Any cutting tool tends to become dull during use. This also applies to carbide saw blades, which must be sharpened regularly in order for wood to be sawed quickly and efficiently.
The easiest way to sharpen teeth on a circular saw is to use a regular file. But when working with your own hands, to bring the cutting tool into working condition, many difficulties arise that only a good specialist with sufficient experience can cope with. It is much easier, faster and more efficient to use a homemade machine for sharpening circular saws or a sharpening machine for circular knives for this operation.
Machine for sharpening circular saws Monolit TD1-600
If you have a homemade electric sharpening machine for circular saws, regardless of whether it is a factory tool or a homemade one, you should know the basic principles of using such equipment. Especially when there is a need to sharpen the teeth of saw blades that have different geometries and sharpening angles.
Machine
A machine for sharpening circular saws is not just one device. This can be called a large group of equipment and tools for special purposes.
– Automatic. The sharpening process is completely mechanized and there is no need for human participation. Such devices are used for production purposes.
- Manual. These can be any devices and tools for sharpening by hand. The productivity of such equipment is much lower than automatic machines. This type has found application in handicraft workshops for domestic needs.
Equipment of this kind is available for sale in a wide range; devices may differ in function, power and price. A manual machine for sharpening circular saws, the price of which will be much lower (about 20 thousand rubles), can be made independently. The equipment consists of dense and hard alloy plates that serve as cutters.
Plates for them are made from alloys of various compositions.
Types of devices
Before you start manufacturing equipment, you need to find out what kind of machines are generally found. They are classified according to two principles.
Automatic - such machines are capable of performing basic functions without direct human intervention. They are most often used in industries where large quantities of materials need to be processed every day.
Semi-automatic units - human intervention is required for their operation. All work is done manually. These are the devices that are used in households.
Masters call this classification conditional, because the main difference between the presented devices is only in performance. A home machine can operate continuously for no more than 20 minutes. As for professional equipment, the time period is much longer.
It is important to pay attention to the configuration of the devices. In this regard, equipment can be divided into the following types:
- with abrasive grinding wheels;
- machines equipped with a sanding belt.
The first type is used more often than the second; all equipment is made from carbide plates and blades.
Professional machines operate continuously for up to 8 hours, but they have significant dimensions and power. The sharpening procedure depends on the device parameters:
- disc thickness (16–40 mm);
- outer diameter (1.2–25 cm);
- holes for fastening;
- manufacturing material.
The last parameter is important: there are diamond, corundum wheels, elements with a reinforcing plate made of hard alloys.
Differences in insert teeth
The tooth of hard alloys has four main planes for work: front, back and lateral (auxiliary). When the planes intersect with each other, cutting edges are formed: the main one and a pair of auxiliary ones.
The shape of the teeth is as follows:
- Direct. The use of this form will be justified when longitudinal cutting is required, which is quick in time and not required in quality.
– Oblique or beveled. The angle of inclination of the rear shape can be right or left, they alternate with each other. This configuration is the most common. Sharpening blades of different sizes are used to work with different materials in any direction.
– Trapezoidal. This tooth dulls its edges more slowly than a beveled tooth. Alternate it with the straight one. In this case, the rough cut was a longer trapezoidal cut, and the finishing cut was a short straight cut.
– Conical. This form of teeth performs a rough cut on the lower edge of the boards, while protecting the upper edge from chipping. Basically, the front edge of such an element is flat. But if you make it concave, then it is possible to use this device for cross cutting in a finishing version.
Read also: Operating principle of a concrete vibrator
Chain teeth
Before considering methods for sharpening chain elements, it is necessary to familiarize yourself with the structure of the link, the shaping and the angles necessary for easy sawing of wood.
Link elements:
- base;
- cutting edges (blade);
- depth limiter.
The link blade is equipped with two cutting edges that cut in horizontal and vertical planes. It tapers towards the rear, allowing for miter sawing. The back angle, which reduces energy costs, is set by the back of the tooth.
