Anchoring another person. How to rewind an angle grinder at home How to fix an electric motor anchor

05.07.2023 House and plot

The anchor of the grinder is subjected to thermal, mechanical and electromagnetic loads more than all nodes. Therefore, it is a common cause of tool failure, and as a result, it often needs to be repaired. How to check the anchor for performance and repair the element with your own hands - in our article.

Bulgarian anchor device

An angle grinder motor armature is a conductive winding and a magnetic circuit into which a rotation shaft is pressed. It has a drive gear at one end, a collector with lamellas at the other. The magnetic circuit consists of grooves and soft plates coated with varnish for isolation from each other.

In the grooves, according to a special scheme, two conductors of the anchor winding are laid. Each conductor is half a coil, the ends of which are connected in pairs on lamellae. The beginning of the first turn and the end of the last are in the same groove, so they are closed to one lamella.

How to check the anchor grinder for serviceability

Types of anchor faults:

Breakage of conductors.

Interturn closure.

Breakdown of insulation to ground is the short circuit of the winding to the metal housing of the rotor. Occurs due to the destruction of insulation.
Soldering of collector conclusions.
Uneven manifold wear.

If the armature is faulty, the motor overheats, the winding insulation is melted, the turns are short-circuited. The contacts connecting the armature winding to the collector plates are soldered. The power supply is cut off and the motor stops working.

Types of anchor diagnostics:

visually;
multimeter;
light bulb;
special devices.

Standard Diagnostics

Before taking the device for diagnostics, inspect the anchor. It may be damaged. If the wiring is melted, the burnt insulating varnish will leave black marks or a peculiar smell. You can see bent and crumpled coils or conductive particles, such as solder residue. These particles cause a short circuit between the turns. The lamellas have curved edges, called cockerels, to connect with the winding.

Due to the violation of these contacts, the lamellas burn out.

Other manifold damage: Raised, worn or burnt plates. Graphite from brushes can accumulate between the lamellas, which also indicates a short circuit.

How to check with a multimeter

Video: how the check is carried out

If you don't have a tester, use a 12 volt bulb up to 40 watts.

How to check the grinder rotor with a light bulb

Take two wires and connect them to the lamp.
Make a break on the negative wire.
Apply voltage to the wires. Attach the ends of the gap to the collector plates and scroll it. If the light is on without changing the brightness, then there is no short circuit.
Perform a short to iron test. Connect one wire to the lamellas and the other to the iron of the rotor. Then with a shaft. If the light is on, then there is a ground breakdown. The winding closes to the rotor housing or shaft.

This procedure is similar to diagnostics with a multimeter.

Checking with an indicator of short-circuited turns (IKZ)

There are anchors that do not show wires connected to the collector due to filling with an opaque compound or due to a bandage. Therefore, it is difficult to determine the commutation on the collector with respect to the slots. The indicator of short-circuited turns will help in this.

This device is small and easy to operate.

First check the anchor for breaks. Otherwise, the indicator will not be able to detect a short circuit. To do this, use a tester to measure the resistance between two adjacent slats. If the resistance exceeds the average at least twice, then there is a break. If there is no break, proceed to the next step.

The resistance knob allows you to select the sensitivity of the device. It has two lights: red and green. Adjust the regulator so that the red light comes on. There are two sensors in the form of white dots on the indicator body, located at a distance of 3 centimeters from each other. Attach the indicator with sensors to the winding. Turn the anchor slowly. If the red light comes on, it means there is a short circuit.

Video: IKZ in action

Diagnostics with an anchor tester (throttle)

An armature tester determines the presence of an interturn winding short circuit. The inductor is a transformer that has only a primary winding and a magnetic gap is cut out in the core.

When we put the rotor in this gap, its winding starts to work as a secondary winding of the transformer. Turn on the appliance and place a metal plate, such as a metal ruler or hacksaw blade, on the anchor. If there is an interturn short circuit, the plate will vibrate or be magnetized to the armature body due to local oversaturation of iron. Rotate the anchor around the axis, moving the plate so that it lies on different turns. If there is no short circuit, then the plate will move freely along the rotor.

Video: How to make a do-it-yourself choke and check the anchor

How to repair an anchor at home

Because of the anchor, a third of the breakdowns of the screwdriver occur. With everyday intensive operation, malfunctions can occur already in the first six months, for example, if the brushes are not replaced in time. With gentle use, the screwdriver will last a year or more.

The anchor can be saved if the balance is not disturbed. If during the operation of the device an intermittent hum is heard and there is a strong vibration, then this is a violation of the balance. This anchor needs to be replaced. And you can repair the winding and collector. Small short circuits are eliminated. If a significant part of the winding is damaged, it can be rewound. Worn and badly damaged lamellas should be machined, extended or soldered. In addition, you should not undertake anchor repair if you are unsure of your capabilities. It is better to replace it or take it to the workshop.

Manifold groove

Over time, brush wear is formed on the collector. To get rid of it, you need:

Remember to clean the rotor of chips so that there is no short circuit.

How to rewind an anchor

Before disassembling the armature, write down or draw the direction of the winding. It can be left or right. To determine it correctly, look at the end of the anchor from the side of the collector. Put on gloves, take sharp wire cutters or a hacksaw. Remove the winding ends. The collector needs to be cleaned, but it is not necessary to remove it. Carefully, without damaging the slot insulators, knock out the rods of the remaining parts of the winding with a hammer and a metal chisel.

Video: We remove the winding

With a file, without damaging the insulator films, remove the remnants of the impregnation. Count the conductors in the groove. Calculate the number of turns in the section and measure the diameter of the wire. Draw a diagram. Cut cardboard sleeves for insulation and insert them into the grooves.

Video: Winding left and right

After winding, weld the conclusions of the sections with the cockerels of the collector. Now check the winding with a tester and a short circuit indicator. Start drinking.

Impregnation instructions (including speed controller)

At the end of the process, lightly machine the manifold. Balance the anchor with dynamic balancing and a grinder. Now turn the finish on the bearing. It is necessary to clean the grooves between the lamellas and polish the collector. Do a final check for opens and shorts.

The peculiarity of the winding for angle grinders with adjustable speed is that the rotor is wound with a power reserve. The current density affects the number of revolutions. The cross section of the wire is overestimated, and the number of turns is underestimated.

