How to change the brushes on the angle grinder interskol

Brush replacement on angle grinder

Angle grinder (or as it is also called “angle grinder”). an indispensable and in-demand tool in the work of the master. It is subject to natural wear and tear just like any other. During the use of the tool, various breakdowns occur, and one of the most common is the sparking of brushes on the angle grinder. In this article, the master plumber will tell you why the brushes on the angle grinder spark, as well as why they burn out and how to replace them.

Before you figure out the causes of sparking brushes on the angle grinder, you need to understand their purpose. Collector brushes are used not only in the design of angle grinders, but also in the construction of all modern power tools. drills, torches, jigsaws and other.

The design of the angle grinder and other power tools uses 2 brushes, which have a simple design.

This design is based on the following elements:

  • The main part. has a rectangular shape, and is made of charcoal or graphite;
  • The contact is a wire core of appropriate diameter, through which the electric current flows. The contact connects the wire to the graphite part;
  • The spring is the mechanism that holds the main part against the collector. There may be no spring on the element, indicating that such a brush is designed for installation in power tools, where brush holders have a built-in clamping mechanism in the form of a curved plate.

The devices are designed to transmit electrical current to the rotor of the angle grinder.

The voltage drawn from the stator is applied to the rotor, which is reproduced by the carbon brushes and the collector. The current flow to the collector allows the collector to rotate.

As the rotor rotates, the devices make contact with the collector (copper lamellas. armature winding leads) thereby ensuring that electrical current flows continuously.


The devices wear out during use, so they are classified as consumables. The service life of the brushes depends not only on the service life of the power tool, but also on the materials of which they are made. Not only is brush wear and tear influenced mechanically by friction, but also thermally. Electric current when passing through a conductor causes it to heat up. The greater the magnitude of the current, the higher the heating temperature. When current flows through the graphite brushes, they also heat up. The higher the load on the power tool, the higher the current, and therefore the higher the temperature, which adversely affects the integrity of the consumables.

Brushes for angle grinder and other power tools are made of different materials, but the main ones are carbon and graphite. This material has a low coefficient of friction, and also has a high resistance to abrasion. To improve the contact, various impurities are added to the graphite or carbon in the making of the brushes. Depending on the impurities used, the following types of brushes are distinguished:

The composition of the core not only affects service life or wear, but also such a parameter as signs of arcing. The magnitude of the sparking of the brushes depends on the composition of the brushes. When buying them, you need to pay attention to the composition, and do not buy equipment of unknown origin and dubious quality.

Causes of strong arcing brushes on bolsters are the following factors:

  • Armature winding faults. If there is a disturbance in the insulation of the armature winding, it eventually contributes to the development of inter-turn short circuits, as well as shorting to the core. A winding breakage may also occur, eventually causing a higher load. A hallmark of armature winding failure is a decrease in speed, an increase in noise and a drop in power;
  • Brushes are not pressing snugly against the collector. For clamping the main part is responsible for the spring, which over time of operation loses its original springing properties;
  • The winding of the rotor broke off from the copper plate of the collector. this phenomenon is very rare, but if you overload the power tool, it may well occur;
  • The electric motor armature is misaligned, resulting in severe brush arcing on the angle grinder;
  • The collector shape is disturbed. The collector, consisting of copper lamellas, has a cylindrical shape which can be disturbed when the rotor is rewound. If there is the slightest deformation in the shape of the collector, there will be arcing of the brushes The collector of an electric motor;
  • The insulation between the collector blades is broken. Each collector plate is insulated to each other, and if the micanite insulation layer is broken, arcing will occur. The insulation between the plates can also be disturbed because of the graphite layer settling in the grooves;
  • If the armature bearings are worn. If the bearings are faulty, there is runout of the rotating armature, and as a consequence, there are signs of sparking;
  • Rotor shaft distortion. It is difficult to bend it, but if it does, the engine starts to run with a load. To keep the tool from failing, it is advisable to replace the rotor;
  • If you improperly solder the ends of the armature windings to the copper plates of the collector. Such errors are not allowed in the factory, but they can be made by the winder who rewinds the armature of the power tool;
  • The wrong type of graphite brushes. The parts in question are made of carbon and graphite, with different types of impurities added. This is done for a reason, but in order to use the brushes depending on the voltage and speed of the shaft. Graphite is either soft or hard. The lower the supply voltage, the softer the graphite grade is chosen. For high-voltage power tools, it is necessary to take hard brushes, which do not have copper in their composition;
  • Deformation of the lamellae due to heat. If the angle grinder is overloaded, one or more of the collector lamellae may be deformed. The plates are lifted relative to the others, resulting in a broken contact. Such a defect causes a strong sparking of the brushes when working with the power toolDamage of the angle grinder’s manifold;
  • Poor contact at brush connection point. If the terminal does not connect tightly to the device, the result of this contact failure may be excessive sparking;
  • Carbon deposits on copper fins. periodic or regular cleaning of the copper fin surface to remove carbon deposits is recommended. Fouling is usually caused by worn brushes, so if you find blackening on the surface of the manifold, wipe it down with alcohol.
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In addition to arcing, often the owners of power tools are faced with the fact that the brushes on the angle grinder burn. What makes this phenomenon different from sparking is the rapid deterioration of the main part of the element. Wear of the new elements immediately after installation of the power tool, when it is used for the first time.

