How to Ring a Stator On an Angle Grinder

Checking the stator and rotor of power tools for interturn circuit

To check the stator and rotor for an interturn circuit with a multimeter, it does not take much time. It will take longer to disassemble the engine. Angle grinder, drill, puncher. Each tool can be repaired by determining a malfunction. It is better to break the check into several main stages, and sequentially take steps slowly.

Dismantling angle grinder

To check the short circuit on the stator and rotor, you need to disassemble the engine of a household tool. Consider performing this operation to troubleshoot an angle grinder.

  • How to Ring a Stator On an Angle Grinder

    Remove the protective cover by unscrewing one screw on the clamp;

  • Unscrew the 4 screws and disconnect the gear with the engine from the handle of the angle grinder;
  • Then on the gearbox side, unscrew 4 bolts and disconnect the gearbox, together with the motor rotor;
  • The stator in our case remained connected to the power and power button.

Having disassembled and disconnected the parts necessary for verification, we proceed to their external inspection by checking for inter-turn closure.

Visual inspection

A malfunction can be detected by uneven heating of the tool body. Touching your hand, you feel the temperature difference in different places of the case. In this case, the tool must be disassembled and tested with a tester and other methods.

In the event of a short circuit of the stator turns and troubleshooting, first of all, we conduct an inspection of the turns and conclusions. As a rule, when closing, the current flowing through the windings increases, and their overheating occurs.

There is a greater closure of the turns in the stator windings and the insulation layer is damaged. Therefore, we begin the determination of malfunctions by conducting a visual inspection. If burn-through and damaged insulation are not found, then proceed to the next step.

Perhaps the cause of the breakdown is a malfunction of the voltage regulator that occurs when the excitation currents increase. To detect a problem, the brushes are checked, they must be sharpened evenly and not have chips and damage. Then check with a light bulb and 2 batteries.

Multimeter application

Now we need to check the possibility of breaking the stator windings. On the multimeter scale, set the switch to the resistance measurement sector. Not knowing the measurement value, set the maximum value for your device. We check the performance of the tester.

Touch probes of each other. The arrow of the device should show 0. We carry out the work, touching the conclusions of the windings. When an infinite value is shown on the multimeter scale, the winding is faulty and the stator should be rewound.

We check the possibility of a short circuit to the case. Such a malfunction will cause a decrease in power of the angle grinder, the possibility of electric shock and an increase in temperature during operation. The work is carried out according to the same scheme. We include resistance measurement on the scale.

We place the red probe on the output of the winding, and attach the black probe to the stator housing. If the winding is shorted to the housing on the tester scale, the resistance value will be less than on a healthy one. This malfunction requires rewinding of the stator windings.

It is time to take measurements and check if there is an interturn circuit of the stator winding. For this, the resistance value on each winding is measured. We determine the zero point of the windings by measuring the resistance for each of them. If the device shows the least resistance of the winding, it should be changed.

Custom check

The most accurate way is to check the stator using a metal ball and a step-down current transformer. The stator is connected to the terminals of the three phases from the transformer. After checking the correct connection, we turn on our low-voltage circuit in the network.

We throw a ball inside the stator and observe its behavior. If it “stuck” to one of the windings. This means that an interturn circuit occurred on it. The ball spins in a circle. The stator is working. A rather unscientific, but effective method for detecting interturn circuit on a stator.

Rotor malfunctions

In the case of optimal use, the rotor does not wear out. Routine maintenance is carried out with the replacement of the brushes when they are worn. But over time, under heavy loads, the stator heats up and carbon deposits form. The most common mechanical failure is wear or misalignment of the bearings.

The angle grinder will work, but at the same time, the plates quickly wear out, and over time the engine breaks. To avoid damage, it is necessary to check the tool and maintain normal conditions of service. Moisture in contact with metal causes the formation of rust. The frictional force increases, the current strength is required more to work. Significant heating of contact groups occurs, solder, a strong spark appears.

Checking motor windings

The electronic rotor tester is a standard digital multimeter. Before proceeding to test the circuit, you should check the multimeter and its readiness for work. The switch is set to measure the resistance and touch the probes with each other. The device should show zeros. Set the maximum value of the measurement and check:

  • First check the rotor for an open circuit. Touching the black probe to the slip ring, the windings should ring red. The arrow of the device is off scale, which means that the winding has an open circuit of turns. The rotor should be rewound;
  • Measure the resistance to determine the possibility of a short circuit to the housing. We fix the black probe on the contact ring, the red rotor should ring to close the rotor case. In the case of a low reading of the resistance value and the sound signal, such an anchor must be given for repair;
  • Conducting ringing on the inter-turn circuit of the turns of the rotor. We reinforce the probes on the contact rings of the anchor. With a value on the scale of the device, from 1.5 Ohms to 6 Ohms, we tested a working device. All other values ​​on the scale indicate a malfunction of the multimeter.

