How to Disassemble a Mechanical Angle Grinder

How to Disassemble a Mechanical Angle Grinder

DIY angle grinder repair is a completely solvable task. The main thing is not to rush, to understand the design, to recall all the circumstances in which it broke, to determine what could have worn out during the work, to diagnose and proceed to repair.

angle grinder and its operation

An angle grinder is called an angle grinder (angle grinder). The name of the tool is due to the fact that it was produced by the Altos-Angle Grinder plant in the city of Plovdiv. It is intended for grinding or trimming hard material:

It performs tool sharpening well.

Nowadays, an angle grinder is a very necessary tool, so almost everyone has it.

There are different power grinding machines: from 500 W to 2500, depending on the thickness of the circle. from 115 mm to 230 mm. The most popular in the work are an angle grinder with a power of 1.2 W, and the most used disk is 125 mm thick.

Every year, the choice for this construction power tool is becoming wider, but the operating rules are almost unchanged. And even if you always adhere to them, sooner or later malfunctions arise in the mechanism, which you can try to fix yourself, having collected all the angle grinders necessary for repair.

Angle grinder device

Any angle grinder consists of the following parts:

  • the rotor is the part of the electric motor that rotates during operation and is adjustable in speed, also called an anchor;
  • collector. a place on the rotor where the control winding wires are located;
  • brushes. parts that serve as current conductors from the cable to the collector winding;
  • gearbox. a mechanism that acts as a drive from a rotating rotor to a spinning disk, consists of a spindle, a bearing, two gears (a large and a shaft gear);
  • stator. the part of the electric motor in which the rotor operates;
  • impeller cooling angle grinder;
  • start button;
  • network cable with electric drive;
  • protection cover;
  • body angle grinder;
  • additional handle.

All these details can be divided into two parts:

How to disassemble an angle grinder

How to disassemble an angle grinder? Not such a complicated process. This does not require special knowledge, but it is necessary to do everything carefully and with caution. Each owner needs to know how to disassemble any working tool, because from time to time it needs to be cleaned internally of dirt and dust, and its longevity of service depends on it.

At the present time on the market you can choose a different type of angle grinder, which differ in operating parameters, sizes, quality. Manufacturers are also different. Whatever model of grinder you have purchased, everyone has one model for assembling parts.

Dismantling an angle grinder will require a few tools, you just need a regular screwdriver or a reversible one with a ratchet mechanism.

Having prepared a screwdriver, you can start disassembling:

  1. We unscrew the screws from the body and remove one side of the product.
  2. We remove the nut due to which the disc is held, we unscrew the bolts of the protective casing.
  3. We remove the brushes.
  4. Disconnect the wires from the engine.
  5. We unscrew the bolts that secure the gearbox inside, and very carefully remove it, the rotor is also removed.
  6. We unscrew the bolts that hold the stator, and remove it.
  7. We assemble the angle grinder back, alternately put everything in place in the reverse order and fasten it.

When disassembling an angle grinder, it is important to remember the sequence of removal of parts in order to assemble correctly.

Types of damage to grinders

Typical minor breakdowns

In the event of a malfunction, it is first necessary to exclude elementary breakdowns:

  1. The angle grinder does not turn on. the angle grinder suddenly became faulty. it stopped turning on. In this case, you need to check the health of the outlet, then the plug and the power cord, maybe the drive simply does not work due to the fact that no current flows into the product.
  2. The cable and plug are intact, but the drive does not work. You need to check the start button. It is easier to repair an angle grinder switch by purchasing a new button and replacing it. Since it is rarely repairable. basically, the plastic breaker rod breaks inside. If you want experiments, you can disassemble it by numbering the contacts, and put everything back in place so that after assembly there is no short circuit.
  3. The above details are unharmed, and the angle grinder does not want to work. so it’s time to check the brushes. Perhaps it’s time to change them in the angle grinder. Brushes from work are constantly heated, so they quickly wear out and more often than other parts need to be replaced, moreover, in pairs.

Video: How to Disassemble a Mechanical Angle Grinder

Significant malfunctions

Having eliminated all minor breakdowns, it is necessary to understand why the tool does not want to turn on, and how to repair it. Most likely, the malfunctions are serious, requiring additional knowledge. This occurs if:

  • the case is deformed;
  • jammed one of the bearings;
  • anchor or stator does not work;
  • the teeth of the gear reducer have broken or worn out;
  • the collector is out of order;
  • The control electronics sensor does not show any signs of life.

