Why the Screwdriver Stop Working Upright

How to do the procedure yourself

The device of electrified tools includes power units consisting of a stator, armature, brushes. They require repair during mechanical overloads, continuous operation. Due to overheating of the wire, its insulation is violated, the turns are closed. In the absence of a bandage ends of the windings from the collector. To eliminate such problems, it is recommended to wind 1000-2000 turns with the help of special devices.

Causes of Stator Failures

Power surges, water ingress, falling and other phenomena lead to sparking brushes. In practice, more often there is a break in the turns, which is associated with large overloads. Experts believe that the electric motor fails due to an anchor, a break in the magnetic circuit.

Why the Screwdriver Stop Working Upright

If the stator malfunctions, the voltage rises, the brushes spark. The last process is related to problem balancing. When diagnosing at home, it is recommended to listen to the sound, take into account the presence or absence of vibration. If resonance is observed, it is necessary to repair the electric motor with your own hands or with the help of specialists.

An anchor is a rotating element, which has a winding to create the desired torque. It is transmitted to the engine gearbox. There are wiring on the stator, which consists of several parts. Current flows to the brushes and the anchor. Such a process is observed until all sectors of the power unit are involved.

The stator differs from other parts of the motor by the number of revolutions, section. The main reasons for its repair:

  • Gap or short circuit of wires;
  • Breakdown of insulation;
  • Burnt winding.

If the chain operates normally, the armature rotates without stopping.

With the help of the gearbox, revolutions and speed mode are supported. If it fails, disassembly is carried out. The casing shifts, a screw opens, which fixes the plate. Since the gearbox is under the hood, it is necessary to unscrew the bolts. The tool is plugged in. If the drive is accelerated at high speed, then a winding is observed. It is recommended to wind the wire from scratch.

The stator rewinding process of an angle grinder takes several hours. The device is first cleaned of dirt. Old wiring is removed from the grooves. To do this, use a steel brush.

If damaged insulation is present, it is also removed. To simplify and speed up the cleaning of insulation, the device is immersed in warm oil. The substance softens the wire. To carry out repairs, you will need the following tools:

After deburring, the studs that hold the core are pulled. Washers are varnished, grooves are insulated.

If the stator burns out, the remnants of the winding are cut off. Work is carried out so as to obtain the appropriate number of turns. The wire should have the diameter with the largest seal. Two coils are mounted in the stator. The conclusions are drawn from the winding. To isolate them, tubes are used.

If the wiring does not close, inserts are mounted to protect it.

The coil is placed above the groove, which is located below the bore. Using a plate, turns are installed. So that they do not cross, they are laid in a sequence similar to winding on a template. Postings are placed strictly parallel. The stator housing is mounted on one compartment, and the gaskets are in grooves. The findings are fixed with twine. Its ends are parallel to the previous elements. In a similar pattern, the bottom of the coils is installed. The process continues until all the grooves in the step are filled.

If winding is completed, a sleeve is carried out. Product parameters depend on the dimensions of the stator. A film with high heat-resistant properties is wound on a special cardboard. The design is fixed with tape. Coils with sleeves are mounted in the grooves.

If the anchor moves freely, the unit is tied with a kiper tape, varnished. The product is dried. At the last stage, an angle grinder is assembled, followed by a check of its operability. In the absence of experience in the repair of power tools, it is recommended to seek the help of specialists.

Calculation of Stator Winding Angle Grinder. Ctln.Ru

Stator rewind angle grinder at the current time will do without the help of others. For this purpose, you need to stock up only with the necessary knowledge. If the master has the necessary tools, the ability to carry out repairs and a certain amount of knowledge in the field of electrical engineering, the question is what actually, how to fix the malfunction of this tool on your own is quite simple.

Manual grinders, referred to simply as “angle grinders”, are variations to fail for various reasons. The most common problem is the breakage of the stator turns, which occurs due to a very heavy load on the device. At the moment, such a malfunction can be corrected without the help of others. Correctly rewind the stator.

There are frequent cases when the breakdown of the electronic part of the device becomes the cause of the breakdown. There are various reasons for this:

  • Water entering the surface, due to which current flows;
  • Power surges;
  • Sharp pulling out the plug from the outlet;
  • Highest overloads and, as a result, overheating.

There is a worldview that rewind

Often the engine breaks down due to a break in the magnetic circuit, violation of the winding or the anchor manifold. With increasing voltage, an abrupt increase in the strength of the spark is noted. As a rule, this is observed only on one brush. This phenomenon leads to the destruction of the insulation of the wires on the stator coil. If, when turned on, the drive accelerates and develops in a short period of time, this indicates a small stator short circuit.

Stator winding schemes

Sparks that occur during the operation of the collector indicate violations in the balancing of the anchor. The collector operation is checked in such a way: when turned on, the sound should amplify evenly with increasing voltage. With all this, no vibrations should appear. If resonance is observed, the angle grinder electric motor asks for repair.

The grinding tool consists of 3 fundamental components:

The anchor is a rotating element with a winding and makes the torque of the electric motor. On the stator, broken into sectors, there are the same winding. The current through the carbon brush passes through the winding, enters the anchor. Then the current runs to other brushes for now, for now it remains to make our client the stator parts will not be involved. When the electron current passes through the winding, a magnetic field constantly interacting with the stator appears. Thus, an electric motor is driven. There are several relevant breakdowns of the “angle grinder” starter:

Scheme of an eccentric orbital sander.

You can rewind the winding at home, without appeal to the specialist. It is only necessary to disassemble the device earlier. If there is no working self-confidence, then an appeal to a specialized workshop will be a more reasonable step. Basically the casing shifts. For this purpose, the screw fixing it is unscrewed. Then you can see what remains to do to our client the details of the angle grinder, except for the gearbox hidden under the iron cap. The screws that secure the iron plate are loosened. Now our customer remains perfectly visible mechanical parts. Only then, of course, run to the stator rewind.