This completes the verification of the rotor. Once again, the main steps in determining the malfunction should be recalled. Before checking, the angle grinder or any other device should be de-energized. Before taking measurements, you should visually inspect the housing, insulation and lack of deposits on the stator and rotor.

It is necessary to clean the contact surfaces from blockages with dust and dirt. Pollution leads to an increase in current during loss of motor power.

When disassembling the tool for the first time, record all your steps. This will allow you to have a hint the next time, to avoid the appearance of unnecessary parts during assembly. When the brush leaves the edge of the brush holder less than 5 mm, such brushes should be replaced. You can check the inter-turn circuit with an electronic tester, that is, a multimeter.

How to correctly determine the malfunction of the stator rotor of a Makita rotary hammer drill and pick up brushes

Any power tools begin to fail over time. Faults are divided into mechanical and electrical. Of electrical malfunctions, malfunctions associated with the failure of the brushes work are most often encountered. In second place: failure of the armature bearings. Failures associated with failure of the stator or rotor are less common. And how to determine the malfunction of the stator, rotor of the Makita 2450 and 2070 rotary hammer, replace the brushes? And here we will be helped by the circuit diagram of the Makita 2450, 2470 punch.

How to repair or replace Makita 2450 and 2470 rotary hammer drills

Replacement of the rotary hammer brushes is indicated by increased sparking in the area of ​​the rotor manifold, burning odor, heating of the brush holders. For a new or repaired rotary hammer, the spark under the brushes is even, constant in length and there is no separation of the spark in a circle. Bearing wear, rotor insulation damage or stator unambiguously indicates a spark throughout the circle of the collector. The appearance of this kind of spark indicates the burnout of the collector plates, the failure of the rotor or stator.

How to remove the electric brush punch Makita

As a rule, it is recommended to change the brushes after 70. 120 operation of the power tool.

To replace the carbon brushes pos.65, they must be reached. The back cover must be removed from the punch; it is fastened with three self-tapping bolts.

Remove the cover

Disconnect lead wires. Using a screwdriver, remove the latches on the brushes and release them.

Remember! During prolonged use of the tool, it is not allowed to reduce the length of the working part of the brushes from the nominal by 1/3 (about 8 mm).When one brush is worn, both must be replaced.

Real and fake brushes

By the way, a fake can also work well if made from the right material and strictly according to the drawings.

How to make brushes yourself?

The cheapest way to pick up electric brushes is from other models of electric tools by grinding them to the right size with a regular file. This is economical but they will last less than the original ones. It is possible as an option to adjust the carbon rod of the battery or other elements.

Various batteries

It is necessary to take the battery and remove the central carbon electrode from it. It is necessary to grind the electrode with the help of files to the required dimensions of the old electric brush. (This is informational information and is not essential for the application)

It is worth noting that the quality of graphite directly affects the life and sparking.

Homemade carbon rod brushes

After making sure that the brushes are worn, select analogues.

Brush installation

Before you insert the brushes into place, it is necessary to clean the brush holders from soot. This is done with rags soaked in a solvent. It is preferable to remove carbon deposits in the form of particles obtained by intense sparking with a small file. The cleaned brush holders are put in place, brushes are inserted into them and clamped on top with latches.

Brush installed in brush holder

How to determine the integrity of the stator without disassembling the punch

To determine the integrity of the stator, it is necessary to ring its windings, measure the resistance of the winding and the insulation resistance.

Stator and rotor continuity diagram

To measure the resistance of the winding of a Makita puncher, one end of the tester must be connected to the freed brush holder, and the other at one end of the plug. If the appliance does not show anything, replace the other end of the plug. If the resistance is infinity, the stator is open and requires replacement or repair. Do not forget, you can not do without the circuit diagram of the Makita 2450.2470 rotary hammer.

Simple wiring for a commutator motor

If some resistance is shown, it is important to measure its exact value. As a rule, the stator winding resistance of a Makita-2450 rotary hammer at a temperature of 20 ° C lies within 25 Ohms.

