Repair of an angle grinder needs to start with finding out the malfunction, find which particular unit is out of order. We deal with the problem of the malfunction, what exactly happened:
- if sparking occurs when turned on, the case is heated, and when turned on, the smell of burning begins to go. In this case, there may be two options. the collector is dirty or the burnout of the collector.
- if Angle Grinder generally not cut. the following options: inoperative power cable, button inclusions broke, brushes worn out.
- if the disk develops and the engine goes “into the spacing”. it is in the stator closed turns.
- if during operation the angle grinder, an unusual mechanical sound occurs. this happens when the gearbox is worn
The main components in the angle grinder are: stator, anchor and gearbox. The stator is equipped with windings, which are divided into two sectors. An anchor, this is the moving part of an angle grinder, also consists of windings. A reducer is a device for transmitting rotation; it serves to contain the frequency of revolutions within these boundaries.
Also emit devices that also become unusable: a collector, these are plates located at anchor, isolated with each other. Brushes. carbon bars in the shape of a parallelepiped, along them the current is supplied to the collector.
Understands Angle Grinder just, just unscrew the screw from the back, it is screwed on the plate. When the plate is not screwed, the casing is removed. An anchor with a stator is placed here, but the gearbox is located under a metal cap, this part of the device is mainly heated.
Does not turn on Angle Grinder. repairing! Angle grinder Interskol 115/900.
In the event of a malfunction of the collector, which is mounted at anchor, sparking, burning smell and overheating of the casing occur. The casing has already been removed, now you need to remove the anchor with the collector. First you need to remove the brushes from the grooves that are held by springs. With the gearbox installed, this is difficult to do, therefore the gearbox must also be disconnected. Only later, of course, pull out the anchor, you need to do this carefully. Otherwise, you can disrupt the bearing, it stands on the back of the axis of the armature. And we check the collector for integrity, we clean the plates from pollution. For which the burnout design of the plates is intended, the collector must be replaced one hundred percent, coupled with an anchor.
If Angle Grinder doesn’t get it. first we check the power cable for kink and break. Later button inclusion is checked for serviceability. And the third option. carbon brushes burned out, disassemble the angle grinder and inspect the brushes. If integrity is broken. we change brushes.
The most labor-intensive repair, if an interturn circuit on the stator windings has occurred. When the car accelerates and is gaining crazy speeds. Here you already have to change the winding itself. It is necessary to pay special attention to the fact that the thickness of the wire should be the same, the density of the winding should go up moderately, and the number of turns must certainly be made identical. Manually achieving uniformity is very difficult, use an electric drill so that the winding rests moderately on the template. Then we install both wound coils with turns of windings into the stator, we remove the winding wire from the stator, we put it on the ends of the wires for insulation of the cambric, suitable across the wire, earlier.
The occurrence of mechanical sound inside the angle grinder indicates wear of the gears of the gearbox. For this purpose, after removing the casing from the angle grinder, you need to disassemble the gearbox itself, unscrew the 4 screws from the cap. From time to time, noise occurs inside the case due to a lack of lubrication, when our client has whole teeth on the gears. Then you just need to add solidol, and the noise will disappear.
Repairing an angle grinder switch is easy!
Mechanical failures of angle grinder
Angle grinder is an angle grinder designed for cutting, grinding, polishing work. during operation, the angle grinder is subjected to heavy loads, works in a dusty environment.
Excessive loads when using the angle grinder in the "Cutting" mode cause increased wear not only of the bearing, but also of the gear teeth of the gears.
The main malfunction is the angle grinder on the mechanical part, wear or destruction of the sliding bearing on the shaft of the large helical gear reducer.
It is not difficult to troubleshoot an angle grinder if you have at hand its circuit, description and recommendations for performing repair work.
Bearing Repair
The weak point of any angle grinder is the bearings. And although there are few of them in the design, there are only three, it is they that most often lead to mechanical breakdowns. Bearings are adversely affected by:
The design of any angle grinder provides for quick and easy replacement of any bearing.
