How to disassemble the grinder Interskol 125

What is this tool?

Angle grinder "Interskol" UShM-125 /1100E is an electric device. In everyday life it is often called a grinder and is used when working with iron, stone, concrete and other materials. "Interskol" UShM-125/1100E. an angle grinder using attachments with a diameter of 125 mm and a power of 1100 W. It is a product of the Russian company Interskol. Working with an angle grinder is not limited to just cutting. With this electronic device it is possible to grind and polish the surfaces of products as needed. Wide versatility in application is possible due to the use of design features and technical abilities of the angle grinder.

Grinder "Interskol" UShM-125/1100E. Design Features

Grinding and polishing work on the surfaces of concrete products is often accompanied by copious emissions of dust, which is very unnecessary for power tools. Settling dust has a negative impact on the service life of any angle grinder. The grinder “Interskol” UShM-125/1100E is assembled in such a way that the dust generated during polishing/grinding does not seep inside the mechanism. This became the likely route for the armature impeller to send air currents through the front of the gearbox.

In many angle grinders, the gears are secured with a keyed connection; they are pressed onto the spindle shaft. The entire mechanism of the angle grinder USHM-125/1100E is assembled in one case, in the back of which there is a comfortable handle. This grinder is a very comfortable and strong machine, created for professional use. The two-handed design (an additional main handle is included) ensures comfort and convenience during operation of this power tool.

How to disassemble the grinder Interskol 125

Angle grinder (grinder) Interskol Angle grinder-125/1100E: diagram, reviews

In household and industrial production, it is often necessary to cut and grind iron, stone or other products made of hard materials. A very effective power tool for this purpose is a grinder

"Interskol" UShM-125/1100E.

What is this tool?

Angle grinder "Interskol" UShM-125/1100E is an electric device. In everyday life it is often called a grinder and is used to perform work with iron, stone, concrete and other materials. "Interskol" UShM-125/1100E.

an angle grinder using attachments with a diameter of 125 mm and a power of 1100 W. It is a product of the Russian company “Interskol”. Working with an angle grinder is not limited to just cutting. With this electronic device it is possible to grind and polish the surfaces of products as needed.

Wide versatility in application is possible due to the design features and technical capabilities of the angle grinder.

Grinder "Interskol" UShM-125/1100E. Design Features

Bulgarian

"
Interskol
" UShM-125/1100E is assembled in such a way that the dust generated during polishing/grinding does not seep inside the mechanism.

This is made possible by the direction of the armature impeller, which sends air currents through the front of the gearbox.

In these angle grinders, the gears are fastened with a keyed connection; they are pressed onto the spindle shaft.

The entire mechanism of the angle grinder USHM-125/1100E is assembled in one case, in the back of which there is a comfortable handle. This grinder is a very comfortable and strong machine, created for professional use.

The two-handed design (an additional main handle is included) ensures comfort and convenience during operation of this power tool.

What is the Bulgarian armed with?

"Interskol" UShM-125/1100E has an electrical system that allows you to adjust the speed as needed (from 10 thousand per minute to 3).

The owner of this power tool can reduce them to the desired level without worrying about the fact that the power of the grinder will also decrease.

This quality, which is possessed by the Interskol grinding machine UShM-125/1100E, is especially appreciated by professional tilers. By lowering the speed, there is an option to simply process glazed tiles and other delicate surfaces.

In addition to the electrical complex of accounting programs, the Interskol angle grinder UShM-125/1100E contains a special soft start board, which greatly simplifies the process of operating the grinder. Having a smooth start of the accounting system is especially necessary when working with heavy grinding discs and diamond bits for stone surfaces.

What ensures reliable retention of an angle grinder?

Comfort during use is ensured by special handles - holders. They are equipped with any angle grinder. "Interskol" UShM-125/1100E has an additional handle.

Despite the fact that this electrical device is small in size, allowing it to be held with one hand, the additional handle is included in the set and is irreplaceable for work involving cutting metal.

Specifications

The power consumed by the power tool is 1100 W.
Voltage. 220 V/50 Hz. Power comes from the electronic network.
Speed. from 3000 to 10,000 per minute.
Weight is 5.2.4 kg.
The power tool is designed for a circle with a diameter of 125 mm.
The main handle is three-position.
Smooth start.
There is a function for adjusting the rotation speed.
There is a fixed spindle.

During the sales process, Interskol UShM-125/1100E is equipped with:

additional handle;
a set of gaskets;
a special key for installing discs and attachments.

pros

The grinder is considered the most reliable and durable product produced by Russian companies.

"Interskol" UShM-125/1100E. Consumer reviews indicate good performance and the highest reliability of this electronic tool.

Among users, the strengths of this grinder include:

the ability to simply rotate the gearbox 90 degrees for which the design of the awkward, as it is also called, unusual location of the release button is intended;
highest power;
presence of a speed controller. According to consumer reviews, the ability to reduce the rotation speed makes this grinder irreplaceable for such work as cleaning weld seams, removing rust, or old paint, from metal structures in the presence of different grinding wheels and attachments;
the complete set with a long cord greatly simplifies carrying and allows you to work with an angle grinder at great distances from the outlet and in other rooms;
small dimensions and weight use Interskol UShM-125/1100E when working with small products, since heavier angle grinders are very inconvenient for this;
the presence of a quick-release protective casing, the installation of which does not require tools;
the presence of a power unit that maintains low speeds;
applicable product price;
the presence of a smooth descent;
the presence of a main handle, which is used in 3 positions;
complete with additional handle.