To understand in more detail why sparking of the collector of the anchor occurs and which brushes are better? It will help to understand the, at the end of the review important tips for choosing brushes

Video: how to pierce an anchor and pick up brushes

How to remove the stator of a Makita 2450 and 2470 hammer drill for accurate diagnosis and repair

To remove the stator pos. 59, it is necessary to remove the brushes, unscrew the four screws that secure the cover of the mechanical unit. They twist at the end of the lid. Pulling the black housing and the green in different directions, you will release the housing with a stator. The stator is fixed in a green case.

To remove it, you need to remove the plastic gasket pos. 58 and knock on the end of the case with a wooden mallet or bar. The stator will stick itself out, it will remain to pull it out, blow it and check it completely.

And here is the stator

If you have a short circuit tester, you can immediately check the stator for a short circuit. The device is called IK-32. The procedure for checking the stator windings For an accurate test, disconnect the two stator windings from each other in an electrical circuit. Check the resistance of each winding, they must be exactly the same. With a difference of resistances, a winding with a lower resistance most likely has an interturn circuit.

Do-it-yourself check of the stator of the Makita 2470 and 2450 puncher Diagnostics of the anchor, stator with a KZ device and homemade

Video: Diagnostics of the anchor and stator Short Circuit Indicator. Checking the anchor. Checking the stator.

How to check the suitability of a Makita rotary hammer rotor

The validation of the rotor in a Makita puncher begins with its dismantling from the housing. But first, you need to conduct external research. If the spark from the brushes on the collector in the rotor covers the collector’s weight, if the hammer does not develop revolutions during operation and its power drops, this is the first sign of a rotor malfunction.

How to get the rotor out of the casing To get the rotor out of the casing, it is necessary to separate the black and green casing as in the case of the stator dismantling.

Pull out the rotor

Having disconnected the stator housing, take the gear housing (black) in the right hand, and the rotor in the left and pull it in different directions until they are completely disconnected. The rotor is held in the gearbox due to the friction of helical gears.

Carefully inspect the rotor manifold. It should not be scratched by brushes. Collector lamellas must be clean.

Clean collector

To check the integrity of the collector, you must use a short circuit detection device. It is easiest to make a chain ring according to the circuit diagram of a Makita 2470.2450 rotary hammer. By the way, you can make such a device yourself if you know how to communicate with a soldering iron.

Short circuit probe circuit

If you are convinced of a rotor malfunction, you can install a new one, or you can try to recover a failed one.

Installation and assembly of a new rotor

Rotor replacement does not require special knowledge and can be performed by any user.

The rotor is inserted into the mechanical block with a helical gear to a snug fit.

Remember! It is very important to correctly install the bearing pos.56 and the rubber ring 10 pos.77. In the Makita 2450 rotary hammer on the rotor, the bearing 607LLB pos.56 or domestic analogue 80017 is used on the rotor side of the manifold, and the bearing 609LLU pos.51 or 609LLU is installed on the impeller side analog 80019.

Properly installed rubber ring 19

After installing the rotor, closing it with the casing, put the electrobrushes in place and check the performance of the punch.

Video: how to check the anchor, stator

Video: The hammer rotates and does not twist. How to fix it? Do not forget to read the description of the!

Video: Lubricating sealed ball bearings, trick

Video: how to disassemble the makita HR2450 puncher in 5 minutes to the smallest detail

All! You have accomplished a difficult task. The hammer drill works.

How to check the motor anchor at home?

An electric motor anchor refers to the rotating part on which dirt is collected, soot is formed. In case of malfunctions, you can carry out diagnostics at home visually and with a multimeter. On rubbing surfaces there should not be chips, scratches and cracks. If any are found, measures are taken to eliminate them.

Typical malfunctions

The motor armature is not subject to wear during normal operation. Only brushes are replaced, measuring the permissible length. But with prolonged loads, the stator windings begin to heat up, which leads to the formation of soot.

Due to mechanical stresses, the motor armature can be skewed if the bearing assemblies are damaged. The engine will work, but the gradual wear of the lamellas or plates will lead to its final failure. But to save expensive equipment, it is often enough to carry out preventive repairs and the device can be used for a long time.

Negative factors affecting the motor armature include moisture on metal surfaces. Critical is the prolonged exposure to moisture and the appearance of rust. Due to red clusters and dirt, an increase in friction occurs, this increases the current load. The contact parts are heated, the solder can exfoliate, creating a periodic spark.

