Main malfunctions and their symptoms
Typical malfunctions of hand-held circulars include the following situations.
- The saw does not start. The mains cable, power plug, start button or electric brushes may be defective.
- The engine of the instrument is very hot. Such symptoms may be the result of an inter-turn short circuit (breakage) in the armature or stator coils, as well as an excessively intensive mode of operation of the unit..
- The gearbox of the apparatus is overheating. Overheating of this unit may occur due to bearing failure or lack of lubrication on the gears..
- The brushes sparkle. This is usually due to excessive wear and tear..
- A burning ring is visible around the engine manifold. If, during operation of the unit, a circular spark is observed around the engine manifold, then its appearance can cause a malfunction of the armature winding or clogging of the space between the collector lamellas with graphite dust.
- The unit does not develop the required power. The drop in power may be due to a drop in voltage in the network, malfunction of the motor windings, wear of the electric brushes, malfunction of the start button.
- During the operation of the unit, grinding and other extraneous sounds are heard. These symptoms can be caused by broken gear teeth or bearing malfunction..
- The engine is humming but the unit is not running. A jam may have occurred in the gearbox..
The saw stops during operation
In most cases, the engine stops due to worn-out electric brushes. When the contact between the brush electrode and the collector lamellae is broken, the unit turns off.
Often, when buying brushes for this device, you come across products with a short conductor connecting the electrode to the plate. This conductor is located inside the spring and does not allow it to fully unclench. When the electrode wears out to a certain length, then pressing it to the collector stops, since this is prevented by a short conductor. If, while inspecting the brush, you find that it is not yet worn out and the spring does not expand, then the part should be replaced..
DIY circular saw repair
When starting to repair the unit with your own hands, it is not necessary to disassemble it completely to find out the reasons for the breakdown. Some malfunctions are characterized by specific symptoms by which you can determine the problem and purposefully disassemble one or another part of the device.
How to repair a circular with your own hands
A circular hand saw is a fairly practical tool with which you can quickly cut a piece of wood of any length and width along or across, cut any sheet material on a wood basis. In addition, after changing the equipment with a circular saw, you can cut plastic, metal corrugated board and corrugated sheet. Despite the simplicity of design and high reliability of this unit, it is susceptible to damage, like any power tool. But in most cases, you can repair a circular saw yourself at home..
Brushes are burning
Strong sparking from under the brushes is caused by excessive wear when the spring can no longer press the electrodes against the collector with the required force. To replace the brushes, you need to disconnect the motor cover or remove them through the special holes in the motor housing (depending on the saw model).
How to install a blade on a circular saw | Milwaukee 2732-20
The saw does not start
If, when pressing the start button, the engine of the unit is “silent”, then the first thing to focus on is the power cable, provided that there is electricity in the outlet (plug the device into another outlet to check).
To check the electrical cable, you need to disconnect the handle. This will help you get to the pins where the power cord wires are soldered. Next, use a tester to ring each wire by pressing one probe to the soldered contact, and the second to the pin of the plug.
If the network cable is intact, then in search of a malfunction, do the following.
- Test the entire circuit with a tester, starting from the cable entry into the unit to the start button. You should also check the contacts of the button at its input and output when the key is pressed. In the normal state, an open circuit should be closed. Ring all the wires after the button, going to the motor brushes.
- If everything is in order with the conductors, check how much the brush electrodes are worn out. After the electrode is worn out by 2/3 of its original size, it should be replaced. Brushes, no matter how worn out each of them, change in pairs.
- If the brushes are in good condition, then, most likely, the engine is out of order. An open circuit or an interturn short circuit could occur in its windings. In this case, it is better to entrust the engine repair to specialists who will rewind the stator or armature coils..
Reducer housing gets very hot
Rapid heating of the gearbox occurs if the shaft bearing has become unusable, on which the gear is fixed and the equipment is attached. In this case, in addition to heating, you can replace the appearance of extraneous noise in this unit of the device. It is necessary to disassemble the gearbox and change the bearing. Also, the gearbox will warm up if there is not enough lubricant in it or it is completely absent..
How to sharpen a circular saw blade correctly and at what angle
The use of circular saws is especially common in construction. Most of the work requires cuts and changes in the shape and size of the finished materials. The circular saw helps you tackle these tasks quickly and get quality results. But the instrument is not capable of serving forever, sooner or later it may become dull. It is for this that you need to know exactly how you can sharpen saw teeth in a domestic environment..
- How to determine wear?
- Types of cutting teeth
- Sharpening principles and angles
- How to sharpen: basic methods
- Manual way
- Using a machine
Types of cutting teeth
There are four planes on the surface of the teeth – front, back and two side.
At the moment of intersection with each other, they create a single cutting edge, due to which the sawing of surfaces occurs.