Proper sharpening creates the necessary angles that form the upper corner, and guarantees increased chain life and the impossibility of its jamming:
- the angle of the edge end relative to the surface being cut is 65° - 85°;
- back angle - 55° - 60°;
- cutting edge cutting angle: for cross cutting - 25° - 35°;
- for longitudinal cutting - 10°.
When turning there are certain rules that must be followed:
- The sharpening angles must correspond to the parameters specified by the manufacturer.
- The overall dimensions of the links after sharpening should not differ.
- The sharpening angle when working in winter or with dense wood should be reduced in order to reduce runout.
Sharpening angles
The fundamental angles are those determined by the shape of the teeth. These are front and rear, as well as bevel along the front and rear planes.
For longitudinal cutting of the front angle, it is recommended to set the degree in the range from 15 to 25. For transverse cutting - 5-10 degrees. For universal saws of both sections, it is more correct to choose the average value of 15 degrees.
The size of the angle is also determined by the hardness of the cutting material.
You can buy a machine for sharpening carbide circular saws at a cost of 15,000 rubles. You can also shell out for more expensive devices. For example, PP-480Z will cost its owner 280,000 rubles. Prices vary and depend on the purpose of the device, its functions, power and performance. For a small workshop or home use, you can purchase a JMY8-70 circular saw sharpening machine. Its cost is within 18,000 rubles.
Self-production of a saw sharpening machine
When an electric unit is available for sharpening sharp surfaces, it does not matter whether it is factory-made or home-made. This topic is especially relevant when it comes to high-quality sharpening of teeth, which are made taking into account different geometric shapes and angles for turning. There are several such mechanisms and they resulted from the optimization of the processing of cutting surfaces, which have different properties.
The most common forms of serrated surface:
- In direct form, when concern about the quality of execution is not necessary.
- Shaped like a beveled tooth; There are two angles of the inclined surface: right and left. Typically used in circular saws. It is very often used in trimming products with lamination on both sides, because it does not show chipping cracks on either edge.
- In the shape of an oblong trapezoid. The surface is capable of holding the edge in a sharp position for a long time, rising above the teeth at a right angle. In such a situation, the teeth can be sawn black, and with straight teeth - clean.
- In the form of a conical fairing. Most often found in work on an auxiliary basis. Most often, the surface section of the laminate is cut, avoiding splinters during axial sawing.
From the front side, all the teeth consist of a flat surface, but some types of saws have a concave surface. The circular saw itself has four main angles, which form a certain shape in the intersecting plane:
- corner located on the front side;
- the angle forming the back surface;
- beveled corners in the plane of the front and rear entrance.
As an additional angle, the option with a sharpened angle is also taken into account, which forms a combination of the angles of the front and rear rows. In reality, the sharpening angle directly depends on the purpose for which the saw is intended.
- For longitudinal sawing, saws with dimensional characteristics at a rake angle of 15-20 degrees are used.
- Cross cutting for a circular saw is performed at a ratio of 5-10 degrees.
- Universal characteristics make it possible to increase the degree of inclination up to 15 degrees.
Very often, to determine the sharpening angle, an indicator such as the hardness of the wood is used. Depending on the level of hardness, the angle and size of the inclination are determined and the saw is selected accordingly.
It is by these principles that a sharpening machine for disc sawing is determined. Machines of this type have a certain design when cutting in a single way:
- During operation of the machine for sharpening circular saws, only the saw moves (the motor itself remains in its original state).
- During operation, two elements come into motion: a saw for sharpening and a motor with a circular motor parameter.
- Two standard elements also move: the saw and the motor.
A typical example is a standard homemade machine for sharpening circular saws, which can be a unit consisting of two interconnected elements:
- Grinding motor with removable shaft.
- A support pad that is attached to the disk base.
To ensure the full sharpening angle of the element, the unit always provides for a system that makes it possible to assist in changing the inclined surface on a blade with a serrated surface.