Repair: Elimination of insulation breakdown

If the insulation breakdown was small and you found it, you need to clean this place from soot and check the resistance. If its value is normal, insulate the wires with asbestos. From above drip with quick-drying glue like "Supermoment". It will seep through the asbestos and insulate the wire well.

If you still have not found the place of insulation breakdown, then try to carefully impregnate the winding with an impregnating electrical insulating varnish. Punched and non-pierced insulation will be impregnated with this varnish and become stronger. Dry the anchor in a gas oven at about 150 degrees. If this does not help, try rewinding the winding or changing the anchor.

Soldering collector plates

The lamellae are mounted on a plastic base. They can be erased to the very core. Only the edges remain, to which the brushes do not reach.

Such a collector can be restored by soldering.

From a copper pipe or plate, cut the required number of lamellas to size.
After the anchor has been cleaned of copper residues, solder with ordinary tin and soldering acid.
When all the lamellas are soldered, do the grinding and polishing. If you don't have a lathe, use a drill or screwdriver. Insert the armature shaft into the chuck. First sand with a file. Then polish with zero sandpaper. Do not forget to clean the grooves between the lamellas and measure the resistance.
There are not completely damaged slats. To restore them, it is necessary to carry out more thorough preparation. Lightly machine the manifold to clean the plates.
The place under the plate must be expanded with a drill carefully so as not to remove a large layer of insulator.
Find two pieces of copper wire large enough to fit snugly into the groove. Lay the cleaned wires in the groove and irradiate.
Make a blank of copper lamella. It should fit snugly into the groove and be higher than the existing lamellas to make soldering easier.
Iron the workpiece so that there is a lot of solder. It will sit tighter in the groove. Lay the workpiece in the groove and attach the soldering iron to it. Hold it until the solder melts.
File off the excess, sand and polish.

If the collector was completely worn out, then after soldering it will last no more than a month of active use. And not completely damaged plates after such a repair can withstand several replacements of brushes and are not soldered.

In my previous article, I talked about one of the NLP techniques, namely anchors and setting them for yourself. In this article, I would like to continue this interesting and undoubtedly very useful topic and tell other people about anchoring, this process in NLP is called anchoring. Let me remind you once again what an anchor is and how it works: an anchor is any external stimulus, stimulus, something that precedes a conditioned reflex, for example, it is a visual image, auditory, olfactory or kinesthetic, everything that affects our senses. The anchor causes a person’s reaction, this reaction is a certain internal state of a person, for example, an external stimulus causes a person to feel fear, or simply attracts his attention, for example, ringing a bell or knocking a hammer on a table, as happens in court, draws his attention audience. Anchors can be set and controlled thereby by your internal state, that is, causing the resource you need, a sense of satisfaction, concentration of attention, various emotional states, such as resentment, anger, a sense of joy, and so on and so forth.

But anchors, as you understand, can be set not only for yourself, but also for other people, and use them to access other people's resources, for example, causing a person to feel shame, pity or trust in you. If you use this technique solely for your own purposes, achieving the set result that meets your interests only, then this can be called manipulation of the behavior of other people, which I will now tell you in more detail. In part, setting the anchor is reminiscent of hypnosis, to some extent being it, only in a less frank form, after all, you don’t zombify a person so much that he unquestioningly fulfills all your desires. Although those people who are very good at setting anchors and have strong suggestion are able to put people into a hypnotic state, I have witnessed such sessions many times, I must say very impressive. But I’ll tell you about hypnosis some other time, but for now let’s get back to setting anchors, which is also a very exciting process that can influence people, both positively and negatively.

First of all, it is necessary to single out the group of people on whom it is easiest to anchor - these are people with a developed right hemisphere of the brain. Such people do not think in a structured way, they rely more on the senses and sensations, acting intuitively, without analyzing or rethinking the information that comes to them. But this does not mean at all that these people are not inclined to think, and therefore not everyone can be anchored, that is, it is more difficult to do this with some people. Having decided to anchor a person, it is necessary to find out which of the organs of perception is the main one for him, setting the anchor through this organ will be the most effective. That is, you need to determine what type of person is in front of you: visual - perceives information better with the help of vision, auditory - the best way to perceive information for them is the auditory canal, kinesthetic - a person who predominantly feels rather than sees, hears or thinks, or this type of people as discretes - that is, people perceive information for the most part with the help of logical thinking, understanding the information received by them, with the help of numbers, facts, various signs and logical arguments.

Of course, it is not necessary that only an anchor similar to their channel of perception will work, setting other anchors will also give a result, but what is closer to these people will work best. Although the kinesthetic method of anchoring is considered the most effective, nevertheless, sensations store information in memory best of all, in most cases. Now about the actual process of installing the anchor, which boils down to creating a certain environment for a person in which he feels as comfortable as possible. Anchoring can happen in any way, you can have a casual conversation about a person’s past, returning to which he experiences positive emotions that are peaceful in nature. That is, in any way you need to create for the other person the most favorable environment in which he feels as comfortable, calm, and at ease as possible.

Music, smells, visual surroundings, your words, behavior and of course touches, including from the side of the person you anchor to. That is, everything is ingeniously simple, certain actions on your part lay in the memory of a person this favorable environment, you can touch a person’s hand in a certain way, say pleasant words, ask, for example, to do something relaxed so that it remains in memory as an action accompanying the situation. Subsequently, when reproducing some moments from this situation, they will cause a person to remember her, about you and bring him to the state in which the person was when the anchor was installed. That is, if you wanted to be remembered as a positive person, then the associations associated with the situation that you created will remind the person of you, and naturally this will be a pleasant memory.

Regarding the setting of the anchor through the memory that I mentioned, here the point is to call out certain emotions in a person with the help of memories, as happens during hypnosis, and associate this situation with oneself. That is, you ask a person to remember the pleasant moments of his life, and when he is at the peak of emotional experiences, perform some action, for example, touch and say pleasant words, that is, those positive memories in which the person is located also allow your presence, thus, for example, you can achieve confidence in yourself on the part of this person and much more. In a similar way, you can establish an anchor that causes a feeling of fear, associating certain actions with a negative feeling for a person, a simple example is a swing at a person with a hand, which can cause him a feeling of fear or other response if he is often beaten. Let's say if you want to anchor a child so that he does not climb into the socket, then you must in any way convenient for you cause fear in him every time he approaches the socket, for example, emotionally explain to him how scary it is, the more emotions, the better, or just punch him in the arms.