Ushm interskol 125\900

Complex repair of an ordinary angle grinder

. Usual and conscientious return of 7% after purchase on Aliexpress and others.

Repair of grinder Interskol (angle grinder 125/900)

Here is a video, I will demonstrate the repair and replacement of a bushing with a needle bearing, and the removal of an armature at an angle grinder office.

The combination of power, dimensions, weight and additional functions are the positive properties that distinguish the Interskol angle grinder UShM-125/1100E. Reviews from users confirm the well-deserved popularity of the tool both among craftsmen who skillfully use this angle grinder in production, and among amateurs who like to make things with their own hands.

Disadvantages of the UShM-125/1100E

According to the recommendations of countless consumers, the weak points of this grinder are:

Possibility of damage to the speed controllers. To a greater extent, this happens and therefore voltage surges from 220 to 260 V. In this mode of operation, the regulator quickly breaks down.
Highest prices for spare parts.
Poor ventilation and lack of armor on the windings. The lack of ventilation, according to user reviews, causes the engine located inside the angle grinder to burn out after several weeks of operation. This is justified, according to the owners of the tool, by the fact that the plastic casing does little to protect the engine from dust.

A long service life of the UShM-125/1100E is possible under the conditions of high-quality lubrication and timely replacement of its carbon brushes

and bearings.

Repair

Every power tool burns out at some point. Interskol UShM-125/1100E is no exception Repair of this device is carried out without the help of others.

What remains for our client to do? Breakdowns of grinders are divided into mechanical and electronic.

To successfully and quickly resolve problems you will need:

annotation, which contains a detailed method of disassembling and assembling the Interskol structure UShM-125/1100E;
product diagram;
open-end wrenches, hammer, vice, press. These tools are used to eliminate mechanical defects;
IK-2 tester for detecting short-circuited turns (used for electronic breakdowns of angle grinders);
lubricant, washing liquid, wipes (auxiliary materials).

Before work, high-quality lighting of the work area should be provided.

Guided by a step-by-step annotation and a nice diagram, of course you can successfully repair the instrument without the help of others.

Stator failure. Symptoms of a problem

The most common stator failure is considered to be burning. To a greater extent, it appears and therefore the burning of power tools. Before you start repairing the angle grinder, you need to inspect the structure and find the nature of the malfunction. When the stator is burned out, the rotor of the angle grinder begins to spin uncontrollably.

How to fix it?

First, the angle grinder must be disassembled and the faulty stator removed from the housing. You can check its functionality without even removing it from the case.

However, a similar procedure is possible only in a special workshop. To check this yourself, use a special device for monitoring short-circuited turns IR-2.

It is intended to detect breaks, or small short circuits in the stator windings, which you do not need to remove from the housing for this purpose.

A burnt stator needs new rewinding or replacement.

How to rewind the stator?

If you cannot purchase a new stator, then there is an option to repair the old one by carrying out repair measures consisting of covering the stator with a new winding.

from one book edge it is necessary to cut the old winding;
count the turns and find in which direction the winding is made;
measure the diameter of the wire;
calculate the percentage of filling of the core grooves;
after removing the damaged winding, you need to check the insulation and clean the grooves, wind the required number of turns;
put an insulating wire on the ends of the windings;
solder the ends of the windings.

When installing stator windings, it is important to impregnate new windings using alternating current. After impregnation, traces of impregnation must be cleaned, both inside the stator and outside, on its body. During operation, it is sometimes necessary to check whether the rotor moves freely inside the stator.

Rotor failures

There are several circumstances causing malfunctions:

wear of carbon brushes
;
power outages and short circuits;
wear of the armature commutator lamellas;
destruction or jamming of the rotor bearings.

Troubleshooting a rotor malfunction requires experience. It is best to purchase a new tool or have your angle grinder repaired at a specialist auto repair shop. If the work is done by your own staff, then it is important to have the necessary material and follow the procedure:

unscrew the nut and key securing the driven bevel gear of the rotor (11);
the gear is removed from the rotor shaft (8);
the rotor is removed from the gearbox housing (19);
Using a special puller, as it is also called, means that are at hand (a vice, iron strips, a hammer), the bearings (9) are removed with its use.

What other breakdowns happen?

One of the most common electronic failures is:

1. Breakage of carbon brushes . You can also deal with this problem yourself. Procedure:

The design of the grinder " Interskol
" UShM-125/1100E is designed in such a way that the carbon brushes are placed in special brush holders. There is an option to get to them after removing the back cover in the stator housing;
Unscrew the screws that secure the brush holder;
find the wear level of the carbon brushes . You can do this after measuring their remaining length. If the brush is in good condition, then its length must be more than 0.5 cm.

2.7. Broken power cable. This malfunction occurs to a greater extent at the points where the wire enters the tool and into the plug. Twisting in these cases will not solve the problem. A faulty electrical cable should be replaced.

What is the Bulgarian armed with?

"Interskol" UShM-125/1100E has an electrical system that allows you to adjust the speed as needed (from 10 thousand per minute to 3). The owner of this power tool can lower them to the desired level without worrying that the power of the grinder will also decrease. This quality is possessed by the Interskol grinding machine UShM-125

/1100E, is especially appreciated by professional tilers. By lowering the speed, it is of course easy to process glazed tiles and other delicate surfaces.