A service center can help, but it will require certain costs. You can deal with the breakdown yourself, having familiarized yourself with the question: how to check the motor armature at home. For diagnostics, you need a device that measures resistance and tools.

How is the malfunction diagnosed?

Checking the motor armature begins with the determination of the fault itself. A complete failure of this assembly occurs due to the scattered collector brushes, destruction of the dielectric layer between the plates, and also due to a short circuit in the electrical circuit. In case of sparking inside the device, it is concluded that the current collectors are worn or damaged.

Sparking of brushes begins due to the appearance of a gap at the point of contact with the collector. This is preceded by a fall of the device, a high load on the shaft during jamming, as well as a violation of the integrity of the solder at the terminals of the windings.

A malfunction on a running electric motor is manifested by typical conditions:

  • Sparking is the main symptom of a malfunction.
  • Hum and friction during rotation of the anchor.
  • Sensible vibration during operation.
  • Change of direction of rotation when the anchor traces less than a turn.
  • The smell of melting plastic or strong heating of the body.

What to do when the listed deviations in the work appear?

The frequency of rotation of the motor armature is kept constant. At idle, the malfunction may not occur. Under load, friction is compensated by an increase in the current flowing through the windings. If deviations in the work of the angle grinder, drill, starter become noticeable, then you need to remove the voltage supply.

Further use of the equipment may result in a fire or electric shock. First of all, it is recommended to inspect the product body, evaluate the wiring for integrity, the absence of fused parts and damage to the insulation. The temperature of all parts of the device is checked by touch. They try to rotate the anchor by hand, it should move easily, without jamming. If the mechanical parts are intact and there are no contaminants, they proceed to disassembly.

Diagnostics of the internal parts

The winding of the motor armature should not have soot, dark spots, similar to the effects of overheating. The surface of the contact parts and the gap area must not be clogged. Fine particles reduce motor power and increase current. It is not necessary to disassemble devices with a plug plugged into the network for the safety of work.

It is recommended to take pictures of the disassembly process to eliminate difficulties in the reverse process. Or you can write on a piece of paper every step of their actions. Some wear of brushes, lamellas is allowed. But if scratches are found, the cause of their origin should be found out. Perhaps this was facilitated by a crack in the body, which can be seen only under load.

Work with an ohmmeter

Sincere could happen due to the loss of electrical contact in one of the lamellas. To measure the resistance, it is recommended to place the probes on the side of the current collectors. Rotating the motor shaft, watch the dial. There should be zero values ​​on the screen. If the numbers slip even a few ohms, then this indicates a burnt. When an infinite value appears, an open circuit is judged.

Regardless of the results, you should then check the resistance between each adjacent lamellas. It should be the same for each measurement. In case of deviations, it is necessary to inspect all the coil connections and the contact surface of the brushes. The brushes themselves should have uniform wear. With chips and cracks, they must be replaced.

Coils are connected to the core by wiring that could peel off. Solder often does not withstand impacts from falls. At the starter, the current through the contacts can reach 50A, which leads to the burning of poor-quality connections. External inspection determine the location of damage. If there is no malfunction, then measure the resistance between the lamella and the coil itself.

If there is no ohmmeter?

In the absence of a multimeter, a 12 Volt power supply and a bulb for the corresponding voltage will be required. Any motorist with this set will not have problems. The positive and negative terminals are connected to the plug of the electrical appliance. An incandescent lamp is placed in the gap. The result is observed visually.

The armature shaft is rotated by hand, the lamp burns without surges in brightness. If attenuation is observed, a faulty engine is judged. Most likely, there was an interturn closure. Complete disappearance of the glow indicates a break in the chain. The reasons may be non-contact of the brushes, a break in the winding or lack of resistance in one of the lamellas.

How to “revive” a faulty device?

Repair of the motor armature begins only after full confidence in the failure of the node. Scratches and chips on the lamellae are cleaned with a circular groove of the surface. Soot and soot can be removed with cleaning products for contact electrical connections. Broken bearings are repressed and replaced with new ones. It is important to keep the shaft balanced during assembly.

The rotation should be easy and without noise. Damaged insulation is restored, you can use ordinary electrical tape. Suspicious connections are best soldered again. For problems with the coils of the anchor, it is recommended to resort to rewinding, which can be done independently.