This is information for the subconscious, which gives out a reflex reaction, a person is afraid not of what is at the moment, but of what was once, and the current situation simply evokes this feeling in him. I think the meaning is clear to you, since there can be a lot of situations in each specific case, as I mentioned earlier in my first article on anchors, the topic is quite deep, but it is interesting and useful to study it. I also want to tell you about setting an anchor through an indirect impact on a person, that is, creating a certain myth about yourself, in the form of a positive or negative image, depending on what you need. This is done by people who create a positive image in the eyes of the public, for example, for some pop star, or a politician, that is, for a person, associations associated with him are artificially created. For example, a political figure against the background of children, family, against the background of workers communicating with him, and similar tricks, create an impression in people about such a person as someone of their own from their world.

Thus, the anchor of the positive attitude of some people to others is established, without direct impact, but indirectly.

In general, I’ll tell you this, calling a person to certain memories and thereby creating a certain internal state for him, already sets an anchor for him on you, as on a positive or negative person. This will be the so-called first impression that you can create with a person by talking to him about a certain topic. You can make it, this impression, the way you want, if you approach this issue with all seriousness, controlling your every word. If you make a person remember the most terrible moments in his life, then he will inevitably connect them with you. And if you help him remember and think about the good, then the pleasant sensations that he will experience will also be associated with you. That is why some competent sellers try to evoke as many pleasant associations as possible in a person during communication, so that he not only buys the product or service he needs from them, but also becomes attached to them - to the sellers, to the store, to the company. Here is an anchor setting that is often used by many people.

By the way, it is difficult for psychologists to use such a technique, since while working with people they often have to touch upon moments that are extremely unpleasant for a person, which, of course, does not add popularity to a specialist, but it helps people cope with their problem. Therefore, if the psychologist with whom you work annoys you or makes you suffer, raising layers of information that are extremely unpleasant for you in your memory, then you should know that he is working, and we can say with all confidence that he is a good psychologist.

In this way, friends, anchors are established, or as it is also called, anchoring occurs. Of course, we have not considered all the examples that can create a complete picture of anchoring for you, but as with everything else, we will also return to this issue, considering specific situations and various ways to control human behavior, after all, we study psychology after all.

In subsequent articles, we will definitely touch on the issue of removing the anchor, ways to recognize the manipulation applied in this way against you, as well as the ability to resist it. Most importantly, remember that everything inexplicable, random, unexpected, incomprehensible and unusual happens in the lives of those people who do not realize much of what is happening to them. And where there is no awareness, suggestion works. In the unconscious life there is only one pleasant moment - it is a pleasant surprise, although, as a rule, there are more unpleasant surprises. But in the life of a person who understands and realizes, there are always more pleasant moments, since he creates them for himself.

Bulgarian is used to perform many tasks on the farm. Regular use may damage the device. The most frequently broken element is the anchor. It is affected by a high thermal load, as well as mechanical and electromagnetic influences. As a result, many craftsmen have to think about repairing this part.

Anchor device

The anchor of the angle grinder consists of a winding that conducts current and a magnetic circuit. In the magnetic circuit there is a shaft that performs torsion. The design of the magnetic wire is formed by plates and grooves, which are isolated from each other by varnish coating. A certain sequence of laying the conductors of the anchor winding into the grooves has been developed. The conductors form a coil. Its endings are connected on lamellas. The layout of the beginning of the starting turn and the end of the last one is drawn up in such a way that they close on one lamella.

With constant overheating of the motor of the angle grinder, the anchor melts. As a result of high temperature, the contacts of the wires that connect the primary winding to the collector may fall off. All this leads to the fact that the current is not supplied.

Anchor failure

There are criteria on the basis of which it can be concluded that anchor repair is required:

the number of sparks emanating from the brushes on the engine manifold increases;
vibration occurs at low speed;
the working shaft begins to move in different positions.

The presence of these signs indicates a breakdown of the anchor. Subsequent use may be hazardous.

The following anchor damage is known:

breakage of conductors of electric current;
short circuit between turns;
violation of insulation, which leads to a short circuit of the winding on the metal surface of the rotor;
soldering the ends of the collector;
unequal abrasion of the collector.

As a result of these malfunctions, the engine gradually stops working. To find out the cause of the failure of the angle grinder, diagnostics should be carried out. It can be carried out visually or with the use of appropriate instruments.

How to check the anchor on the grinder?

Visual Inspection Rules

Standard diagnostics involves visual analysis of the device. It is necessary to analyze the integrity of the wire and the current supply to the motor collector. With a normal power supply, you should inspect the grinder from the inside. Disassembling the device is not difficult. It is best to take a picture of the location of the main modules of the device when disassembling. After disassembly, visually check the anchor for the following properties:

the anchor must be free;
the absence of black spots and smell, which may indicate the melting of the winding, the insulating varnish of which leaves traces;
lack of crumpled turns and solder residues, which leads to a short circuit;
there should be no burnout on the contacts of the lamella, otherwise the connection of the lamella cockerel and the winding shank should be checked;
no worn or burnt records;
the space between the lamellas should not contain graphite residues from the brushes.

If visual inspection does not reveal deficiencies, then it is necessary to check with instruments. The anchor on the grinder can be checked both with the help of a tester and using an ordinary light bulb.

Inspection with a tester

The multimeter is set to the ohmmeter position. The resistance is set to 200 ohms. The probes are connected to the lamellas located next to each other. If the value on the device is less than 1 ohm, then there is a short circuit. If the value is greater than the average, there may be a break in the turns. With a high resistance value or the absence of any value (in the case of using a digital device), one can also judge a break.

There are situations when a break is not detected. Then a mass test is done. At maximum resistance, one of the probes is placed on the shaft, and the other moves along the plates. If the value is zero, then there is no damage. Then the rotor is checked in the same way with a multimeter. The probe in this case moves along the lamellas. If it is impossible to perform a check by the tester, a light is used.

