We repair the corner grinding with our own hands: how to disassemble the corner grinding, check the brushes, replace the stator and other video

It is not difficult to press out a new needle bearing, but the use of the original puller is required to remove. In the next video, the author describes the manufacture of such a device and shows its practical action.

The puller is a foster zanga with bundles at the ends of movable petals. The dimensions of the tsangi are made on a lathe, and the central hole is sparkled under the piercing petals of the rod. The puller is inserted into the bearing and the beams after moving the rod along the hole are uplift and rested with the side surface against the end of the ring. With the help of not very spectacularly looking, but reliable levers of reinforcement with sharpened edges, resting on the puck inserted, the bearing can be removed from the case.

Important: The needle bearing has a much larger resource than a sliding bearing. However, the shaft of the spindle wears out, which also needs to be changed

In the video described, the author found a replacement option. However, in most cases, this can create additional problems.

The main malfunctions, the reasons for their appearance and repair methods

To simplify the task, searching for a malfunction and repair must be carried out systematic. No need to rush to disassemble the tool. First, decide on the type of malfunction. The most important nuisance is that corner grinder does not turn on. What needs to be checked:

The anchor of the electric motor

If these elements are working, then examine the contact brushes. The brushes serve to transfer the supply voltage to the contacts of the electric motor collector. The windings of the anchor are soldered to these contacts. If one of the brushes does not contrast or at all a broken, then the electric current will not enter the winding and the corner grinder will not want to work.

In order to inspect the condition of the brushes, you need:

The brushes are loaded, so you have to try not to lose the springs. The extracted brushes should be the same size. They will have some wear, but there should not be chips and transverse cracks that could violate the contact.

If the brushes are in normal condition, then you will have to inspect the engine anchor. This node is only called an anchor, but in fact with an anchor has absolutely nothing in common. This is the central shaft of the engine on which the winding and the collector crown are located. Sometimes, due to the large loads between the brushes and contacts of the collector, a strong spark arises. As a result, copper contacts are covered with a layer of oxides and the current does not go to the winding.

What needs to be done to put the anchor in order? You need to take ordinary white gum, which is used by drawers and lovers to draw. The corner of the elastic band needs to rub the contacts. A film made of oxides should be cleaned and shone with a copper luster.

If this operation did not give results, then it is necessary to open the body of the corner grinder and inspect the condition of the internal wires, the phase.Drive capacitor and the winding. The winding should have an even color of the varnish, which is covered with a winding wire. Darkening or blackening of the wire or its sections indicates a short circuit of the winding. It is difficult to eliminate this malfunction with your own hands, you will need to replace the anchor.


The task of the gearbox is to convey the rotation of the electric motor shaft to the disk of the corner grinder. Over, since we have an angular grinding machine, then the gearbox is a corner. To inspect it, you need to:

Output elements of the gearbox must be replaced. The replacement of the gear is difficult to imagine anything. Then the gearbox is lubricated with a good layer of thick lubrication and installed in place.

remove, stator, corner, grinder, call, angular

Grinder. How to put on and take off grinding blade without the tool.

Repair of the stator corner grinder

The stator is called that part of the electric motor, which is motionless in the case. It is designed to create an electromagnetic field in which the anchor rotates.

The main malfunction of the stator is a break in the winding or its strong overheating. What is the danger of overheating? When overheating of the winding wires, protective insulating varnish, which covers them, also overheating. Violation of lacquer isolation leads to a short circuit of the turns of the winding.

Even the closure of one turn of the winding completely removes the corner grinder out of order. The winding immediately begins to overheat and smoke. The shaft rotates slowly or even ceases to rotate.

To repair the stator will have to change windings to new ones or rewind. But the rewinding of the stator is not for beginners.

Ringing the stator of the corner grinder: DIY repair

Wholesale production of manual grinding machines was launched in the USSR in 1940. The name “Corner grinder” received this device due to the fact that at first it was produced in a small Bulgarian town of Lovech, which had a patent for this invention.

Today, no production is complete without this tool. However, any tool once breaks, but many details can be fixed in household conditions.

The electric part often burns. The reason for this may be:

  • Severe heating from high overloads;
  • Voltage jump;
  • Water that fell on the conductive surfaces;
  • Sharply pulled out fork from a socket;
  • Shock on the switch and so on.