Better than a perfect repair you will like only the correct operation, with which it does not happen at all breakdowns. If you set a goal “Angle Grinder“Worked longer, the following easy rules must be observed:

  1. It is not necessary to exceed the amount of grease and the timing of its addition as it is also called shift.
  2. If the tool worked at reduced speeds, it is strictly forbidden to immediately turn it off. If you leave it to work for at least 1 minute, it is really possible to avoid overheating.
  3. The long-term operation of the tool at reduced speed under load should not be allowed.

A repaired stator will allow the grinder to operate normally for a long period.

Special tools are useful for rewinding the stator:

  • Hammers: wooden, iron;
  • Pliers and pliers;
  • Iron brush;
  • Calipers;
  • Megohmmeter;
  • Electric drill;
  • Ruler;
  • Varnish.

The first and most important step is to clean the stator from contamination. The ancient winding is removed from the grooves. The entire spectrum is done using a metal brush. Cleaning is carried out manually using iron brushes, electric drills. You also need to remove the old insulation. To facilitate the task, use transformer oil. It needs to be slightly warmed and the starter device lowered there. Such a measure will soften the warped insulation and simplify its removal. For cleaning, a weak caustic solution (temperature. 80ºс) mixed with compressed air is also used.

After processing stator Wash thoroughly with water and dry. The condition of the stator and iron packets must be perfectly checked. Then pull the studs tightening the core, the grooves are cleaned from burrs. Insulation resistance is measured using a megohmmeter. Parts of the core, thrust washers and grooves are varnished. Washers and slots need to be isolated.

Rewind stator. Repair angle grinder.

The accompanying note, where the main data is displayed, can facilitate subsequent work:

  • Phase connection diagram and their number;
  • Coil and phase resistance;
  • Number of grooves and their sizes;
  • Winding section, coil pitch along grooves;
  • Groove insulation method, the number of interlayer gaskets and their sizes.

The remaining frontal is removed further winding and brand new. There is a special pattern for the production of windings. It is fixed on an axis holding 3.5 huge metal plates made of metal.

During operation, it is important to get a strictly defined number of turns. It is identical to the number of turns of an old winding. The wire must be wound so that the seal is the largest. Coils are placed in stator. From the same material from which it is made winding for coils, conclusions are drawn. Their ends must be insulated with cambric. Tubes made of plastic.

As a competent installation will be made how to install the coils, you need to check that the groove boxes are symmetrical. It is necessary to close the winding. If this does not happen, when inserting the wires of the coils, temporary inserts are placed. This routine measure avoids damage.

The coil is mounted above the groove, which is located below the bore. Coil conductors are installed using a special plate. The wires located in the groove do not have to be crossed. They must be laid in exactly the same way, in the same sequence as the winding. Conductors must be installed strictly in parallel.

To perform the subsequent operation, the stator needs to be turned a little. Only by one division. Coils from the same group fit into the groove. At the end of installation, lay the interlayer gaskets. Screw the terminals to the outer loop so that they are parallel to the outer loop. The underside of the coils is installed similarly. The operation is repeated until the grooves of this step are full.

Retracting the stator winding on the BC-2A machine

When winding finished, the ends can be plugged. The dimensions of the sleeves depend on the size of the stator. The thickness of the liner is usually 0.4 mm, but the length should not be simpler than the size of the starter. In most cases, this value is about 1.5 mm. For the manufacture of liners used special cardboard. At this address, it is necessary to wrap the film (preferably heat-resistant). The entire resulting structure is wrapped with tape. Coils with sleeves must be installed in the grooves of the stator. Then you can check whether the anchor is moving correctly. The coil is one hundred percent ready. It remains only to wrap with kiper tape, and on top to cover with a layer of varnish. When the varnish dries, the device is one hundred percent ready for use.

Simplified repair angle grinder. Meander. Entertaining electronics

The article describes technological tips that simplify the complex and time-consuming processes of winding anchors and stators of an electrified tool. The article briefly describes the design of electric motors for hand tools, shows the schemes of windings and their connection, drawings of the device and a detailed description of the technological processes for their repair and installation.

Most hand-held electrified tools (mainly electric drills, rotary hammers, an “angle grinder”, circular saws, screwdrivers, chain saws, etc.) contain network collector electric motors, which mainly consist of a stator with two electromagnetic poles, anchors (fig. 1) and a brush mechanism with two graphite brushes. The main causes of motor failures are a violation of the technology during production, mechanical overloads and excess duration of continuous operation. As a result, the winding wire overheats, which at the same time expands, which destroys its insulation and leads to the closure of the turns. Breakages of the ends of the windings from the lamellas of the collector are also possible if they do not have a bandage. The methods for repairing the windings of anchors and stators described in the literature recommend a sophisticated technology of rewinding with a wire of the same diameter, as a result of which it is necessary to wind 1000-2000 turns of thin wire using special devices [1]. And this requires appropriate experience, knowledge and painstaking work.

Most often, engine anchors fail, which have a more complex design and a more dense stacking of the winding wire in the grooves of the anchor. The presence of short-circuited turns or breaks of the ends of the windings in the armature with serviceable brushes and collector manifests itself in the form of circular arcing of the brushes, rapid heating of the tool and loss of engine power. Breakages of the ends of the windings are eliminated by soldering the ends to the collector lamellas, applying a bandage of threads and uniformly impregnating it with epoxy glue. The complexity of rewinding the anchor is an order of magnitude higher than the rewinding of the stator, moreover, it requires static and dynamic balancing, therefore, most authors of publications propose replacing them with new, factory-made ones. This is easiest, but expensive.

Faced with a similar problem with my “angle grinder” and having determined that its mechanical part is in good condition, I began to throw it away, and it was decided to rewind its anchor, which had windings with darkened insulation. I was also convinced of the presence of short-circuited turns by measuring the inductance of the windings between adjacent collector lamellae with a Mastech MY6243 multimeter. It is impossible to determine this with a tester, since the fraction of the resistance of one short-circuited coil is negligible compared to the resistance of the whole winding, but the short-circuited coil significantly affects the winding inductance. Authors of publications on the online repair of electric motors recommend burning the windings of the anchors, since they are saturated with glue or varnish. It is simply impossible to remove or unwind them. The burning process requires the removal of ball bearings and can lead to shaft deformation, which is recommended to be eliminated after high-precision grooving of the armature on the lathe after it is rewound. Naturally, I rejected this and used a different technology.

