How to Change Bearing to Angle Grinder

This hand tool has become indispensable in various fields, especially in construction and metal processing. With its help increases labor productivity. The appearance of a large number of different nozzles has led to a significant expansion of the functionality of the device.

But not all workers who regularly use it in their activities know how to use an angle grinder. It should be borne in mind that non-compliance with elementary rules for the safe handling of an angle grinder is fraught with dangerous injuries, sometimes fatal. Compliance with the operating instructions will help to avoid this. An important place in the prevention of injuries is the serviceability of the tool, the use of suitable personal protective equipment, as well as the correct choice of disks for cutting and grinding various materials.

how to exchange a bearing for an angle grinder

Operations that can be performed with an angle grinder

angle grinder is a multifunctional tool. The driving mechanism in it is an electric motor, which through the gearbox transmits the movement to the shaft with a replaceable nozzle attached to it. A general view of the device is shown in the photo below.

The market presents models that differ in power and design:

Powerful devices are powered by a three-phase voltage of 380 V, while household devices are powered by a single-phase network of 220 V. There are also low-power battery models.

The angle grinder (angle grinder) can be made with various materials as follows main types of work:

If you fix the angle grinder motionless, then you can grind different tools on a circle: cutters, drills, knives, etc.

Angle grinder is designed to work with such materials:

  • concrete;
  • metal;
  • a tree;
  • glass;
  • ceramic tiles;
  • a stone;
  • brick;
  • plastic.

Angle grinders are widespread both in everyday life and in industrial conditions. This is due to their wide functionality, due to the following factors:

At the same time, you must constantly remember that only special discs are used to process each material.

What is the danger of angle grinder

Angle grinder is a traumatic tool. This is due to the following reasons:

  • high speed of rotation of the working nozzle. it exceeds 10,000 rpm;
  • openness (insecurity of the casing) of most of the disk;
  • the possibility of breaking the abrasive disk into fragments of different sizes, which in this case fly apart at a considerable speed;
  • the frequent lack of the ability to properly organize the workplace;
  • the formation of metal (or other material) during cutting or grinding of small particles.

When a disc is jammed, which occurs even due to its slight distortion, the angle grinder is almost impossible to hold in hands, especially a powerful tool. This is caused by the high speed of rotation of the nozzle. Therefore, beginners are recommended to work with low-power models, equipped with disks with a diameter of 115-125 mm. The latter should be without the slightest defects that could lead to their sudden destruction and tearing of angle grinders from the hands with uncertain consequences.

General safety rules

To reduce the risk of injury when working with an angle grinder, this tool must be handled correctly. It is necessary to observe the following rules of use:

  1. Must use personal protective equipment. The health of the operator must be in good condition.
  2. Before work, it is necessary to check the correctness and reliability of the casing fastening so that it does not fall off in the process, and sparks do not fly off to the operator.
  • Use only whole discs without defects (cracks, chips, breaks) and strictly for their intended purpose for processing a specific material.
  • Protective shield must be located between the operator and the circle so that there is protection when the latter is destroyed.
  • Before starting work, it is necessary to check the operation of the tool at idle for about 1 minute: uniform rotation at maximum speed, lack of vibration.
  • Saw the tree very carefully, because falling on the branch may cause a jerk of the instrument from the hands.
  • It is forbidden to install nozzles from a circular saw due to the fact that they are designed for a different spindle speed.
  • Tool needed hold with two hands.
  • Getting to work, you need to remove all unnecessary and make sure that there are no objects on the cutting plane except the workpiece.
  • Regularly take breaks in work.
  • If the workpiece is jammed, immediately turn off the tool.
  • A stable (equilibrium) body position should be maintained.
  • Power cord Keep away from the rotating part so as not to cut it or cause a short circuit.
  • Only after a complete stop of the circle is it allowed to release the tool from the hands.
  • When navigating the workplace, the angle grinder should be turned off, and this should also be done when the supply voltage is turned off.
  • It is necessary to cut only at full speed.
  • The safety measures outlined have been developed by manufacturers of angle grinders, as well as special organizations (services) involved in labor protection.