The most common malfunction that you can try to repair is a break in the stator turns. This happens mainly due to large overloads. Ringing the stator of the corner grinder with your own hands today is quite possible. However, such work requires certain experience and relevant knowledge.

Most often, the electric motor fails for a number of characteristic reasons:

Signs of a broken stator

The principal circuit of the controller of the angular grinder.

Когда повышается напряжение, сила искры увеличивается скачкообразно. Over, only one brush is subjected to this phenomenon. As a result, the insulation of the wire wound on the stator coil is broken.

See also  How to replace a bearing in a corner grinder. Replacement of corner grinder bearings

When the collector is very sparking, this means that the anchor has low.Quality balancing. When checking the collector, the voltage is increased, the sound of the engine is obliged to slowly and smoothly intensify, while no vibration should occur.

When resonance appears, we can talk about poorly made balancing. It is required to repair the electric motor.

The device of the corner grinder

Collection engine connection diagram.

An anchor is a rotating detail that has windings to create the deserves that is transmitted to the electric motor gearbox. The same windings have a stator that is divided into several parts. The electric current comes to the winding through the coal brush and goes to the anchor. Then the current comes to the next brush and so on, until all the stator sectors are involved.

Anchor is installed in this stature. This element of the structure of the corner grinder is considered the most difficult, since almost all windings are pressed in it.

The stator of the electric motor has the same appearance. Characteristic differences are:

When electricity runs through anchor windings, a magnetic field occurs, constantly interacting with the same stator field. This interaction launches the electric motor into the work. Sometimes the stator includes constant magnets. For example, such parts have an electric motor of the glass cleaner of a car. Each collector electric motor is able to work from any type of voltage. When changing its value, it is possible to configure the right number of revolutions.

The characteristic malfunctions of the stator are considered:

When the chain works normally, the anchor begins to rotate and with the help of gear drives the disc set in motion.

Collection engine check scheme.

The gearbox maintains certain speeds and the desired speed. Repair of corner grinder is quite available in household conditions. You just need to first disassemble the device.

In order to move the casing, you need to unscrew the screw that fasten the plastic plate. All details will be in sight, except for the gearbox, which hides a metal cap. It does not allow the gearbox to have strong heating. To remove the gearbox, you need to unscrew four screws. Thus, all mechanical parts of the corner grinder will be exposed.

When the device is included in the outlet and acceleration of the disk occurs at increased speeds, this means that the stator winding received a turns of closure. The stator requires repair, most often it requires its rewinding.

It seems that the rewinding of the stator is the work of increased complexity. There is an opinion that it is almost impossible to carry out such work at home. After all, sometimes even experienced windows of the electric motor refuse to work. However, having appropriate experience and certain technical knowledge, an ordinary three.Phase stator can be repaired in a few hours with all preparatory work.

Before starting repair and rewinding, the stator must be cleaned of dirt and remove the old winding from the grooves. This work is done using steel brushes. In addition, damaged isolation is removed. To facilitate cleaning of isolation, the stator is lowered into a heated transformer oil, which softens the remaining insulation.

What may be required for stator repair?

Tools necessary for work: round.Liners, ruler, calipers, pliers, electric drill, steel brush, megammeter.

To carry out the work, the master will need:

  • Ruler;
  • Calipers;
  • Pliers;
  • Roundbones;
  • Kusachki;
  • A steel hammer;
  • Wooden hammer;
  • Steel brush;
  • Electric drill;
  • Megommeter;
  • Varnish.

After cleansing the stator from dirt, it is necessary to carry out such a sequence of actions:

  • Metal packages are checked;
  • Burrs are removed;
  • The studs holding the core are pulled;
  • The insulation resistance is determined;
  • Pressing washers, the edges of the core, are covered with varnish;
  • Pass isolation is done.

Repair of the stator electric motor angular grinder

Reversing rotation of the collector engine.

First, the frontal remains of the winding are cut off. Then a new winding is made. It is made according to the template mounted on the axis, which holds two large plates. It is very important in such work to get the right number of turns. The wire of a certain diameter should have a maximum seal. Two coils are inserted into the body of the stator. Conclusions are drawn from the winding wire, which are isolated by flexible plastic tubes, Cambrics.

Before starting laying the winding, according to the technological process, the symmetry of the groove boxes is checked. If they do not close the winding, then in order to prevent their damage, when the coil wires are laid, temporary liners are installed.

