The contact group of the drill button can be replaced with what. Connecting and repairing drill buttons

Many users of electric drills may sooner or later begin to wonder how the drill button is connected to the tool wiring. This question usually appears when a malfunction occurs in the old button, which requires connecting a new one. In this article I will tell you how it should be connected - what goes where.

I will not describe here how to disassemble the body of an electric drill to get to the insides, since I assume that since you are already asking the question of replacement, disassembling the body will not be difficult for you. I think that anyone who does not know how to disassemble the case will not even think about self-replacement anything in the instrument.

So, first you need to purchase a new button. It should match the old one in size and power characteristics, so when you go shopping, take it with you for a sample and write it down exact model your instrument.

How to detach the old button?

To disconnect it, you will need a thin slotted (straight) screwdriver and a pin. Using a screwdriver, unscrew the existing bolts that clamp the cables coming from the power plug.

The remaining wires are secured with a spring clip. To disconnect them, you need to insert the tip of a pin into the recess where the terminal is located. Thanks to this action, the terminal is decompressed and the wire is removed along with the pin.

When disconnecting, I advise you to leave the wires coming from the capacitor in place so as not to forget which contacts it is attached to. Since it is not attached anywhere else except to the button terminals, they can be removed together and taken in this form to the store to buy a new copy. After purchasing, the first thing to do is plug the capacitor into a new place, after which you don’t have to think about it.

Connection diagram for a drill button with speed control and reverse

The actual visual connection diagram is shown in the image below.

Let me give you a few clarifications.

• The picture shows the most common type of spare part in question. The electrical wires from the power plug are fastened to terminals that are bolted. The rest are stuck into self-clamping contacts. If your button is not like this, then it is better to make notes from the old copy of what is attached where. Also, a diagram can be drawn on the body itself, which can also be used to guide you.
• If you connected the capacitor as described above, then after connecting the wires from the plug, you will only have two contacts on the bottom of the case, where you need to plug in two cables from the stator. They usually have the same position on the stator as in the picture. Their length must be longer than the other two so that they can reach their clamps. In this case, it makes no difference which wire is plugged into which of the two contacts.
• The remaining two electrical wires from the stator, as well as cables from the brushes, are connected to the reverse terminals. In this case, the connection is made diagonally: the wires from the stator are plugged in along different sides into diagonally located contacts; and from brushes too. At the same time, the only direction in which the cartridge will rotate at a certain position of the reverse trigger depends on where exactly the wires will be inserted. The main thing is to connect diagonally.

This is the connection diagram. I hope that you will be able to connect everything correctly and the drill will work as it should.

Any power tool consisting of electromechanical components, no matter how carefully it is treated, becomes unusable over time. This is largely due to mechanical components that require periodic lubrication.

Carrying out preventative maintenance or repairing a drill yourself is not so difficult if you are familiar with the structure of the tool and understand the principle of its operation.

Operating principle and main components

The drill owes its appearance to the demand for underground drilling to replace manual labor with automated labor. In 1870, the American inventor Simon Ingersoll introduced the ancestor impact drill. In its work, the tool used a steam drive and a drill. The emergence of electric motors in late XIX centuries allowed us to improve the instrument. So, in 1889, engineer Arthur James Arnot proposed using an electric motor in conjunction with a drill, and already in 1895 a tool appeared that could be held freely in the hands when working.

In early 1917, Arthur Arnot, working for the BLACK&DECKER company, connected a button to a drill and added a pistol grip, making the device one of the most popular power tools in the world. Since then, the design of the electric drill has not undergone fundamental changes.

A classic drill only works in drilling mode, but with the development of manufacturing technology modern devices began to be equipped with a shock mode. When connected to a 220 volt network, a gear drill, transforming electrical energy into a mechanical one, it forces the cartridge attached to the device mechanism to perform a rotational movement. The number of revolutions of the cartridge is controlled using a rheostat built into the power button, and the direction of rotation is set by reverse. The drill, clamped into the chuck, due to its shape and under the influence of high speed of rotation, easily makes a hole in hard or soft material.