Light bulb control

In the absence of a device at hand, many are interested in the question of how to check the angle grinder for possible anchor failures. The power supply wire is broken, and a light bulb is placed in the place where one wire is broken. Then the shaft rotates. By changing the brightness of the light bulb, one can judge the circuit between the turns. In the absence of combustion, the following conclusions are possible:

the location of the brushes does not correspond to the working position, due to the operation of the retaining spring;
rupture of the supply circuit;
short circuit or break in the stator winding.

You can ring the indicator of short-circuited turns and the anchor tester. This can be done by an experienced person.

Is it possible to repair the anchor

Repair of the anchor of the angle grinder cannot be performed if there is vibration, as the balance is disturbed. This situation calls for a replacement. It is possible to eliminate the short circuit and replace the winding.

First you need to disassemble the engine and remove the rotor. But before that, disconnect the power terminals and remove the brushes. The rotor of the angle grinder comes with a thrust bearing and an impeller for cooling.

Anchor rewind

Anchors for angle grinders can be rewound at home. To do this, you need to have certain skills when working with a soldering iron. To rewind the anchor with your own hands, you will need:

a wire with a copper core that matches the previous conductor;
dielectric paper to insulate the winding;
varnish for filling coils;
soldering iron.

Rewind scheme:

removing previous windings - try not to spoil the surface of the case. If damage occurs, grind with emery or a file;
inspection of the collector - the value of the resistance of the contacts of the lamella in comparison with the shell should not exceed 0.25 Mohm;
cleaning the collector from old wires - developing grooves for inserting the ends of new wires;
setting sleeves - they are made of a material that does not conduct current, for example, electrical cardboard. Their size is 0.3 mm;
rewinding coils - the end of the new wire is attached to the end of the lamella. Rewind in a counterclockwise direction. Fasten the wires near the collector with cotton thread;
control for the absence of short circuits - measure the resistance with a tester;
applying varnish or epoxy to secure the winding - dry in the oven or use products that dry quickly.

If it is not possible to perform such actions, then you can replace the anchor of the grinder.

Anchor change

Replacing the anchor on the grinder is carried out simultaneously with the replacement of the thrust bearings and the motor cooling impeller. To perform, you will need the following devices:

a new anchor for the angle grinder, suitable for your device;
screwdriver and key;
brush with soft bristles and a cloth for wiping the elements.

Disassembly steps:

removing brushes;
unscrewing the gearbox;
removing the gearbox cover;
removing the ring that fixes the small gear on the anchor;
extraction of the armature together with the gear and bearing;
removal of the bearing with a special removable device;
removal of the gear and fixing disk;
wiping the main elements with a napkin.

The installation of a new part for the grinder is carried out in the reverse order:

installation of the fixing disk on the shaft;
bearing pressing;
installation of a small gear and its fastening with a retaining ring;
placement of the anchor in the gearbox with the docking of holes;
fixing the gearbox in the body of the grinder;
installation of brushes;
device check.

Thus, do-it-yourself anchor repair can be done quickly and easily. But in order to prevent such cases, you need to use the device carefully and not subject it to prolonged high loads. Keeping the tool in a dry place and proper care will prolong its life.

Every self-respecting man should have a “Bulgarian” on a shelf with tools. Indeed, it is almost impossible to do without this tool in the economy. You always remember about the grinder when you need to cut off a piece of any product made of dense material, be it metal, stone or ceramics. But, like any other tool, the grinder can break. At the same time, in 60 percent of cases, the cause of the malfunction is the failure of the electric motor, or rather, the collector or armature brushes. Do not rush to throw away the tool, because with the help of simple manipulations you can still fix and rewind the engine with your own hands.

First you need to disassemble the tool and carefully examine the structural elements. In particular, we are most interested in the electric motor. Before removing a burnt or broken winding, it is necessary to calculate the number of its turns. To do this, the upper coil is separated from the winding and cut off. In this case, it is necessary to burn the coil on an open fire and calculate the required number of turns.

If you plan to rewind without the use of special devices, then it is not recommended to remove the anchor immediately. It is necessary to slowly inspect the collector. It will not be superfluous to measure the insulation resistance. In this case, the value should not be less than 200 kOhm relative to the case. After that, it is necessary to carefully clean the collector if there were remnants of the winding, and also make new grooves in the collector into which the ends of the coils will be inserted.

As soon as the anchor is cleaned, it must be sleeved. To do this, it is necessary to make sleeves, which are quite realistic to build from electrical cardboard. Next, they must be inserted into the existing anchor grooves. Thick cardboard is not recommended. Its thickness should not exceed 0.2 mm. After the armature has been cleaned, the sleeves will find their place in the grooves and the converted collector will be installed, you can wind the coil.

If the winding is carried out according to the circular type, then the turns must be laid in series until the grooves in the anchor are completely filled. It is quite simple to understand which side to lay on - you just need to look at the device from the side of the shaft. In this case, the winding must be done counterclockwise. This type of laying is called "right".

Be sure to put a bandage on the winding. It is best to do this next to the collector, so that it is more convenient to fasten the turns of the coils. Many do not know what a bandage is. In fact, this is a pair of turns of thick thread, which must be tightly wound and tied. It is better not to use kapron thread, because it can melt during engine operation. It is best to use cotton products.

After completing the work, be sure to check the rewound armature for breaks or interturn short circuits. This must be done before the armature is saturated, otherwise it will be more difficult to replace the winding. Impregnation must be carried out in order to fasten the turns of the coil. It can be done with epoxy or varnish.

The last stage is the groove. It depends on the quality of this work how much the rewound anchor will spark. In this case, the beats should not exceed 0.05 mm. After completing the groove, it is necessary to again check for the presence of short circuits between the turns and to the body.

pue8.ru

Do-it-yourself electric motor rewinding at home from professionals

Equipment is often subjected to overload and mechanical damage. It is worth just once to drop or spill something on the tool, as rust appears on the rotor winding, and the armature itself is displaced. The consequences are deplorable: the electric motor overheats, sparks and vibrates. Working with such a tool is dangerous.

If you have the skills to repair equipment and a minimal set of tools, then rewinding the anchor at home will help fix the problem. The fact is that it is the winding that takes on the first “blows” of improper operation. Conductor strands are torn and burnt. Replacing them will extend the life of the equipment and increase engine performance.