Grasping the anchor with a strip of thick soft cardboard, he clamped it in a vice so that it held tight and did not deform. Close to both ends of the grooves of the working part of the anchor, a hacksaw for metal with small teeth cut the windings, turning and moving the anchor several times. The ends of the cut sections of the windings should not protrude from the slots of the armature. After that, the anchor is slightly clamped in a vice by the ends of the working part. A steel rod with a flat end and a diameter slightly smaller than the width of the anchor groove is selected. This rod and hammer extrude parts of the cut sections of the windings. At the same time, wedges are pressed out, which fasten the windings in the upper parts of the grooves. Wedges must be kept. After this, the anchor must be prepared for winding the wire.

To facilitate the process of winding the anchor, it was decided to use a thicker wire than the one used in the anchor and the available PEV-2-0.5 wire, as a result of which, with the corresponding winding of the stator windings, the motor will become low-voltage. What will be the working voltage of the instrument is not so important, and will be determined during the tests by feeding it from LATR. The main thing is that the tool works. Given that the engine will be low voltage, it was decided to abandon the insulating gaskets and create insulation of the grooves and ends of the armature by applying a thin layer of epoxy glue. All sharp corners at the joints of the grooves and the end of the anchor before applying glue are rounded off with a round file. It is advisable to polish the collector lamellas with a zero emery cloth and clean the gaps between them. The places for connecting the ends of the windings to the lamellas must be cleaned and tinned. After applying and polymerizing the glue, the anchor is ready for winding.

This anchor has 12 grooves and 24 collector slats. Brushes are placed perpendicular to the axis of the stator poles. Given that the loop winding scheme is used in the anchor, four sections will be placed in each groove. The winding diagram for such an engine variant is shown in fig. 2 [2]. The poles of the anchor are shown above, and the collector lamellas below. The diagram shows that four sections begin to appear in the groove between the poles 5 and 6, and end to appear at the end of the winding between the poles 4 and 5. If the motor brushes are located along the axis of the stator poles, then the ends of the windings should be offset 90 °, i.E. The ends soldered to the lamella 1 should be soldered to the lamella 7, etc. This important point in the literature is mentioned very unclear or not mentioned at all [1].

Based on the cross-sectional area of ​​the groove, the cross-section of the new winding wire, and taking into account the fill factor, it was determined that 40 turns are placed in one groove. The number of turns of one section will be 10. A small number of turns of the section and an increased wire diameter of up to 0.5 mm allows the armature to be wound manually without special tools and large labor costs. To wind the wire, the anchor is gently clamped into the table vice with the fan impeller to itself through soft pads. A coil with a wire is located below on a horizontal rod. The end of the wire is cleaned and soldered to the lamella 1.

At the beginning of the winding, the wire near the collector with the left hand is slightly pressed in the direction of the shaft, and the first turn is wound with the right hand. The deflections of the ends of the wire near the collector are necessary for winding the bandage at the end of the winding of the anchor and should be the same. In the process of winding, it is necessary to constantly monitor the absence of short circuits of the wire being wound on the case, so that then you do not rewind everything again. For this, several turns of bare wires are wound around the collector and the armature shaft, to the ends of which an ohmmeter is connected. Subsequent turns continue to be wound with the right hand, and with the left hand the wire is evenly laid on the ends of the anchor and adhered to align and lay the wire in the grooves. The end of the section is molded into a bandage, stripped, folded in half, compressed with pliers to eliminate the loop, soldered to the next lamella and is the beginning of the next section.

As winding, the anchor in the vise is rearranged to the desired angle, and the wire in the grooves is sealed with a flat wooden stick. The end of the last section is soldered to the lamella 1. After winding all the sections onto a wire near the collector, a bandage of thin threads is wound. After that, it is necessary to update all rations and make them the same if possible. This and the subsequent uniform impregnation of the windings and bandage are necessary to maintain the static and dynamic balancing of the armature. In the author’s version of the repair, this was possible. Before impregnation, you can heat the anchor and epoxy glue to about 40 ° C on a room battery or oil cooler. On the collector, to protect from the ingress of glue, wrap a couple of turns of electrical tape. The glue is evenly applied with a narrow wooden spatula, first on the bandage then on the end parts of the sections from the side of the collector. Hold the anchor vertically upward with the collector. After that, apply glue into the grooves and insert the wedges. Next, fasten the anchor vertically with the collector down to the ball bearing through a soft cardboard in a vice and apply glue to the end parts of the sections on the side of the fan impeller. Such fastening will make it possible to rotate the anchor and monitor the emerging glue in order to timely remove excess and level its surface.

For this purpose, a spatula must be soaked with machine oil. The process of polymerization of epoxy adhesive takes place slowly and lasts about 4 hours, so after the first 30 minutes you can monitor the process less often and periodically turn the anchor in an upright position. After complete glue polymerization, the anchor is ready for installation in its place, but after rewinding the stator windings.

To rewind, the stator must be removed from the housing. In the author’s version, the stator is tightly inserted into the seat formed for it in the housing, to the rear of the stop. Its front part is fixed by a plastic cylinder, which abuts against the stator between the windings with two protrusions, and four protrusions into a removable gear housing. To remove the stator, it is necessary to disconnect its four terminals and pull it out of the housing.

If the stator cannot be removed in a simple way, then it is necessary to use a screw mechanism, for example, shown on fig. 3,

1. Upper base plate;

2. Stator housing;

3. Stator iron;

4. Centering washer;

5. Lower support plate.

Perhaps between the upper plate and the body it will be necessary to lay wooden battens on the sides of the stator.