The main cause is not in the brushes themselves, but in the manifold. If the lamellae on the collectors are falling out or fraying, it causes the load to increase. This is the stress on the graphite elements that begins to wear quickly when the angle grinder is turned on. this accelerated wear process is called combustion. Elements literally burn due to the passage of high currents. Many people call this process abrasion, but in reality, brushes do not erase quickly due to mechanical stress. Combustion is caused by intense sparking, which literally burns out the graphite.

The reasons why the brushes on an angle grinder burn out are as follows:

  • Copper lamellas on the manifold are dropping out or wearing away.
  • Inter-twisted connections between the lamellae or rotor windings. causes an increase in current that heats up the brushes and starts to burn. To find the cause, you need to test the armature
  • If the power tool is overloaded strongly. if you use the angle grinder for a long time without interruption, the result of such use will appear in the form of brushes burning for 5-10 seconds.

There is also such a thing as a circular fire. This phenomenon occurs when there are large armature current surges such as overloads, short circuits, and undervoltage. Circular fire appears when the arc is repeatedly ignited. Increased loads and even short circuits occur when using an angle grinder for wood sawing. When wood is processed, the cutting disk is clamped, thus increasing the current by 15-25 times of the rated current. Most often, the causes of burning elements is the manifold, so if you had to change 2-3 pairs of brushes in a month, it is time to diagnose the power tool.

Many replace the brushes only when they find that the tool is strongly sparkling and smells foul. Many craftsmen are not deterred even by these signs and continue to operate the tool until it no longer turns on. When it is necessary to change carbon brushes, in order not to harm the device of an electric tool. There are the following signs for this:

  • Strong arcing. If there are signs of strong arcing, disassemble the tool and inspect the consumables. Sparking is the first indication that the consumables must be replaced;
  • The appearance of the smell of burning. if you can hear the smell of fouling when working with the tool, then it is recommended to disassemble the angle grinder and make a replacement of the graphite brushes;
  • If the main part is worn more than 30% to 40%. However, it is almost impossible to determine their initial length unless you measure them before installing the elements;
  • If signs such as jerking and “growling” occur in the power tool.

The devices must also be replaced if they have uneven wear and tear, and if they are of inadequate quality.

When proceeding to replace the brushes, as with any penetration into the body of the power tool, it is necessary to turn off the power supply by removing the plug from the socket.

Angle grinder brushes can be replaced without disassembling the housing

Some manufacturers have taken a very rational approach to the possibility of replacing brushes. There are threaded plugs in the machine housing. And the whole process of checking or “repairing” takes two minutes (for both graphite contacts):

  • If a brush has lost 70% to 80% of its length compared to a new one, it is worth replacing it. Otherwise, the old graphite contact must be replaced with the same side as before it was removed in order to eliminate the lapping process. After all, the brushes wear unevenly because they are in contact with the rotating cylindrical surface;

This is the easiest way to replace the brushes on an angle grinder without having to disassemble the housing. You can therefore take this into account when selecting a new angle grinder.