Coil Recovery

You can rewind the motor anchor in a garage, only you need to be careful when applying each turn. Copper wiring is selected similarly wound. The section can not be changed, this will lead to a violation of the high-speed modes of the engine. Dielectric paper is required to separate the windings. Coils at the end are varnished.

You will need a soldering iron and skills to use it. The joints are treated with acid, rosin is used to apply tin-lead solder. When dismantling the old winding, the number of turns is counted and the same amount of new winding is applied.

The case must be cleaned of old varnish and other inclusions. A file, sandpaper or burner is suitable for this. Sleeves are made for the anchor, the material is electrotechnical cardboard. The resulting blanks are laid in grooves. Wound coils should be done in right turns. Conclusions from the side of the collector are rewound with kapron thread.

Each wire is soldered to the corresponding lamella. The assembly should end with the next measurements of the resistance of the contact joints. If everything is normal and there are no short circuits, you can check the operation of the electric motor under voltage.

Check the rotor angle grinder

Breakdowns in the failure of the electrical part of the angle grinder can be divided into only two categories:

  1. Mechanical rupture of current conductors, which can be detected in the lead wires, power buttons and contact points of the working windings. To determine the absence of breaks, the electrician “multimeter” is used in the resistance measurement mode or an ohmmeter. All electrical sections are checked separately: supply to the electric motor, connections on the contacts of the stator and rotor windings.
  2. Electrical breakdown of working coils, which can be detected by darkening of conductors, or can be visually hidden. In any case, the tester will have to check the anchor and stator for an angle grinder for the absence of short-circuited turns, which may not always be effective, and a specialized device will be needed for accurate diagnosis.

Checking the performance of the stator

How to check the stator angle grinder with improvised means:

  • The stator can have two main failures. A break in the conductor or the occurrence of short-circuited turns. At the same time, testing by a tester in the resistance measurement mode of up to 200 Ohms is able to show only the absence of breaks with average resistance indices, which should not differ between phase windings.
  • The absence of breaks in the stator windings can be determined by any low-voltage probe: a pair of wires, a battery, a light bulb. But there is no way to detect the presence of a short circuit in the circuit in this way, therefore, experienced electricians test it experimentally: voltage is applied to the phase coils, and a metal ball is placed in the center between the poles of the windings, which, under normal windings, will “search” for the point of electromagnetic balance. The rotation of the ball indicates the absence of short circuit in the coils, the offset from the center is a short circuit in the conductors on the opposite side.

Attention. This method is unsafe due to the use of high voltage and unpredictable movement of the metal ball.

  • It is safe and accurate to check the stator angle grinder only with a professional tool.

Checking the performance of the anchor angle grinder

An anchor angle grinder is stronger than the rest of the nodes subjected to various electromagnetic, mechanical and thermal influences, therefore it is precisely the rotor that most often causes the tool to fail.

How to check the anchor for an angle grinder with improvised tools:

  • An anchor breakdown involves two types of faults: a break in the conductors on the lamella contacts, a short inter-turn short circuit in one or several windings. An electric tester in the resistance measurement mode up to 200 Ohm makes it possible to detect breaks and complete shorting of the winding (it will show an immensely low resistance), and in the resistance measurement mode of about 1 MΩ, the reliability of the electrical insulation of the windings of the working coils to the metal rotor case is checked.
  • The absence of a pronounced short circuit in the armature windings does not completely disable the tool, but there is an increased heating of the engine, a decrease in its speed, which will eventually lead to a complete engine failure. Therefore, for any repair of the tool, it is absolutely necessary to ring the anchor of the angle grinder not only with a tester, but also check with a specialized device that detects even minor short circuits.

Repair or replacement of electrical components angle grinder

When repairing a power tool, it is necessary to clearly understand how to correctly check the anchor and stator of an angle grinder:

  • The tester allows you to measure the resistance of the windings and detect breakages in the conductors, therefore, even compliance with the table readings of the measurements does not guarantee the operability of the device, but only indicates severe mechanical breakdowns.
  • Checking the short-circuited turns in the coils is carried out by professional or home-made devices that measure the changes in the inductance of each working winding, because Short circuit reduces the level of EMF.
  • When repairing a tool, it is often found that externally all the windings are intact, but they have short circuits. The operation of such a tool is unsafe, so the question arises of the need to rewind the stator, rotor or replace the “punched” unit.
  • Practice shows that recovery measures (rewinding) even in a repair shop does not guarantee long-term reliable operation of the device, therefore it is recommended not to risk it, but immediately install spare parts from the manufacturer.
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