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.
Tool design features
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.
Disadvantages of UShM-125/1100E
According to numerous consumers, the weaknesses of this grinder are:
- Possibility of damage to the speed controllers. This mainly occurs as a result of voltage surges from 220 to 260 V. In this mode of operation, the regulator quickly breaks down.
- High cost of spare parts.
- Poor ventilation and lack of armor on the windings. Lack of ventilation, according to user reviews, leads to the fact that the engine located inside the angle grinder burns out after several weeks of operation. This is due, according to the owners of the tool, to 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 subject to high-quality lubrication and timely replacement of its carbon brushes and bearings.
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.
Purpose
The tool is very convenient for working in tight, narrow places; it cuts metal, tiles, natural stone, wood, concrete and other materials well. Used for quickly cleaning welds and grinding various surfaces, working with brushes and flap wheels.
The machine is intended for professional use in industrial enterprises and construction, as well as for non-professional users in private households, households and similar conditions.
The machine is intended for operation at ambient temperatures from -10°C to +40°C, relative air humidity of no more than 80% and in the absence of direct exposure to precipitation and excessive dust in the air.
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.
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.
How to repair the rotor of an angle grinder Interskol
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.
Dismantling bearings from the armature ushm 125
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.
Dismantling bearings from the armature ushm 230
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 the grinder Interskol
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.
DIY video of repairing the stator of an angle grinder Interskol
Video:
Maintenance and care
Attention! Before performing any maintenance or adjustments on the machine, unplug the power cord from the electrical outlet. To ensure quality and safe operation, power tools and ventilation openings should be kept clean at all times.
Inspecting the Machine: Using worn tools reduces the efficiency of the job and can cause engine damage. If severe wear is detected, the tool must be replaced.
Electric motor care:
- It is necessary to treat the electric motor with particular care and avoid getting water or oil into its windings.
- It is recommended to replace brushes at technical service centers.
- After work, thoroughly blow out the machine with a strong jet of dry air.
- The ventilation openings of power tools must always be open and clean.
- Before using the machine, check that the cable is in good condition. If the cable is damaged, it must be replaced.
Attention! The machines use a Y-type power cord and must be replaced by the manufacturer or an authorized repair facility for safety reasons.
Mechanical malfunctions of the grinder Interskol
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.
Repair of the grinder gearbox Interskol ushm 125
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.
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.
Repair of the grinder gearbox Interskol ushm 230
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
Video:
How to check the stator for interturn short circuit with a multimeter
The anchor is the part on which a large amount of dirt most often accumulates. If the grinder has any malfunctions, you can identify them by yourself using a multimeter or, in other words, an ammeter.
The test begins with finding the faulty component. If your device is completely out of order, this may be evidence of scattered brushes or a damaged dielectric layer that is located between the plates. If you observe sparking inside, this means that the current collectors in the angle grinder are damaged.
Regardless of what result you get during the examination, you need to check the resistance. It should be the same for each measurement.
If the indicators show a deviation, this indicates a violation of the connection of the coils and a poor fit of the brushes.
Pay attention to the brushes, their wear should be the same, and if there are scratches, they must be replaced with new ones. If you do not find any malfunctions, then you need to measure the resistance at the lamella and coil.
Assembling an angle grinder Interskol
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.
How to assemble an angle grinder gearbox Interskol
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.
How to assemble an angle grinder Interskol
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.
The power button does not lock
Frequently pressing the button with force leads to wear on the contacting surfaces, and the button no longer locks. This defect is one of the most common that occurs during the operation of grinders.
In the following video, the Makita model grinder does not have the button locked in the required position . After disassembly, the worn surfaces on the button and the fixing groove on the body of the angle grinder are clearly visible. Repairs are made in two ways.
Replacing the worn button with a new one
Here you should remove the radius of curvature on the fixing groove and align the landing plane under the button. In this case, the processing is carried out very carefully with minimal removal of plastic material. The properties of plastic, as a fragile soft material, make it possible to select a machining mode with low tool speeds, which allows you to regulate its optimal feed when eliminating surface defects.
With worn button fix
The author is right that it is not always possible to find a new button to replace a worn one. The button restoration method is relevant, especially for craftsmen working outside the scope of specialized retail outlets. Important: clean the seating surface of the button with a file no more than a few tenths of a millimeter, and just level the contact surface of the “tendril” of the button without removing excess material.
These methods are one-time in nature; the next such breakdown may lead to the replacement of parts with new ones.
A few words about lubrication of the Interskol grinder
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.
Conclusions:
- 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.
I wish you success!