Apart from the electric one that allows you to keep accounting records (software), the Interskol angle grinder UShM-125/1100E contains a special soft start board, which greatly simplifies the process of operating the grinder. Having a smooth start of the accounting system is especially necessary when working with heavy grinding discs and diamond bits for stone surfaces.

How to disassemble the grinder Interskol

to disassemble an angle grinder without the help of others

Disassembling an angle grinder does not require any special metalworking skills; it does not cause serious problems. But the work must be done very carefully and with the greatest vigilance. how to disassemble an angle grinder on web pages.

The sites show videos with a detailed technological process.

It is necessary to disassemble the angle grinder, not only when it is out of order and it is necessary to change some part, this must be done to clean the tool from dirt.

If an angle grinder breaks down, you should first disassemble it and clean it well; the tool almost always starts working.

It is for this reason that the actions that are needed to disassemble an angle grinder should be known to anyone who owns such equipment and wants it to work for a long time and perfectly. The stores offer a large assortment of this mechanism, made by controversial companies. They differ:

But what remains for our client to do? Models from any manufacturer have a similar technological assembly. Our client is left with grinders equipped with a similar set of parts.

Main modules used

Housing, usually made of special impact-resistant plastic.
The most powerful electronic engine.
High quality gearbox.
Smooth launch.
Electric motor switch.
SJS system.
The presence of accounting software (software) allows the tool to work smoothly without jumps. Already today, it turns off the grinder for which the disc jamming design is intended, and greatly reduces vibration. It saves the operator from serious injuries.
Protective cover.
Additional handle.
With its help, of course, you can delay the grinder while doing the work. This handle can be installed in different positions, which gives the tool versatility.

What will you need at work?

The process of disassembling an angle grinder requires several tools:

spanners;
screwdrivers;
pliers;
vice;
hammer;
lubricant;
rags;
gas key.

The difficulty of disassembling the angle grinder is due to the fact that the parts are in very close contact. This allows you to cope with the highest loads. The parts do not move operation Naturally, disassembly will be best done by a master, but our client can try and do it himself with the greatest care.

Tools needed to complete the work: pliers, ruler, calipers, pliers, electric drill, iron brush, megger.

Ushm interskol 125\900

Complex repair of an ordinary angle grinder

. Usual and conscientious return of 7% after purchase on Aliexpress and others.

Repair of grinder Interskol (angle grinder 125/900)

In solving this issue video

, I will demonstrate repairing and changing the bushing to a needle bearing, removing the armature on the company’s angle grinder.

Before you start disassembling the angle grinder, you need to prepare the work area by removing unnecessary parts from the workbench that remain for our client to do. An unstained table allows you to occasionally support some small detail.

First, the bolt holding the casing is unscrewed. Removing it is not at all difficult; there are no particularly tight connections here. Then you need to unscrew the screw and remove the plastic plate. The outer casing must be moved towards the cord.

Mainly for our client, the models of grinders have a variety of devices. But the common part is the electric motor, which includes:

An additional essential part of the angle grinder is the gearbox, designed to regulate power and speed. The electric motor together with the gearbox is mounted in the housing.

Device reducer

It is held in place by four bolts. They must be unscrewed and, with extreme care, the gearbox must be pulled out of the angle grinder body. Disassembly of the gearbox is necessary to clean it and replace worn parts. This is one of the important components of the angle grinder, which experiences heavy loads during operation.

It includes:

frame;
big gear;
driven gear;
bearing. It must be lubricated to reduce friction.

To remove the rotor from the gearbox housing, you need to unscrew the nut that holds the rotor. Use a special puller to remove the rotor. Such an operation is associated with certain difficulties; if there are no special abilities, it is better to leave such work to experts. You can't do this without a puller.

It should be noted that for the usual removal of dirt, such detailed disassembly is not necessary. It is only needed to replace a worn bearing or a rotor that has become unusable.

To remove the armature, you must first remove the brushes and gearbox, carefully remove the armature, holding it by the gear.

This operation will require some effort. Removing the anchor from the housing must be done very carefully, because it simply breaks.

When strong sparking and high heating of the housing are observed operation The device will be ready for use again.

How to disassemble the gearbox correctly: tips

When the gearbox completely refuses to work, it requires complete disassembly to change parts and painstaking cleaning. To carry out the work, you need to prepare a bench vice. The full range of work is carried out in a certain technological sequence:

Use a wrench to unscrew the bolt holding the gearbox housing.
The rotor body is secured with great care in a vice.
By making gentle blows with a hammer, the body is removed.
The rotor is in a comfortable position for removing the bearing. The vice is clamped again.

By placing a wooden block, the bearing is knocked out. To remove the gear from the gearbox axis you need:

Wrap the rotor with a rag and secure it with the lips of a vice.
The gear is also wrapped with rags, using a gas wrench , and turned counterclockwise.

How to remove a spindle: tips

The spindle axis works together with the main gear, which contains:

To disassemble the spindle housing, you must first remove the main gear, which is why special devices are used.

After removing the gear, the housing is placed in a vice. Applying a wooden block and hitting it with a hammer, remove the spindle with the greatest care, where the bearing is mounted. Bearing removal is done using the above method.

Disassembly of the gearbox should be done frequently, especially when the tool has been subjected to intense use. After disassembling, change the lubricant. In most cases, Litol-24 is used.

It should be noted that the lubricant must be changed constantly after a certain period. This allows you to increase the life of the gearbox by more than one year, due to reduced wear of its component parts.