    To ensure the safety of work, it is better to purchase not the cheapest, high-quality materials from reliable manufacturers.

    A working angle grinder should be adequate and be in a balanced psychological state.

    Protective equipment used

    When working with an angle grinder, the user must use the following personal protective equipment:

    • face mask or glasses that close your eyes from all sides;
    • gloves from dense fabric or leather;
    • special shoes (whole, stable) and work clothes;
    • respirator, which will provide protection against the penetration of small particles into the respiratory system when cutting concrete, glass or ceramic tiles, bricks, porcelain stoneware, foam block, stone and other dusty materials.

    To work with an angle grinder, the use of protective equipment is mandatory. This helps to work more safely.

    How an angle grinder cannot work

    Safety when using angle grinders should be in the first place. According to it, it is prohibited:

    • to make working manipulations without PPE;
    • works in light clothing that does not completely cover the body (arms, legs);
    • use a machine that is not equipped with a casing for protection against sparks;
    • without checking the operability of the tool at idle, start using it;
    • work defective disk or unsuitable for material;
    • located in the plane of the cut;
    • press with force on the tool;
    • work so that the direction of rotation of the circle was in the direction of the operator;
    • to do the work without interruptions, because the hands get tired, and it is difficult to hold the angle grinder firmly;
    • so that the workpiece being processed is not fixed (for example, in a vice or clamps);
    • sharpen metal parts with the side of the disk;
    • perform cutting workpieces, the thickness of which exceeds half the size of the radius of the used circle;
    • the presence of unauthorized persons in the working area;
    • touch the nozzles until they cool, because they become very hot during cutting and grinding from friction;
    • when deepening the circle, include the tool in the workpiece;
    • grind with thin disks;
    • use nozzles of a larger diameter than the angle grinder is designed for;
    • position the workpiece so that when cutting occurs circle clamping (the cut should be on a fault, and not on compression).

    Safe use of the saw in an angle grinder is ensured by the fact that it is replaced only when the device is disconnected from the mains.

    Which side can be cut angle grinder

    Before you start cutting the material, you need to figure out which way the angle grinder should turn: sparks from itself or towards itself. There is no single answer among users; they work in both ways. If the nozzle rotates counterclockwise, then sparks (as well as a broken circle) fly in the opposite direction from the operator, but the tool will return during jamming to the user. In the second case, everything happens the other way around. According to safety measures, it is believed that the correct rotation is when sparks fly towards the operator, because when jammed the jerk of the tool will be in the opposite direction.

    In any case, manufacturers recommend that the movement of the angle grinder and the rotation of its circle be directed one way. This greatly reduces the likelihood that the disk will come out of the slot during the workflow. But with this method, the marking on the material is often hidden by flying sparks.

    Change nozzle rotation You can, rearranging the handle and cover on the other side. This is the easiest option (if possible). A more complicated way is to make changes to the electrical circuit of the device. But this does not always help.

    An important point is to ensure the correct position of the working tool: it is necessary that the fishing line is located on the side of the operator. Then, if the nozzle suddenly seizes, the angle grinder pulls to the side.

    Read more:  Mounting The Disc On An Angle Grinder

    When cutting, it is necessary that the working plane does not change, and also there are no distortions. Discs should be used in accordance with the material being processed. So, concrete, tile, stone is cut using circles of different diameters with diamond spraying.

    The nuances of cutting some materials

    At concrete cutting comply with the following recommendations:

    • before work, check for the presence of pipes, fittings, electrical wiring embedded in concrete (with a metal detector or devices to search for wiring);
    • to reduce dust, the work surface is moistened with water (for example, from a spray bottle or with a brush);
    • periodically cool the cutting element with air or water.