To carry out an impact, the device uses reciprocating movements resulting from the operation of the motor. A ratchet representing a toothed ring is installed on the axis of the cartridge, and teeth are made on the body to create a stop. When the impact drill is switched to hammer drill mode, the ratchet engages and then slides off the fence. The shaft strikes in a vertical direction.

Before you start repairing a drill with your own hands, you need to determine which part of it needs to be restored.

The main parts of the drilling tool are:

Thus, the electric drill components are divided into electrical and mechanical modules. It should be taken into account that the impact unit has low productivity and, with frequent use of this operating mode, quickly wears out.

Wear of the impact unit not only negatively affects the chiselling work, but also increases the load on the electric motor, causing it to overheat.

Device motor

The engine is the main element of the device that drives the tool gearbox. It consists of a stator and a rotor, while the rotor is a moving part, and the stator, accordingly, is not. The rotor design includes an armature with a commutator. An armature is an engine element assembled from steel plates. Conductive windings are wound on them electricity material - copper. The collector is a cylinder. It is made of dielectric and current-conducting plates, and the armature windings are connected to these plates.

Due to the magnetic flux created around the armature by the stator windings, it rotates, which leads to the occurrence of a torsion moment. The magnetic flux arising under the influence of direct current is always directed only in one direction.

Power is supplied to the windings through brushes made of graphite. The brushes are positioned in such a way that they provide constant electrical contact with the armature.

The wear of the brushes should not exceed 70-80 percent; if this value is higher, then the contact deteriorates, resulting in sparking in this place. Before replacing brushes, pay attention to the brush holder and clean it if necessary. Thus, the main parts of the electric motor are:

• stator;
• anchor;
• brushes

The easiest way to check the windings is with a multimeter. To do this, touch the brush holder with one contact wire of the measuring device, and touch the contacts of the 220-volt power plug with the second. If the tester shows infinite resistance, then this means the winding has burned out. The operating resistance of the stator winding is in the range of 30−60 Ohms. For example, the popular electric drill Interskol DU-13/580 ER has a resistance of 40 Ohms. When replacing the stator, you will have to disassemble the engine. To do this, four screws are unscrewed and the case is disassembled into two halves. As a result, access to the remaining parts of the engine is freed.

The anchor is connected to the gearbox. Often, by visually inspecting it, you can conclude about its integrity. There should be no scratches or blackening on the anchor. When replacing the armature, it is important to correctly install the bearing with the rubber gasket. With a simple tester it is possible to measure the armature only for a winding break, but to check for an interturn short circuit you will need a specialized device. The measurement is carried out in the mode of checking the resistance between the armature windings on the lamellas. The amount of resistance between all lamellas should be the same.

Speed ​​controller

The speed of the power tool is controlled by a triac regulator located in the device's power button on a special gasket made of textolite. When the button is pressed, an alternating voltage is supplied to the control output of the triac. The triac opens and current flows into the load. When the input polarity changes, the semiconductor device closes. Then everything repeats in a cycle.

As a result, the signal at the output of the triac will be in the form of pulses. The higher the signal level supplied to the semiconductor, the longer time it is open, which means the pulse length at its output is longer. The degree of opening of the triac is regulated by a variable resistance, which limits the magnitude of the signal supplied to the semiconductor.

Besides, The rotation speed of the chuck in an electric drill depends on the force of pressing the start button. This is realized by connecting a button with a speed controller. Drills, depending on their type, may have different scheme connection of the switch, but its structure is the same. The button housing contains a contact group and spring-loaded plates (resistors). These plates are made in the form of sliding contacts.

When the button is pressed, they are set in motion and returned to their original state under the action of a spring. The pressure is limited using an adjusting screw with a flywheel. By determining the length of sliding of the contact plates over the resistors, he thereby sets the highest speed of the device. If the flywheel is removed from the structure and unscrewed, then when you press the button, the contacts will simply close and the electric motor will begin to operate at maximum speed.

Connecting an electric drill circuit with reverse and speed control is different, since these are nodes independent from each other. The electrical connection diagram, for example, used in Interskol electric drills, looks like this: the power cord, consisting of two wires, is connected with one wire to the speed controller. The contact wire coming out of it is connected to the beginning of the first stator winding. In the absence of reverse, the end of the first winding is connected to the armature brush, while the second armature brush is closed to the beginning of the second stator winding. The second wire of the cord is connected directly to the stator winding.