Faults in the angle grinder associated with wear or destruction of the sliding bearing on the gearbox shaft are characterized by the appearance of an unpleasant extraneous sound.
Destruction of the sliding bearing is detected by checking the play of the shaft of the installation of the working tool. It is determined by swinging in different directions of the shaft when installing the working tool.
At the next installation of the working tool, check the shaft play by swinging at its end in different directions. Backlash should be absent or minimal.
The appearance of play indicates the need to replace the plain bearing.
Bearing repair consists of removing it from the housing and removing it from the gearbox shaft.
It is better to remove the bearing from the shaft using a puller. It is best to get the inner cage of a destroyed bearing with a tap of the desired diameter, previously screwed into the cage.
Bearings are removed from the rotor using a puller or in a folk way.
Keys or strips of metal are inserted into the vise, the bearings are laid on the keys and, using soft metal and a hammer with a weight of at least 400 g, are pushed out of the shaft axis.
Gearbox repair angle grinder
The degree of wear of the gears of the gearbox angle grinder is checked for a contact spot. Previously, the gearbox is completely cleaned of old grease. A special blue is applied to the small gear wheel of the gearbox, the gearbox rotates. Next, you need to remove the driven large helical gear and look through the magnifying glass at the contact spot. It should occupy a total of at least 50% of the tooth surface.
Otherwise, the gears must be replaced or the tooth profile corrected. Correction of the tooth profile has been repeatedly described on the pages of this site.
But such a malfunction is eliminated only by an experienced craftsman. Most often, the gears that are licked, cut or destroyed change completely, and in pairs.
How to disassemble the gearbox angle grinder
When repairing a gearbox of any angle grinder, the most difficult task is to remove the gears and press out the thrust bearing.
Dismantling of the gearbox begins by removing the gearbox cover pos.1 and disconnecting the stator housing and releasing the rotor pos.2. The freed rotor is clamped in a vice and the nut of fastening pos. 3 is unscrewed of the driving small gear.
A spindle bearing is pressed into the gearbox cover. To get the bearing, in some angle grinders it is necessary to remove the circlip securing the support bearing and remove the bearing.
The destroyed bearing pos.1 in the gearbox housing pos.2 is easiest to get by prying it with a screwdriver.
On other models, the locking ring locks the gear in the spindle.
The driven large gear on the spindle is mounted in several ways:
- The gear is pressed onto the spindle.
- The gear is mounted with a key.
The driving small gear is either screwed onto the shaft along the left-hand thread (in some Sparky models, the right-hand thread), or is fixed with a keyed connection and clamped with a nut.
How to remove gear gears
In angle grinders up to 1000 watts, spur gears are used, and in angle grinders, helical gears are used.
Gears are attached in different angle grinders in different ways. The pinion gear is mounted on the rotor shaft with a keyed connection or mounted on the thread. The driven gear is mounted on the spindle shaft by interference fit or by keyway. Details on how to remove gears and bearings from the shaft.
Gear repair consists in their replacement, and only in pairs.
Long and uninterrupted operation of the gearbox depends on the availability of a sufficient amount of lubricant and its timely replacement.
Spindle Lock Button Repair
The spindle lock button is designed for quick removal of the working tool. The button breaks when pressed on it at the time of rotation of the disk. Repair angle grinder is a complete replacement button.
The button should only be pressed in the fully stopped state of the angle grinder.
Electrical malfunction angle grinder
The electrical circuit of the main part of the grinders is almost the same. The rotor transmits torque through the gearbox to the working tool. The rotor rotates in the stator field. The control circuit consists of a button that regulates the speed and provides a smooth start-up of the tool, carbon brushes, providing the transmission of alternating voltage to the collector lamellas. Power is supplied to the instrument via a connecting cable.
Video: Lock Button On Angle Grinder Broke
The main malfunctions of the angle grinder in the electrical part include:
- breakage of the power cable at the entrance to the tool;
- destruction or wear of carbon brushes;
- failure of the power button;
- open or short circuit of the stator;
- open or short circuit of the rotor;
- delamination or production of collector lamellas.