How to rewind the armature of an electric motor at home

Before proceeding with the repair, prepare the tools and materials:

multimeter. If it is not there, then you will need a voltage indicator, a megger and a 12 V light bulb with a power of 30–40 W;
new winding. The core diameter must be identical to the diameter of the old winding;
soldering iron;
dielectric cardboard 0.3 mm thick;
varnish or epoxy resin;
a skein of thick cotton threads;
sandpaper.

In order not to do unnecessary work, it is important to correctly identify the cause of the breakdown of equipment. To do this, inspect the tool and check whether current is supplied to the collector and the start button using a multimeter or indicator. If everything is in order, then you need to inspect the device from the inside.

Engine Diagnostics

Disconnect the instrument from power, and disassemble the case. Smell the rotor. If an interturn short circuit occurs, then the insulating coating melts and exudes a pungent odor.

When there are no external signs of a malfunction, it is worth checking the armature lamellas with a multimeter. Switch the instrument to ohmmeter mode, and set the range to 200 ohms. With two probes, "ring out" the adjacent lamellas. A change in resistance indicates a breakdown in the coil.

An ohmmeter can be replaced with a light bulb. Connect the plus and minus terminals to the plug of the device, and put a lamp in the gap. Rotate the armature shaft by hand. If the lamp "blinks", then an interturn circuit has occurred. Lamp not on? This means that an open circuit has occurred or there is no resistance in one of the lamellas.

Replacing the winding and new insulation will prevent the motor from burning out. To extend the life of the electric motor, it is recommended to rewind the rotor at least once every two years.

Instructions: how to rewind the armature winding

Before rewinding, you need to fix the main indicators of the engine. Count and write down: the number of anchor slots and collector lamellas. Determine the winding pitch. The most common step 1-6 is when the coil fits into the initial groove, then into 7 and is fixed on 1 groove.

Some factory windings use reset to the right or left. For example, when winding and resetting to the right, the coil goes to the right of the initial groove. So, with the number of armature slots 12, winding pitch 1–6 and reset to the right, the winding is laid in 1 slot, then 8, and after winding the required number of turns, it is fixed in 2 slots. All this must be taken into account. Otherwise, the winding will be laid incorrectly, which will adversely affect the direction of rotation.

Do-it-yourself rewinding of the motor armature will take about 4 hours. In order to avoid difficulties during assembly, it is recommended to photograph the original location of the parts during each stage of work:

Consolidation. Wrap a few turns of cotton thread tightly around the winding near the collector to secure the coils. Synthetic threads cannot be used - they melt.
Checking circuits. As with diagnostics, check the winding for open circuits and turn-to-turn short circuits.
Treatment. If the test does not reveal any faults, then coat the winding with varnish or epoxy and dry. To speed up the process, you can send the anchor to a conventional oven for 20 hours at a temperature of 80 degrees.

Rewind completed. With a certain skill, repairs do not take much time. If you changed the winding for the first time, and are not quite sure about the correct laying of the wire, then you can conduct an additional check.

Do-it-yourself static balancing of the motor armature

The key to trouble-free operation of equipment after rewinding the anchor is proper balancing. In large electric motor repair companies, dynamic balancing is done on a special machine. Since it is difficult to rewind the anchor yourself for the first time, then to identify blunders, the device for static balancing "On knives" will help. It is easy to construct it yourself.

Pick up two blades of steel. They must have good straightness and cleanliness. Set the blades on a rigid base parallel to each other. The distance between the blades is the size of the anchor. The end result should be something like this:

Schematic representation of the device "On the knives", where 1 is the armature of the electric motor; 2 - steel blades; 3 - base; A and B - points for soldering loads.

The balancing method is simple: the anchor is placed on the blades and its movement is observed. The anchor will rotate as the heaviest part will be at the bottom. The task is to move the center of gravity as close as possible to the axis of the anchor, which is indicated by the dotted line. With high-quality balancing, the anchor remains motionless. To equalize the weight, plasticine weights are hung on points A and B. When equilibrium is reached, the weights are removed, weighed, and metal equal to their weight is soldered.

The balancing method is simple: the anchor is placed on the blades and its movement is observed. The anchor will rotate as the heaviest part will be at the bottom. The task is to move the center of gravity as close as possible to the axis of the anchor, which is indicated by the dotted line. With high-quality balancing, the anchor remains motionless. To equalize the weight, clay weights are hung on points A and B. When equilibrium is reached, the weights are removed, weighed, and metal equal to their weight is soldered.

Now you know how to rewind the anchor with your own hands. Thanks to the skills of balancing, your tool will not vibrate and overheat, even with minor flaws in the winding laying. Regular checks of contacts and routine cleaning of the case will help minimize the likelihood of equipment breakdown.

remonteldv.ru

Do-it-yourself check and repair of an anchor grinder 1

Features of the asynchronous motor grinder

Almost all electrical appliances used in everyday life use an asynchronous electric motor. An important advantage of this type of motor is that when the load on it changes, the speed does not change. This means that if, for example, you cut a stone with a household grinder for a long time and without stopping, there will be no noticeable external signs of engine overload. The disk rotation speed will be constant, the sound will be monophonic. Only the temperature will change, but this may not be noticed if the hands are wearing gloves.

The collector of an induction motor is sensitive to overheating

With a careless attitude, an advantage can turn into a disadvantage. Asynchronous motors are very sensitive to overheating, a significant excess of the operating temperature entails melting of the insulation on the rotor windings. At first, the motor will work intermittently, and then - when an inter-turn short circuit occurs - the engine will stop completely. It is worth overheating the engine of the grinder several times and, most likely, the anchor will melt. In addition, the contacts connecting the wires of the primary winding to the collector are soldered from the high temperature, which leads to an interruption in the supply of electric current.

How to determine the malfunction of the anchor angle grinder

Signs of breakage of the anchor of the angle grinder are: increased sparking of the brushes on the motor collector, vibration of the motor at low speeds, rotation of the working shaft in different directions. If such symptoms are present, the tool should be stopped - it is dangerous. Suspicions are easy to check with simple tests.

Visual inspection from the outside

Troubleshooting should begin with a visual inspection of the angle grinder:

Conduct a general inspection of the instrument.
Pay attention to the integrity of the power cord, the presence of voltage in the outlet.
Using a voltage indicator, verify that current is flowing to the motor manifold and the start button.

