly cut a wide variety of materials, while the cutting speed is very high, and the quality of the cut is the best. The constant use of the equipment in question determines that the cutting tool begins to become dull, which has a significant impact on the efficiency of the work performed and its quality. This is why many people think about how to sharpen circular saws with their own hands. After all, the ability to do such work efficiently will allow you to save a lot.

Sharpening a circular saw

Required Tools

You can sharpen disks for a circular plate with your own hands only if you have special tools. There is also a machine that allows you to automate the process and make it more efficient.

To carry out the work of sharpening a disc with your own hands, you can use the following tools:

assembly vice;
file;
block of wood.

You can also use a circular saw sharpener, which does not require the above tools.

When is it necessary to carry out restoration work on circular saws?

Enough important issue can be called a determination of when circular saw blades should be sharpened. Excessive wear may make it impossible to carry out such work. There are three clear signals that determine the need to sharpen a circular saw blade:

Smoke appears, the protective casing heats up. The device, as a rule, has a special protective casing, which can heat up if the disk becomes dull. It should also be noted that in special cases, smoke appears due to the strong heating of the cutting zone.
Also, with mechanical feeding, when the pressure is adjusted with your own hands, great force should be applied to obtain the desired result.
When processing wood or other material, traces of soot and a corresponding odor appear in the cutting area.

Principles and angles of sharpening circular saws

The saw has four main sharpening angles for the circular saw blade along the working part. The hums in question, like the shape of the tooth itself, can be called the main performance characteristics. Each tooth can be characterized as follows:

front and back angle;
cutting angles of the front and back surfaces.

The values of the above parameters depend on the purpose of the sawing device and the type of workpiece material.

Circular saw tooth surfaces

Based on the above parameters, several saws can be distinguished:

for performing longitudinal cutting. In this case, the rake angle should be from 15° to 25°.
when performing cross cutting, the considered indicator should be from 5° to 10°.
The universal version is recommended to be sharpened at an angle of 15°.

The type of material being processed also determines what characteristics the tooth should have. As a rule, the harder the material, the more difficult it is to machine. That is why it is recommended to sharpen the cutting teeth to a lesser extent.

With prolonged use of a carbide saw, significant wear occurs on the uppermost cutting edge. When considering the tooth plane, it is worth noting that most wear occurs on the front surface.

Types of Circular Saw Teeth

Sharpening circular saws at home

You can sharpen the saw yourself without using a special sharpening machine, which is expensive and is rarely used for its intended purpose due to the use of carbide material when creating the cutting edge. However, you cannot simply hold the circle in your hands, since you need to achieve certain cutting parameters to ensure the required performance indicator.

To fix the gear wheel in a strictly specified position, an ordinary flat stand is used. It has the following features:

The surface of the flat stand should coincide with the level of the axis of the sharpening disc.
We place the toothed wheel on the stand so that the sharpening plane is perpendicular to the saw blade.
The device in question for teeth located at a certain angle is equipped with a rotary hinge.

The device in question makes it possible to fix the element being processed in relation to the abrasive material used. Using a colored marker, marking lines are drawn that allow you to select the correct angle. A vice is also needed in which the created fixing device is attached.

Sharpening using a machine

If it is possible to purchase a special machine, then the process in question can be carried out with maximum indicator efficiency. This device is compact in size and can be used at home.

Particular attention is paid to the choice of abrasive wheel. In this case, we note the following nuances:

Carbide blades are difficult to sharpen.
When choosing, you should pay attention to wheels made of CBN, with diamond chips or green silicon carbide.

Machine Enkor Corvette 472 Electric machine SZTP 600T Electric machine JMY8-70 (MTY 8-70)

The sharpening process when using professional equipment is very simple. The disk is secured using a special clamp. It was created taking into account the design features of the circle. We will pay special attention to the fact that when using special machines it is very easy to sharpen circular saws while maintaining the required parameters. In this case, the error is minimal. This is due to the fact that the design has a special angle indicator meter. In order not to be mistaken at the time of work as to which teeth have already been processed, you should use a marker to mark the starting point.

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Among the tools that are used for working with wood, the circular saw is quite popular. Its design includes teeth made of hard alloy; it also uses steel plates that are soldered onto them. To create the plate, hard alloys are used, which ensures a cutting effect. But over time, the saw teeth are no longer able to perform their main function as effectively, which is why they require certain processing. You can prevent premature dulling of your saw teeth by using a circular saw sharpening machine.