Source: https://vdiweb.ru/kak-razobrat-bolgarku-interskol-video/

Specifications

The power consumed by the power tool is 1100 W.
Voltage. 220 V/50 Hz. Power comes from the electronic network.
Speed. from 3000 to 10,000 per minute.
Weight is 2.4.5 kg.
The power tool is designed for a circle with a diameter of 125 mm.
The main handle is three-position.
Smooth start.
There is a function for adjusting the rotation speed.
There is a fixed spindle.

During the sales process, Interskol UShM-125/1100E is equipped with:

additional handle;
a set of gaskets;
a special key for installing discs and attachments.

Typical design of an angle grinder (angle grinder) 125 mm

Interskol company is a Russian manufacturer of a variety of power tools. The company's products are popular in our country due to their affordable prices, good ergonomics, ease of use and ease of maintenance.

The company produces several series of angle grinders, differing in the diameter of the equipment. The series for 125 mm wheels is the most popular (65-70% of sales of all angle grinders). Grinders in this series have different engine power - from 700 to 1400 W. At the same time, structurally these models differ from each other insignificantly.

All models for 125 mm circles are characterized by the following design features:

Interskol angle grinder 125/900 Bearing replacement

The spindle is mounted on 2 rolling bearings;
The body and handle are made as a single whole, or rather, the back part of the body serves as the handle (with the exception of the UShM-125/1400EL model).

Interskol angle grinders for 125 mm equipment, which will be discussed a little later.

pros

The Interskol angle grinder UShM-125/1100E is considered the most reliable and durable product made in Russia. Consumer reviews indicate good performance and the highest reliability of this electronic tool.

Among users, the strengths of this grinder include:

the ability to simply rotate the gearbox 90 degrees if there is an awkward or unusual location of the release button;
highest power;
presence of a speed controller. According to consumer reviews, the ability to reduce the rotation speed makes this grinder irreplaceable for such work as cleaning weld seams, removing rust, or old paint, from metal structures in the presence of different grinding wheels and attachments;
the complete set with a long cord greatly simplifies carrying and allows you to work with an angle grinder at great distances from the outlet and in other rooms;
small dimensions and weight use Interskol UShM-125/1100E to perform work with small products, since heavier angle grinders are very inconvenient for this;
the presence of a quick-release protective casing, the installation of which does not require tools;
the presence of a power unit that maintains low speeds;
applicable product price;
the presence of a smooth descent;
the presence of a main handle, which is used in 3 positions;
complete with additional handle.

Disadvantages of the UShM-125/1100E

According to the recommendations of countless consumers, the weak points of this grinder are:

Possibility of damage to the speed controllers. To a greater extent, this happens due to voltage surges from 220 to 260 V. In this mode of operation, the regulator quickly breaks down.
Highest prices for spare parts.
Poor ventilation and lack of armor on the windings. The lack of ventilation, according to user reviews, causes the engine located inside the angle grinder to burn out after several weeks of operation. This is justified, according to the recommendations of the owners of the tool, by the fact that the plastic casing does little to protect the engine from dust.

A long service life of the UShM-125/1100E is possible under conditions of high-quality lubrication and timely replacement of its carbon brushes

and bearings.

Basic electrical faults of the grinder Interskol

As a rule, the most common cause of failure of an angle grinder is an electrical fault. The main percentage of electrical failures of grinders is the failure of carbon brushes.

Repair of control circuits for angle grinders Interskol

The control circuits of grinders of different models are slightly different from each other. It all depends on the power of the tool and the availability of innovative developments. Some angle grinders have a built-in electronic unit that regulates the smooth start.

Repair

Every power tool breaks down at some point. Interskol UShM-125/1100E is no exception. Repair of this device is carried out without the help of others.

What remains for our client to do? Breakdowns of grinders are divided into mechanical and electronic.

To successfully and quickly resolve problems you will need:

annotation, which contains a detailed method of disassembling and assembling the Interskol structure UShM-125/1100E;
product diagram;
open-end wrenches, hammer, vice, press. These tools are used to eliminate mechanical defects;
IK-2 tester for detecting short-circuited turns (used for electronic breakdowns of angle grinders);
lubricant, washing liquid, wipes (auxiliary materials).

Before work, high-quality lighting of the work area should be provided.

Guided by step-by-step instructions and a nice diagram, you can successfully repair the instrument without the help of others.

How to fix it?

First of all, the angle grinder must be disassembled

and remove the faulty stator from the housing. It is possible to check its functionality without even removing it from the case.

However, a similar procedure is possible only in a special workshop. To check this yourself, use a special device for monitoring short-circuited turns IR-2. It is intended to detect breaks or small short circuits in the stator windings, which does not need to be removed from the housing for this purpose. A burnt stator needs new rewinding or replacement.

How to rewind the stator?

If you are not able to purchase a new stator, then you can repair the old one by carrying out repair measures that consist of covering the stator with a new winding.

from the textbook edge you need to cut the old winding;
count the turns and find in which direction the winding is made;
measure the diameter of the wire;
calculate the percentage of filling of the core grooves;
after removing the damaged winding, you need to check the insulation and clean the grooves, wind the required number of turns;
put an insulating wire on the ends of the windings;
solder the ends of the windings.

When installing stator windings, it is important to impregnate new windings using alternating current. After impregnation, traces of impregnation must be cleaned, both inside the stator and outside, on its body. During operation, you need to check from time to time whether the rotor moves freely inside the stator.