The indicator checks the integrity of the electrical circuit

Inspection of the device from the inside

If everything is in order with the power, but the grinder does not work, you will have to open the case to gain access to the motor. As a rule, disassembly is not difficult. But you need to follow simple rules that will help you avoid trouble during reassembly:

Be sure to unplug the appliance before disassembling.
Remove the working disk and protective cover from the spindle.
Open the case in a well-lit place, on a clean table surface.
Remember the location of all parts and assemblies before disassembly. It is recommended to draw or photograph the internal structure of the device.
Store screws and fastening screws in a separate place so that they are not lost.

It is best to inspect the motor under bright lighting so that all small details are clearly visible. The armature should rotate freely around its axis, properly operating bearings should not make a sound during operation. There should be no traces of melted wiring on the anchor, the circuit windings should be intact, without breaks. You can smell the rotor. During an interturn circuit, the insulating varnish burns and emits a persistent specific odor. But such a diagnosis requires some experience.

Continuity testing with a tester

If a visual inspection did not give clear results, it is recommended to continue the examination with a multimeter. By setting the mode switch to the ohmmeter position (range 200 ohms), it is necessary to “ring out” two adjacent armature lamellas with two probes. If the resistance on all turns is the same, this means that the windings are working. If, on some pairs, the tester shows a different resistance or an open circuit, there is a malfunction in this coil.

Using a multimeter in resistance measurement mode, check the integrity of the coils

A break in the wiring can occur between the winding and the core. You should carefully examine the connection points of the coils with the collector lamellas in the lower part of the armature, visually check the soldering of the contacts.

Checking contacts with a light bulb

If there is no tester, you can get out of the situation with a simple 12 volt light bulb. Power can be any, optimally 30-40 watts. The voltage from the 12 volt battery must be applied to the grinder's plug by inserting a light bulb into the gap of one wire. With a working anchor, if you rotate the spindle by hand, the light should be on without changing the brightness. If the glow changes, this is a sure sign of an inter-turn short circuit.

If the light does not light up, then this may indicate the following:

It is possible for the brushes to hang in the non-working position. The retaining spring has worked.
The supply circuit has broken.
A short circuit or a break has occurred in the stator winding.

There are other diagnostic methods, but they require more sophisticated equipment, which is usually not used at home. An experienced craftsman will determine the breakdown with a high degree of accuracy using a “punch” or a simple transformer with a cut toroidal core and one primary winding.

In what cases can you save the anchor and restore it yourself

If the armature damage is established with guaranteed accuracy, the part must be removed from the electric motor. The disassembly of the motor must be done with extreme care, after removing the brushes and disconnecting the power terminals. The rotor is removed along with the support bearings and the motor cooling impeller, they form a single whole with it.

Diagram of the anchor device grinder

If most of the wiring in the armature is damaged and balance is disturbed as a result of overheating, it is better to replace it entirely. An imbalance is indicated by increased vibration and an uneven hum during the operation of the mechanism.

How to rewind an anchor - step by step instructions

If the armature balance is not disturbed, and the problem is only in damaged windings, then such an armature can be restored independently by rewinding the coils. Rewinding a rotor at home requires a lot of patience and accuracy.

The master must have skills in working with a soldering iron and devices for diagnosing electrical circuits. If you are unsure of your abilities, it is better to take the engine to a workshop for repair or replace the entire anchor yourself.

For self-rewinding the anchor you will need:

wire for a new winding. A copper core is used with a diameter that exactly matches the old conductor;
dielectric paper to isolate the winding from the core;
varnish for filling coils;
soldering iron with tin-lead solder and rosin.

The rewind process consists of the following steps:

Dismantling of old windings. They must be carefully removed without damaging the metal body of the anchor. If any burrs or damage are found on the body, they must be smoothed out with a file or sanded with emery. Sometimes, in order to completely clean the case from slag, craftsmen prefer to burn it with a burner.
Preparing the collector for connecting a new wire. There is no need to remove the manifold. You should inspect the lamellas and measure the resistance of the contacts with respect to the housing with a megger or multimeter. It should be no more than 0.25 MΩ.
Removing old wiring on the manifold. Carefully remove the remnants of the wires, cut the grooves in the part of the contacts. In the future, the ends of the wires of the coils will be inserted into the grooves.
Installation of anchor sleeves. Sleeves are made of a dielectric material 0.3 mm thick, for example, electrical cardboard. Cut a certain number of sleeves and insert into the grooves of the cleaned anchor.
Rewinding coils. The end of the new conductor is soldered to the end of the lamella and wound in successive circular motions, counterclockwise. This laying is called "laying to the right." Winding Repeat for all coils. Near the collector, tighten the wires with a thick thread of cotton fabric (nylon is prohibited, as it melts when heated).
Winding quality check. Upon completion of laying all the windings, check with a multimeter for the absence of interturn short circuits and possible breaks.
Finishing processing. Treat the finished coil with varnish or epoxy to fasten the winding. In the factory, the impregnation is dried in special ovens. At home, this can be done in the oven. As an option - use quick-drying varnishes for impregnation, applying a coating in several layers.

Replacing the anchor yourself at home

Practice shows that if it is decided to replace the anchor of the grinder, then it is best to change it together with the support bearings and the engine cooling impeller.

To replace you will need:

New anchor angle grinder. Must match your model. Interchange with other models is not allowed.
Screwdrivers, wrenches.
Soft brush and rags for cleaning the mechanism.

How to remove the anchor

Replacing the anchor begins with disassembling the grinder. The following steps are taken:

The brush knots are unscrewed with a screwdriver on both sides. The brushes are removed. To remove, you will need a wide flat screwdriver
4 screws securing the gearbox housing are unscrewed. Carefully remove the housing
The gearbox cover is carefully opened and removed to gain access to the inside of the gear mechanism. To disassemble the gearbox, you will need a puller
The retaining ring is removed, fixing the small gear on the anchor.
The armature retainer is released from fastening, the armature is removed together with the small gear and bearing.
The gear, bearing and armature fixing disk are removed, wiped with a rag. The bearing is removed with a special puller. The puller is driven by the rotation of the stop screw

Video: replacing bearings on a grinder

How to anchor in place

To install the new anchor of the angle grinder, you should take a new part, and then assemble the tool in the reverse order. The action sequence is the following:

A fixation disk is installed on the armature shaft.
The bearing is installed by pressing.
A small gear is mounted and fixed with a retaining ring.
The anchor is inserted into the gearbox housing, the docking holes are combined.
The gearbox mounting bolts are tightened.
The anchor with the gearbox is inserted into the body of the angle grinder and fixed.
The brushes are deposited in their places, closed with lids.