Types of machines for sharpening circular saws

The machines offered today can be classified into two large classes:

machines for household use;
machines for professionals.

Such a division is conditional. Moreover, the difference between these equipment lies only in productivity, which refers only to the time during which the sharpening equipment can operate in continuous mode. For models intended for home use, this figure is no more than 15-20 minutes. After this period of time, the user must give the machine time to rest. Professional models significantly superior to similar machines according to the parameter under consideration, since they are able to work for 8 hours, and to ensure effective work they need the same pause, which is enough to arrange only twice per work shift.

The equipment in question also deserves special attention. Based on this parameter, machines can be classified into two groups:

having abrasive grinding wheels;
equipped with sanding belt.

The equipment with circles is most often used. As for the models that provide a sanding belt, then they are most widespread in industrial production. They allow not only to give circular saws the necessary cutting ability, but also to ensure the final grinding of saw blades.

Saw sharpening procedure

Also, circular saws may differ from each other in tooth sizes. Based on this feature, the following tooth shapes can be distinguished.

Straight teeth

Most often it can be found on saws that used for fast rip cutting, where special attention is not paid to the quality of the cut.

Beveled teeth

Trapezoidal teeth

Bevel teeth

Homemade saw sharpening machine

When the saw blade is placed on the stand, its tooth plane forms a right angle with the saw blade. In some cases, it is possible to manufacture this stand in a movable version. With this task you can easy enough to handle: a hinge is used to install one side of the surface, and the other part must be made in such a way that it is rigidly fixed at the edges, using bolts for this purpose. By creating a sharpening machine in this version, the user will have the opportunity to position circular saws at any angle and sharpen in any plane.

Basic rules for sharpening

In order to achieve the desired result in the process of sharpening circular saws, certain rules should be followed when performing this work:

To ensure that you are satisfied with the result of saw sharpening, you must adhere to the following simple rules:

make sure that the disk being sharpened is positioned in a certain way in relation to the grinding wheel: the optimal position is when the disk interacts with the wheel with its entire plane;
It is also important to prevent the blade from overheating to critical temperatures. This can be achieved by setting the appropriate rotation speed of the wheel, and it would be a good idea to pour water on the wheel before sharpening;
You can determine that sharpening helped achieve the desired result by the presence of a uniform burr on the entire edge. The procedure is completed to give the saw blade the necessary cutting ability by processing it with a grinding wheel.

Conclusion

Circular or circular saw - indispensable assistant in households and in production when cutting wood materials. It is more efficient than other types of saws, such as chain saws, reciprocating saws, and rip saws. To get the perfect cutting of workpieces, you need to monitor the sharpening of circular saws with carbide tips.

Circulating saws - what are they?

Saw blade at correct sharpening and setting the teeth, it is able to qualitatively and accurately cut the workpiece in any cutting direction relative to the fibers.

There are several types of cutting blades for a circular saw:

Discs with a base and cutting area made of solid metal;
Discs with a solid metal base and coating of hard structure materials on the teeth;
Metal blades with carbide tipped.

High-quality cutting of workpieces is impossible when the teeth are worn out or dull. An accompanying phenomenon of working with a blunt tool will be excessive load on the engine, the risk of jamming, and unsafe cutting operations. Circular saws need to be sharpened.

For cutting hardwood, it is permissible to use only discs that have special grooves. Technological breaks in the blade prevent general deformation of the tool during possible heating during operation. This eliminates the appearance of a vibration background and deterioration of the cut line.

Geometry of cutting elements

The working element of the saw - the tooth - has a certain geometric shape with the presence of not one, but several cutting edges. There is always one main edge and additional ones formed by the intersection of planes “A”, “B” and “C” in certain combinations. To work with different materials It makes sense to select discs with the most suitable shape of cutting teeth.

Straight tooth

A saw blade with such a working zone is intended for rough cutting of lumber. The cut is rough, of low quality, and the operations are carried out relatively quickly.

Types of circular saw teeth

Beveled tooth

The front plane of the cutting edge, made in this form, ensures cuts with an accurate and even line. The saw is ideal for working with composite type materials: plywood, chipboard (with single-sided and double-sided lamination). After cutting blanks of solid lumber, it is chipped, practically no chips are observed.