Sharpening rules
The main wear of saw teeth occurs on the top edge, which is directly involved in cutting. Its rounding can be 0.3 mm. The central face changes earlier than the others.
– We must not allow significant wear on the saw. The edge can be rounded no higher than 0.2 mm. It is more difficult to sharpen a saw that is duller than this value. This will take longer than for a tool with normal wear. The degree of wear is determined either by the type of cut or by the teeth.
– We must not forget about the maximum possible number of sharpenings performed. This value is in the range of 30-35 times. To achieve this result, both surfaces are treated at once.
– Before starting work, you should clean the working disk from dirt, and also measure the angles of inclination. Preparation for sharpening is carried out from the front of the tooth. The layer of metal that can be removed is 0.20 mm.
– If abrasive diamond wheels are used for sharpening, they must be cooled with a liquid of a special composition (coolant). For better quality and lower specific gravity, it is better to choose a high-grit wheel.
– Jagged edges and irregularities should not be allowed, even if this is a homemade machine for sharpening circular saws. They can lead to untimely exit from work and crumbling of the metal.
Chain sharpeners
To restore the functionality of the chain saw tool, a device for sharpening the saw chain links is required. Devices are classified as follows:
- By installation method: mobile;
- stationary;
- factory;
- manual;
Stationary models of sharpening equipment have a rigid mount and are placed in close proximity to the workplace or on a workbench. They are mechanically driven by an electric motor. Mobile devices are distinguished by the fact that the work is done manually, they can be taken with you to a place of work remote from a source of electricity, and also by their small size and weight.
artisanal
Sharpening it yourself won’t be too difficult. Especially if you have the necessary equipment. And if not, then you can make it yourself. You can make a machine for sharpening circular saws, the price of which will only please you, from simple parts. To do this you will need the following basic elements:
The circle is fixed on the engine, the disk blade is on the caliper, the screws will ensure the movement of the workpiece along the axis of the circle, which will provide the desired angle.
The main task for such an element as a machine for sharpening circular saws is to fix them in the required position relative to the circle. This is necessary to accurately maintain the angles; this can be provided by a stand mounted on the machine frame in the same plane as the circle.
When placing the disk on a stand, the teeth must be perpendicular to the plane of the sawing machine.
Exploitation
Before you start making this unit yourself, you need to think through the drawings of a machine for sharpening circular saws. You can calculate them yourself, or you can turn to a professional. In any case, in order to understand all the intricacies of the future device, you cannot do without a preliminary paper version. If you have the necessary knowledge, you can cope without turning to a specialist.
A machine for sharpening circular saws, created with your own hands, has a big advantage in terms of price over a factory unit. It also does not require any special skills to operate.
Sharpening without a machine
You can sharpen a saw at home without the help of a machine. But you shouldn’t hold it by hand while sharpening on a grinding wheel. For correct operation, hand effort will not be enough, and the eye will not be able to adjust the desired angle. To simplify the task, you can use some kind of fixation device; for this purpose, a regular flat delivery will be useful. The axis of the sharpening disk must coincide with the surface of the stand. And the circle, in turn, should be placed perpendicular to the saw. If it is necessary to make corners, the structure is made movable using hinges. But here the difficulty arises in maintaining the same angle of the front and rear sharpening. Rigid fixation of the saw wheel in relation to the abrasive disc will help to avoid this. This can be done by using an arbor groove or attaching stops in the stand, which will allow you to secure the corner.
Features of using the machine
To carry out sharpening, the owner does not need special skills. You just need to be careful and follow the rules of behavior around the machine:
- You should regularly clean the surface of the grinding wheel from dirt and monitor its condition.
- The saw blade must be positioned correctly during operation.
- When performing the procedure, you need to monitor the heating of the material being processed.
- If there is a uniform burr on the edge of the saw blade, then sharpening must be considered completed.