Small breakdowns and their elimination

In cases where the corner grinder refuses to turn on when the start button is pressed, the reason can be insignificant and, most likely, the repair can be done without the help of a specialist. In this case, you need to be guided by the main rule. To start with the simplest knots and move to more complex. In this case, the reason for the breakdown of the corner grinder may be the wiring on the section of the power wire and brushes.

First of all, it is necessary to turn off the angular grinder from the network, and then inspect the cable for damage. After that, you need to disassemble the housing and check the connection of the power button and brushes. If the wire is damaged, it can be replaced with a new, and the torn electric circuit is restored. If, after checking the cable and the electric circuit, the current comes to the mechanism, but the start is not made, then the problem may be in the start button itself.

You should check the button and eliminate it if the malfunction is detected or replace the button. The button must be carefully disassembled, while it is desirable to mark the terminals and wires. When connected, it is important to correctly connect the contacts, since the wrong installation can cause blocking the winding and jamming of the anchor.

After checking the operability of the power wire and the button, you need to check the speed controller, which is available in some models of the angular grinder. If the malfunctions are not detected, then you need to pay attention to the brushes and, if necessary, replace them, as well as clean all the contacts.

Graphite brushes are faulty

The main cause of the malfunction may be brushes. Depending on the loads and duration of the angular grinder, the brushes can last six months, a year or two, then worn out, and the tool may stop working. Replacing old parts with new ones is made with a cable turned off and a disassembled case. Using a screwdriver, you need to unscrew the brush holders and remove the old brushes. They can also be closed with plugs in the housing, and then the case will not have to disassemble.

Brushes should only change to similar in size and material, and after replacing the brush is rubbed. The corner grinder works for a while. With a faulty start button, it is forbidden to work with a corner grinder, as this can lead to jamming of the cutting disk, its destruction and unpredictable consequences. Speed ​​regulator is a smooth launch of a corner grinder, and after malfunctions in its work, it requires a replacement, since the repair will be difficult and almost impossible.

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Why the instrument malfunction most often concerns the rotor?

During work, the grossing of the largest loads occur on the rotor, namely:

With incorrect or too long operation, the breakdown of the electrical appliance can be anchor, it is also called the rotor, which may need to be repaired or complete replacement. But before it is convinced of a malfunction of this particular detail, it is necessary to make sure that it really failed.

Stator rewinding

If the bearings are not replaced by the anchor of the power tool, the anchor begins to touch the rotor and at the place of touch there is local heating. Typically, such heating occurs from the side of the “broken” bearing over the entire circumference of the anchor and at one point of the stator. Since the temperature is distributed in a larger area by the anchor, and on the stature in one place, then the stator usually fails the first. The insulation in the groove and the wire burning from the elevated temperature, touching the metal groove, closes on the case.

Another reason for the failure of the stator may be ordinary overheating. When the tool works under a long load for a long time. In both cases, stator coils must be rewound or replaced by the entire stator.

If certain knowledge and skills are needed to rewind the anchor, as well as a current machine for the collector groove after winding. And a balancing machine for dynamic balancing anchor after winding, impregnation and grooves. Then rewinding the stator is available to anyone who has desire and enamel.

You just need to carefully disassemble the burned stator and calculate the number of turns in each coil. Often, the number of turns in both coils coincides. The exception is only a small percentage of engines with several operating modes. For example, mixers.

Also, when unwinding the coils, we notice the direction of winding and the number of wires soldered to one conclusion. The stator of a more powerful tool can be wound in 2 wires.

After disassembly, it is necessary to measure the diameter of the wire. The wire is measured without enamel. Next, we look at which wire was used in the stature, copper or aluminum. If there was aluminum, and you want to wind copper, then you need to find out by the table, or by the formula, find out the cross.Section of the burned wire. And multiply it by a coefficient of 0.7-0.8. So we learn the cross.Section of the copper wire. Now again by the table we translate the section into diameter. Copper wire will always be thinner than aluminum.

After we recognized the diameter of the wire, the number of turns, the direction of winding and the number of wires of the soldered to the output, it is necessary to check the grooves of the stator and prepare the sleeves. The grooves should be clean, without sharp edges, burrs.

The old sleeves must be removed, and the possible fusions of the burned wires are cleaned. We make new sleeves from the electrocardon (Preshpana), given the direction of the fibers, and protecting the edges from ruptures with tape.

The length of the sleeve should be 4mm more than the length of the stator iron.