There are discs with a beveled leading edge of the cutter, some with a beveled trailing edge, or a variant with alternating teeth (variably beveled blade). When working with a tool with a beveled surface of the trailing edge of the cutting element when cutting hard wood, a clear, high-quality cut is observed, but the saw quickly becomes dull.

Trapezoidal tooth

The main advantage of such a saw is the slow wear of the disc due to the absence of the need for frequent sharpening on a sharpening machine. Typically, the entire blade line consists of alternating cutting elements - straight and trapezoidal teeth, working in tandem. The taller trapezoid tooth roughs the cut, allowing the main straight edge to cut more easily. The tool can be used for cutting plastics and hard laminates.

Circular saw blade - characteristics

Conical tooth

An auxiliary type of tool designed for cutting materials with a laminated surface prior to the main cut. The operation is carried out to avoid the appearance of chips on the front part of the product. This saw blade is not used as an independent working unit.

Crescent tooth

Blades with a concave tooth shape are convenient for cutting material in the transverse cutting direction relative to the location of the fibers.

Determining the degree of wear of the circulation disc

Obtaining a high-quality result when working with a circular saw is only possible if you sharpen circular saws in a timely manner. Otherwise, damage to the workpieces, rapid wear of the saw drive mechanisms, and an increase in injuries at work may occur. To avoid this, it is necessary to clearly monitor the wear of the cutting blade, focusing on the following signs:

The movement of the workpiece on the work table during cutting occurs with the use of great physical force;
Cracks and chips are observed along the cut line;
During operation, the engine overheats;
There is a burning smell in the air;
The material burns, which appears as dark areas along the cut line.

If any of these signs are detected, you must immediately begin sharpening your circular saws yourself. Also, before carrying out work, you can check the sharpness of the saw, focusing on tactile sensations or visually using a magnifying glass. The permissible rounding radius of the cutting angle should correspond to a value of 0.1-0.2 mm. When cutting large workpieces, all working edges wear out.

How to sharpen a saw blade - rules

Only the pobedit disk, cleaned of dust and dirt, is subjected to sharpening;
The disc is cleaned using detergents, without the use of mechanical processing;
All working surfaces are sharpened;
The permissible thickness of metal removal is in the range of 0.05-0.15 millimeters;
The permissible number of sharpening operations is no more than 25 times;
Saws are sharpened manually with a file or on machines.

Sharpening saw blades with carbide teeth

Pobedit tips are sharpened using a special machine or a homemade attachment for a grinding wheel. The device is a clamp in which the disc is clamped, maintaining certain sharpening angles relative to the emery. A diamond wheel is considered the best for sharpening a pobedit.

A marker marks any point as a reference point. Position the main working surface of the tooth against the grindstone so that they are in the same plane. Grind each tooth in turn until the entire circle is completed. Rearrange the disk with the auxiliary plane to the grinding wheel. They grind a different plane for each tooth. This is how the carbide-tipped discs are completely sharpened step by step.

Sharpening circular saws

Material and properties of carbide teeth

In domestic saws, sintered tungsten-cobalt alloys of grades (6, 15, etc., the pattern means the percentage of cobalt) are used as the material for cutting inserts. At 6 the hardness is 88.5 HRA, at 15. 86 HRA. Foreign manufacturers use their own alloys. Hard alloys consist mainly of tungsten carbide cemented with cobalt. The characteristics of the alloy depend not only on its chemical composition, but also on the grain size of the carbide phase. The smaller the grain, the higher the hardness and strength of the alloy.

Carbide plates are attached to the disc using high-temperature soldering. As a material for soldering best case scenario silver solders are used (PSr-40, PSr-45), in the worst case. copper-zinc solders (L-63, MNMC-68-4-2).

Carbide tooth geometry

The following types of teeth are distinguished in the form.

Straight tooth. Typically used in fast rip saws where quality is not particularly important.

Oblique (oblique) tooth with left and right angle of inclination of the rear plane. Teeth with different angles alternate with each other, due to the fact that they are called alternating. This is the most common tooth shape. Depending on the size of the grinding angles, saws with alternating teeth are used for sawing a wide variety of materials (wood, chipboard, plastics). both in longitudinal and transverse directions. Saws with a high back angle are used as a trimmer when cutting plates with double-sided lamination. Their use allows you to avoid chipping along the edges of the cut. Increasing the bevel angle reduces cutting force and reduces the risk of chipping, but at the same time reduces the strength and durability of the tooth.