Reverse operation is ensured by changing the connection of the stator windings. As a result, the direction changes magnetic field and, accordingly, engine rotation. To do this, the first brush is connected to the beginning of the second stator winding, and the second to the end of the first. Quite often, a winding connection diagram is depicted on the reverse block.

To avoid sparking during switching and filter out interference, a capacitor is used that is connected in parallel with the wires of the power cord.

Disassembling an electric drill

In order to find a malfunction and repair the device, you often have to disassemble the tool. Since all devices are similar in appearance, disassembling them can be represented in the following form:

To carry out lubrication mechanical parts, you will need to disassemble the gearbox. To do this, remove the protective casing, after which the screws are unscrewed and the top cover is removed. Viscous materials such as Agrinol are used as lubricants. It should be noted that repairing a power tool with your own hands if the gearbox is damaged is almost impossible, since it is difficult to purchase replacements for worn gears separately.

During repairs, you often have to face the need to disassemble the cartridge. It is a quick-release design. Secured with threaded connection or Morse taper. With the first method, you will need to unscrew the fastener using a hex key, and then, placing the key in the chuck, tighten it tightly. The cartridge itself is unscrewed by turning the key. Removing the fastener using a Morse taper occurs by carefully striking the end of the cartridge.

Typical tool failures

Knowing the design of an electric drill, it is easy to determine the reason why one or another of its functions does not work. It should be noted that you can avoid breakdowns of power tools if you periodically carry out preventive maintenance related to replacing the lubricant of mechanical parts.

After completing drilling work, it is necessary to remove dust from the tool, especially from its ventilation holes. The nature of faults is divided into electrical or mechanical origin.

Electrical damage

This type of breakdown occurs due to excess permissible load on the device and violations in its operation. They manifest themselves in the refusal of the tool to turn on, in a malfunction of the reverse or speed controller. Most often, to restore functionality, you will need to disassemble the start button and clean all places associated with the electrical contact.

The appearance of a burning smell indicates an overload in the operation of the electric motor. In this case, the condition of the brushes and windings is first checked, and the connection points of the power wire are examined to ensure there are no burns. Burning is associated with the ingress of dust, as a result of which the contact resistance increases, which leads to heating. Electrical faults are easily calculated using a multimeter and visual inspection.

Mechanical breakdowns

Mechanical faults are more difficult to detect. This kind of breakdown is usually accompanied by the appearance of extraneous sounds, and it will not be possible to eliminate them without disassembling the instrument. If the drill is poorly fixed in the chuck, it will need to be replaced, since the wear of the gear connection cannot be restored independently.

The appearance of a wedge during operation associated with damage to the gearbox or bearing. If you disassemble the device, the damaged unit will be immediately visible. Wear on gears or splines will indicate the need to replace them. Bearings are checked by rocking them on the shaft. If the movement is not smooth or extraneous sounds are heard, then the bearing is replaced. After you manage to find the faulty unit and repair it, before putting the device back together, you need to clean the gearbox of old lubricant and apply new one. Then the device will be able to serve for more than one year.

An electric drill occupies a special place in the home workshop. Therefore, tool breakage is quite a big nuisance. Despite the complexity of the design, produce do-it-yourself repair quite possible.

1. body and power cord;

2. key with switching block – can be equipped

reverse switch (speed controller);

3. shaft rotation speed regulator (or reverse switch);

4. gear housing - performs load-bearing functions for rotating

elements;

5. gears and gear mechanism;

6. bearings of the cartridge shaft and motor armature;

7. electric motor;

8. brush assembly of the electric motor;

9. chuck with a mechanism for holding a drill or cutter.

The entire drill never breaks down: one of the elements fails. Having understood the design and interconnection of power tool components, it will be easier to localize the fault.

Algorithm for finding and eliminating electrical failures

Drill repair is carried out according to the principle “from simple to complex”. You should not immediately disassemble the tool down to the screw and evaluate the condition of all components at the same time.

• The drill does not turn on. We start with the power cord (at a minimum, you should check the voltage in the outlet and extension cord before doing this). Having disassembled the case, we find the cable contacts and “ring” them using a multimeter.

