How to remove the anchor on the angle grinder. Few tips

Repair of Bosch angle grinder with your own hands

Working with tools brings me pleasure, I am guided by the rule: “if you want to do well. do it yourself!”This post, rather my notes, so to speak the memo and a checklist of necessary maintenance work, which may be useful not only to me The article is formed on my personal experience and knowledge of the underlined by authoritative sources, so the title of the guru or the only right opinion, I do not pretend.

Preventive maintenance. the head!)) Timely maintenance of the tool, I think it is not news to anyone, saves money and minimizes the likelihood of sudden breakage and a number of inconveniences.

Thinking along the lines of medicine, “the main thing is do no harm!” Initially, it is correct to realize the option of the result of your own repair as the last for this tool, t.е. be aware of the risks and willingness to purchase a new angle grinder, but this is in the worst of circumstances. Т.к. As in any other case, there are a number of nuances and subtleties, without experience is very easy to make mistakes that will lead to additional expenses on spare parts or even break a few expensive nodes, making the repair unprofitable. On the other hand, not all repair shops are a panacea. Professionals and good craftsmen are not many, but a negative “aftertaste” after contacting the service center, is not uncommon. Here is just a post in which I will try to cover the maximum knowledge and tips that can help with self-service and repair of lathes.

Replacing the Anchor on the angle grinder

Check, repair and replacement of the anchor angle grinder by yourself

Anchor angle grinder than just all units are subjected to temperature, mechanical not electromagnetic loads. Therefore, it is a frequent cause of tool failure, not as a result, often needs repair. How to check the armature for serviceability not to repair the element at home. in our article.

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Angle grinder armature design

Anchor motor angle grinder is a conductive coil is not a magnetic wire, in which the shaft of rotation is pressed. It has a drive pinion at one end and a manifold with lamellae at the other. The magnetic wire consists of grooves not soft plates coated with varnish to insulate each other.

Two conductors of the anchor winding are placed in the grooves according to a special scheme. Replacing a burnt out armature on an Interskol 125/900 angle grinder,back armature bearing and brushes. Which conductor makes up half a coil, the ends of which are connected in pairs on the lamellae. The beginning of the first coil and the end of the last coil are in the same groove, so they are connected to the same lamella.

How to check the armature of the angle grinder for serviceability

If the armature is defective, the motor overheats, the winding insulation melts and the turns are shorted. The contacts that connect the armature winding to the collector plates are soldered off. The current flow stops and the motor ceases to run.

Standard diagnostics

While you get the diagnostic tool, examine the armature. There will be damage. If the wiring is melted, the burnt insulating varnish will leave black marks or otherwise a peculiar smell.

Bent not crumpled coils or conductive particles, nettles, solder residues are found. These particles are the cause of the short circuit between the coils.

The lamellae have bent edges, called roosters, to connect to the winding.

These contacts are broken and cause the lamellas to burn out.

Other manifold damage: raised, worn or burned plates. There may be graphite from the brushes accumulated between the lamellae, which also indicates a short circuit.

How to test with a multimeter

  • Set the resistance to two hundred ohms. Connect the probe to two adjacent blades. If the resistance is the same between all neighboring plates, it means that the winding is in order. If the resistance is less than one ohm is not very close to none, there is a short between the coils. If the resistance is two or more times higher than average, then there is a winding breakage. If there is a break, the resistance is so high that the instrument goes off the scale. On an analog multimeter the arrow will go all the way to the right. Nothing will show on the digital one.

how the test is carried out

If you do not have a tester, use a twelve volt bulb up to forty watts.

How to check the rotor of an angle grinder with a light bulb

  • Take the two wires and don’t connect them to the lamp.
  • Make a break in the minus wire.
  • Apply voltage to the wires. Place the ends of the break at the manifold plates do not twist it. If the lamp is lit without changing brightness, there is no short circuit.
  • Perform a short circuit test on the iron. Connect one lead to the lamellae and the other to the rotor iron. Then with the shaft. Replacing the Armature on an Interskol 125/900 angle grinder. If the light is on, it means you have a ground fault. The winding is shorted to the rotor case otherwise known as the shaft.

This procedure is similar to the multimeter diagnosis.