Teeth can be inclined not only to the rear, but also to the front plane.

Trapezoid tooth. A feature of these teeth is the relatively slow rate of dulling of the cutting edges compared to alternating teeth. They are usually used in combination with a straight tooth.

Moving with the latter and slightly rising above it, the trapezoidal tooth performs a through cut and a straight line, following it. clean. Saws with alternating straight and trapezoidal teeth are used for cutting double-sided laminated plates (chipboard, MDF, etc.) and also for sawing plastics.

Conical tooth. Saws with a conical tooth are auxiliary and are used to remove the bottom layer of the laminate, protecting it from chipping during the passage of the main saw.

In the vast majority of cases, the front side of the teeth is flat, but there are saws with a concave front surface. They are used for cross cutting finishing.

Teeth grinding angles

The grinding angles are determined using a saw. those. one for cutting the material and in which direction it is intended. Rip saws have a relatively large rake angle (15°.25°). In crosscut saws, the γ angle typically ranges from 5-10°. Universal saws designed for cross-cutting and longitudinal cutting have an average rake angle. usually 15°.

The grinding angle values are determined not only by the cutting direction, but also by the hardness of the saw material. The higher the hardness, the smaller the rake and back angles (less narrowing of the tooth).

The front angle can be not only positive, but also negative. Saws with this angle are used for cutting non-ferrous metals and plastics.

Basic principles of sharpening

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When sawing massive workpieces, the side surfaces are also subject to rapid wear.

Do not overdrive the saw. The radius of curvature of the cutting edge should not exceed 0.1-0.2 mm. In addition to the fact that when a blade is severely dull, productivity drops sharply, it takes several times longer to grind it than to sharpen a normally dull blade. The degree of dullness can be determined by both the teeth themselves and the type of cut they leave.

Proper sharpening of circular saws must ensure, at the same time, that the cutting edge is properly sharpened to provide the maximum number of cutters, which in the optimal case can be up to 25-30 times. For this purpose, it is recommended to use a carbide tooth, which should be ground along the front and back planes. In fact, teeth can be ground along one front plane, but the amount of possible sharpening is almost half as much as when sharpening on two planes. The picture below clearly shows why this happens.

The last pass when sharpening saw blades is recommended to be done on the back plane of the tooth. Standard metal removal value. 0.05-0.15 mm.

Before sharpening, it is necessary to clean the saw from any dirt, such as resin, and check the grinding angles. On some saws they are written to disk.

Equipment and materials for sharpening saw blades

When using abrasive wheels (especially diamond wheels), it is advisable to keep them cool.

As the temperature increases, the microhardness of abrasive materials decreases. Increasing the temperature to 1000 °C reduces the microhardness by almost 2-2.5 times compared to microhardness at room temperature. Increasing the temperature to 1300 ° C leads to a decrease in the hardness of abrasive materials by almost 4-6 times.

How to sharpen saw blades yourself using a simple device

Sharpen carbide disks very easy with the help of a simple device, and such disks times

How to sharpen a saw blade with your own hands

Dull saw blade on my Makita 2704. At the moment there is no finance to buy a disk from Makita or SMT

Using water for cooling may cause rust on machine parts and components. To eliminate corrosion, water and soap are added to the water, as well as some electrolytes (sodium carbonate, soda ash, trisodium phosphate, sodium nitrite, sodium silicate, etc.), which form protective films. During normal sanding, soap and water are most often used. soda solutions and with fine grinding. low concentrated emulsions.

However, when grinding saw blades at home with low grinding intensity, the wheel is often not used to cool the wheel. not wanting to waste time on this.

To increase the grinding ability of abrasive discs and reduce specific wear, you should select the largest grain size that provides the required surface finish of the pointed tooth.

To select the abrasive grain size according to the grinding stage, you can use the table in the article on grinding rods. For example, if diamond wheels are used, 160/125 or 125/100 grit wheels can be used for roughing. 63/50 or 50/40. Wheels with grit sizes ranging from 40/28 to 14/10 are used for removing teeth.

The peripheral speed of the wheel when sharpening carbide teeth should be about 10-18 m/s. This means that when using a 125 mm diameter wheel, the engine speed should be around 1500-2700 rpm. More brittle alloys are sharpened at lower speeds in this range. When sharpening carbide tools, using harsh modes results in increased stress and cracks, and sometimes grinding of the cutting edges, while increasing wheel wear.