Replacing the brushes of an angle grinder without a backhandle

For grinders that do not have a back handle, the brushes are replaced in the following sequence:

  • Insert a new brush, close the contact block with the cover;
  • Repeat all steps with the other brush;
  • Put the cover on the angle grinder and fix it with a self-tapping screw.

Sometimes there is another way to attach the brushes

In this case, the sequence of operations will be as follows:

  • Connect the contact of the new graphite rod to the connector, insert the brush into the guide block and press down with the spring;
  • Repeat all steps with the second brush, cover the housing with the hood and screw it on with the self-tapping screw.
change, brushes, angle, grinder

These are the two most common ways to replace the graphite contacts.

Brush replacement on angle grinder with backhandle

Angle grinders that have a back handle allow you to get to the brushes in a slightly different, simpler way:

  • Near the handle, you need to find a small repair window, closed by a plastic plate that is secured by a bolt;
  • It is necessary to unscrew the self-tapping screwdriver, pick up the plastic plate in the slot with a screwdriver, remove it from the housing, opening the repair window;
  • The following steps for changing the brushes are the same as for low power grinders: release the belt spring (1), release the plug (2), pull the brush out of the guide block by the wire;
  • Then insert the new brush, connect the plugs, secure the graphite rod with a tape spring, cover the repair window with plastic and screw the bolt;
  • Repeat all steps with the second brush on the opposite side of the housing.
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It is possible that there may be other ways to replace graphite brushes, due to the design features of the grinder.

change, brushes, angle, grinder

In the story. What happens if you don’t change the brushes on your angle grinder in time

In the story. Why do brushes burn, spark on the angle grinder, what are the causes of faults

Structurally, angle grinders differ from each other, so the method of replacing brushes may differ slightly from the basic methods described above. But the general features are still visible:

  • The brushes are near the back handle or the part of the body that is supposed to hold the tool.
  • The most common designs of graphite brushes: with and without spring.

The first type has a simplified replacement method because it has a wire, a contact plate and a pressure spring.

Spring-less brushes are a bit more time consuming to change because the fixing spring is attached to the housing and is stiffer, and the wire is attached in a separate location with a plug.

Interskol brush replacement

Interskol brushes have become very popular in recent years. They are reliable in operation, easy to repair. They are easy to get replacement parts for.

Interskol brushes have a wide selection. The tools are roughly divided into two parts: SDS-plus-type chuck and SDS-max-type chuck.

Repair of Interskol peorator can be carried out as in the service centers, and without the help of others. What to do the repair of Interskol torators by your own forces, you need to have the ability of a mechanic and knowledge of electrical engineering in high school.

And remember to follow the safety instructions at all times.

Which tool has a corresponding marking plate. Example: Interskol P-18/450Er. Deciphering:

  • The marking P indicates that the tool belongs to the family of torches;
  • The number 18 indicates that a drill with a cross section of up to 18 mm can be used with this torch;
  • The number 450 indicates the power of the torch in watts.

The range of Interskol torches with SDS-plus chucks includes 13 models: P-18/450ER, P-20/550ER, P-22/620ER, P-24/700ER, P-24/700ER-2, P-26/750ER, P-26/800ER, P-26/800ER-2, P-28/800ER, P-30/900ER, P-30/900ER-2, P32/1000ER, P-32/1000ER-2.

Peorator Interskol with SDS-max chucks are represented by the following models: Interskol P-35/1100E, P-35/1100EV-2, P-40/110EV-2, P-45/1100E, P-50/1200E.

Other Interskol peorator models are considered in the economic market

Interskol P-600 ER and Interskol P-710 ER. These models were first produced by Interskol. Among home users the most common models are Interskol P26/800ER, P30/900ER, P710/ER.