Based on the fact that the stator windings are connected in series with the armature brushes, and the upper and lower parts of the armature windings are connected to the brushes in parallel, the cross section of the stator wire should be twice as large as the armature wire. Given that the stator windings are less dense and better cooled, this ratio can be reduced to 1.8-1.9. The ratio of the number of turns of the stator to the number of turns in the groove of the armature in a real engine is 3.4. In this embodiment, both stator windings should have 40 × 3.4 = 136 turns. As a result, the stator windings were wound with PEV-2-0.62 wire of 70 turns.

To winding the windings, it is necessary to make a mandrel. For this, a rectangle with rounded ends is cut out of plywood with a thickness equal to the width of the stator groove. The width of the rectangle is equal to the width of the narrow part of the pole plus 5 mm, its length is 2 cm more than the length of the stator. Two cheeks are cut from thin plywood or textolite, the width and length of which are 2 cm larger than the previous part. At the corners, one cheek is attached symmetrically to the inner part with short screws (4 pcs.), In which a hole is drilled near the inner part to secure the coil start wire (fig. 4).

The second cheek is attached with a nut during assembly. A through hole with a diameter of 8.2 mm is drilled in the center of the mandrel. A bolt or stud with M8 thread is inserted into this hole and the mandrel is clamped using nuts, as shown in fig. 5 where are indicated:

4. Inner part;

To attach this device, a drill is used, which is attached to the table in any way, for example, it is tied to a vice so that its chuck protrudes beyond the edge of the countertop.

The fixture is clamped into the cartridge, and you can proceed to winding coils. Before starting winding from both ends of the mandrel, it is necessary to glue the insulating strips of about 8 cm long with the sticky side inward to the inner part and to the cheeks to secure the coil turns after winding. The wire of the beginning of the coil is inserted into the hole, fixed on the hairpin, and winding is done by rotating the mandrel with one hand and laying the wire with the other hand without much stretching. After winding, the nut 7 is unscrewed, the mandrel with the coil is removed from the stud, placed on the table and the upper cheek is removed. The lower ends of the electrical tape are shortened so that they do not bend when the upper ends are applied to their sticky surface. After this, the coil is removed and its turns are finally fixed with electrical tape.

In the same way, a second coil is wound. The conclusions of the coils should be directed towards the collector and have a margin in length in case of polarity reversal of the conclusions with respect to the brushes of the collector if the engine rotates in the wrong direction. The motor stator is laid on the table with the pole down. The first coil is mounted on it. Strips of paper insulation are glued into the grooves of the poles with quick-drying glue. First, one side of the coil is inserted, then by stretching it in width, the second side of the coil is inserted. After that, the stator is turned over and the second coil is also mounted in the same way. It is very important that when installing the coils, when they are at the bottom, their beginnings are on the same side. And in assembled form, the beginning of the coils will be diametrically opposite. The protruding end parts of the coils are molded as shown in fig. 6, and impregnated with epoxy glue along with the side parts.

After adhesive polymerization, the motor is assembled, the ends of the stator windings are soldered to the contacts of the brush holders according to the scheme fig. 7, check the insulation resistance, which should be at least 1 megohm.

Graphite brushes are replaced by copper-graphite brushes, since at the same power and lower supply voltage the motor current will increase, at which the graphite brushes will overheat. In the author’s version, used brushes from the starter of a car processed on a grinding machine in terms of the size of graphite brushes were used. After that, the engine is connected to the LATR and a smooth increase in voltage is started. If the direction of rotation is reversed, then it is necessary to exchange the stator leads connected to the brushes. After that, the tool is finally assembled and tested for operability and heating under conditions of real metal cutting for about 10 minutes. In this case, the voltage is measured with a voltmeter at which the tool works the same as before, based on the experience of its previous operation. In the author’s version, the tool works normally from a voltage of 50 V. For ease of operation, a step-down transformer with secondary terminals of 40 V, 50 V and 60 V for cases of voltage fluctuations is manufactured. In addition, the transformer decouples the 220 V network from the tool, which increases the electrical safety of the work. If you feed the instrument with direct current, then its power will increase with a lower supply voltage, and heating will decrease due to the absence of Foucault currents in the stator.

Why the Screwdriver Stop Working Upright

In conclusion, it is useful to note that increasing the diameter of the winding wire increases the percentage of copper in the groove with respect to its insulation, since several thin conductors with the same total cross section contain internal insulation, which takes up more space than the insulation of one thick conductor. Observing the above recommendations and the ratio of the turns of the stator windings and the armature, you can repair most of the above power tools in this way, as well as make a 12 V tool and repair it from the vehicle’s onboard network in places where there is no 220 V / 50 industrial network Hz

Literature

  1. Kokorev A.S. Electrician repairing electrical machines. M.: Higher School, 1989. P.40-51.
  2. Krems R.V. Repair of anchors of electric motors of low power // Electric. 2005. No. 11-12.C. Thirteen.
  3. Khrushchev V.V. Electric machines of automation systems. L.: Energoatomizdat, 1985. S. 124-126.

Author: Anatoly Zhurenkov, Zaporozhye

Source: Radioamator magazine No. 9, 2015

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Do-it-yourself anchor inspection and repair of an angle grinder. City of Masters

Features of the asynchronous motor angle grinder

In almost all electrical appliances used in everyday life, an asynchronous electric motor is used. 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 for a long time and without stopping a household angle grinder, there will be no noticeable external signs of engine overload. The speed of rotation of the disk will be constant, the sound is monophonic. Only the temperature will change, but this may not be noticed if the hands are wearing gloves.

Asynchronous motor manifold sensitive to overheating

With an inattentive attitude, an advantage can turn into a disadvantage. Asynchronous motors are very sensitive to overheating, a significant excess of the operating temperature entails a melting of 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 necessary to overheat the engine several times with an angle grinder and, most likely, the anchor will melt. In addition, contacts connecting the wires of the primary winding to the collector are soldered from high temperature, which leads to an interruption in the supply of electric current.