Important! Do not test the supply wire with voltage applied! If the current-carrying wires are broken, you can get an electric shock or cause a short circuit.

We connect to the connector of the power plug and the opposite terminal of the cord. Then we bend the cable several times along its entire length. Losing contact or its complete absence indicates the presence of a break inside the insulation. If the fracture of the current-carrying core is close to the edge, the cable is cut and reconnected. It will just be a little shorter. If the break is in the middle of the length, it is better to replace the wire. Splicing will be unsafe.

• The cord is working - check the switch. We connect the multimeter to the terminals and press the key. A large current passes through the contacts, sparking occurs (especially when dust gets into the case). The contacts may simply oxidize. Carefully disassemble the switch body and clean the contact groups with fine sandpaper.

In case of breakdown metal parts, it is better to purchase a new unit.

• If there is an additional contact group in the circuit between the switch and the electric motor (for example, a reverse switch or speed controller), we diagnose this unit as well.
• Next, we check the connecting wires from the switch to the motor brushes. If they are in order, we diagnose the brush assembly.

The springs must confidently press the brushes against the armature slats, and we check the carbon elements themselves for wear. If necessary, we replace: spare parts are included in the delivery set, or can be purchased in specialized stores. The armature contact lamellas may be oxidized or clogged. They can be carefully cleaned with fine sandpaper.

• A more complex breakdown is the failure of the armature or stator windings. Using a multimeter, a short circuit is checked between the unit body and the winding contacts. Then the resistance is measured. The value should be the same on each winding, the spread of readings should not be more than 5%. Faulty windings must be rewound.

• You can do this yourself, or in a repair shop (in any case, it will be cheaper than buying a new engine).

Mechanical faults of the electric drill

Such breakdowns manifest themselves quite clearly. Extraneous noise, grinding, shaft jamming, etc.

• The motor rotates slowly and the windings become very hot. Or during normal rotation a characteristic hum (grinding) is heard. Most likely, the rotor bearings are worn out or clogged. Having disassembled the drill body, carefully remove the rotor. It is removed along with the bearings. By twisting the outer ring, you can immediately determine the malfunction. If the bearings rotate tightly, they must be washed with a penetrating liquid (WD-40 or regular kerosene)

Important! Make sure that no liquids get into the armature winding! Otherwise, the insulating varnish may dissolve and an interturn short circuit will occur.

Then, grease for high-speed units is placed between the races. Litol or graphite grease for automobile bearings is suitable.

If there is play between the bearing races, the units must be changed.

Dismantling is carried out with a special puller or using an open-end wrench.

If there are no balls, be sure to find them in the body. Fallen objects can get between the parts of the engine or gearbox and damage the entire assembly.

• The chuck shaft bearings are diagnosed and repaired in the same way. You just can't dismantle them without a puller.
• If the mounting location of the outer race of the bearing (bed) is worn out (this happens when the bearing is jammed), it will be necessary to make liners from thin sheet metal. Otherwise, beats will occur when the shaft rotates.
• The engine rotates in normal mode, noise and grinding noises are heard from the gearbox housing. The shaft rotates unevenly. Worn or damaged gears of the gearbox.

We disassemble the housing and inspect the gears.

It is advisable to wash the assembly of old grease and rotate the shaft 360°, controlling the gear engagement. If play or excessive wear of the teeth is detected, the mechanical part will have to be replaced.

Perhaps there is simply accumulated in the gearbox housing a large number of dust. Together with the lubricant, an abrasive paste is formed. In this case, after washing the unit, simply apply new grease.

Advice: The lubricant should be changed periodically, without waiting for a breakdown.

Especially if you often drill into stone walls.

• Broken cartridge. This is a rarity for cam devices (turnkey), the design is reliable and simple. The unit is exposed to dust, so the internal mechanism may simply jam. Most often, the gripper guides become clogged with small abrasive particles.

If the cartridge does not tighten well, it is enough to blow it out compressed air and treat with penetrating lubricant.

Attention: The jaw chucks are not lubricated inside!

Disassemble the part without special tool It's hard enough. If any component inside is mechanically broken, you will still have to replace the entire assembly.

But quick-release chucks, on the other hand, are easy to disassemble and repair.