There are several forms of teeth:
- Straight tooth. Most often it is used only for a quick longitudinal cut. During such work, quality and accuracy are practically unimportant..
- Oblique tooth. The back plane of such a part is tilted to the right or left. On saws, these teeth often alternate, which is why they are called “alternately cut”. These teeth are most commonly used in tools. The size of the corners can be different, this is due to the coating of the treated surface – wood, chipboard, plastic. They are used for longitudinal and transverse movements. A large angle of inclination on the tools is used when cutting boards with double-sided lamination. This helps to avoid chipping of the material. The larger the chamfered corner, the easier the saw will cut through the surface. But this greatly increases the likelihood of tooth breakage. On some products, the teeth are inclined not only at the back, but also at the front..
- Trapezoidal tooth. The main advantage of this type is that the edge dulls slowly. But they are rarely used separately, usually alternated with straight teeth. During the operation of the device, the trapezoidal teeth are located above the straight ones, therefore, they take over the main (rough) sawing work. Straight teeth for finishing. This saw design is used for sawing plastic, chipboard and MDF..
- Conical tooth. This type of tooth is considered optional because it only helps to cut the lower part of the material (most often the laminate). This design allows you to protect the surface from chips and cracks. Bevel teeth usually have a straight front edge, but it can also be concave. This type is used for finishing the saw cut..
Important! Each type of teeth requires a thorough grinding when sharpening. You can’t sharpen them at the same angle..
Special saw blade sharpening machines are rarely used in a domestic environment because their cost is high. Therefore, in the absence of such a device, you can cope with sharpening with improvised devices, for example, an angle grinder. In this case, it is forbidden to hold the circle in your hands without fixing it with anything. Otherwise, it will not be possible to achieve a sufficient cutting angle for further work with the material..
To securely fix the circle in the correct position, use a flat stand.
- the surface of the stand coincides with the level of the axis of the grinding wheel;
- on it, the gear wheel is placed in such a way that the sharpening plane becomes perpendicular to the saw blade;
- the design of the device is complemented by a swivel joint.
The stand will help you to comfortably position the saw blade for cutting in relation to the abrasive material. Before starting work, clear markings are carried out. A colored marker is used for this. They draw a mowing line, which will allow the element to be sharpened at the desired angle. The vise will help secure the disc to the surface.
Video of sharpening a circular saw blade angle grinder:
It is allowed to sharpen the saw with your own hands only when using special devices. For this, there is a grinding machine that helps to carry out the process on an automatic machine, and not manually. Then the result becomes more accurate..
In addition, other improvised devices are used for sharpening:
- Mounting vise;
- Piece of wood.
You will not be able to replace the listed devices. If at least one of them is not available, then sharpening will not work.
How to determine wear?
Checking the saw blade for wear is an important issue that should be given special attention. Deep damage leads to the inability to sharpen the circle. There are three main signs by which you can understand that the saw needs to be sharpened or replaced:
- Excessive heating of the protective cover and the formation of smoke. The circular saw has a special cover that signals when the saw has become blunt due to heating. In especially difficult situations, smoke may appear from it..
- Sometimes the saw device involves a mechanical feed (if you need to adjust the pressure with your own hands). In such a situation, wear can be noticed if the pressure has to be increased..
- If carbon deposits and strong unpleasant odors form on the workpiece when sawing wood.
All situations described above tell the user to sharpen the device..
Sharpening principles and angles
There are four main sharpening corners at the edges of the saw. Together with the shape of the tooth, they can be the main performance characteristics of the tool. The following are used to describe each tooth:
- Front and back angle.
- Cut angles of the front and back surfaces.
These characteristics may depend on the type and weight of the circular saw, its purpose, as well as the density of the specific surface..
Sharpening angles in the diagram
Based on the parameters indicated above, all circulars can be divided into several types:
- For slotting longitudinal holes. A 15 to 25 degree rake angle should be used for this task..
- For cross-cutting. In this situation, the rake angle can vary from 5 to 10 degrees..
- Universal sharpening. Saws are sharpened at an angle of 15 degrees for any operation.
The size of the sharpened angle is not only determined by the direction of movement of the saw, it is also related to the material of the workpiece. When cutting through very hard materials, the smallest angle should be chosen. To work with softer products, the angle increases.
Important! If a carbide saw has been used long enough, maximum wear will be seen at the top cutting edge. A detailed examination of the plane of the tooth shows that the anterior surface of the material suffers the most..
How to sharpen: basic methods
There are two methods available for sharpening circular saws – manual and machine. In order to sharpen the disc correctly at home, you need to take into account some of the nuances.
Most often, discs are made of high speed or chrome vanadium steel (HSS or CV marking, respectively). The addition of tungsten and molybdenum gives the tooling significant strength, making it less brittle under stress.