Checking with a Short Circuit Leakage Indicator (SCL)

You may find some armatures where you can’t see the wires connected to the collector because they have been filled with opaque compound, or because they have a bandage. Therefore, it is difficult to detect commutation on the collector relative to the groove. A short-circuit indicator may be helpful in this case.

Such a device is small in size and not easy to use.

First check the armature for open circuits. Otherwise, the indicator will not be able to detect a short circuit. For this purpose use a tester to measure the resistance between the two adjacent blades. If the resistance is at least twice the average, then there is a break. If no breakage occurs, continue to the next step.

Issue #29: How to remove the anchor from an angle grinder without breaking anything | Lifehack

After watching a lot of videos of removing the anchor from the angle grinder, I came to the conclusion that no one knows how to remove.

The resistance control allows you to choose the sensitivity of the device. It has two lights: a red one and a green one. Change the armature to angle grinder Makita ga9020/repair. Adjust the controller until the red light starts to illuminate.

On the body of the indicator there are two sensors in the form of white dots, located three centimeters apart from the native edge. Place the indicator with the gauges against the winding. Slowly turn the armature.

If the red light comes on, there is a short circuit.

Get Another Angle Grinder

Anchor Test Tool (Reactor) Diagnostics

An armature tester will test for inter-turn winding shorts. A choke is a transformer that only has a primary winding and no magnetic gap cut in the core.

When we put the rotor in this gap, its winding begins to work like the secondary winding of a transformer. Turn on the apparatus and place on the armature a metal plate, a nettle, a metal ruler, or put a hacksaw blade.

If there is inter-turn short circuit, local iron oversaturation will cause the plate to vibrate or become magnetised to the armature body. Rotate the armature around the axis, moving the plate so that as oil lies on different turns.

Tips for removing the bearing from an armature timely replacement of carbon brushes on an angle grinder. If there is no short circuit, then the plate will move freely across the rotor.

How to Repair an Armature at Home

The armature is the reason for one-third of all screwdriver malfunctions. In the case of daily intensive work, faults already occur in the first six months, nettles, if the brushes are not replaced in time. The screwdriver will last a year or less if used sparingly.

Anchor can be saved if it is not out of balance. If in the time of operation of the device is heard intermittent hum does not go strong vibration, then it is a violation of the balance. Such an anchor must be replaced. And you can repair the winding is not a collector. Small short circuits can be repaired.

Tools needed for repair

To repair the Bosch angle grinder, you can not do without a tool. Let’s say at once that if you have an electric screwdriver, it will greatly speed up the process of disassembly and assembly of the tool.

but you can get by with a set of screwdrivers, preferably with a ratchet mechanism. Do not do without the open-end wrench to unscrew the nut securing the helical drive pinion.

It is best to have a special bearing puller for disassembling bearings.

An electrical diagnosis can be made with a tester or a short-circuit wire tester.

It is especially useful in that it allows you to determine if there is a rotor or stator fault without removing the assembly.

Bosch angle grinder diagram will help to perform the repair yourself, and this manual will help to deal with any problem with dignity.

Possible electrical faults

Electrical faults on the Bosch angle grinder can be divided into simple and complex faults.

Simple electrical problems on the Bosch angle grinder

If you have turned on your angle grinder and it refuses to work, start looking for the problem with a broken power supply wire. Most often a wire break occurs at the angle grinder inlet or at the plug. Avoid twisting, this will cause a short circuit in the tool.

To determine if this is a problem, open the handles of the angle grinder. In Bosch angle grinders up to 1000 W, the cover is fastened with one screw in the end. Bosch Power Tools 1000 watt and above have several screws for the handle cover.

Use a tester to test the power circuits from the input plug pos.5 up to the switch. If the circuit is intact, go on to check the switch. Bosch angle grinders have simple switches that are controlled by the trigger lever.

But the electrical contacts of the switch burn out and cause the angle grinder to malfunction. The contacts on the plastic switch can not be repaired, it must be replaced with a new switch.

If the switch is intact, use a tester to check the circuit from each prong of the plug to each carbon brush.If the circuits are intact, the angle grinder should turn on. If it will not turn, then the problem is on the mechanical side. Jamming of gears or destruction of bearings is possible.