They are not as reliable and do not carry the load well. To disassemble such a cartridge, it is enough to remove a couple of lock washers. You will easily find a broken or worn part that will be easy to replace.

How to remove the cartridge?

There are two types of fastening: Morse taper and threaded. In the first case, you need to apply several blows with a small hammer to the back of the cartridge. After which it can be easily removed.

To unscrew the threaded fastening, the shaft is held wrench(there are special flats on the shaft).

There are no malfunctions that cannot be corrected with your own hands. If a separate unit cannot be restored, only it is changed, there is no need to buy a new drill.

To prevent breakdowns, you should follow simple rules:

• After dusty work, blow ventilation holes and the internal cavity of the cartridge. Keep the tool clean.
• Do not overheat the engine - take breaks during prolonged use.
• Periodically renew the lubricant on the rotating parts.

Most in demand electric tool in repair - an electric drill, which often breaks down due to frequent and intensive use. If you have basic skills and experience in repairing such tools, repairing a drill will not be too difficult.

There can be several reasons for breakdowns of this kind of tool; there is an opinion that the main reason is improper operation of the drill or the tool is not “branded”, which is why its insides consist of low-quality components.

Other more technical reasons include:

• Failure of the moving part of the electric motor, its stator or armature
• Bearing failure
• Broken button (speed control)
• Reversing switch failure
• Wear of commutator brushes and their burning
• Cutting the wire in the cord, in the drill itself, or on the motor coil itself
• Breakdown of the gearbox or the chuck itself

In order to understand the cause of a breakdown, sometimes it happens that it is not immediately visible, for example, the drill just won't spin. The inspection begins with the power cord; often, due to intensive use, the cord is broken either in the area of ​​the plug or somewhere else. The button and various controls are also inspected. They try to turn the cartridge. This is where all diagnostic procedures end; the drill needs to be disassembled to gain access and inspect it from the inside.

To do this, you need to unscrew (all) the screws around the perimeter of the drill body and remove the upper half of the body. When unscrewing the screws, pay attention to their length and remember in which hole the screws of what length were located; it is easier to immediately leave them in the removed part of the case.

We inspect the power cable and internal wiring for burnouts, breaks and reliability of the contact connection.
In the place where the power cord enters the drill body, you can often see the outer layer of insulation damaged, broken, and the power cord itself eventually twisted.

If your button or reverse switch is faulty, it’s easier to replace it with a new one. You can, of course, disassemble it and clean the contacts, but it will be troublesome to assemble, there are a lot of small spare parts and springs that all tend to jump out.

One of the most common types of failure is brush wear engine, you can easily replace them yourself at home. Sometimes, brushes can be replaced without disassembling the drill body, if the design allows it. For some models, it is enough to unscrew the plugs from the installation windows and install new brushes. For other models, replacement requires disassembling the housing; in this case, you must carefully remove the brush holders and remove the worn brushes from them.

A characteristic sign of a problem with electric brushes is strong sparking and unstable operation of the electric motor when it operates intermittently or jerkily. What happens from inconsistent electrical contact between the brushes and the plates on the commutator.

You should also not allow the brushes to wear down to their minimum size. This is dangerous because the gap between the brush and the collector plates may increase. As a result, increased sparking occurs, the collector plates become very hot and can “move away” from the base of the collector, which will lead to the need to replace the armature.
It is necessary to regularly clean the commutator plates from carbon deposits and constantly check the tightness of the brushes to the commutator drum.

Other electrical faults may manifest themselves as a lack of rotation of the drill motor, when there is no sign of the motor turning on (no humming is heard). If the drill does not turn on and its chuck is easily turned with normal force, then we can most likely assume that the electrical part is faulty.
The specificity of the cause is checked when available; the power cord, speed control button, starting capacitor and motor windings are checked, everything is simply checked with a multimeter in resistance mode.

Among electrical faults you can note the breakage of the anchor. Armature or stator failure occurs for two reasons - improper operation and poor-quality winding wire. Top world-famous manufacturers use high-quality wire with double insulation and heat-resistant varnish, which significantly increases the reliability of motors and can significantly extend the life of your drill. Cheap models cannot withstand prolonged and intense work with overheating.