Rotor failures

There are several circumstances causing malfunctions:

wear of carbon brushes ;
power outages and short circuits;
wear of the armature commutator lamellas;
destruction or otherwise jamming of the rotor bearings.

Troubleshooting a rotor malfunction requires experience. It is best to purchase a new tool, as it is also called, and have your angle grinder repaired at a special service center. If the work is done by your own employees, then it is important to have the necessary material and follow the procedure:

unscrew the nut and key securing the driven bevel gear of the rotor (11);
the gear is removed from the rotor shaft (8);
the rotor is removed from the gearbox housing (19);
Using a special puller or means at hand (a vice, iron strips, a hammer), the bearings (9) are removed using it.

The gearbox is broken, causes and common malfunctions

Increased vibration, the presence of an uncharacteristic sound during operation, strong heating of the case, jamming of the gearbox during operation of the angle grinder require immediate intervention to determine the causes of the appearance of these factors and eliminate them. As the practice of operating angle grinders shows, the most common gearbox malfunctions are caused by the following reasons:

wear of bearings with the appearance of critical play;
bearings can, as they say, “crumble” due to shock loads during “hard” operation of the angle grinder;
increased wear of a bevel gear pair, tooth breakage;
untimely replacement of the gearbox lubricant or the presence of low-quality lubricant in it.

Bearing wear (Lepse)

In the following video, the author completely disassembles a Lepse brand grinder made in Russia (electrical machine-building plant in Kirov) in order to determine the absence of spindle rotation with a normally operating electric motor. In this case, a complete analysis of all disassembled parts is performed. Even high-quality Soviet bearings after 10 years of operation have slight wear, determined manually by the amount of play. For a detailed description of actions in such cases, see the article at the link “Replacing bearings in an angle grinder gearbox.” In the case of the Lepse model grinder, play in the front rotor bearing requires replacing it. After replacing a defective bearing with a new one, it must be lubricated , just like all other bearings of the angle grinder.

Lack of gear clutch (Interskol), gearbox is noisy/clatters

When the Interskol model grinder is operating in the next video, there is a rattling noise , characteristic of a gear pair failure. The assumption was confirmed after opening the gearbox housing, where a breakdown of the drive small gear . Further disassembly of the angle grinder made it possible to determine the probable cause of the gear failure. Increased play in the front rotor bearing could cause increased forces in a pair of bevel gears, which led to failure of one of them.

Backlash (CROWN, Bosch)

Increased play not only of the rotor, but also of the spindle can cause an emergency.

The CROWN model grinder from the following video had increased spindle play . The author drew attention to the strong end runout of the working tool. Working in such conditions can lead to the destruction of , for example, a cutting wheel, which will create an unsafe situation for the person working with the angle grinder and the people around him. The author replaced the bearing using a puller.

In the next video, the spindle play is noticeably larger . This is due to the wear of both bearing units - the ball bearing located in the housing cover and the plain bearing located in the gear housing. Lack of lubrication - this is the conclusion the author draws by analyzing the defects. It should be noted the method by which the plain bearing is removed from the housing. A calibrated rod (in this case, a drill guide) creates pressure on the grease, which tightly fills the cavity of the inner diameter of the sliding sleeve. After loading, the lubricant penetrates into the gap between the bushing and the body and squeezes the bushing out of the seat.

By analogy with the previous two, in the next video there is spindle play in a Bosch model angle grinder . This shows that no special tool is required . to remove and replace rolling and sliding bearings without the use of pullers ; only available means are used, including a latch that matches the diameter.

Stator faults

Failure of the rotor bearing units may cause failure of the stator winding . Therefore, replacing the bearings will not solve the problem of the grinder’s performance. It is required to know how to rewind the stator winding . The video describes how to solve this problem yourself. The main thing is to successfully make a template and select a frame for winding copper wire (in the video this is an air freshener can).

The author once briefly mentioned the impregnation of the finished winding, naming only the impregnating material used - tsaponlak . It seems that there is a certain technology for this operation. However, it won’t be very difficult to fully understand some questions - the main thing is to adopt the basic principles of the technology for self-manufacturing the stator winding presented in the video.

It gets very hot, reasons and solutions

take up significant loads during operation . Therefore, during tooth contact, friction generates a significant amount of heat . Heat removal is ensured by the gear housing material, which has good thermal conductivity, by blowing through the impeller and part of the heat is removed by lubricant .

If the turns of the stator or rotor windings are shorted or the contacts in the brush assembly are broken, the circuit resistance increases, which affects the increase in heat generated. If the temperature of the gearbox housing exceeds the value indicated by the standards, then the reason should be sought in deviations from the normal operation of the above-mentioned components and parts of the angle grinder.

The following videos show the importance of using the lubricant material required by the technical documentation and the timely replacement of used lubricant. Over time, the lubricant becomes contaminated with abrasive materials due to gear wear and when working with materials that emit large amounts of abrasive dust (concrete, stone, ceramic tiles and others). If you use a lubricant that is not intended for use in gearboxes, the gears will quickly fail.

In the next video, the author proposes to remake the contact system of the brush assembly . The previous one included a spring in the electrical circuit, which heated up and quickly lost its electrical properties. The proposed contact system includes parts with a relatively large cross-section relative to the spring and avoids the generation of additional heat.

A set of problems emerged when disassembling the angle grinder in the video. The main source of increased heating here is a broken stator winding . In addition, during repairs, the broken bearing and brushes should be replaced.