    In the absence of a tile cutter, the angle grinder also cuts the tile. Specialists carve even circles in tiles. Stone with tiles cut in two ways:

    • wet (wet the work area with water);
    • dry (without moisture).

    In the first option, cooling improves, but dirt remains, and in the second, a lot of dust is released. The wet method is used for large volumes of upcoming work, and the dry method is used for one-time cutting.

    Any material should be cut smoothly, so that the disc is immersed in it with a slight pressure, almost exclusively under the influence of the own weight of the angle grinder. This is necessary to prevent distortion of the disk and reduce the likelihood of jamming. If the process slows down, it is necessary to replace the nozzle with a new one.

    The angle grinder should be used in accordance with the operating instructions and safety regulations. The working part should rotate in the direction of movement of the tool. Before starting the process, be sure to turn on the device at idle. In this case, vibration, heating, angle grinder, as well as extraneous sounds from it should be absent. Circles must be used without damage. The most dangerous factor is a kickback. To prevent it, it is necessary to avoid jamming of the circles when cutting materials on a fault.

    These two phenomena are not connected. IT DIDN’T come off BECAUSE they put the washer on the gearbox. Well, think for yourself, what’s the difference, if all the same it is clamped on both sides with metal circles of the same diameter.
    Also always put a metal washer to the gearbox, so as not to use the key. So the circle will never snap! The explanation is simple and logical. metal on metal slides much easier than metal on abrasive!))) And therefore, when we remove the circle, unscrewing it ourselves, it easily slides on the spindle support washer, but pulls the nut (under it abrasive, not metal!). So it turns out that the nut is easily unscrewed!
    When I unpack a new angle grinder, I immediately hang the key on the carnation. it is not needed. (There already hangs a lot. I have only eight working grinders now. And in twenty years. and not count))))))). There has never been a case that I did not unscrew by hand. I take the key with me only when I work with metal circles (stone, wood). Here they are sometimes very strongly clamped, and there is no difference in the forces of friction. metal on both sides.

    I completely agree with this. And also what was voiced above. a cut back to sparks.

    And what is there to think about. This is already known to all. When the firm "Sparky" I came up with this high-speed machine with an angular gear, there were no technologies yet that made it possible to produce reinforced abrasive wheels from electrocorundum that could withstand such loads !! And therefore, initially they were equipped only with thick "stones" and used exclusively for grinding. Later, such technologies appeared and this tool began to be used more for cutting than for grinding. But the name remained.
    After all, when the company "Dremel" came up with her typewriter, she also began to be called "engraver". And it is called so now. Although, can anyone argue that an engraver cannot be peeled, cut, or sanded. Does everyone use engravers only for engraving? )))
    (By the way, I meet more and more with what engravers call "Dremel", even if they are produced by other companies.)))
    Apparently "to the" for the time when "Dremel had the exclusive right to release his invention for some years. (Like "Xerox", eg). Then they were already able to do everything. but they still call "Dremel" and "Xerox".
    (By the way, everything in Belarus is also called Xerox, but here engravers are not dozing))) These are engravers!))) Not "has grown" for some reason.)
    "Angle Grinder" By the way. from the same opera))). Only "Sparky" supplied this instrument to the USSR. And only "Husqvarna". chainsaws "Swedes" ))))

    Practice is a great thing. I did not argue. It was never possible to read about the correct operation of such a tool. The instructions are written
    , that the gearbox can be rotated as you wish.
    Then the angle grinder worked for half a day. not a single bite. In difficult places, the disc is automatically squeezed out of the cut zone without biting. And the disk rotates. uh. well, sparks fly under your feet. Socks of course, kerdyk, but the legs remained intact

    Video: How to Change Bearing to Angle Grinder


    Later, to figure it out, I drew a diagram of the cutting mechanism for myself, but I never entered. Something is connected with the angle formed between the cutting line and the longitudinal axis of the machine (angle grinder) and also the force arising for a certain direction of rotation of the disk. In the variant, when sparks fly away from you, the angle is sharp, so the disk bites to death. And when the disk rotates, when sparks under the legs, the angle is almost turned around. :saw:

    I apologize for the verbosity. I just wanted to explain, warn and understand.