A broken armature (failure of coils) can be diagnosed by a characteristic smell and an increase in spark formation during operation. And upon inspection, you can see burnt wire windings. But you can also observe a drop in engine power, which will indicate that the windings have begun to burn out, their resistance has already changed as a result of this, which can be seen with the help of a tester.

You can observe the following breakdowns of the armature and stator: interturn electrical breakdown, breakdown to the “case” (magnetic circuit) and winding breakage.

Breakdown to the body can be determined using a megger (multimeter) by touching any winding output and magnetic circuit with probes. A resistance of more than 500 MΩ indicates no breakdown. You should know that ideally measurements should be made with a professional megger with a measuring voltage of at least 100 volts. By taking measurements with a simple multimeter, it is impossible to accurately determine that there is definitely no breakdown, but you can determine that there is definitely a breakdown.
Another sample can be measured simple method, using a light bulb connected with one terminal to a 220 volt network, and the second terminals to the housing and collector plates.

Interturn breakdown of the armature will be a little more difficult to determine. To do this, you can use a special transformer, which has only a primary winding and a break in the magnetic circuit in the form of a trench for installing an armature into it. In this case, the armature with its core becomes a secondary winding. Rotating the armature so that the windings alternate in operation, we apply a thin metal plate to the armature core. If the winding is short-circuited, the plate begins to rattle strongly, and the winding heats up noticeably.

Often, an interturn short circuit can be seen during normal inspection; the turns can be bent or wrinkled. You can try to fix it yourself by bending closed or bent turns of wire to the sides.

To find winding break You can measure the armature if you connect a milliammeter to the adjacent plates of the armature and slowly turn the armature. In intact windings, a certain identical current will appear; a broken winding will show either an increase in current or its complete absence. Using the comparison method, you can find the faulty one or make sure it is working properly if all windings produce same values on the multimeter.

Broken stator windings determined by connecting an ohmmeter to the disconnected ends of the windings; the absence of resistance indicates a complete break.

In this case, make the repair yourself by rewinding the armature or stator, without special devices impossible.
When rewinding the windings, the following conditions must be met: the windings are wound in one direction, the beginning of the winding is marked at the coil, the wire is wound clockwise, after which the end of the output is marked. The second winding is wound in the same direction, with the terminals marked beginning and ending.

To replace the rotor or stator, it is necessary to disassemble the housing, disconnect the wires, brushes, remove the drive gear if necessary, and remove the entire motor along with the support bearings. Buy a replacement and put everything back.

If there is a suspicion of button failure(speed controller), you need to make sure that there is voltage at the input and output terminals of the button. If, when you press the button, no voltage appears at the output, you need to disassemble the button body and inspect all contacts. As a rule, burning or sticking of contacts is determined visually. All contacts must be thoroughly wiped with alcohol and sanded with sandpaper. Then check the voltage again.
Do-it-yourself button repair is only possible if you have certain skills. It is important to understand that after opening the case, many switching parts will simply fall out of the case. This can only be prevented by smoothly and carefully lifting the lid initially.

When replacing a button with a new one, you need to make sure that the new button is designed for the power of a specific drill. For example, for a 750-watt drill, the regulator must have a current of at least 3.4 amperes.

The reverse button is checked in the same way sequentially.

The reverse mechanism is based on a system of normally open and closed contacts. Its prevention is carried out similarly to the start button.

The reason for the electric motor not working can also be the failure of the starting capacitor. Usually, the non-working state of the capacitor can be noticed by a change in color. But it is more reliable to measure its capacity and compare it with the nominal value.

Mechanical part

In the mechanical part of the impact drill, there may also be various breakdowns, for example drill shaft jamming.
If the cartridge cannot be turned by hand, and the engine hums when turned on, then the reason is most likely a breakdown of the gearbox or bearings. Common cause malfunction, destruction of the support bearings can be observed. Gearbox failure may also occur when the cartridge is rotated by hand and the electric motor is running, but rotation is not transmitted to the main shaft. All faults in the mechanical part can cause periodic stops and failures during operation, humming, grinding and insufficient shaft rotation speed.