Checking the motor

If your Bosch angle grinder picks up speed regardless of you, begins to get very hot, sparks, it is necessary to pay attention to the integrity of the windings of the rotor, stator.

Unintentional revolutions of the angle grinder indicates a malfunction of the stator windings. The integrity of the windings checked with a tester, and the short circuit between the coils checked with a special device.

How to find a defective rotor

Repair of the rotor is a complex technological process, accessible to craftsmen with straight hands.

A rotor malfunction is indicated by a drop in motor RPM, or a long, sparkling trail on one of the brushes. This is the first sign of a shorted armature winding winding.

It is preferable to repair the rotor in a special workshop. And you can rewind on your own, if you decide to do the repair of the Bosch angle grinder with your own hands.

Dark color of rotor winding and burned manifold lamellae indicate short circuit in rotor circuits. The fault can only be eliminated by exchanging for a new rotor.

Stator repair

Repairing a Bosch angle grinder also includes rebuilding the stator. The main sign of stator failure is the spontaneous increase in the speed of the working angle grinder, which can not be reduced by adjustments.Overheated stator winding changes color, becomes darker. Stator core also becomes darker with heat.

The stator is easier to rewind, although certain rules and sequence must be followed.

If you have removed the stator housing cover, carefully inspect the carbon brushes and rotor header lamellae.

The carbon brushes should be at least 8 mm long. By the way, Bosch angle grinders use carbon brushes with a “shot”, a device that stops the angle grinder at the minimum length of the carbon brush.

The manifold blades must not show any signs of soot or wear. Remove soot easily with absorbent cotton soaked in alcohol.

Speed regulator malfunctions

The Bosch brushcutters, especially the smaller ones, are equipped with speed controllers. Access to speed regulator is gained by opening the knob on the stator housing, held on one endscrew.

The speed range of the regulator can be set with a potentiometer, hidden in the handle panel.

Faulty regulator is quite easy to remove, because it is mounted only on the guide rail.

Repair of the speed regulator of the angle grinder is a complex process, which requires not only special knowledge but also tools and equipment.

If the speed regulator is defective and a new one is not available, disconnect the leads and install a bridge.

The jumper that is installed in case of failure of the speed regulator is shown in red.

How to remove the bearing from the shaft without puller, without damaging the equipment

Malfunctions of automobile alternators are conditionally divided into two groups: electrical and mechanical. In the second case, it is, as a rule, wear of the rotor shaft bearings.

It might seem that the question is not worth a bollock: to remove and replace the assembly with faultless one However, the bearings pressed in the factory are dismantled using special equipment. a puller. You don’t always have the right tool in the garage, let alone repair on the road or in the field. How to remove the bearing from the shaft without a puller? We adopt experience from homebrew craftsmen.

How to disassemble the generator case?

The first difficulty you will encounter is the removal of the pulley of the crescent belt. Shaft turns freely even with defective internal bearings. It is necessary to enter an allen key into the hole on the end of the shaft, and with the help of a socket head unscrew the pulley nut.Then the housing halves must be removed starting with the back cover.

The outer ring is stuck to the housing and the bearing of the alternator remains in the cover

In that case it can be easily pressed out (or carefully knocked out) using a piece of pipe or a socket with a suitable diameter. In practice, this is most often the case with the rear bearing. To remove the inner ring on the shaft you need to spray WD-40 here. The assembly then remains in the housing.

You have removed the back cover. bearing remains on the shaft

By the law of mean, this is exactly what happens during urgent repair. Not only that, both ball bearings can remain on the armature and you can’t remove them with a pipe.

If the construction allows, it is possible to remove the bearing from the armature without a puller using two strong slotted screwdrivers. The main thing is to have something to hold on to and not to damage the contact block or the winding.

Of course before you start it is necessary to treat the shaft with penetrating liquid, like WD-40. Then it is easier to remove the assembly. Make sure no liquor gets on the contact pads or in the winding.

Otherwise, over time, the lacquer insulation can dissolve and interwinding will occur.

The same method applies to the motor armature: for example, on the starter.