How to remove the gearbox

Some designs of angle grinders, where the front rotor bearing is fixed with a flat washer secured to the body with screws, create problems when disconnecting the rotor from the gearbox . The author of the following video suggests making a technological hole in the impeller and unscrewing the screws of the flat washer securing the bearing through it. Problems in removing the gearbox can be eliminated in this way.

How to change

The presented video describes the complete technological process of disassembling , identifying defective parts, replacing them and subsequent assembly of the Makita model angle grinder. This technology contains general repair principles for angle grinders of any model. damage to the housing was discovered , making normal operation impossible. The gearbox was repaired by replacing it with a new housing with an installed fixing mechanism. In addition, worn brushes were replaced.

What other breakdowns happen?

One of the most common electronic failures is:

1. Broken carbon brushes

. Of course, your employees must also cope with this problem. Procedure:

The design of the Interskol angle grinder UShM-125/1100E is designed in such a way that the carbon brushes are placed in special brush holders. There is an option to get to them after removing the back cover in the stator housing;
Unscrew the screws that secure the brush holder;
find the wear level of the carbon brushes
. This can be done after measuring their remaining length. If the brush is in good condition, then its length is preferably two or more than 0.5 cm.

5. Damage to the power cable. This malfunction occurs to a greater extent at the points where the wire enters the tool and into the plug. Twisting in these cases will not solve the problem. A faulty electrical cable should be replaced.

How to properly repair an Interskol grinder with your own hands

Angle grinders (grinders) from Interskol are very reliable and durable. They are distinguished by good performance and high reliability. But improper operation of the tool, untimely replacement of carbon brushes, lubricant and bearings leads to premature failure.

You can also repair the Interskol grinder yourself.

To do this, you need to know the structure of the Interskol angle grinder, the assembly diagram, the procedure for performing technological operations when disassembling and assembling the angle grinder. To properly repair the Interskol angle grinder, it is enough to study the proposed diagram and instructions.

Interskol angle grinders have recently become increasingly popular not only among professionals, but also among DIY enthusiasts.

The Interskol company is a Russian leader in the development, production and sale of various power tools, recognized by world manufacturers. Interskol products are distinguished by ergonomics, simplicity and ease of maintenance, environmental friendliness, and increased power.

Interskol grinders are classified by disc diameter: 115,125,150,180,230.

Among those who like to make things with their own hands, Interskol grinders of two classes are especially popular: with a disk diameter of 125 mm and 230 mm.

In the presented classes, several models are produced, differing in power.

In the 125 mm class, 4 (four) Interskol models are produced: angle grinder 125/900, angle grinder 125/1000, angle grinder 125/1100E, angle grinder 125/1400EL.

In the 230 mm class, 10 (ten) Interskol models are produced, differing from each other in power. Grinders Interskol class 230 are produced with a power exceeding 2000 W.

The Interskol UShM 230/2300 marking stands for: an angle grinder with a maximum wheel diameter of 230 mm, a power of 2300 W.

For grinders Interskol ushm 125, the driven gears on the spindle are secured using a keyed connection.

Grinders Interskol angle grinder 125 are assembled in one body, which serves as a handle.

Grinders Interskol angle grinders 230 have a convenient rear handle on the back of the body. These are powerful professional machines with a two-handed design. For angle grinders of this class, the driven gears are pressed onto the spindle shaft.

In the proposed repair instructions we will consider diagrams of two classes of angle grinders Interskol: angle grinder 125, angle grinder 230.

Necessary tool for repairing an angle grinder Interskol

It is impossible to repair Interskol angle grinders without having a simple, necessary tool. A set of screwdrivers, open-end wrenches, a vice, a hammer, and a press will help you repair the mechanical part of the Interskol angle grinder.

To repair electrical circuits, you will need a tester. It’s good if you have the opportunity to use an IK-2 type device to find short-circuited turns in windings.

Auxiliary materials you will need are lubricant, wipes, and washing liquid.

To carry out high-quality repairs to an angle grinder of the Interskol family, you need to prepare a workplace and select the right lighting. It is impossible to carry out high-quality repairs on the floor or in a dark room.

To repair an Interskol angle grinder quickly and correctly, you need a diagram of the angle grinder you are planning to repair.

Malfunctions in angle grinders are divided into mechanical and electrical.

Basic electrical faults of the grinder Interskol

As a rule, the most common cause of failure of an angle grinder is an electrical fault. The main percentage of electrical failures of grinders is the failure of carbon brushes.

Wiring diagram of the control circuits of the angle grinder Interskol ushm 125

In Interskol angle grinders 125 angle grinders, electric brushes pos. 55 are mounted in special brush holders pos. 44, which can only be reached by removing the back cover pos. 51 of the stator housing pos. 42.

After removing the cover, you need to unscrew the screws pos. 50 holding the brush holder housing.

Brush wear is determined by their remaining length. The length of working carbon brushes cannot be less than 5 mm.

Power is supplied via cable pos. 53. At the points where the cable enters the angle grinder and into the plug pos. 53, the cable may break off. The malfunction can be resolved by replacing the entire power cord or the failed part. Twists are not allowed.

The power cable supplies voltage to the switch pos. 41, inserted into the housing at pos. 47. To control the switch button there is a lever pos. 46. When performing maintenance, clean the switch lever with silicone grease.