We carry out winding by fixing two metal plates on the status for the formation of frontal parts. The output ends of the wire is isolated by Cambrics. Observe the direction of winding and carefully consider the turns. After winding, seal the wire in the grooves.

To do this, we use a screwdriver, or a metal rod wrapped in a pushpan. We fix the front parts of the coil with braid or severe thread and tie each other, so that the coil sits in the grooves tightly and does not vibrate. And also so that the wires do not get fared.

Когда обе катушки намотаны, уплотнены и увязаны, можно приступать к пропитке.

The main malfunctions

The main malfunctions of the stator are the following:

remove, stator, corner, grinder, call, angular

For high.Quality diagnosis of an angular grinder stator, a complete disassembly of the power tool should be performed in order to eliminate all other structural elements, including the rotor to ensure free access to all its parts. At the initial stage, it is necessary to perform a visual inspection. For a more complete picture, it is necessary to check the presence of defects using electrical devices. What devices and how to call the stator of the corner grinder is described in detail at the link “How to call the stator of the corner grinder”.

Frequent malfunctions: others are warming up, reasons

The main reason for the failure of the stator is a violation of the electrical insulation of its windings. Such a defect is led by prolonged work in the conditions of overloading the device. The corner grinder is very hot, which adversely affects the insulating coating. As a result of which there are closes of the turns among themselves, the breakdown of the windings of the coils on the core body, or with a sharp increase in the current, the wires are cut off.

remove, stator, corner, grinder, call, angular

Before performing repair work, diagnostics are performed in order to determine parts and nodes, due to which the angular grinder cannot function normally. The electric part of the corner grinder is examined visually for the subject of the traces of burning the surface in places of short circuit. In the absence of obvious signs of malfunctions, the electric part is checked by nickname using special devices (multimeter, short circuit indicator and others). After finding and analyzing the damage, the method of eliminating it is accepted.

There are two main ways to repair the stator with your own hands:

  • A burned stator is removed from the corner grinder body. In a specialized store, the device is identical to the failed device and is used in the corner grinder instead.
  • The burned winding is removed from the core body and a new one, corresponding to the old turns of the turns and the diameter of the wire, is wound.

Call and rewinding

If the burned stator is the cause of the corner grinding of the corner grinding, it turns out in more detail what part of it is involved in this. In the presence of defects in the coil windings, some users independently rewind new. A detailed description of the production of such works on the links “How to call the stator of the corner grinder” and “rewinding the stator of the corner grinder with your own hands”.


For the corner grinder of the DWT model in the next video, a new stator was purchased in return for the burned out. The new stator was positioned as a knot precisely from the corner grinder of this model. The process of disassembling the angular grinder is described in detail before extracting a faulty stator from the body. When examining the appearance of the new and old stators bought, some difference was observed. However, after the assembly and verification of performance, it turned out that they practically did not affect the operation of the corner grinder.

Burned, rewinding

The impregnation with varnish described during the repair should not be copied one to one. Because ordinary carpentry varnish does not have the necessary electrical insulation properties. With difficulties in choosing a prophet substance, it is better to use an epoxy resin basis, which is easy to find. The quality of the impregnation will improve if the stator is heated, and not wait until the varnish stops penetrating the winding.

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Bosch, replacement

In the next video, the author repairs the angular grinder of the Bosch model. Work in a very dusty atmosphere, of course, can cause a strong wear of the collector lamella, but for the unambiguous reason for the failure of the stator windings, it should not be taken in any way. Here you should also consider other operating conditions (overload, duration of work and others).

Diagnostics by the author is in the nature of fortune telling on coffee grounds. A sharp change from a burned rotor, which was still quite efficient, to a burned isolation at a stature that really failed, speaks of the absence of a systematic approach in repair work.

During disassembly of the corner grinder, the stator is freed from the body under the influence of strong beats of the hammer. Although it is wooden, it can cause damage to the protruding parts of the body.

Why not immediately make the output ends of the stator of normal length, remains a mystery. The author twice does the same, very laborious work without explaining the reasons.

Electric malfunctions of corner grind

The electrical circuit of the main part of the Bulgarians is almost the same. The rotor passes the rotational moment through the gearbox to the working tool. The rotor rotates in the stator field. The control circuits consist of a button that regulates the turnover and the smooth launch of the tool, coal brushes that provide the transmission of alternating voltage to the collector’s lamellas. Power supply for the tool is supplied through the connecting cable.