There are carbide products (TC marking), in which the main part is made of chrome vanadium steel, and the teeth – they are soldered onto the disc – from tungsten carbide. Although these attachments are more expensive than conventional steel discs for circular saws, they last 10 times longer..
A tooling with diamond cutting segments is also used, which are attached to the disc by laser welding. They are highly durable and capable of handling hard materials such as stone and concrete.
The thickness of the disc can be from 0.7 to 2.8 mm, the thickness of the cut depends on it.
Teeth vary in size, shape, angle, and set pattern. The following types of teeth are most common: divorced, with a straight-sided profile, multidirectional, trapezoidal. Depending on this, it is determined how the load is exerted on the cutting part. For example, set teeth are subject to the greatest load at the ends of the cutting segments, while in multidirectional cutting, the load is evenly distributed during sawing..
A little about the operation of saw equipment
Use only sharp blades for safe sawing, as damaged or dull tips can cause seizure in the material. This will block the motor of the tool..
It is required to select the optimal feed mode and not exceed the maximum allowable speed of the tooling.
In order for the blade to serve for a long time and not to frequently sharpen the teeth, it is recommended to clean it of adhered sawing waste after working with a circular saw..
The saw blade is an accessory for circular, miter, combined saws and angle grinders, designed for sawing workpieces, as well as cutting off work.
Types of saw blades
- Woodworking is used for processing solid wood and sawn timber. They differ in the operations performed. For a fast cut, a tool with a small number of large teeth is used, creating a rough cut. For a clean cut, you need a saw blade with a small number of fine teeth. The sawing process will be slow, but it will be possible to achieve a neat cut. For rip sawing, discs with coarse teeth are intended, since the workpiece is processed along the wood fibers, for transverse sawing – with fine teeth. For circular saws, there are also universal discs that have a combination of fine and large teeth. Thus, it is possible to carry out longitudinal and transverse cuts without changing the equipment..
- For metal, they are intended for sawing profiles, pipes, angles, fittings. They differ in the type of processed metals: tooling for aluminum, low-carbon steel, brass, bronze and others. As a rule, a blade without a liquid cooling system has special slots in the body, which serve as temperature compensators, which reduces heating during sawing. There is also a tooling designed for machines with a liquid cooling system.
- Stone cuttings are used for working with bricks, tiles, marble, granite, concrete and reinforced concrete. As a rule, the cutting edge of these discs is diamond-coated. There are products for dry and wet cutting. The feature of the former is a segmented cutting edge with teeth and cooling holes. In the process of work, it is necessary to take frequent breaks to allow such a nozzle to cool down. The latter have no teeth, diamond soldering goes along the entire edge, the height of the diamond layer can reach 5.5 mm – this is a professional equipment for intensive use. Cooling is carried out due to the liquid supplied to the working area.
- For plastic, they are used to work with plastic, fiberglass, metal-plastic. Usually the teeth of this equipment have a negative sharpening angle, so even thin workpieces can be accurately cut. This saw blade ensures a clean cut. Some types of equipment in this group can be used to work with laminate and wood fiberboard and chipboard blanks.
The disc diameter can be from 130 to 500 mm. The higher this value, the larger the workpieces the circular saw can handle with this blade, the same condition applies to the miter saw attachment..
The landing diameter is indicated in millimeters and is matched to the size of the circular saw. The most common discs with a diameter of 16, 20, 22, for side saws – 20, 22, 24, 30, for an angle grinder – 22.2.
The number of segments can be from 10 to 150 pieces. The more of them, the more accurate the cut will be. For rough cuts, for example, usually take a tooling with the number of segments up to 20 pieces..
Saw equipment is a consumable item and should be replaced as it is worn out. But you can postpone its purchase by sharpening the blunt teeth of an existing disc. How to do it? You don’t need special skills and equipment. A simple instruction is in our article.
The first step is trying to determine what is broken. This does not mean a specific knot, but the nature of the damage. It can be mechanical or appear in the electronic part of the saw. In other words, if smoke came out of it, this is one thing, but when there is an outside noise or whistle, this is completely different. Specifically, these two aspects are the main ones in fault localization. There is, but, and the third, when the saw does not make any sounds at all. Let’s start with him.
Circular saw device.
Surprisingly, the fact that the saw is silent can be a good sign. Repair of the circular saw interskol with its own that the contact of the brushes with the terminals is replacement. Here it would be useful to mention those defects that are usually printed on the last page of the operation department. At first glance, they seem funny, but show them a little respect. Check if there is voltage at the outlet and if the power cord is working. If everything is fine, then there is only one chance to avoid a complete disassembly – check the brushes.
On the vast majority of circulars, in order to get to the brushes, you need to unscrew two bolts. This unit consists of two carbon elements that abut against the manifold. Because it spins all the time, the brushes are subject to wear and tear and over time “freeze”, i.e. do not reach him. This should be the focus of attention first. In addition, the carbon brushes are connected to the stator terminals. In this place, contact is lost from time to time. Check it. If everything is fine, disassembly cannot be avoided..