When using saw blade sharpening machines, changing the relative position of the saw and the grinding wheel can be done in different ways. movement of one saw (the motor with the circle is stationary), simultaneous movement of the saw and the motor, movement of only the motor with the circle (the saw blade is stationary).

Produced by machines various functions. The most complex and expensive programmable systems are capable of providing complete auto mode grinding, in which all operations are performed without the participation of a worker.

In the simplest and cheapest models, after installing and securing the saw in a position that provides the required sharpening angle, all further operations. turning the saw around its axis (turning on the tooth), feeding it for grinding (contact with the wheel) and controlling the thickness of the metal removed from the tooth. are made by hand. It is advisable to use such simple models at home when sharpening circular saws is occasional.

An example of the simplest machine for is the system photographed below. It consists of two main nodes. a motor with a wheel (1) and a support (2) on which a pointed saw is mounted. The rotating mechanism (3) serves to change the angle of the blade (when sharpening teeth with a beveled front plane). Using the screw (4), the saw moves along the axis of the abrasive wheel. This ensures that the specified front grinding angle value is set. The screw (5) is used to set the stopper in the desired position, preventing the wheel from excessively entering the interdental cavity.

Saw blade sharpening process

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The saw is mounted on a mandrel clamped using a conical (centering) sleeve and nut, and then installed in strictly horizontal position using mechanism (3). This ensures that the front plane inclination angle (ε 1) is 0°. In disc grinding machines that do not have a built-in angular scale in the tilt mechanism, this is done using a conventional pendulum goniometer. In this case, check that the machine is level.

The rotation of the screw (4) of the mechanism, which ensures horizontal movement of the mandrel with the wheel, sets the required cutting angle. In other words, the saw moves to a position where the front plane of the tooth fits tightly against the working surface of the wheel.

The marker marks the tooth from which sharpening begins.

The engine is turned on and the front plane is sharpened. inserting the tooth into contact with the wheel and moving the saw back and forth several times while pressing the tooth against the wheel. The thickness of the metal removed is regulated by the number of sharpening movements and the force of pressing the tooth on the abrasive wheel. After sharpening one tooth, the saw is removed from contact with the wheel, it turns on one tooth and the sharpening operation is repeated. And so on until the marker pen makes a full circle, showing that all the teeth are pointed.

The tooth sharpening is inclined on the front plane. The difference between sharpening a beveled tooth and sharpening a straight tooth is that the saw cannot be mounted horizontally, but at an angle. with an angle corresponding to the angle of inclination of the front plane.

The angle of the saw blade is set using the same pendulum goniometer. First the positive angle is set (in this case 8°).

After this, every second tooth is sharpened.

After half the teeth have been sharpened, the saw blade angle changes from 8° to 8°.

And every second tooth is sharpened again.

Back sharpening. To sharpen a tooth on the back plane, it is necessary that the saw blade grinder allows you to set the saw so that the back plane of the tooth is in the same plane as the working surface of the abrasive wheel.

If there is no machine for sharpening saw blades

Precisely maintain the required sharpening angles while holding the weight of the saw in your hands. The task is impossible even for a person with unique eye and enviable stiffness of hands. The most reasonable thing in this case. for creating simple device for sharpening, which allows you to fix the saw in a certain position relative to the circle.

The simplest of these tools is a grinding stand, the surface of which is at the same level as the axis of the grinding wheel. By placing the saw blade on it, you can ensure that the front and back planes of the tooth are perpendicular to the saw blade. And if the upper surface of the stand is made mobile. fixing one side hinged and the other. Relying on a couple of bolts that can be screwed in and out. then it can be installed at any angle, making it possible to sharpen an inclined tooth on the front and rear planes.

True, in this case one of the main problems remains unresolved. Extracting the same front and back corners. This problem can be solved by fixing the center of the saw in relation to the abrasive wheel in the desired position. One way to implement this. Make a groove on the surface of the mandrel support on which the saw is mounted. By moving the frame with the wheel in the groove, it will be possible to maintain the required tooth cutting angle. But to sharpen circular saws of different diameters or sharpening angles, it must be possible to either move the motor or the support, and with it the groove. Another way to ensure the desired sharpening angle is simpler and install stops on the step that lock the disc in the desired position. At the end of the article there is a video demonstrating this adaptation.