Faults An electric angle grinder is best identified by a tester or other device. Suitable for these whole and home-made device, popularly called "Arcade".
The scheme of the angle grinder is quite simple and does not require special knowledge. It is only necessary to observe caution and safety when performing repair work and to know electrical engineering in the volume of a secondary school.
Finding a power line break
One of the common failures of an angle grinder is the inability to turn on the tool or a spontaneous stop during operation. The cause of such malfunctions is a break in the power cable, item 27 at the entrance. The malfunction is eliminated by replacing the cable or throwing out the failed section. The fault is easily found with a tester.
If there is no tester at hand, but there is a screwdriver with a neon indicator light, then the malfunction can be found by alternately connecting the power wires to the phase.
Carbon brush malfunctions
The reliable operation of any power tool to a large extent depends on the integrity and proper operation of carbon brushes. Qualitative fit of carbon brushes, their correct location relative to the collector lamellas affects the efficiency of the rotor collector.
Remember! The length of the carbon electric brush cannot be less than 8 mm.
Timely replacement of carbon brushes avoids most of the malfunctions.
The degree of wear of carbon brushes is characterized by the types of sparking in the collector. Sparking should be uniform throughout the contact patch of the carbon brush and lamellas and not exceed a length of more than 8 mm. Circular arcing indicates a malfunction in the rotor circuits.
In angle grinders, it is recommended to use carbon brushes only by tool manufacturers. Homemade carbon brushes can be installed, but only for a short period and immediately replaced as soon as possible.
Repair of the power button and speed controller
Malfunctions of the power button are most often manifested in the difficult and unreliable turning on of the tool during start-up. Such a malfunction spontaneously appears and disappears.
It is unacceptable to work an angle grinder with a faulty power button. This malfunction leads to jamming of the cutting discs during operation and their destruction with unpredictable consequences.
The malfunction is eliminated by completely replacing the button with a new one.
In modern models of grinders, a soft starter with a speed regulator is built-in. It cannot be repaired, but will require a complete replacement. No, advanced left-handed masters, of course, can fix such a knot.
Stator Repair
The stator breakdown is indicated by spontaneous unwinding of the machine shaft, the angle grinder begins to gain maximum speed. Such a malfunction indicates the appearance of an interturn circuit in the stator winding.
Some malfunctions can only be fixed by specialists. Stator uptime can only be extended by timely cleaning, lubricating and replacing carbon brushes and bearings.
Usually the stator fails quite rarely. This leads to frequent overheating of the tool during operation. The malfunction is manifested by a strong heating of the body of the angle grinder and the smell of burning insulation.
The stator can have either an open or a short circuit. Without disassembling the stator, these malfunctions can be easily found using the IK-32 device.
Faults are eliminated by replacing the stator. For those who like to craft with their own hands, we can recommend rewinding a failed stator with their own hands. There is nothing complicated about it.
The stator is removed easily, but in different models of angle grinders in its own way.
Stator removal procedure:
- remove the gear angle grinder;
- remove the rotor by first removing the mounting plate;
- remove the plastic protection of the stator;
- unscrew the screws securing the stator in the housing;
- remove the handle cover and disconnect the power wires to the stator;
- remove the stator by tapping the housing with a wooden mallet or block.
Repair of rotor UShM
Rotor failure in the angle grinder is caused by improper operation of the tool, frequent overheating, untimely replacement of carbon brushes, and abrasive particles and dust getting on the collector lamellas.
First, the length of the spark on the collector increases, then a burning smell and, at the last stage, smoke appear. The operation of a faulty gearbox is accompanied by a knock and a hum.
Destruction of even a pair of teeth leads to improper operation of the tool.
It is possible to extend the life of the rotor by preventing dust from entering the tool, preventing the tool from overheating, timely changing of carbon brushes and lubricants, using only those working tools and the diameter recommended by the power tool manufacturer.
The rotor is a complex unit that requires repair in service centers. But DIY lovers can repair the rotor on their own.