If the motor shaft does not rotate or rotates jerkily, the motor is defective. Disassemble it and watch the bearings. The first one stands in the engine housing, the other on its rotor. We can confidently assume that one of them is to blame. It would be nice to have the first one, it is quite easy to change it.
If the bearing on the engine anchor is to blame, you can safely carry it for repair. It is almost impossible to remove it yourself without a special device. In addition, any attempt to do so may damage the armature. You will not have to carry the entire saw to the workshop, but only the rotor. It’s easier and cheaper..
The main malfunction of the gearbox is the wear of the gear teeth. In this case, it must be replaced. You should also pay attention to the splines of the anchor. They shouldn’t be damaged either..
Disassembly and its features
The operation itself is quite difficult for itself, some workshops take money for it, regardless of the result of the repair. Any saw has its own device, and clear advice cannot be given. This can be dealt with without the help of others. But what to disassemble first, let’s see in more detail.
The operation itself is quite difficult for itself, some workshops take money for it, regardless of the result of the repair. Any saw has its own professionalism device, and clear advice cannot be given. There is an option to deal with this without the help of others. But what to disassemble mainly, let’s see in more detail.
A very common damage, regardless of brand, is a faulty switch button.
Circular saw device with separate motor.
For all models, it is located in the handle, which, when untwisted, crawls into two parts..
If the motor shaft does not spin or spins in jerks, the engine is faulty. Disassemble it and watch the bearings. The first one stands in the motor housing, the other on its rotor. There is no doubt that one of them will be guilty. The 1st would be nice, it’s easy to change.
In that case, the bearing on the anchor of the motor will turn, you can safely carry it for repair. It is impossible to remove it without the help of others without a special device. Today, what remains to be done for our client is that it will damage the anchor. You will not have to carry the entire saw to the workshop, but only the rotor. It is easier and cheaper..
The main malfunction of the gearbox is the wear of the gear teeth. In this case, it must be replaced. You also need to find out on the splines of the anchor. They also do not usually have damage..
The symptoms of such defects, of course, manifest themselves in different ways, alas, almost always the work is accompanied by external noise. You will like whistles, rattles or clicks more. At the moment, while the engine and gearbox are still assembled, it is necessary to establish what is defective there. Try to twist the engine by the shaft. It should spin hard enough, but moderately, i.e. should not wedge.
Circular saw layout.
Armature and stator malfunctions
These faults are the most common. In due course of work, a strong sparking occurs suddenly in the brush area. There will be smoke and a burning smell. Such damage cannot be diagnosed from time to time. Let’s start with the most common and expensive option..
Circular saw performance check circuit.
After opening the motor, it turns out that there are traces of burning on the rotor, on the stator. Here what remains to be done by our client is clear. You need to change this and that. The option is expensive, but the possibility of error is excluded. It is more terrible when the stator is smoked, and the anchor is like new. At first it seems simple – you need to change the stator. Completely optional. The rotor is also possibly faulty, alas to be “in the cliff”. In addition, he could serve as a prerequisite for a more severe breakdown. It is quite easy to find its malfunction under such circumstances..
- Disconnect the stator terminals from the brushes. In their place, fix the tester probes, it should show a tiny resistance.
- Slowly turn the motor shaft, if at some moment the resistance increases, it means that the armature is faulty.
And the last, most difficult case, when visually what remains to be done by our client properly. When you apply the method described a little higher, it will not guarantee that the rotor is working properly. But if the device shows a break, then there is an option to try changing it. Basically, it is better to contact the master here. You can’t do without special devices here..
How to Change the Blade in a Circular Saw
Often a circular saw is bought for a specific purpose. With all this, a person does not even think if it is suitable for this purpose. That there is, that there are professional circulars designed for long-term work, and there are those that work only 3 hours during the day, well, even then with interruptions.
Therefore, before using the circular saw intensively, read the annotation and consult with the experts. The same applies to the work of chainsaws and other tools. You will like it better, after which there will be no need for repairs. Fortune!
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High quality circular saw repair
The advantages of any home tool can be fully appreciated only after it fails. This theorem is known to every home craftsman. The presence in the arsenal of a huge number of devices has led to the fact that most people simply cannot imagine how to do this or that operation without them..
The circular saw is used for even cutting of various materials..
In the case of a circular saw, this is especially true. The fact is that it is irreplaceable for longitudinal sawing of a tree species; it does not have a worthy analogue in the middle of a hand tool. This cannot be done with an ordinary hand saw. Therefore, when the circular for some reason refuses to work, all work stops. We urgently need to solve something. But do not rush to carry it to the workshop, you can completely repair the circular saw yourself.
Changing the anchor and brushes on the circular saw
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