    P.S. I thought of changing the direction of rotation of the armature (so that everything would be “handy”), but I don’t know whether it is possible to apply reverse for the armature itself and for the angular gearbox. : idontnow: It is necessary to consult with specialists. And can someone tell me from those present?

    Best regards, Sergei.

    I have been repairing power tools for eight years already, during this time I heard so many terrible first-hand stories from the owners that God forbid. Including about pieces of a disk in a neck. The last example: a man does not take his tool out of repair for a long time, for several months, when I call him on the phone, I don’t understand what he says. Finally it appears: there is no voice, there is a terrible scar on the neck. An angle grinder worked without protection, then everything is clear. It saved that he worked in the immediate vicinity of the regional hospital, did not have time to bleed, everything was sewn up, but he damaged the ligaments forever.

    The disc is placed the way someone whose hands are sharpened. The disk on the left and, accordingly, the rotation on itself is a consequence of the fact that when working instinctively they put their right hand forward, holding the gear knob to it. The same thing when working with a shovel. Whoever holds a shovel, that is how an angle grinder works. Although the effort of will, you can force yourself to change your hand. Because I work forward with my left hand (the disk is on the right, rotation is from myself), then, of course, I consider this option to be the only correct one: rolleyes :. Pros:

    1. Sparks fly away without causing any harm to me or the angle grinder. When they work with sparks on themselves, they are sucked in by the fan inside the engine and over time all the windings begin to redden with pure uninsulated copper, as if someone had rubbed it with a special sandpaper.

    2. When biting, the angle grinder jumps out of the cut directly into my hands. You just need to always remember that you have a car with several horsepower in your hands and hold these animals with your hard hand. According to the working conditions, of course, you have to turn the angle grinder, unless you pick it up differently, but I always return to the usual version.

    When working with an angle grinder I try to avoid deep cuts. It is better to cut the corner in two steps, cut through the shelves in turn. I cut the channel in three steps, first the core and then the shelves. thereby eliminating accidental pinching of the tool. Cutting thick metal sometimes has to be cut, deliberately expanded by cutting in two steps, especially if the cutting area is uncomfortable and an unintentional skew of the disk is possible.
    I cut the line of the cut in thick metal immediately and cut it by 5-7 mm, cutting the edges of the cut. when cutting, bag cutting should be avoided; displacement of the stack is fraught with skewing of the lower layers. It is not necessary to cut two elements of spatial structures when the disk cuts simultaneously two spaced apart elements; when the disk is thin, the cuts of the cuts are not parallel (not coaxial).

    Why is angle grinder used and how is it arranged

    Angle grinder (angle grinder), or “angle grinder”, has firmly entered the household and production life of not only a craftsman, but also a simple layman who likes to conveniently solve locksmith and carpentry tasks. The popularity of this power tool is due to the simplicity, versatility and versatility of use.

    With the help of various additional nozzles, an angle grinder can cut metal, grind various surfaces, and clean them of rust or old coatings. The angle grinder has such features as sharpening cutting tools, chipping concrete walls, cutting ceramic tiles or stone.

    Read more:  Can I Use A Polishing Machine As An Angle Grinder

    Angle grinder device

    Structurally, the angle grinder is an electric motor with a power from 500 to 2000 W, which converts the electric current into rotational motion. A planetary gearbox consisting of two main gears with a direct or bevel gear serves the same purpose. The rotation of the spindle of the working shaft is carried out in direct transmission mode, the speed is determined by the ratio of the number of gear teeth. Some angle grinders are equipped with an electronic soft start engine and speed control.