If it is determined that a malfunction has occurred in the mechanical part of the angle grinder, then one must pay attention to the condition of the large gear located on the shaft and to the bushings. If the teeth are partially erased or a shafting of the shafts occurs, they must be replaced immediately.

The most common breakdowns

Failures of the angle grinder happen quite often. Everyone who works with this tool knows about it. What fails most often?

The spindle lock button has broken.

Just one awkward press on the spindle lock button when the disk rotates causes it to break. Sometimes it can be broken if it is used to remove a jammed disk. To prevent this from happening, you need to use an open-end wrench inserted into special holes near the disk mount.

Gear teeth

It mainly occurs when jamming occurs. If rumble is heard in the gearbox, this is a sign of just such a malfunction. When a gear has more than one clove broken, the angle grinder will not be able to cut the necessary material.

The electric motor does not work.

This type of breakdown occurs with an angle grinder, which work in places where there is a lot of dust, and when they are given rest, they leave it on the ground. Dust that gets inside spoils the winding. Large loads, especially for a small power angle grinder, result in a motor breakdown.

If the angle grinder is used to cut materials that create a lot of dust, it is recommended to cover the places of the ventilation holes with something.

Bearing rained down

The weakest link, and not only for grinders, are bearings. The high rotational speed quickly wears out the mechanism. The good news is that changing the bearing is easy. Replacing the sprinkled bearing at the angle grinder should be done on time so that there is no breakdown that can no longer be fixed.

Stator failure

This breakdown is easy to determine when the angle grinder is turned on, but the disk speed is too intense and differs from normal operation. which means that there is a winding in the stator on the winding. Stator failure is considered the most serious, special skills are needed to eliminate it. When there is doubt in your abilities, it is better to turn to professionals so that you do not have to buy a new tool later.

If the decision to fix it yourself is made, it starts with cutting the frontal parts of the winding, all the residues are removed. The next step is a new pattern winding. It should be identical in the number of turns, with the same density and from a wire of the same thickness as the previous one.


An angle grinder whose power is less than 1,100 watts is usually equipped with spur gears. They are on the stator. For grinders with greater power. helical gears. Each of the options has a cone shape, the gearbox shaft angle grinder intersects with the stator shaft at an angle.

Gearbox repair angle grinder mainly consists in the replacement of gears. In the event of a breakdown of the disk gear, it is difficult to replace it, because it is very firmly fixed. It is easy to disassemble the gearbox:

  • you need to unscrew the nut from his side;
  • gently take the rotor housing in a vice and knock the gear housing out with light strokes;
  • change the position of the clamped rotor and knock out the bearing through a wooden board;
  • unscrew the gear from the shaft.

Everything. the gearbox is disassembled.

Speed ​​control

Self-repair of an angle grinder is not always feasible. If suddenly something does not work out or everything is not clear, it is better to contact a service center.

Common symptoms

Before it breaks down completely, the angle grinder signals the beginning of the malfunction.

Pay attention to the work of your assistant: you should be alert if:

  • the brushes began to spark too much;
  • during operation, the angle grinder is heated;
  • the motor buzzes inside the case when the tool is turned on;
  • the vibration of the case has become much greater when performing work;
  • reducer angle grinder cracks inside;
  • the sound of a creak of bearings is heard during spin-up or periodic wedging when the rotor shaft rotates;
  • the angle grinder is smoky, or an uncharacteristic burning smell emanates from it.

In order not to buy a new angle grinder, you need to be careful about the tool. In the event of any deviations from the usual work, start troubleshooting, determine the cause and repair the power tool.

Breakage prevention angle grinder

The life of the grinder directly depends on the care of the owner for her. Each tool needs good care, then it will work properly for a long time.

Any angle grinder will warm up during operation, but in order to postpone the angle grinder repair for a long time, it is necessary to adhere to some rules in operation:

  1. Do not overload the tool to avoid overheating and smoke.
  2. Do not press hard on him while working.
  3. Clean and lubricate the necessary parts inside the housing in time.
  4. If there is a noticeable malfunction, stop operation and inspect for malfunctions.
  5. Replace wearing parts in a timely manner.
  6. If the angle grinder is smoking, immediately stop working and do not turn it on anymore.
  7. Do not use the tool when processing wood type material.
  8. Hold the angle grinder firmly during operation so as not to drop or damage.

Adhering to the listed simple recommendations and rules in working with a tool called an angle grinder, you can extend its service life longer than provided for by the warranty period.