Why thousands of customers have already chosen us

Experience reliability guarantee

  • On the market since 2002
  • Over 1000 customers have already chosen us
  • Own production and extensive contacts with suppliers
  • Significant stock of warehouse products
  • Dealer discounts

Price Matching Production

  • All kinds of brushes for electric motors can be bought from us
  • Brush selection by motor brand and brush holder
  • Production in accordance with GOST
  • Full compliance with technical parameters
  • Flexible discount system
  • Selection of domestic and imported analogues

Process work result

  • Assigning a personal manager to each customer
  • Technicians have academic degrees
  • Shipment by any mode of transport to any part of the country
  • Reliable packaging

We are engaged in electric brushes for electric motors for 12 years already

Complex deliveries of electrical equipment from TPK “Electromashina”. it is an effective link between the Customer and the Manufacturer. Our company aims to provide the most convenient terms of cooperation and stable product quality. Our close partnership with the largest companies in Russia and the CIS allows you to significantly reduce the cost of production of well-known and time-proven manufacturers, as well as guarantee optimal delivery conditions in terms of price-quality ratio. All this makes our the most profitable for the consumer.

Some general useful tips on how to organize the repair of angle grinders

Before we start repairing the angle grinder, let’s look at some useful tips:

  • Before starting to disassemble the angle grinder, carefully read its description, the assembly diagram, and the sequence of operations.
  • Be sure to follow the sequence of technological operations.
  • Strictly obey the safety instructions.

The most common cause of angle grinder failure is wire breakage near the handle. First you need to check the presence of voltage on the button, this is done with an ordinary voltage tester. Then we check the button itself for performance.

Replacement and repair of the armature of the angle grinder with their own hands

Angle grinder is widely used both in everyday life (repair work at home, in the country), and in industrial activities (construction, production shops). No matter how reliable the design of the angle grinder, in the process of operation of some nodes and parts fail. Failure of the armature, which works in fairly harsh conditions, is often the cause of the lack of normal operation of the electric drive. Ways to repair or replace the anchor are discussed in the article.

  • Anchor device
  • How to check the rotor for proper function
  • How to Disassemble
  • How to fix
  • How to fix, repair
  • Rotor Winding Repair
  • Collector repair
  • Replacing a fan impeller
  • Rotor Sparks, Cause How to Repair
  • How to change
  • How to clean
  • How to choose

READ Brush on angle grinder to remove paint

Brush changes for different brands of angle grinders

A wise craftsman does not wait for the tool to show signs of failure. Since the replacement of brushes is part of the maintenance of the angle grinder, he will regularly clean the collector of contamination and inspect these parts.

It is worth remembering that manufacturers of brushes for angle grinder always indicate the minimum size at which the product still retains its performance. This may vary slightly depending on the manufacturer.

change, brushes, angle, grinder

Most models of the tool assume two arrangements of electric brushes. In the first case, they may be inside the handle. With the second method, the brushes are placed on the housing. However, regardless of the location of these parts, it is worth disassembling the tool and lubricating all of its components for preventive purposes.

Before you start disassembling the angle grinder, you need to de-energize it. Then you need to disconnect the tips, inspect the holder. After removing the brushes themselves require a thorough inspection for mechanical damage, which will indicate wear and tear that requires replacement of the part.

Here are examples of repair work on bolsters from leading manufacturers:

Repair of Interskol models begins with removing the stator cover, and then you need to unscrew the screws from the holder. The minimum rest length of the brushes on the mechanisms of this company can not be less than 5 mm.

See also  Corner grinder for what is needed. Types and design features of angle grinders

On Bosch-made lathes, to remove the brushes, it is enough to open the handle of the stator housing. The unit of this brand will not work if the length of the working brushes is less than 8 mm.

Buying an angle grinder, in the starter kit you can find the required spare parts. They can be used to determine which brushes to choose.

Not all types of angle grinders are easy to find a suitable option, even in a special store. In this case you need to buy bigger brushes to file them up to the required size.

Collector-brush assembly

Before you start to disassemble the angle grinder, the first thing to remove the brushes, which are pressed to the collector by a spring. Otherwise, there may be damage to the brushes and brush holders when the rotor (armature) is removed. If the graphite body of the brushes is less than 50% of the new brushes, it is worth replacing them.