How to determine the malfunction of an anchor angle grinder

Signs of an anchor breakdown in an angle grinder are: increased sparking of brushes on the motor manifold, vibration of the motor at low speeds, rotation of the working shaft in different directions. If such symptoms are present, work with the tool should be stopped. This is dangerous. Suspicions are easy to verify with simple tests.

Visual inspection from the outside

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

  1. Carry out a general inspection of the tool.
  2. Pay attention to the integrity of the power cord, the presence of voltage in the outlet.
  3. Using a voltage indicator, make sure that current flows to the engine manifold and start button.

The indicator checks the integrity of the electrical circuit

Inspection of the device from the inside

If everything is in order with power, but the angle 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 adhere to simple rules that will avoid troubles during the reverse assembly:

  1. Be sure to unplug the appliance before disassembling.
  2. Remove the working disk and the protective cover from the spindle.
  3. Open the case in a well-lit place, on a clean table surface.
  4. Remember the location of all parts and assemblies before disassembling. It is recommended to sketch or photograph the internal structure of the device.
  5. Fold the screws and fastening screws in a separate place so as not to get lost.

Inspecting the motor is best done under bright light, so that all the small details are clearly visible. The anchor should rotate freely around its axis, properly working bearings should not make a sound during operation. There should be no traces of melted wiring at the anchor, the circuit windings must be intact, without breaks. You can smell the rotor. During interturn closure, the insulating varnish burns and emits a stable specific odor. But for such a diagnosis, some experience is needed.

Circuit Tester

If a visual examination does not give obvious results, it is recommended to continue the examination with a multimeter. Having set the mode switching toggle switch to the ohmmeter position (range 200 Ohms), it is necessary to “ring” two adjacent anchor lamellas with two probes. If the resistance on all turns is the same, it 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

Rupture of the wiring may occur between the winding and the core. It is necessary to carefully examine the junction of the coils with the collector lamellas in the lower part of the armature, visually check the soldering of contacts.

Checking contacts with a light bulb

If there is no tester, you can get out of the situation with a simple 12 volt bulb. Power can be any, optimally 30–40 watts. The voltage from the battery 12 volts must be fed to the plug angle grinder, inserting a light bulb into the gap of one wire. With a working anchor, if you rotate the spindle by hand, the bulb should light up 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, then this may indicate the following:

  1. Hanging of brushes in a non-working position is possible. The retaining spring worked.
  2. There was a break in the supply circuit.
  3. A short circuit or rupture 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 master will determine the failure 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 with your own hands

If damage to the armature is established with guaranteed accuracy, the part must be removed from the electric motor. The motor must be disassembled with special care, after removing the brushes and disconnecting the power terminals. The rotor is removed along with the thrust bearings and the cooling wheel of the motor, they form a whole with it.

Anchor device diagram angle grinder

If most of the wiring is damaged in the anchor and the 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 balancing of the armature is not broken, 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 for repair to the workshop or replace the entire anchor yourself.

For independent rewinding of the anchor you will need:

  • Wire for a new winding. A copper core with a diameter exactly matching the old conductor is used;
  • Dielectric paper to isolate the winding from the core;
  • Varnish for pouring coils;
  • Soldering iron with tin-lead solder and rosin.

Before rewinding, it is important to count the number of turns of wire in the winding and wind the same amount of new conductor onto the coils.

The rewinding process consists of the following steps:

  1. 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 case, they must be ironed or sanded. Sometimes, to completely clean the body of toxins, masters prefer to burn it with a burner.
  2. Preparing the collector for connecting a new wire. There is no need to remove the collector. It is necessary to inspect the lamellas and measure the contact resistance with a megger or multimeter with respect to the housing. It should be no more than 0.25 megohms.
  3. Removing old wiring to the collector. Carefully remove the remnants of the wires, cut the grooves in the part of the contacts. Subsequently, the ends of the wires of the coils will be inserted into the grooves.
  4. Installation of sleeves for an anchor. The sleeves are made of dielectric material with a thickness of 0.3 mm, for example, electrical cardboard. Cut a certain number of sleeves and insert into the grooves of the peeled anchor.
  5. Rewind reels. The end of the new conductor is attached to the end of the lamella and wound in successive circular motions, counterclockwise. This installation is called “right installation”. Winding Repeat for all coils. Pull the wires near the collector with a thick thread of cotton fabric (nylon is prohibited, since it melts when heated).
  6. Checking the quality of the winding. At the end of laying all the windings, check with a multimeter for the absence of inter-turn short circuits and possible breaks.
  7. Finishing Finish 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. Apply 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 with an angle grinder, then it is best to change it together with the thrust bearings and the cooling wheel of the engine.

To replace you will need:

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

How to remove the anchor

Replacing the anchor begins with the disassembly of the angle grinder. The following steps are taken:

  1. The brush nodes are twisted with a screwdriver on both sides. Brushes are removed.To remove, you need a wide flat screwdriver
  2. 4 screws securing the gear housing are removed.Remove the housing carefully
  3. 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
  4. The snap ring is removed, fixing the small gear on the anchor.
  5. The anchor retainer is released from attachment, the anchor is removed along with the small gear and bearing.
  6. The gear, the bearing and the fixing disk of the anchor are removed, wiped with a rag. The bearing is removed with a special puller.The puller is driven by rotation of the stop screw
Video: replacing bearings with an angle grinder

How to anchor in place

To reinstall the new anchor, the angle grinder should take a new part, and then assemble the tool in the reverse order. The sequence of actions is as follows:

  1. A fixation disk is mounted on the armature shaft.
  2. The bearing is mounted by pressing.
  3. The small gear is put on and fixed by a lock ring.
  4. The anchor is inserted into the gear housing, the docking holes are combined.
  5. The gearbox mounting bolts are tightened.
  6. An anchor with a reducer is inserted into the body of an angle grinder and fixed.
  7. Brushes are deposited in place, closed with lids.