Repair of the collector and rotor lamellas
Dismantling the rotor is not particularly difficult.
The procedure for extracting the rotor from an angle grinder:
- remove the grinder handle cover;
- release and remove the carbon brushes;
- unscrew the screws securing the gear housing to the main body;
- remove the gear housing;
- remove the rotor.
The removed rotor must be carefully inspected. If large grooves are rubbed on the sipes, they should be removed by turning the collector in a lathe.
With minor grooves, the defect is eliminated by grinding. The rotor is clamped into an electric drill chuck and the output is removed with the help of a file and sanding paper. The process is simple.
The drill is clamped in a vice or securely mounted on a flat surface. The end of the rotor on which the lamella is placed is inserted into the drill cartridge and is securely clamped. Bearings are previously removed from the rotor.
The second end of the rotor must be supported by a set of wooden blocks. The drill turns on and a small number of revolutions is set. At the first stage, use sanding paper of coarse grain No. 40.80, at the final stage, finer No. 120.200.
After grinding, it is necessary to mill the grooves between the lamellas. This is best done with a hacksaw blade specially sharpened. After milling the grooves of the collector, the edges of the lamellas must be deburred using a diamond file. Properly sanded lamellas must not have any burrs.
In addition to general malfunctions in models of angle grinders of different manufacturers, there are also specific breakdowns that are characteristic only for the tool of this manufacturer. But more about that in another article.
Video repair angle grinder
DIY angle grinder repair (start button)
Electrical Equipment Angle Grinder
For 40 years, the angle grinder has not actually changed its appearance: an elongated body with an internal built-in engine and gearbox, a screwed handle and a protective casing on the side.
Angle Grinder, as well as at least some tool, at some point it is refused to work. But there are situations when, for troubleshooting, a fairly simple repair of electrical equipment. In order to carry out the myth of small repairs, you must have a concept of how such equipment works inside, and be able to read its electronic circuit.
The electronic circuit of the grinding machine consists of the following parts:
- anchor;
- collector;
- electric brushes;
- gearbox;
- stator;
- handles holders;
- power cable with plug.
Any of these parts makes its purpose in the electronic circuit, a malfunction of each leads to a stop of the tool. For example, an anchor, being a rotating element of a chain, is responsible for grinding wheel rotation. To force the disk to spin, the anchor must spin with even greater speed. Because the simpler the speed of rotation of the anchor, the more than the power of the tool.
The collector is a platform at anchor, to which our customer faces power and control cables. Its task is to translate the signals passing through the windings into a language that is understandable to the engine and control unit. If you remove the lid of the case, then its polished plates immediately appear in sight, all the more so since they have a comparatively huge size.
Fault conditions angle grinder.
The purpose of the electric brushes is to provide current to the collector from the power cable. If they are in normal working order, then through the ventilation hole their even glow will be visible. When the glow is inconspicuous or it pulsates, then this is a sign that there are difficulties with the brushes.
The gearbox is a very important detail, not so much an electronic circuit, but the whole construction is an angle grinder. Its purpose is to supply energy from a rotating armature to a grinding disk, thus providing its rotation with a macar. In practice, the gearbox is responsible for speed and power. grinding rotation disc angle grinder.
The stator is a technically more complicated unit in the electronic circuit of an angle grinder. They pressed in what remains for our client to make the windings of the armature and rotor, which determine their rotation. The coil windings located in the stator are designed up to the last turn. According to the stator’s readiness for failure, the rewinding successfully performed by a layman is a very rare case. If the stator breaks into the angle grinder, then it is better not to risk it and fix its malfunction in the workshop.
Reading electronic circuit
Alas, there is not much to know the purpose of the main parts of the electrical circuit of the tool; you still need to be able to read this circuit. Although the electronic circuit of an angle grinder is not the most difficult thing that you can come across from electronic circuits, even here a person who is far from electricity can find it difficult to understand without outside help.
2nd life angle grinder ejected button.
broke down button on the Angle Grinder. not a failure. make an external switch and the ear works again as it should. after.