    Type of electric motor. asynchronous, single-phase. An electromotive force occurs when the rotor winding interacts in the magnetic field of the stator, which is fixedly mounted in the housing. Thanks to the angular transmission of torque, the level of safety during operation is significantly increased. In the case of jamming of the disk in a viscous material, there is no reactive rotation of the tool body, which prevents possible injury to the operator.

    Many have experienced in their own practice the phenomenon of reactivity when operating an electric drill. When the drill sticks, for example, in hardwood, the body of the device starts to rotate with force in the opposite direction, breaks out of the hands and can lead to injury or even injury.

    Diagnostics of malfunctions in the angle grinder

    Signs of malfunctioning an angle grinder for a sensitive ear and a keen eye appear long before the actual failure of the tool. Before finally breaking down, the angle grinder usually starts to give distress signals. It could be:

    • increased vibration of the case during operation;
    • excessive sparking of collector brushes;
    • uterine buzz of the motor during start-up;
    • gear cracking with broken teeth or dry gears without lubrication;
    • wedging by bearings of rotor shaft rotation or their piercing creak during acceleration;
    • a specific smell or even smoke emanating from the angle grinder body.

    To save the angle grinder from large and expensive repairs, you should carefully consider the technical condition of the tool and respond in a timely manner to changes in its operation.

    If the first symptoms of improper operation appear during operation of the angle grinder, it is necessary to urgently diagnose the device and find the cause of the malfunction. To do this, you need to check two main systems of the device. electrical and mechanical.

    Checking the electrical part

    The electrical part of the angle grinder consists of:

    • electric motor;
    • power buttons;
    • electronic control unit for starting and rotation speed.

    The electric motor, in turn, is divided into two main parts. the stator and rotor (or anchor).

    The task of the wizard is to consistently check all these systems and find out the causes of malfunctions. To do this, you need a multimeter or tester.

    Power circuit check

    First of all, you need to check the integrity of the power cord. Many troubles can occur only due to the fact that the cable is damaged and the power to the device is uneven. The cord must be completely intact, with no signs of damage. During operation, it should not be heated or sparked in places of bends and connections to a power outlet or angle grinder. If at least one of these conditions is not met, the cord should be repaired or replaced.

    Using a tester included in the voltmeter mode, check the input voltage in the angle grinder, it must correspond to the rating indicators: 220 V. In the ammeter mode, the current consumption is measured. it should not exceed a value of 6 A.

    Checking the starter and control unit

    Next, test the start button and the electronic control unit. Perhaps the contact group of the inclusion of the device in the work was oxidized or clogged. If the device is equipped with a soft start system, the disk should accelerate to working revolutions gradually, without a sharp set of speed. Using a multimeter, you need to make sure that the voltage when the button is turned on is transmitted to the electrical circuit.

    If during operation the angle grinder it was noticed that the brushes in the place of contact with the collector sparked excessively or the disk rotates unevenly, abruptly changing the number of revolutions per minute, then most likely the stator windings or the armature are involved in this. Since the stator is less prone to overloads. it only creates a magnetic field, most often attention should be paid to the rotor of the electric motor.

    Rotor diagnostics. how to “ring” an anchor with a tester?

    To make sure the rotor is in good working order, it is necessary to “ring” it with a tester.

    By setting the multimeter toggle switch to 200 Ohm, successively measure the resistance of the windings on two adjacent armature slats. If the resistance is the same everywhere, then the anchor is intact and operational. If the tester shows a value different from the rest on any of the pairs of lamellas, an interturn closure occurred at this point. Anchor is subject to repair or replacement.

    The inter-turn circuit, as a rule, occurs when the instrument overheats during operation. The insulation of the windings is melted and this leads to the fact that the neighboring turns, consisting of copper wire, come into contact. As a result, the balance of the electromotive force is disturbed and this leads to a power failure at a certain position of the armature.