- After sharpening the blades, they must be thoroughly polished.
Any circular saw loses its primary characteristics with regular use. Sharpening the saw blade teeth will help restore cutting ability. To make it efficiently and quickly, you need to build a special machine. It has a simple design but is highly efficient.
Types of teeth
The main cutting element of the disc is the teeth. They are made from carbide material. A tooth consists of four sides: front, back and two sides. Also from the main cutting edge and two additional ones.
Teeth requiring sharpening are divided into:
- Direct. Used for longitudinal sawing of blades.
- Beveled. They have an angular cut on the back plane of the tooth. They can cut not only wood, but also plastic 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 that need to be sharpened after dulling. These are the front and back angles. Also the cutting angles formed by the front and back surfaces.
Depending on the direction of sawing, they need to be sharpened correctly. When longitudinal cutting, the rake angle ranges from 15 to 25 degrees. In the case of cross cutting, the sharpening angle is reduced to 5-10 degrees. If universal cuts are required, then the tooth is sharpened at an angle of 15 degrees.
The density of the material has an important influence on the angle. The lower it is, the more urgently the tooth is needed. If the material being processed is plastic, then the angle can be negative.
Sharpening circular saws with pobedit tips
It is not easy to maintain sharpening angles for circular saws with carbide tips because pobedite is applied to the tooth. This alloy is attached by soldering. The geometry of the cutting part is complex, and the sharpening parameters require precise control.
Work is carried out by smoothing the cutting edge to a radius of 0.3 mm. A greater value should not be allowed.
Recommendations for sharpening:
- 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.
- You should start working from the front plane.
- The part of the tooth that is soldered must fit tightly to the abrasive wheel.
- Turning time ranges from 3 to 5 seconds. Can't go any longer. This leads to excessive heating of the metal. It is overheated and tempered with a decrease in hardness.
- The thickness of the material being ground is around 0.15 m.
Application of the machine
The simplest machine for working at home is a motor with an abrasive. The wheels can be diamond, CBN or silicon carbide.
It is difficult to keep the blade in a certain position relative to the abrasive. You need to use the tools. This can 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 located on the plane so as to be perpendicular to the blade. After turning on the engine, the blade is brought to the circle and pressed against it with a tooth. The layer of metal being removed is regulated by the pressing force. Having finished working with one tooth, the next one is approached using the same method. And so on in a circle until the end.
For the purpose of universalization, the stand is being modernized. The front part is made movable, and a pair of bolts are screwed into the rear. With their help you can adjust the tilt of the canvas. It becomes possible to sharpen the front and back planes of an oblique tooth.
The problem of maintaining the same front and rear sharpening angles remains. To do this, it is necessary to fix the blade relative to the center of the abrasive wheel. To do this, the disk is inserted into a special mandrel, and a groove is made in the stand for it. The required sharpening angle is maintained by moving the mandrel along the groove. If the diameter of the disks 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.
Types of machines
All machines for sharpening circular saws are divided into automatic and mechanical according to the method of control (handling).
An automatic machine for sharpening saw blades, as the name suggests, does not require much effort on the part of the master; it is enough to simply set everything up (in particular, set the angle and pitch of the teeth) and turn it on. Such units can be seen at large enterprises and industrial workshops.
Mechanical sharpening tools have lower productivity than automatic sharpening tools. Here you have to manually perform an operation such as turning the disk to the next tooth. Mechanical equipment is mainly used in home workshops.
In addition, all sharpening machines can be divided according to the operating principle into three groups. The first includes tools on which, when sharpening, only the saw rotates (the grinding wheel and the electric motor, respectively, are stationary). The second type includes sharpening machines, during operation of which both the saw and the motor with the abrasive wheel move. In machines of the third type, only the engine with the circle attached to it moves (the circular saw remains motionless).
There are no sharpening machines that do not have at least one of these elements (a motor with a sharpener attached to its shaft or a support for securing a circular saw).