The main malfunctions of the corner grinder in the electric part include:

  • A break in the supply cable at the entrance to the instrument;
  • Destruction or wear of coal brushes;
  • The failure of the power button;
  • Cliff or short circuit of the stator;
  • Cliff or short circuit of the rotor;
  • Mattering or production of the collector lamellas.

The malfunctions of the corner grinder through the electric part are best determined by the tester or other device. Suitable for these goals and a home.Made device, among the people “Arkashka”.

The circuit of the corner grinder is quite simple and does not require special knowledge. It is only necessary to observe caution and safety measures when performing repair work and know electrical engineering in the volume of secondary school.

Finding a cliff of power wire

One of the common breakdowns of the corner grinder is the inability to turn on the tool or spontaneous stop in the process. The cause of malfunctions of this kind is the break in the power cable of poses.27 at the entrance site. The malfunction is eliminated by replacing the cable or throwing out the failed site. The malfunction is easily located with a tester.

If there is no tester at hand, but there is a screwdriver with a neon indicator bulb, then the malfunction can be found, alternately connecting the power wires to the phase.

Malfunctions of coal brushes

The reliable operation of any power tool is largely dependent on the integrity and proper operation of coal brushes. High.Quality fit of coal brushes, their correct location relative to the collector lamella affects the operability of the rotor collector.

Remember! The length of the coal electrode cannot be less than 8 mm.

Timely replacement of coal brushes avoids most of the malfunctions.

The degree of wear of coal brushes is characterized by types of sparking in the site of the collector. Sparking should be uniform throughout the stain of the contact of the coal brush and lamellas and not exceed a length of more than 8 mm. Circular sparking indicates the appearance of a malfunction in the rotor chains.

In the grinder, it is recommended to use coal brushes only tool manufacturers. Homemade coal brushes can be installed, but only for a short period and immediately replace as soon as possible.

Repair of the inclusion button and revolutions regulator

The faults of the inclusion buttons are most often manifested in a difficult and unreliable turning on the tool when starting. Such a malfunction spontaneously appears and disappears.

It is unacceptable to work with a corner grinding with a faulty power button. This malfunction leads to the jamming of cutting discs during operation and their destruction with unpredictable consequences.

The malfunction is eliminated by the complete replacement of the button with a new.

In modern models of the Bulgarians, a smooth starting device with a revolutionary regulator is built. It is not subject to repair, but will require a complete replacement. No, advanced Master of Lysha, of course, will be able to fix such a knot.

Stator repair

The stator is indicated by the spontaneous promotion of the shaft of the machine, the corner grinder begins to gain maximum speed. Such a malfunction indicates the appearance of an interval circuit in the stator winding.

Some malfunctions can only be eliminated by experts. The extension of the uninterrupted operation of the stator is possible only by timely cleaning, lubrication and replacing coal brushes and bearings.

Usually the stator fails quite rarely. This leads to frequent overheating of the tool when working. The malfunction is manifested by a strong heating of the corner of the corner grinder and the appearance of the smell of burning insulation.

The stature can have either a cliff or short circuit. Without analyzing the stator, these malfunctions are easy to find using the IK-32 device.

Malfunctions are eliminated by the replacement of the stator. For lovers of crafts, we can recommend to rewind the failed stator with your own hands. There is nothing complicated about it.

The stator is removed easily, but in different models the corner grinder in its own way.

  • Remove the gearbox of the corner grinder;
  • Extract the rotor, after removing the mounting bar;
  • Remove the plastic protection of the stator;
  • Unscrew the screws of the stator mount in the case;
  • Remove the handle lid and disconnect the power wires to the stator;
  • Extract the stator by tapping the body with a wooden hammer or bar.

Corner grinder rotor repair

The failure of the rotor in the corner grinder is caused by improper operation of the tool, frequent overheating, with untimely replacement of coal brushes, and the collector of abrasive particles and dust falling on the lamelon.

At first, the length of the spark on the collector increases, then the smell of Gary appears and, at the last stage, smoke. The work of a faulty gearbox is accompanied by a knock and hum.

Destruction of even a pair of teeth leads to improper operation of the tool.

It is possible to extend the life span of the rotor’s lifetime to prevent dust from getting into the instrument, preventing the tool overheating, timely changing coal brushes and lubricants, using only those working tools and such diameters that the manufacturer of the power tool recommends.

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