Repairing the angle grinder switch is easy!
Circuit breaker repair Angle Grinder simply!
The device is an ordinary angle grinder.
The scheme of an angle grinder is as follows: two stator windings are connected alternately through a cable to a network with a voltage of 220 V and are not electrically connected to each other. They are turned on / off by using a switch mechanically connected to the start button of an angle grinder. Any winding through a contact is connected to a graphite brush.
Next, the electronic circuit by the method of 2 parallel connected to graphite brushes the winding goes to the rotor, where it closes at the contacts of its collector. It is catchy that the anchor winding is a huge number of windings, but specifically to graphite brushes only two are connected. In 9 out of 10 cases, the breakdown of the grinding machine, as well as any electric tool, occurs due to a break in the electronic circuit.
To diagnose the circuit and detect defects here, they use a special device. a multimeter. This common rumor will need a portable tester not only for diagnosing an angle grinder, but also for some other power tool, right before wiring in your house.
Testing should always begin in this area of electronic current input and alternately ring with a multimeter, what remains to do to our client are the elements of the electronic circuit. To check the conductivity of electricity, the multimeter should be set to the low resistance position.
Elimination of small defects
If the angle grinder does not start when you press the Start button, it is possible that the cause of the breakdown is a little severe and the machine can be repaired at home. There is a rule of repairing any kind of power tool. moving from simple to complex.
Anchor device angle grinder.
In the given situation, in 9 cases out of 10, the cause of the malfunction will be a break in the electronic circuit in this area from the power source to graphite brushes. First you need to remove the casing and check with a tester whether the electricity is connected to the "Start" button. If the electronic current does not flow to the button terminals, then it’s enough to change the old electronic wire to a new one to repair the tool.
If the current flows to the trigger, but does not go further, then there is a problem in the start button itself. It must be replaced, but this should be done slowly. At first, you need to carefully disassemble the trigger, with all this, do not be lazy to mark the contacts to be removed. It does not matter which one, suitable in size and with similar parameters, is suitable for changing a button that has become unusable. It is especially necessary to be careful when reversing the connection of contacts, since their incorrect installation will probably result in a sealed winding along another wedged anchor.
If both the electronic wire and the launcher button in a workable version of serviceability, however, the current does not flow to the graphite brushes, it is necessary to first clean the contact plates of the brush holders attached to the collector. In that case, and after performing this procedure, the angle grinder does not cut, then the brushes themselves should be changed.
Change graphite brushes
As practice shows, specifically graphite brushes in most cases become the cause of a malfunction of an angle grinder. Their service life is limited to 1.5-2 years. Replace old brushes with new ones is not difficult. To check the brushes, the housing must be open. Getting to them is not difficult. At first, it is necessary (when the cord is disconnected from the socket) with a straight screwdriver to carefully lift and move the brush holders attached to the collector to the side. A screwdriver is also used to remove the brushes. If you have a proprietary tool, then here, most likely, the brush is held by a spring, and to remove it, use a screwdriver to squeeze this spring. When the tool is Chinese, then there are plugs that will have to be removed with a screwdriver, only then of course remove the brush.
If she does not cling anywhere, then there is the option of fixing the brush in the brush holder. Then drown it inward and you can put the brush holder in the seat. Change the second brush in the same way. As a result, check how neatly and correctly you laid the wires, whether they will be pinched anywhere. After which, of course, close the case and try to turn on the machine.
Changing brushes is the maximum that intuition allows you to repair without the help of others in an angle grinder, without risking, due to inexperience or inability to spoil the tool.
complex repairs, such as cleaning the collector, changing the gearbox, in other words, anchors, without suitable experience, it is better not to do without the help of others. If such a need arises. invite a friend to visit who has already done a similar repair many times. You can do the repair yourself at home, but only under his supervision and at the prompts.
You are better off. take your own tool to the workshop. All the same, the angle grinder, even quite serviceable, remains source of excessive threat. Better to pay experts for repairs than to pay doctors for their own mastery of healing.