After performing these steps, the angle grinder is ready for use. Replacement of the anchor made.

Video: how to check the angle grinder

Ancient Sufi wisdom says: “The person who is able to get out of a difficult situation with dignity is smart. But wise is he who does not fall into such a situation. ” Observing the rules for operating household appliances, preventing the motor from overheating, you can avoid breakdowns and troubles in the work of an angle grinder. Keeping the instrument clean and dry will prevent its mechanisms from contaminating and oxidizing current-carrying elements. Timely maintenance of the tool is guaranteed to relieve unpleasant surprises during operation.

Self-troubleshooting

An angle grinder is used to perform many tasks on the farm. Regular use may damage the device. The most commonly breaking element is the anchor. It is subject to high heat load, and also affects the mechanical and electromagnetic effects. As a result, many craftsmen have to think about repairing this part.

Anchor device

An anchor angle grinder consists of a winding that conducts current, and a magnetic circuit. There is a torsion shaft in the magnetic circuit. The design of the magnetic wire is formed by plates and grooves, which are isolated among themselves by coating the varnish. A certain sequence of laying the conductors of the anchor winding in the grooves is developed. 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 is drawn up in such a way that they close on one lamella.

With constant overheating of the motor, the angle grinder melts the armature. 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 no current is supplied.

Anchor malfunction

There are criteria based on which we can conclude that the repair of the anchor is required:

  • The number of sparks coming from the brushes on the engine manifold increases;
  • Vibration appears at low speed;
  • The working shaft begins to move in different positions.

The presence of these signs indicates a broken 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 the closure of the winding on the metal surface of the rotor;
  • Soldering the ends of the collector;
  • Uneven 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, a diagnosis should be made. It can be carried out visually or using appropriate instruments.

How to check the anchor for an angle 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. During normal power-up, the angle grinder should be inspected from the inside. Disassembling the device is not difficult. It is best to photograph the location of the main modules of the device during parsing. After disassembling, conduct a visual check of the anchor for the following properties:

  • The course of the anchor should be free;
  • The absence of black spots and smell, which can talk about the melting of the winding, the insulating varnish of which leaves traces;
  • The absence of crumpled turns and solder residues, which leads to a short circuit;
  • There should be no burnout on the contacts of the lamella, otherwise you should check the binding of the lamella cockerel and the winding bars;
  • Lack of worn or burned-out plates;
  • The space between the lamellas should not contain graphite residues from brushes.

If visual examination does not reveal any flaws, then it is necessary to carry out a check with devices. An anchor for an angle grinder can be checked both with the help of a tester, and using an ordinary light bulb.

Tester Inspection

The multimeter is set to the ohmmeter position. The resistance is set to 200 ohms. The probes are connected to 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, a break in the turns is possible. With a high value of resistance or the absence of any value (in the case of using a digital device), you can also judge the break.

There are situations when a cliff is not detected. Then a breakdown is made on the mass. 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 not possible to carry out the test with a tester, a light bulb is used.

Bulb control

If there is no device at hand, many are interested in the question of how to check the angle grinder for possible breakdowns of the armature. The power supply wire breaks, and a bulb is placed in the place where one wire breaks. Then the shaft rotates. By changing the brightness of the light bulb, you 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 gap in the stator winding.

You can ring the indicator of short-circuited turns and a device for checking anchors. This can be done by an experienced person.

Is anchor repair possible

Anchor repair angle grinder cannot be performed if there is vibration, as the balance is disturbed. This situation requires replacement. It is possible to eliminate a 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 angle grinder is delivered together with the thrust bearing and the impeller for cooling.

Rewind anchor

Anchors for grinders angle grinder rewind 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, which corresponds to the previous conductor;
  • Dielectric paper to insulate the winding;
  • Varnish for pouring coils;
  • Soldering iron.

It is important, before starting the winding of the armature, to count the number of turns in the old winding and perform the same amount on the new coil.

  • Removing the previous windings. Try not to spoil the surface of the case. If damage occurs, sanding with a file 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 MΩ;
  • Cleaning the collector from old wires. Developing grooves for inserting the ends of new wires;
  • Sleeve design. They are made of material that does not conduct current, for example, electrical cardboard. Their size is 0.3 mm;
  • Rewinding reels. The end of a new wire joins the end of the lamella. Rewind counterclockwise. Secure the wires near the collector with a cotton thread;
  • Short circuit monitoring. Measure resistance with a tester;
  • Applying varnish or epoxy to fix the winding. To 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 angle grinder.

Anchor change

An anchor is replaced with an angle grinder simultaneously with the replacement of thrust bearings and the motor cooling impeller. To perform, such devices will be required:

  • A new anchor for an angle grinder that suits your device;
  • Screwdriver and wrench;
  • Brush with soft bristles and a cloth for wiping items.

Disassembly steps:

  • Brush extraction;
  • Unscrewing the gearbox;
  • Removing the gearbox cover;
  • Removal of the ring, which fixes the small gear on the anchor;
  • Anchor extraction together with gear and bearing;
  • Removal of the bearing with a special removable device;
  • Removal of a gear wheel and a 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 mounting;
  • Installation of a small gear and its fastening with a snap ring;
  • Placing the anchor in the gearbox with the docking of the holes;
  • Fixing the gearbox in the body angle grinder;
  • Installation of brushes;
  • Device check.

Thus, do-it-yourself anchor repairs can be completed quickly and easily. But in order to prevent such cases, use the device with care and not expose it to prolonged high loads. Keeping the tool in a dry place and the necessary care will extend its life.

Stator Rewind

Stator rewind angle grinder can now be done independently. For this you need to stock up only with the necessary knowledge. If the master has the necessary tools, repair skills and a certain amount of knowledge in the field of electrical engineering, the question of how to fix the malfunction of this tool with your own hands is quite easy.

Stator winding circuit.

Causes and signs of stator failure

Manual grinders, popularly called “angle grinders”, can fail for various reasons. The most common problem is the breakage of the stator turns, which occurs due to an excessively strong load on the device. Now, such a malfunction can be corrected independently. Correctly rewind the stator.