    Diagnostics of the motor stator

    If the armature turned out to be serviceable, the testing procedure should be carried out with the stator, by measuring the resistance of the windings in a similar way. The inter-turn short circuit in the stator is characterized by surges in the increase in speed of the angle grinder when turned on. The engine, for no reason, begins to "rush" to rotate at high speed.

    The insulation defect in the stator windings is repaired by repair or replacement. Repair, as a rule, consists in rewinding a copper wire.

    A specially made pattern is used to rewind the stator coils. As a rule, it is made of plywood. The size of the template is determined with a margin of 10 mm for each frontal part. To prevent the wire from jumping off the plywood during winding, cheeks are attached to the sides to it.

    Rewinding is done at home in the presence of the necessary tools and devices. It is important to choose a copper conductor with a cross section that exactly matches the original one. The number of turns of the winding can also not be changed.

    Video: how to rewind the power tool stator

    Checking the mechanical part of the machine

    The mechanical part of angle grinder consists of:

    • gearbox;
    • spindle lock button;
    • flange fastening of the working tool;
    • bearings of a rotating rotor shaft.

    To determine the malfunction of the mechanical part, the angle grinder must open the gear housing made of aluminum alloy. As a rule, the gearbox cover is fastened with four screws, which must be unscrewed in order to gain access to the gear pair.

    Reducer gear inspection

    Inspection of the gear transmission of the gearbox is to determine the strength of the gears, the presence of a sufficient amount of lubricant and the integrity of the teeth.

    Check Lock Button

    The lock button for fixing the spindle is a spring-loaded steel rod that prevents the working shaft from rotating. The button is used when changing cutting blades. Damage to the locking rod usually occurs when the disk is jammed or the motor is turned on with the button pressed.

    Inspection of flange for attaching nozzles

    The disk is mounted with an angle grinder (or other working nozzle) using a flange threaded clamp. They fail extremely rarely, as they are simple to set up and operate. During inspection, you should pay attention to the condition of the thread on the shaft, if necessary, it can be greased with solid oil, graphite grease or Lithol.

    In practice, there is often a situation where the flange nut is “hopelessly” tightened on the disk, and the keys do not help even with great physical effort. This can happen, for example, when a disk ruptures. The following method will help to unscrew the nut:

    1. A metal plate with a thickness of up to 2 mm is fixed in a vice.
    2. The remnants of the disc break and bite with pliers.
    3. The angle grinder motor turns on.
    4. With the help of a fixed plate from under the nut, the remains of the disk are “chipped”.
    5. When the space under the flange is freed, it will easily loosen.

    When performing this operation, it is necessary to use personal protective equipment: gloves and goggles. fragments of the disc fly at high speed and can cause injury.

    Checking the rotor shaft bearings

    Checking the operation of the bearings on the rotor shaft consists in their visual inspection. A serviceable bearing should have a solid color (without the blue that occurs in the case of overheating of the part, and smudges of grease), when scrolling, it should rotate easily, without sound. If this is not the case, the bearing is being repaired or changed.

    General rules for repairing a power tool

    If the causes of the malfunction were determined during the diagnosis of angle grinders, it is necessary to start repair in compliance with certain rules.

    • the device must be turned off from the power supply;
    • repairs should be made on a well-lit, non-cluttered table or workbench;
    • observe the procedure for disassembling and, accordingly, reassembling the device.

    If it is difficult to remember the location of the parts inside the mechanism, it is recommended to photograph them.

    When the device is disassembled, it is strictly forbidden to connect it to the electrical network.

    The main causes of malfunctions angle grinder and their elimination

    Below are the most common problems and their solutions.

    Collector brushes burn (spark)

    Sparking in the manifold is most often observed when it is time to replace the carbon brushes. This usually occurs after several years of operation of angle grinders.

    Read more:  How to Work a Wood Angle Grinder

    Standard brushes are designed for 7000 hours of operation, after which they are erased.