After completing these steps, the grinder is ready for work. The anchor has been replaced.

Video: how to check the angle grinder

An ancient Sufi wisdom says: “A smart person is one who is able to get out of a difficult situation with dignity. But wise is he who does not find himself in such a situation. By observing the rules for operating household appliances, preventing the motor from overheating, you can avoid breakdowns and troubles in the work of the grinder. Keeping and storing the tool clean and dry will prevent its mechanisms from contamination and oxidation of current-carrying elements. Timely maintenance of the tool is guaranteed to save you from unpleasant surprises during operation.

100uslug.com

Repair of collector electric motors

In household equipment, electric motors of various types are used, depending on the operating conditions, purpose and functionality of the electrical appliance. For example, for electrical equipment with a stable operating mode, asynchronous motors are more suitable, and for electric drills, washing machines, food processors, etc., the use of collector electric motors is necessary, since frequent changes in the speed of rotation of the shaft are required.

The failure of the collector motor makes the electrical appliance completely unusable, and the expensive services of repair shops make the owners of damaged household equipment decide to purchase a new product. But with some skills and a limited budget, many home craftsmen are thinking about the feasibility of repairing electric motors with their own hands.

Disassembled commutator motor

Checking the power circuits

When repairing failed electrical equipment, sometimes it doesn’t come to repairing the collector motor - it turns out that the extension cord socket is faulty, the power cord is broken, the connection terminal is unscrewed, or the switch is stuck. It is necessary to check the presence of voltage at the nodes of the power supply circuit of the 220V collector motor, starting from the plug, ending with the connection terminal block.

Ring the power cord and power button

Since in collector motors the comparison of electromagnetic fields occurs due to the constant switching of the rotor windings (collector brushes), the mechanical cause of the loss of electrical contact in the collector is the most common. The principle of operation of collector motors is described in the previous article, and below will be given some tips for repairing and replacing rotor (armature) contacts.

Rotor (armature) of the collector electric motor

Various stand-alone power tools, kitchen appliances, and children's toys often use a DC brushed motor. These motors are powered by DC voltage supplied from batteries, rectifiers, or control controllers. The presence of voltage does not always indicate the operability of the power source (the battery can be planted), therefore, the current of the collector and the entire circuit should also be checked when the collector motor is turned on.

Low power DC commutator motor with control controller

If the electric drive of the equipment has stopped rotating, first of all, you should check the voltage supply to the input contacts of the collector motor when it is turned on.

Briefly about the device of collector electric motors

In collector electric motors, the magnetic fields of the stator and rotor interact at an angle that is most beneficial for imparting torque to the shaft. The rotation angle sensor (rotor position) and at the same time the switching system are the collector brushes on the rotor. A system of coils with magnetic circuits that creates a resulting electromagnetic field to impart torque is called an armature.

The principle of operation of the collector electric motor on the example of a DC motor

In most collector electric motors, the rotor is the armature, the electromagnetic field of which “clings” to the magnetic fields of magnets or stator field windings. Therefore, the word "armature" is often understood as the rotor of a collector motor, since switching the stator windings is more complex and less efficient.

Anchor (rotor) of the electric motor

DC commutator motors with magnets are mainly used in children's toys and in electric drive devices of cars. To create a powerful magnetic field and a stronger torque, excitation coils are used, which are connected in several ways:

Series connection (collector current and excitation coils are equal). The advantage is a large maximum torque, which, however, can become a disadvantage at idle, spinning the shaft of the collector motor to critically high speeds;
Parallel connection. The advantage is the good stability of the rotor speed of the collector motor when the load on the shaft changes, but the maximum torque is less compared to series excitation;
Mixed excitation, in which one part of the rotor and stator windings is connected in series, and the other in parallel. The most popular example of the use of mixed excitation in collector motors is an automobile starter;
Independent excitation, in which the rotor and stator collector currents are controlled separately. It is used in powerful collector electric motors on electric locomotives.

Wiring diagrams for excitation coils in a DC motor

Leaving theory aside, it should be noted that series-excited DC commutator motors can also operate on AC voltage, in fact, being universal. These motors have an additional output for connecting AC voltage and are widely used in various power tools, due to the "flexible" characteristics of changing the speed and torque.

Excitation coil connection diagram and designation of the universal collector motor

Checking the excitation coils

Based on the device of the collector electric motor, troubleshooting can be divided into checking the excitation coils (or permanent magnets) and the rotor windings. When repairing DC motors with magnets, you should pay attention to them for cracks, as they degrade the magnetic field strength, which reduces the overall performance of the electric motor.

Cross section of a collector motor with permanent magnets

Excitation coils are checked with an ohmmeter, checking their conductivity, as well as with a megohmmeter, excluding a breakdown on the case. Since the turn-to-turn short circuit in the turns of the excitation coil is extremely difficult to detect using only a multimeter, indirect methods are used, checking the color of the winding wires for signs of overheating or visible damage. Knowing the exact resistance of the excitation coils from the passport of the electric motor, you can compare the data with the results of measurements with an ohmmeter.

Stator field coils

Since the interturn short circuit in the turns of the excitation coils is a rare malfunction, they are limited only to checking these windings, shifting attention to checking and repairing the motor armature. The collector motor armature can be divided into several parts:

Rotor windings with magnetic circuits;
Collector consisting of brushes and contact plates (lamellae);
Shaft with bearings.

Motor armature device

Inspection of the mechanics of the commutator engine

When repairing any electric motor, the free play of the shaft should be checked, which depends on the wear of the bearings. Continuous inertial rotation of the rotor, the absence of rattle, squeaks, radial and axial runout of the shaft indicates the good quality of the bearings when looking for the cause of excessive heating of the collector motor. After making sure that the mechanics are working, you can check the electrical component of the electric motor.

It often happens that a breakdown in the mechanics of an electric motor or all electrical equipment is the cause of a malfunction in the electrical part of the engine.