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Using the handy tools of a mechanic

It was not possible to remove the bearing without a puller, what to do? Don’t rush to a workshop, inspect an alternator armature. If there is no thrust pad, you will have to use a welding machine.

A metal eye made of a 4-5 mm bar is welded to the outer ring and a rope or chain is attached to it. The assembly is still to be thrown away, the main thing is not to damage the contacts and winding during welding.

To do this, vulnerable parts should be wrapped with at least masking tape.Then we fix the second chain end and work on the principle of a reverse hammer.

Good moment of inertia is achieved by the weight of the armature: only a couple of jerks are needed to remove the bearing.

The only disadvantage of this technique. if you do not have a welder, this method to remove the bearing from the generator is not suitable.

This technique is used both in garages, and in travel (of course, provided that you have a spare bearing, or you bought it at a roadside auto supply stall). The improvised puller is made of usual open-ended wrenches.

The rounded shape of the wrench jaws is ideal for a lever that can produce serious tension.Practice shows that it is not convenient to work with one wrench. Skewed inner ring jams the bearing on the shaft, making it difficult to remove.

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And by gripping the assembly with two wrenches positioned evenly, you can distribute the force.

If you work in a garage. clamp the shaft in a vice (better with wooden spacers under the jaws, so as not to damage the anchor). And in road conditions you’ll need an assistant, who will hold the rotor.

In such a way even strongly prikazhennyh cages are removed. The main thing is that there should be a thrust pad under the wrench heads. And how to remove the assembly from the other side, where the contact group for brushes is installed? Temporary supports must be in place: e.g. sockets with the same diameter.

In the same way you can remove the bearing from the air conditioner compressor or even from the crankshaft.

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The bottom line: Repair of an alternator without a puller is possible, even in the field. And yet, it is better to acquire this useful tool: the more so that its cost is not great.

How to Remove an Anchor from an Angle Grinder?

Often, during operation, the power tool gets clogged with small mechanical debris. There is a risk of overheating and causing the unit to malfunction. To prevent such situations, it is recommended that the tool be periodically disassembled to assess wear and clean contaminants from the tool.

An angle grinder also requires regular preventive maintenance. When sawing or grinding various solid materials with it, fine mechanical dust flies in different directions.

It is not uncommon for it to get directly inside the tool. To clean the device, you will need to disassemble it, and you need to be guided in the question of how to remove the anchor from the angle grinder.

Such manipulations are also performed when repairing or replacing any part of the tool.

It is the armature in the angle grinder that is subject to natural wear. Overheating or regular use can lead to short circuits in the contacts. You can also remove the armature from the angle grinder to check that it is in good working order.

In most cases, the failed part is not suitable for further use. It must be replaced by a new one.

But how to disassemble the tool without breaking it, and how to remove the armature of the angle grinder? In this article we will try to give you detailed information to help you understand the process.

How to remove the anchor from an angle grinder. preparation for work

Disassembly of the tool usually does not require any special preparation. Just be attentive and careful, and you will be able to correctly remove the anchor from the angle grinder. The surface on which you disassemble the power tool must be flat, dry and clean. Take care of sufficient lighting so that you can clearly see all the parts and fasteners.

The process of removing the anchor from the angle grinder

Every serious job requires close attention. When disassembling the tool and removing the anchor from the angle grinder, you should try to remember the location of the components inside the body in order to successfully perform the subsequent assembly. Allocate a separate place for the bolts, so as not to lose parts. When disassembling the device you may need the following tools:

You may also need grease and a rag. All parts of the equipment are in tight contact with each other. This is to ensure that under load they do not vibrate and break, hitting each other.

Sometimes this tight placement can make it difficult to disassemble, including removing the anchor from the angle grinder. But just be extremely careful and attentive and you will succeed.

Analysis of the elements, units and systems of the device involves disassembly of the gearbox, since they form a single unit.