Wiring diagram of the control circuits of the angle grinder Interskol ushm 230

Power is supplied via cord pos. 50 to the switch pos. 46, to which the electronic unit pos. 40 and carbon brushes pos. 38 inserted into brush holders pos. 37 are connected. The electrical part of the angle grinder also includes a stator, pos. 32, and a rotor, pos. 27.

Replacing carbon brushes on angle grinders Interskol USHM 230 does not require removing the back cover. It is enough to unscrew the cap of the brush holder pos. 36 and pull out the brush holder with the carbon brush. But you can replace the switch, electronic unit, capacitor pos. 42 only by disassembling the rear handle pos. 44, 45. To do this, you need to unscrew four 4x16 screws, pos. 44.

Rotor failure occurs for the following reasons:

The carbon brushes have worn out or are faulty;
Short circuit or breakage of windings;
The lamellas of the armature commutator have worked:
The rotor bearings are damaged or jammed.

Rotor repair requires special knowledge, instruments and equipment. It is preferable to buy a new rotor or send it to a specialized service center for repairs. But remember, it costs money. For those especially gifted, we recommend rewinding the rotor with your own hands.

Use a puller to remove the bearings from the armature. But you can also use improvised means. For example, a vice, strips of metal, a hammer, a soft metal attachment.

There are two bearings installed on the rotor, pos. 31: the rear one, near the collector, pos. 32.

Bearing size 608Z.

And on the impeller side there is a bearing, pos. 28, size 6000-2 RS. Russian analogue 180100.

The bearings are removed after removing the rotor from the gearbox housing. To remove the rotor from the gearbox, you need to remove the bevel gear drive, position 26, sitting on the rotor shaft.

To do this, you need to unscrew the M8x3.5 nut, pos. 25, and remove the drive gear Z=12. It is fixed with a key pos. 30. The bearings are removed using a puller.

To remove the bearings from the armature, pos. 27, it is necessary to pull the rotor out of the gearbox housing, pos. 19. Unscrew the M8 nut pos. 20, remove the locking washer pos. 21, remove the drive gear pos. 22.

gently rocking, pull the rotor out of the gearbox housing. The bearing will remain in the gear housing. It is closed by a bearing cover, pos. 25, which is attached to the gearbox housing with three M5x8 screws, pos. 26.

A bearing of size 6201-2RS is installed in the gearbox housing. Russian analogue 180201.

On the collector side, bearing pos. 28 is removed using a puller.
Bearing size 608RT. Russian analogue 180608 .
Repair of the stator of any angle grinder Interskol is carried out after determining the nature of the malfunction. Most often the stator burns out. This occurs due to overheating of the tool. A malfunction of the stator is indicated by involuntary uncontrolled spinning of the rotor of the angle grinder.

To repair the stator, it is necessary to remove it from the housing. The performance of the stator can be checked without removing it from the housing. But this can only be done in specialized workshops.

Or if you have an IK-2 short-circuited turns monitoring device. It is possible to determine a break or short circuit in the stator windings without dismantling the stator.

The burnt stator is removed, rewound, or a new one is installed instead.

You can rewind a burnt stator yourself.

The rewind algorithm is as follows:

Cut the damaged winding from one edge in any way;
You count the number of turns of the winding, determine the direction of its winding, the percentage of filling of the stator core groove, measure the diameter of the wire;
After removing the burnt winding, clean the core grooves and check the insulation;
Using the prepared wire, wind the required number of turns of the stator windings into the prepared grooves;
Solder the ends of the windings, having first put an insulating wire on them;
Impregnate the stator windings using alternating current;
Clean traces of impregnation inside and outside the stator housing;
Check the free movement of the rotor inside the stator.

Repairing the stator of an angle grinder Interskol with your own hands

Of the mechanical faults in Interskol angle grinders, the gearbox remains the weak point. The gears used in the gearbox wear out over time, the teeth are destroyed, and backlash appears in the connections.

In order to repair the Interskol angle grinder gearbox, it is necessary to establish the nature of the malfunction. Most mechanical gearbox malfunctions are determined visually or by ear.

Large runout of the spindle shaft, jamming or turning of the gears of the gearbox are determined by a simple inspection of the condition of the spindle shaft.

Increased noise during operation of the gearbox, uncharacteristic sounds, and overheating can be detected by ear or by touching the housing with your hand.

To disassemble the gearbox, you need to unscrew (4) four M4x14 screws, pos. 11, remove the DU-1000ER locking washers, pos. 12, and pull out the gearbox cover, pos. 13. The mounted spindle, pos. 10, will remain in it. The spindle is mounted in bearing pos. 14. Bearing size 6201-2RZ. Russian analogue 180201.

To press the spindle out of the bearing housing, you need to use a press. But you can carefully knock it out with a hammer. The main thing is not to damage the gear housing cover.

https://www.youtube.com/watch?v=vJ_rhzIzItw

The bevel gear wheel, pos. 16, is held on a keyed connection and secured with a retaining ring, pos. 17. A ball with a diameter of 3 mm is used as a key in the Interskol angle grinder 125/900. If you remove the retaining ring, removing the gear is not too difficult. In other models of angle grinders Interskol USHM 125, a key is used.

Remove the gears and inspect them for licking teeth, destruction or snagging, or any play in the key joint.

To disassemble the USHM 230 gearbox, you need to remove the cover pos. 6 by unscrewing 4 (four) screws. The spindle, pos. 8, is held in a bearing, pos. 9, pressed into the cover body, pos. 6. Bearing size 6203zz. Russian analogue 180203.