For example, parts of a bearing scattered inside the electric motor or the ingress of fragments from other mechanisms can damage the rotor and stator windings of the collector motor. Therefore, when disassembling an electrical appliance or power tool, you should always pay attention to the serviceability of other mechanisms, because the collector motor inside the case is open and unprotected from small objects that can damage it.

In many power tools, the motor is not protected from small objects.

Prevention and repair of brushes

In commutator motors, the contact brushes make noise during normal operation, therefore, when manually testing the free play of the motor shaft, it is necessary to be able to distinguish between the nature of the sounds made by the brushes. Characteristic clicks and rustles should be uniform, without chaotic grinding and jamming. Very often, the cause of the loss of electrical contact is mechanical jamming of the commutator contact brushes.

Some components of the commutator engine

The commutator brush consists of a holder, a graphite contactor and a clamping spring. Sometimes the spring gets weak and needs to be stretched a bit for more downforce. Due to the abrasion of the graphite, small crumbs are formed, which, together with dust and moisture, pollute the gap between the graphite contactor and the holder. Layers form in this space, which dry out and harden from the heating of the brushes, thereby fixing them.

Collector brush device

This jamming of the brushes, due to hardened dirt in the holder, is often the reason for the impossibility of starting a previously properly working commutator motor. As long as the running engine vibrates, the pressure spring can overcome the resistance of the layers, and contact with the collector lamellas is maintained. But after turning off, the accumulated dirt solidifies, the brush is fixed and decreases due to cooling, forming a gap that breaks contact with the lamellas.

Electric motor armature collector lamellas

You can check the clamping force of the brush by prying the graphite with a knife or a small screwdriver - the contactor should move freely in the holder, rebounding elastically, hitting the lamellas. Otherwise, the brush and holder can be cleaned, washed in solvent, or the edges of the graphite contactor can be slightly sawn off for a larger gap. If the brush output has almost reached the resource threshold, then it is better to replace it with a new one. If it is impossible to find an identical replacement for the brush, the closest option is selected and the edges of the graphite contactor are cut to the desired size.

New brushes need to be ground with a file to give the desired size.

Collector repair and maintenance

The motor collector consists of contact plates - lamellas connected to the terminals of the anchor windings. The large operating current of the collector, and the formation of reactive EMF of switching windings due to electromagnetic induction, leads to increased sparking at the contact of brushes and lamellas. Strong sparking leads to burnout of the lamellae, due to which they become covered with pores and cavities. The deterioration of the surface quality of the lamellas leads to even greater sparking and accelerates their wear in an avalanche-like progression.

Collector pollution

The initial cause of collector wear is the contamination of the lamellas with graphite chips from erasable brushes. The gaps between the lamellae are designed to isolate them, but the graphite dust that enters the gaps is a current conductor, which worsens the characteristics of the collector motor and leads to the formation of a so-called circular spark. If during the operation of the electric motor a spark seems to stretch from the brushes along the circumference of the collector, then its lamellas are dirty and need to be cleaned.

Circular spark in manifold

Collector lamellas are cleaned with an eraser, sponge, or fine sandpaper, cleaning the gaps with an awl. If the contamination is severe, a file can be used, but care must be taken not to distort the geometry of the collector circumference by uneven sawing. Another cause of collector contamination is the corrosion of the lamella material with the formation of oxide layers, which also need to be cleaned.

Cleaning the manifold with a sponge

If, after cleaning the lamellas, deep cavities from corrosion or sparking are found, then the collector is repaired by applying copper to the plates by welding or galvanizing to seal the flaws. Since it is very difficult to give the correct shape to the collector with a file, it is turned on a lathe. In some cases, if it is possible to purchase a new collector, it is replaced, but in this case, painstaking work is required to connect the numerous leads of the anchor winding.

Turning the manifold on a lathe

Checking and rewinding windings

If the excitation coils, brushes and collector lamellas are in a satisfactory condition, the integrity of the rotor windings must be checked. First, a visual inspection of the windings and leads connected to the contact plates of the collector is carried out.

The blackening of the winding wires will immediately indicate the need to rewind or replace the armature. If the winding looks to be in satisfactory condition, then it is necessary to check the integrity of the terminals, which are filled with glue, epoxy resin at the factory, or covered with a special insulating material.

Carefully inspect the collector and winding terminal connections

If it is impossible to visually check the integrity of the connections of the winding leads, you can attach the multimeter probes to two adjacent lamellas and remember the resistance by repeating this procedure in a circle. If at some stage the measurements show a strong deviation, then a break in the armature winding or an interturn circuit is possible.

The measured resistance depends on the power of the electric motor, as well as the type of armature winding (wave or loop), so you need to study the connection diagram of the armature windings of a particular electric motor for a more accurate check. There are special devices for searching for interturn short circuits in armatures.

Choke for checking the armature - if there is an interturn circuit, the plate will rattle

Excitation coils are simpler, so they are easier to rewind. The armature windings are placed in the outer grooves of the rotor magnetic circuit and are connected according to a complex scheme, depending on the type of engine. The replacement of stator and rotor windings (rewinding) is carried out in workshops using special equipment - winding machines.

Self-rewinding the armature of a small collector motor at home is possible manually if you have the exact parameters of the windings, an identical winding wire, wiring diagram, as well as time and diligence. The workshops have special winding machines, as shown in the video:

The video below shows the process of repairing the collector motor of the hair dryer:

As Shakespeare said, "Nothing lasts forever under the moon." Home appliances, alas, are no exception. It happens that even the most reliable mechanism fails. And we must be ready to meet this fact without panic, with the firm conviction that there are no hopeless situations. How does the grinder work, what kind of malfunctions can there be, how to check the armature of the electric motor, determine the cause of the breakdown and troubleshoot? Knowledge of the structure of the main components of the power tool will allow the master to diagnose and repair the angle grinder with his own hands.

Features of the asynchronous motor grinder

The collector of an induction motor is sensitive to overheating

How to determine the malfunction of the anchor angle grinder

Signs of breakage of the anchor of the angle grinder are: increased sparking of the brushes on the motor collector, vibration of the motor at low speeds, rotation of the working shaft in different directions. If such symptoms are present, the tool should be stopped - it is dangerous. Suspicions are easy to check with simple tests.