How to remove the armature from an angle grinder. a step-by-step guide

The process is carried out in several stages:

  • In order to remove the anchor on the angle grinder, you must first unscrew the bolt that holds the hood. You can easily perform this manipulation, since there are no tight joints. To carry out the work will need a universal multifunction screwdriver with a ratchet mechanism.
  • After unscrewing the screw, the outer casing slides toward the cable. Separate models of lathes are created using a variety of components. A detail that is present in all power tools is the motor. It consists of the stator, armature, collector and brushes. After removing the housing it is necessary to remove the brushes. To extract it, you must first move the springs, after which they can easily be removed.
  • After you remove the brushes, you can proceed to remove the rotor. To do this unscrew the four outer bolts. Unscrew it with a screwdriver. Then the rotor head is removed. It’s easy enough to remove it. manually by pulling up. It remains to remove the rotor. It can be removed along with the plastic cushion. This action can also be performed manually.
  • Having removed the anchor from the angle grinder, it is necessary to remove the rubber seals on its axis. Then it remains to free the part from the plastic cushion with bearing and pinion. Clamp the upper nut with a gas wrench and unscrew it. This step requires only little effort. After that the plastic pad, the pinion and the bearing are removed. Anchor removed from angle grinder. Therefore, the process is completed.

To assemble the power tool, all steps must be repeated in reverse order.

Mandatory manipulation while removing the anchor from the angle grinder

On contaminated parts you may not be able to see the breakage. Performing manipulation to remove the anchor from the angle grinder, as well as other components of the tool, do not forget to thoroughly clean them and wipe with a dry rag.

If all parts are intact and working, removing dirt from their surfaces will still be an excellent preventive measure to increase the life of the appliance.

How To Use An Angle Grinder-Angle Grinder Safety Tips

Perform this action periodically to reduce stress on tool parts while working in a challenging environment.

When removing the armature from the angle grinder and its general disassembly for cleaning or repair, check the need to replace the grease metal parts of the tool. The grease normally used is “Lithol-24”.

By timely changing the lubricant and removing internal mechanical clogs, you can significantly extend the life of the electric angle grinder.

This uncomplicated process will help prevent premature wear of components and the tool as a whole, as well as improve its performance.

The main difficulties that can arise in the process of removing the anchor from the angle grinder

Note the sequence of operations when disassembling the tool and the position of all the parts in the housing. Sometimes there can be some difficulty in removing the armature from an angle grinder:

  • It can happen that bolts and joints become rusty or the threads break off during disassembly;
  • A short circuit can melt the plastic parts of the appliance;
  • deformed plastic parts stick to the metal parts making it very difficult to disassemble the tool.

If you are not confident in your abilities, it is better not to open the angle grinder at home. In this case, you will need the help of an expert to correctly remove the armature from the tool.

Disassembling the Bosch angle grinder with your own hands

For the owner of a power tool, knowledge of the tool and the ability to disassemble it is a must.

Knowing how to disassemble the angle grinder allows you to perform such work as changing grease, bearings and carbon brushes on your own.

To remove the gear housing pos.821 from the stator housing pos.888, you must disassemble (remove) the angle grinder handle housing pos.24.

This operation must be performed to get the carbon brushes pos.810 holding the rotor head.

In the second step, unscrew the four (4) screws pos.61 securing the gearbox and stator housings.

Having removed the rotor together with the gearbox, proceed to disassemble the gearbox.

Repair of angle grinder Bosch starts with disassembly of the gearbox pos.821. Disassembly begins by removing the four (4) screws pos.60. Screws are normally sealed at the factory. Some effort is required.

It should be noted at a glance! Bosch low-wattage bucking machines have spur gears in the gearbox. Grinders with power over 1000 watts have helical gears in the gearboxes.

How to remove idler pinion

After removing the gear cover, you can get the helical gear unit pos.26.

To remove the pinion, you need to use a press or a tacker. But it is difficult to use a puller, since it requires special thin jaws.

Before removing the helical pinion, check the play of the tooth joint, the integrity of the teeth, the contact patch.

On the spindle shaft pos.26 the bearing pos.50. If the bearing has a large backlash, noises when cranking, grease has dried up, it is preferable to replace it.

To remove the bearing, remove the pinion, the retaining ring and remove the bearing. If the bearing remains in the gearbox housing during disassembly of the rotor shaft assembly, disassemble bearing with a hammer and soft spacer.