    A simplified brush replacement system is provided on angle grinders, so repairs are quite easy and quick:

    1. Unscrew the two plastic covers on both sides of the casing with a flat screwdriver.
    2. Remove the old brushes from the nests.
    3. Wipe the collector with an alcohol swab, as the lamellas are left with soot from the work of the old brushes. You can also use tweezers with cotton wool or rags soaked in cologne.
    4. Install new brushes in the sockets.
    5. Screw in plastic covers.
    6. Check angle grinder in operation.

    Video: replacing the brushes the angle grinder will help eliminate sparking

    angle grinder does not turn on

    To determine the exact cause of this malfunction, it is necessary to examine the electrical circuit of the device. It is advisable to start from the outlet and end with testing the electric motor. After the place of circuit interruption is found, the flow of electric current in the instrument should be restored. The most common cause of breakage is the dusting or oxidation of the terminals or contacts of the start button.

    Spindle lock button failure

    The defect is purely mechanical in nature. This happens when the circle is jammed or when the stem cavity is severely clogged. In this case, replacing the disk will help to produce a special key for the flange, which, as a rule, is always in the kit of the sold tool. You can hold the shaft from turning using an open-end wrench. At the base of the flange mount there is a specially machined turnkey plane.

    Video: spindle lock repair at home

    Engine stopped working

    If voltage is supplied to the motor but it does not rotate, check the condition of the brushes and bearings. Brushes can get stuck, bearings can jam.

    1. If the brushes are sunken, they must be thoroughly cleaned, and then blow the nests in which they are located. In addition, check the rubber bands on the covers that cover the brush sockets. After all, the isolation of brushes and the collector from dust depends on them.
    2. If the cause of the engine stop in the bearings, they must be removed from the rotor shaft, repaired or replaced. Sometimes flushing and lubrication are enough for the old bearing to continue its work.

    Angle grinder works in fits and starts, does not develop full power

    The angle grinder operates jerkily if an interturn circuit is formed in the rotor coils. The most common reason is abnormal operation of the tool, as a result of which the motor overheats. Rewinding the coils of the anchor is a rather complicated and painstaking task, without certain skills doomed to failure. Therefore, when the anchor fails, it is recommended to replace the entire part, together with the bearings. The nominal value of the spare part must exactly match the nominal value of the original.

    the angle grinder gets very hot

    Most often, the angle grinder body is very hot due to improper operation of the device. Since the angle grinder is equipped with an asynchronous type electric motor, an increase in the working load does not affect the rotation speed in any way. This can be misleading for an inexperienced user, as a result of which he continues to work without interruptions for an unlimited time. But this cannot be done. The passport of each tool indicates the optimal operating time of the angle grinder under load, usually it is 5-7 minutes. After this, it is recommended to take a break of 1 minute or let the angle grinder idle.

    When working with the tool, it is important to observe the correct stopping order for the angle grinder. After turning off the start button, you must wait until the engine stops completely. If the rotary angle grinder is placed on the ground or on a dusty floor, small particles of sand will be sucked in through the ventilation holes. They will get inside the engine and will erase the protective insulating layer.

    angle grinder is not gaining momentum

    If the tool is equipped with an electronic control unit for shaft rotation speed, a malfunction in its operation can lead to the fact that under load the speed of the shaft “floats”. Most likely, there was a circuit on the board, the control unit should be replaced.

    Gearbox failure

    The gears of the transmission gearbox play an important role in the supply of rotational motion from the electric motor to the working tool. In addition, there is a decrease in speed and, accordingly, an increase in power. In angle grinders up to 1100 W, spur gears are used. If the engine power exceeds this indicator, helical gears are used, which have greater fracture strength.

    If a crunch or a rattle is heard from the gearbox when the motor is switched on, the angle grinder must be switched off immediately. You cannot work with such a gearbox, this will lead to total cutting of the remaining gear teeth. After the engine is completely stopped, the gearbox cover must be removed to establish an accurate “diagnosis”.