The gear wheel pos. 11 is pressed onto the spindle with tension. To remove it you will need a press. Craftsmen manage to remove it with a hammer, after heating the gear.

Remove the gears and inspect them for licking teeth or destruction.

Repair of grinder Interskol ushm 230

Assembling an Interskol grinder is no different from assembling grinders of other brands. Serviceable parts and assemblies, free of old grease, are allowed for assembly. Assembly consists of several stages.

To assemble the gearbox assembly, it is necessary to assemble the spindle by putting bearings and bevel gears on it.

The gear housing cover pos. 13, bearing pos. 14, bearing caps pos. 15, and bevel gear wheel pos. 16 are put on the spindle pos. 10. The gear is fixed on the spindle with a keyed connection.

In the 125 angle grinder, a ball with a diameter of 3 mm is used as a key. To fix it on the spindle, the gear is fixed with a locking ring, pos. 17. The assembled spindle is inserted into the needle bearing pos. 18.

And the needle bearing is pressed into the gearbox housing, pos. 21.

The assembly of the gearbox USHM 230 begins with the assembly of the spindle assembly, pos. 8, onto which the bearing, pos. 9, and the retaining ring, pos. 10, are mounted. The gear wheel, pos. 11, is pressed onto the spindle. The spindle is inserted into the roller bearing pos. 12. Bearing size NK1210.

To facilitate the process of pressing the driven gear, pos. 11, onto the spindle, pos. 8, heat the gear and cool the spindle.

The assembly algorithm for the Interskol grinder is as follows:

The stator is inserted into the housing;
The stator is covered with plastic protection;
A rotor with a protected rubber bushing on the commutator bearing is inserted into the stator;
The second end of the rotor is inserted into the gearbox housing;
The drive gear is mounted on the rotor and secured with a nut with a right-hand thread;
The gearbox housing is attached to the stator housing with four screws;
The smooth rotation of the rotor is checked;
A cover with a driven gear is placed on the gearbox housing;
Tighten 4 (four) screws securing the gearbox cover;
The smooth rotation of the tool spindle is checked;
Carbon brushes are installed;
The back cover is put on or the handle is assembled;
A test run of the tool is carried out to check the smooth operation.

According to the given algorithm, all grinders of the Interskol family are collected without exception.

Several features when disassembling and assembling the Interskol grinder:

To efficiently remove old grease from the gearbox housing, it is better to heat the latter with a professional hairdryer until the lubricant becomes liquid and then remove it;
In some models of Interskol angle grinders, the drive gear is fixed on the shaft with two nuts, one of which is a locking nut S=12;
Carefully unscrew or tighten the fixing nut of the rotor driven gear in the Interskol angle grinder 115;
Place lubricant in the gearbox housing that is less than half its volume;
When disassembling, carefully inspect the condition of the collector lamellas; there should be no signs of burning or worn out tracks.

Before assembling the mechanical components of the Interskol angle grinder, be sure to lubricate the parts with the recommended lubricant.

Lubricants from foreign and Russian manufacturers are widely represented on the Russian lubricants market. Today you can purchase high-quality lubricants from domestic manufacturers.

They are in no way inferior in quality to their foreign counterparts, but are several times cheaper.

A special lubricant with high adhesion has been developed for grinder gearboxes. Adhesion is the property of a substance to adhere to a lubricated surface.

When choosing an angle grinder, opt for a Russian angle grinder from Interskol;
You will receive a reliable, durable, ergonomic, cheap tool;
Give preference to Interskol grinders of the USHM 125 class;
In the household they are more in demand and safer.

Source: https://vizada.ru/2018/08/07/kak-pravilno-vypolnit-remont-bolgarki-interskol-svoimi-rukami/

Final step

After all the necessary repairs have been carried out, the angle grinder is reassembled in the same sequence as it was disassembled. However, before assembly itself, it is necessary to lubricate the mechanical components of the angle grinder, which remains for our client to do.

For this, experts recommend Russian-made lubricants. On the shelves of stores selling household electrical appliances you can easily find lubricants from foreign manufacturers, but they are significantly more expensive, although their quality is no better than Russian ones. Among the enormous selection of lubricants, you should choose those products that require the highest adhesion characteristics (they are recommended for gearboxes of all angle grinders). Such lubricants adhere better to the surface.

Source

Diagram of a commutator motor with a rotation direction switch

So, we open the device and see a bunch of dust and dirt that has accumulated over a long period of use, we clean it all and wash it with napkins and degreasers.

We check the brushes, and all electrical connections on the terminals, having tightened and cleaned, we take out the rotor of the commutator electric motor and check it by visually inspecting the windings and plates, so that nothing sticks, the bearings should be intact without cracks, and they should rotate freely without jamming, noise and play .

Next, we proceed to the switch, as it turned out, it became the culprit, here the switch button switches two conductors of the circuit at once. We clean the drive lever itself with silicone grease so that it moves more easily in its guide groove all the way to the switch.

The switch can be removed and disassembled; I couldn’t repair the burnt out half, so I shorted one of the wires directly, and the second is now used to turn it on and off.

Over time, the contact came loose in the switch, began to spark and heat up, and part of it melted.

You can, of course, replace the entire switch, which would be correct, but the owner wanted it as cheaply as possible, since the tool is not very expensive, and it’s not new anymore, so I had to do this, a new switch costs about 400-500 rubles in the city, which not very cheap.

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After assembling the angle grinder, we make sure to test and check the operating modes at idle before handing it over to the owner.