How to remove the drive pinion of a Bosch angle grinder

Pinion pos.27 is removed from the rotor shaft in the following sequence:

  • Clamp the rotor by hand and use an open-end wrench to unscrew the counterclockwise nut pos.45.;
  • Remove the washer pos.59.;
  • Pull out the bevel drive pinion pos.27.

Visually check the integrity of the gear teeth, the contact patch.

If the gears are heavily worn (chipped), have chipped teeth, replace them. over, the replacement of gears is always done in pairs.

Bosch low-power angle grinders use a needle bearing in the gearbox as a support bearing.

Angle grinder Bosch repair with your own hands strictly follow the attached instructions. If you need to remove the needle bearing from the housing, you cannot be too clever. Only remove it if it fractures.

To remove a destroyed bearing rim, you can use the following proven method.

Take a tap with a diameter slightly larger than the inner diameter of the destroyed needle bearing cage

The tap is inserted into the chuck of an electric screwdriver and turned carefully at low speed into the cage. When the tap reaches the bottom of the gearbox housing it begins to lift the cage

In addition to the spindle shaft needle bearing, Bosch angle grinders have two bearings on the rotor shaft.

How to remove the bearings from the rotor of a Bosch angle grinder

To remove the bearings from the rotor pos.803 Bosch angle grinder we recommend using extractors.

Bearing pos.15 near the manifold is easy to remove, but to remove the bearing pos.14 on the impeller side is complicated by the fact that it is necessary to do a number of preparatory operations.

Bearing pos.15 is covered with a soft rubber socket. The same rubber guard pos.33 covers the bearing pos.14.

To disassemble the bearing pos.14 you need to unscrew the nut pos.45, remove spur gear pos.17 and plastic protection pos.33. It is easy to remove the bearing from the rotor shaft by using a bearing puller.

Peculiarities of operation of asynchronous motor of angle grinder

Virtually all appliances used in everyday life, are used asynchronous electric motor. An important advantage of this type of motor is that the speed does not change as the load on the motor varies. This means that if, for example, you cut a stone with a household angle grinder for a long time without stopping, there are no outward signs of motor overload. The speed of the disc will be constant, the sound will be monotonous. Only the temperature will change, but this may not be noticed if hands are wearing gloves.

An advantage can become a disadvantage if not handled carefully. Induction motors are very sensitive to overheating. If the operating temperature rises considerably, the insulation of the rotor winding will melt. At first, the motor will run roughly unevenly and then, after a short circuit between the coils, the motor will stop altogether. Just overheat the angle grinder motor a few times and, most likely, the armature will melt. In addition, the high temperature causes the contacts connecting the primary winding wires to the collector to become unsoldered, which leads to an interruption of the electrical current supply.

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Asynchronous motors

Before you check the armature of the electric motor, you must check the other nodes and parts (because the cause may be damage). connection cables, magnetic starters, thermal relay, capacitor, as well as check the presence of voltage. If everything is OK, check that there is no power supply and disassemble the motor.

The causes of stator windings failure are most often the following:

If the inspection does not reveal any faults, further diagnosis is made with a multimeter. On 380V machines, which are connected in delta or star connection, each winding is checked individually. The deviation of the resistance value on them should not be more than 5%. Then the windings should be tested with each other and with the body. The resistance should be infinity; any other reading could indicate a breakdown between the windings or to the frame. This problem can be solved by a complete rewind.

For 220 V motors, it is sufficient to check the operation winding and the starter winding. The resistance of the first winding should be 1.5 times lower than that of the second.

The most difficult part of the test. the search for the inter-turn short circuit, as visual inspection to identify it is not possible. Use a special inductance meter. If all the windings have the same value, there is no fault. The lowest value on any of the windings indicates that the winding is defective.

The insulation resistance of the windings can be checked using a megohmmeter for 1000 V connected to a separate power supply. One wire should be connected to the machine body in a place that is not painted, and the other to each winding terminal in turn. The value should be greater than 0.5 Mohm, a lower value indicates that the engine needs to be dried. Avoid touching cables and be extremely careful when measuring

To avoid accidents, de-energize the motor and observe all safety precautions.

Now you know how to check the motor armature with a tester, and you can without the involvement of a specialist to identify the cause of failure and fix it, saving money and time.

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