    If the cause of extraneous sounds is a chipped tooth, damaged gears must be replaced. In this case, the cavity of their rotation should be thoroughly cleaned of grease and metal fragments that were formed from the previous mechanism. After replacing parts, the grease inside the gearbox must be completely renewed.

    Video: how to repair and adjust the gearbox

    If the angle grinder smokes during operation

    Carried away by the processing of stone or grinding metal, it is easy not to notice how the tool overheated. If the work is not stopped, very soon, pungent smelly smoke will come out from under the casing. This is the winding of the armature, in which, unable to withstand the heat load, the insulation layer melts. If you do not interrupt the work, the angle grinder may burn out.

    If you feel an unpleasant odor, immediately turn off the angle grinder and unplug the power cable from the outlet.

    The disassembly of the tool can only be started after the body has completely cooled down and the emission of caustic fumes has ceased.

    Excessive sparking on the manifold

    A fan of sparks flying out from under the brushes of the collector indicates, as a rule, a violation of the insulation at the armature or a short between the wires in the windings. In this case, stop working and turn off the angle grinder from the network. Next, you need to disassemble the case and examine in detail the anchor of an angle grinder. The easiest repair option is a complete replacement of the anchor.

    Bearings are broken

    If something is wrong with the bearings, the angle grinder vibrates a lot and makes noise under load, the low-frequency hum dominates in the sound. This is due to the fact that a damaged bearing starts to buzz during operation. Vibration occurs from the appearance of additional backlash on the sleeves of the mounting of the rotating shaft. This malfunction is eliminated by replacing the bearings. To do this, do the following:

    1. Remove brushes from brush holders.
    2. Remove the plastic housing by unscrewing the fixing screws.
    3. Remove gearbox cover and disengage pinion gear.
    4. Pull out the armature shaft with cooling impeller and bearings.
    5. Using a puller, separate the bearings from the shaft axis.
    6. Assemble the structure in reverse order.

    Video: how to exchange a bearing for an angle grinder

    If the angle grinder is humming but not spinning

    If the shaft of the angle grinder does not rotate, two reasons are most likely, both related to the mechanical part of the tool.

    1. Jammed gear.
    2. The bearings are jammed.

    To check the versions, turn off the angle grinder and try to turn the tool disc manually. If the spindle does not rotate or rotates tightly, the reason is not in the electrical part, it is necessary to disassemble the gearbox and look for the reason there.

    If soft start does not work

    If soft start does not work, the reason lies in the malfunction of the electronic control unit. The solution is to replace the entire unit. Disassemble the unit and look for the cause of the problem can only a specialist who has the appropriate knowledge and diagnostic tools.

    Preventative maintenance of the angle grinder

    Unexpected breakdowns can be avoided by regularly conducting not only visual inspection but also tool maintenance. The manufacturer usually indicates the rules of prevention in the passport. In order for the angle grinder to serve for a long time and without "surprises", it follows:

    • timely maintenance of the tool;
    • comply with operating and storage standards;
    • avoid prolonged operation of the tool under load at reduced speed;
    • avoid pinching the working part of the tool;
    • monitor mechanisms and change worn parts in a timely manner.

    If the angle grinder worked at reduced engine speeds, it must be kept at idle for about a minute before turning it off. This will enable the motor to recover, adjust the temperature of the windings.

    Preventive disassembly, cleaning and lubrication of mechanical parts will increase the tool life by several times. Such simple maintenance will avoid expensive repairs.

    The optimal conditions for storing the angle grinder are dry rooms, protected from sudden changes in air temperature. For long-term preservation of the tool, it is preferable to pack it in a plastic bag in a cardboard box.

    All repair work carried out with a power tool must strictly comply with safety standards. In no case can you disassemble the case when the device is connected to the network. Do not place containers with combustible or flammable materials near the disassembly site.