There are frequent cases when the failure of the electrical part of the device becomes the cause of the breakdown. Various factors lead to this:

  • Water entering the surface through which current flows;
  • Power surges;
  • Sharp pulling out the plug from the outlet;
  • High overloads and, as a result, overheating.

There is an opinion that it is impossible to rewind the stator yourself. In fact, it’s enough to understand the design of the device. If you have experience with such work and the necessary knowledge, you can repair a three-phase start-up device at home. Given the preparatory work, the process can take several hours.

Wire winding circuit.

Often the engine fails due to a break in the magnetic circuit, violation of the winding or the anchor manifold. With increasing voltage, an abrupt increase in the strength of the spark is noted. Usually this is observed on only one brush. This phenomenon leads to the destruction of the insulation of the wires on the stator coil. If, when turned on, the drive accelerates very quickly and gains speed, this indicates a stator short-circuit.

Sparks that occur during the operation of the collector signal the occurrence of violations in the balancing of the armature. Checking the operation of the collector can be done in this way: when turned on, the sound should amplify gradually with increasing voltage. No vibrations should occur. If resonance is observed, the angle grinder electric motor needs repair.

Hand Grinder

The grinding tool consists of three important components:

The anchor is a rotating element with a winding and creates the torque of the electric motor. On the stator, divided into sectors, there is the same winding. The current through the carbon brush passes through the winding, enters the anchor. Then the current passes to other brushes until all parts of the stator are involved. When electric current passes through the winding, a magnetic field constantly interacting with the stator arises. Thus, an electric motor is driven. There are several characteristic failures of the “angle grinder” launch device:

  • Burning or rupture of the winding;
  • A short circuit between the turns of the winding;
  • Destruction of insulation.

Scheme of an eccentric orbital sander.

You can rewind the winding with your own hands, without contacting a specialist. You only need to disassemble the device first. But if you are not completely confident in your abilities, then contacting a specialized workshop will be the most reasonable step. First of all, the casing shifts. To do this, the screw fixing it is unscrewed. After that, you can see all the details of the angle grinder, with the exception of the gearbox hidden under the metal cap. The screws that secure the metal plate are loosened. Now all the mechanical parts are clearly visible. Only after this can you move on to rewind the stator.

Better than a well-made repair can only be the correct operation, in which there will be no breakdowns at all. In order for the “angle grinder” to work longer, the following simple rules must be observed:

  1. In no case do you need to exceed the amount of grease and the timing of its addition or replacement.
  2. After the tool has been operating at reduced speed, it is strictly forbidden to immediately turn it off. If you leave it to work for at least 1 minute, you can avoid overheating.
  3. Do not allow long-term operation of the tool at reduced speeds under load.

A refurbished stator will allow the grinder to operate normally for a long time.

Repair preparations and necessary tools

To rewind the stator, you will need special tools:

  • Hammers: wooden, metal;
  • Pliers and pliers;
  • Steel brush;
  • Calipers;
  • Megohmmeter;
  • Electric drill;
  • Ruler;
  • Varnish.

The first and most important step is to clean the stator from contamination. The old winding is removed from the grooves. All this can be done with a steel brush. Cleaning is carried out manually using steel brushes, electric drills. It is also necessary to remove the old insulation. To facilitate the task, transformer oil can be used. It is necessary to warm it a little and lower the launching device into it. Such a measure will soften the damaged insulation and simplify its removal. For cleaning, a mild caustic solution (temperature. 80ºс) mixed with compressed air is also used.

After treatment, the stator should be washed well with water and dried. The condition of the stator and steel bags must be well checked. Then pull the studs tightening the core, the grooves are cleaned from burrs. Insulation resistance is measured with a megger. Parts of the core, thrust washers and grooves are varnished. Washers and slots must be insulated.

The accompanying note, where the main data is displayed, can facilitate further work:

  • Phase connection diagram and their number;
  • Coil and phase resistance;
  • Number of grooves and their sizes;
  • Winding section, coil pitch along grooves;
  • The method of isolating the groove, the number of interlayer gaskets and their sizes.

Then the remaining frontal winding is removed and a new one is wound. There is a special template for making a winding. It is fixed on an axis holding 2 large-size plates made of metal.

Stator Rewind Stages

When working, it is important to get a strictly defined number of turns. It should be identical to the number of turns of the old winding. The wire must be wound so that the seal is maximized. Coils are placed in the stator. From the same material from which the winding for the coils is made, conclusions are drawn. Their tips need to be insulated with cambrices. Tubes made of plastic.

Before installing the coils, it is necessary to check that the groove boxes are symmetrical. They must close the winding. If this does not happen, when inserting the wires of the coils, temporary inserts are placed. This simple measure avoids damage.

The coil is mounted above the groove, which is located below the bore. Coil conductors are installed using a special plate. The wires located in the groove should never cross over. They need to be laid in the same way, in the same sequence as the winding. Conductors must be installed strictly in parallel.

To perform the next operation, the stator needs to be slightly rotated. Only one division. Coils from the same group fit into the groove. After laying, lay the interlayer gaskets. Screw the terminals onto the external circuit so that they are parallel to the external circuit. The underside of the coils is mounted in the same way. The operation is repeated until the grooves of this step are full.

When the winding is finished, the ends can be plugged. The dimensions of the sleeves depend on the size of the stator. The thickness of the sleeve is usually 0.2 mm, but the length should be greater than the size of the launcher. Most often, this value is about 1.5 mm. For the manufacture of liners using special cardboard. A film must be wound on it (it must be heat-resistant). The entire resulting structure is wrapped with tape. Coils with sleeves must be installed in the grooves of the stator. After that, you can check whether the anchor is moving correctly. The coil is completely ready. It remains only to wrap with kiper tape, and on top to cover with a layer of varnish. After the varnish has dried, the device is completely ready for use.