The old kit, with at least 30% left over, should be reserved as an EO for re-installation. To be used in case of a long search and delivery time of a new set or other force majeure situations. If the brushes are not equipped with an autostop function (“shot or tapped with a counter pin in the brush holder”), critical wear will likely result in destruction of the manifold, up to and including replacing the entire armature. IT IS IMPOSSIBLE TO SAVE MONEY ON BRUSHES!

In cases of extreme need and the inability to find the right size brushes (in the category described in more detail) and willingness to adjust the size, do it right!:

  • If you pick up, it is desirable to have a mismatch on only one side, preferably the smaller (width).
  • Use a fine grit emery cloth (abrasive cloths no coarser than 1000 grit, the brush is very brittle and brittle).
  • Work on a flat surface (e.g. glass), no hold-down. After each few cycles, check the dimensions with a caliper and the parallelism of the flats of the brush.

During use, the brush wears down, leaving a graphite-carbon deposit on the parts of the entire assembly. How to clean the manifold and prepare it for the installation of a new set of brushes, I have a separate post and video. It is difficult to overestimate the importance of this procedure.

Also worth paying attention to brush holder shafts. A layer of graphite particles and dust, makes it difficult to advance nominally, which can serve to “hang” the brush, causing a break in contact with the collector, accompanied by increased sparking, up to and including interruption of the circuit, t.е. stopping the motor, and in rare cases the burnout of the lamellas and the known outcome of the anchor. Cleaning, only takes a couple of minutes. If the shaft is lightly soiled, a dry rag will suffice (it is convenient to use as a guide a small flat screwdriver, the edge of which is wrapped in several layers of rags). Sometimes it’s worth using extra alcohol, on a rag 😉

Drilling machine from a washing machine motor and a gearbox from an angle grinder

Materials and tools used by the maker:

The list of materials:- Motor from a washing machine 650W / 1350 RPM;- Gearbox from the 180th angle grinder;- Angle;- Round pipes;- Sheet steel;- Bolts and nuts;- Springs;- Switch;- Cable with a good insulation.

The process of manufacture of a drilling machine:

Step 1. Revision of gearboxFor the machine tool it is needed gearbox

piece of pipe from the angle grinder at 180, it lowers the speed of the motor more than thethe gearbox from 125 angle grinder, as a consequence, we get the highest torque, and the axis of the gearbox is thicker. The maker cuts off a piece of armature with an angle grinder and knocks the rest of the armature off the axle. It is also useful to cut off a piece of angle grinder body to screw this part with a bearing seat to the gearbox. If you do not have such a part, you can weld it yourself from sheet steel, using a piece of pipe as a cage.

Step 3. Make the base for the drilling machine, it must be very strong, so that the whole structure will not fall off. You can use a piece of a suitable channel as a base. If you do not have a channel, it can be welded from thick sheet steel. Weld to the base ears, to fix the machine to the base with bolts.

Also, 4 stands, which can be pipes or iron bars, are welded to the base. At first we insert the rods into the carriage, and then we screw them to the base. This is the only way to install the standoffs correctly.

Step seven. Put a drill chuck on the gearbox shaft, to screw a chuck, you can weld a nut for angle grinder to it, or cut a thread directly into the chuck.

Paint the frame to prevent rusting, now the machine looks great. Put a good switch to sharply turn off the machine in case of emergency. The machine is ready, the creator has put a large drill bit in the chuck and drills with his monster everything in order, from wood beams, and ending with thick sheet steel.

The machine is excellent, the machine for the real man. At this point the project is complete, I hope for you self-made attracted, and you found yourself a useful idea. Fortune and creative inspiration, if you decide to repeat a similar. Do not forget to share with us your ideas and self-made!

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A way to quickly replace graphite brushes for an angle grinder

Earlier, angle grinders for the Soviet Union were made in Bulgaria, hence the household name of the tool. The USSR has not existed for many years, but such devices, whoever produced them, continue to carry that name among users. Like any technically complex product, this tool will sooner or later begin to need repair, which most often consists in replacing the brushes for angle grinder.

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