How to wind a stator winding angle grinder

Rewinding the stator of a grinder

Stator rewind angle grinder can now be done independently. For this you need to stock up only with the necessary knowledge. If the master has the necessary tools, repair skills and a certain amount of knowledge in the field of electrical engineering, the question of how to fix the malfunction of this tool with your own hands is quite easy.

Stator winding circuit.

Causes and signs of stator failure

Manual grinders, popularly called “angle grinders”, can fail for various reasons. The most common problem is the breakage of the stator turns, which occurs due to an excessively strong load on the device. Now, such a malfunction can be corrected independently. Correctly rewind the stator.

There are frequent cases when the failure of the electrical part of the device becomes the cause of the breakdown. Various factors lead to this:

  • Water entering the surface through which current flows;
  • Power surges;
  • Sharp pulling out the plug from the outlet;
  • High overloads and, as a result, overheating.

There is an opinion that it is impossible to rewind the stator yourself. In fact, it’s enough to understand the design of the device. If you have experience with such work and the necessary knowledge, you can repair a three-phase start-up device at home. Given the preparatory work, the process can take several hours.

Wire winding circuit.

Often the engine fails due to a break in the magnetic circuit, violation of the winding or the anchor manifold. With increasing voltage, an abrupt increase in the strength of the spark is noted. Usually this is observed on only one brush. This phenomenon leads to the destruction of the insulation of the wires on the stator coil. If, when turned on, the drive accelerates very quickly and gains speed, this indicates a stator short-circuit.

Sparks that occur during the operation of the collector signal the occurrence of violations in the balancing of the armature. Checking the operation of the collector can be done in this way: when turned on, the sound should amplify gradually with increasing voltage. No vibrations should occur. If resonance is observed, the angle grinder electric motor needs repair.

Hand Grinder

The grinding tool consists of three important components:

The anchor is a rotating element with a winding and creates the torque of the electric motor. On the stator, divided into sectors, there is the same winding. The current through the carbon brush passes through the winding, enters the anchor. Then the current passes to other brushes until all parts of the stator are involved. When electric current passes through the winding, a magnetic field constantly interacting with the stator arises. Thus, an electric motor is driven. There are several characteristic failures of the “angle grinder” launch device:

  • Burning or rupture of the winding;
  • A short circuit between the turns of the winding;
  • Destruction of insulation.

Scheme of an eccentric orbital sander.

You can rewind the winding with your own hands, without contacting a specialist. You only need to disassemble the device first. But if you are not completely confident in your abilities, then contacting a specialized workshop will be the most reasonable step. First of all, the casing shifts. To do this, the screw fixing it is unscrewed. After that, you can see all the details of the angle grinder, with the exception of the gearbox hidden under the metal cap. The screws that secure the metal plate are loosened. Now all the mechanical parts are clearly visible. Only after this can you move on to rewind the stator.

Better than a well-made repair can only be the correct operation, in which there will be no breakdowns at all. In order for the “angle grinder” to work longer, the following simple rules must be observed:

  1. In no case do you need to exceed the amount of grease and the timing of its addition or replacement.
  2. After the tool has been operating at reduced speed, it is strictly forbidden to immediately turn it off. If you leave it to work for at least 1 minute, you can avoid overheating.
  3. Do not allow long-term operation of the tool at reduced speeds under load.

A refurbished stator will allow the grinder to operate normally for a long time.

To rewind the stator, you will need special tools:

  • Hammers: wooden, metal;
  • Pliers and pliers;
  • Steel brush;
  • Calipers;
  • Megohmmeter;
  • Electric drill;
  • Ruler;
  • Varnish.

The first and most important step is to clean the stator from contamination. The old winding is removed from the grooves. All this can be done with a steel brush. Cleaning is carried out manually using steel brushes, electric drills. It is also necessary to remove the old insulation. To facilitate the task, transformer oil can be used. It is necessary to warm it a little and lower the launching device into it. Such a measure will soften the damaged insulation and simplify its removal. For cleaning, a mild caustic solution (temperature. 80ºс) mixed with compressed air is also used.

After treatment, the stator should be washed well with water and dried. The condition of the stator and steel bags must be well checked. Then pull the studs tightening the core, the grooves are cleaned from burrs. Insulation resistance is measured with a megger. Parts of the core, thrust washers and grooves are varnished. Washers and slots must be insulated.

The accompanying note, where the main data is displayed, can facilitate further work:

  • Phase connection diagram and their number;
  • Coil and phase resistance;
  • Number of grooves and their sizes;
  • Winding section, coil pitch along grooves;
  • The method of isolating the groove, the number of interlayer gaskets and their sizes.

Then the remaining frontal winding is removed and a new one is wound. There is a special template for making a winding. It is fixed on an axis holding 2 large-size plates made of metal.

When working, it is important to get a strictly defined number of turns. It should be identical to the number of turns of the old winding. The wire must be wound so that the seal is maximized. Coils are placed in the stator. From the same material from which the winding for the coils is made, conclusions are drawn. Their tips need to be insulated with cambrices. Tubes made of plastic.

Before installing the coils, it is necessary to check that the groove boxes are symmetrical. They must close the winding. If this does not happen, when inserting the wires of the coils, temporary inserts are placed. This simple measure avoids damage.

The coil is mounted above the groove, which is located below the bore. Coil conductors are installed using a special plate. The wires located in the groove should never cross over. They need to be laid in the same way, in the same sequence as the winding. Conductors must be installed strictly in parallel.

To perform the next operation, the stator needs to be slightly rotated. Only one division. Coils from the same group fit into the groove. After laying, lay the interlayer gaskets. Screw the terminals onto the external circuit so that they are parallel to the external circuit. The underside of the coils is mounted in the same way. The operation is repeated until the grooves of this step are full.

When the winding is finished, the ends can be plugged. The dimensions of the sleeves depend on the size of the stator. The thickness of the sleeve is usually 0.2 mm, but the length should be greater than the size of the launcher. Most often, this value is about 1.5 mm. For the manufacture of sleeves used joint venture