The wavy surface of the ratchet of the large gear slides along the wavy surface of the second ratchet, rigidly fixed into the gearbox housing, thereby performing impact actions.
Over time, during long-term and intensive use of the drill in impact drilling mode, the wavy surfaces of the ratchets wear out, the impact becomes weaker and weaker or does not occur at all. It is necessary to inspect worn gearbox parts and, if necessary, replace them with new ones.

At chuck jamming or an audible grinding noise, first of all, you need to disassemble the drill body and inspect the condition of the gears in the gearbox. Wear of the fastening splines or damaged gear teeth indicate failure of the part. This gear needs to be replaced. The gears are inspected along the entire circumference, smoothly turning the shafts by hand.

Bearings can be checked by turning the shaft in them. If the shaft runs too hard, you should start by lubricating the bearings. If this does not help, then they are removed from the axle using a special puller. The bearing race is turned by hand. If movement is difficult or extraneous sounds are heard, the bearing should be replaced.
A bearing replaced at the wrong time will lead to jamming of the armature, or, in best cases, the bearing will simply turn in its seat.

To get to the drill bearings, it is necessary to completely remove the motor along with the gearbox, first removing the brushes so as not to break them and so that they do not jump out.

Before removing the insides of the drill, carefully examine what was located where, so that during assembly, as is often the case with “experienced” craftsmen, there is not a bunch of unnecessary elements left, the use of which is difficult to find.
Do not lose the ball, which is located at the end of the shaft of the drill chuck; it is responsible for the drilling mode with and without impact.

If necessary and the drill chuck is heavily worn, unscrew the fixing screw located inside the chuck. After this, unscrew the chuck with the left-hand thread and remove it from the shaft. The cartridge is replaced with a new one.

Often, a drill breaks down during serious work, during an undertaking repair, or in other conditions, so as not to waste time and so that this does not become a problem for you, you should remember how to repair a drill yourself. You should know the design of the drill you are using and easily and quickly determine the cause of the malfunction and eliminate it.

Repairing an electric drill can be done on your own. To do this, you need to know certain types of breakdowns and methods for restoring units. Special attention requires a wiring diagram for the electric drill button. Malfunctions associated with its operation should also be considered. If you know the intricacies of your instrument, it will be easy to repair it at any time. Before repairing, you should find out which drill button connection diagram is used in a particular model.

Possible faults

If the drill's performance begins to deteriorate, it is worth having it diagnosed. First you need to check the drive for various damages. Also, first of all, the presence of voltage in the network from which the device is powered is checked.

Battery models can be diagnosed using a special device - a tester. The voltage specified by the manufacturer must correspond to the value given by the testing device.

If the voltage is lower, replace battery. The most common drill malfunctions:

• problems arising when the button mechanism malfunctions;
• engine breakdown;
• brush wear.

If you know how to connect the tool button, you can easily deal with damage associated with this part. It should also be remembered that many problems that arise when operating a drill are associated with dustiness of the device. It should be cleaned after each use. Otherwise, the tool will last much less.

Connection diagram

To check the functionality of a tool, using only a tester is not enough. The main part of the device buttons is equipped with a smooth speed control mechanism. This is why the tester can produce incorrect values. In this case, you should familiarize yourself with the specific button connection diagram.

Often in electric drills there is only 1 wire going to the terminal. Due to this, when the contact is closed by the button, the terminals are tested. In this case, the blinking light means that everything is in order with the button. In the case of a faulty mechanism, the tester will not respond.

When replacing a button, it should be taken into account that the circuit may have a fairly simple structure, or it may be made in reverse. Due to this, each process associated with replacing a tool button must be carried out in accordance with the diagram. Nothing can be added. For example, the size of the new part must be appropriate. Drills with reverse will have to be checked for malfunctions a little longer than simple models.

Connecting a button

Despite the complexity of the process of replacing the button, you can do it yourself. At the same time, it is important to comply certain rules. For example, you must remember that careless opening of the case often results in some parts falling out. If this is not avoided, assembling the device will be quite difficult.

To open the drill, you need to very smoothly lift the lid, and then mark the locations of the various elements of the device on paper. Repairing the button is carried out as follows:

• First you need to pick up the casing clamps and tighten them.
• Each terminal that has carbon deposits or rust must be cleaned. For this purpose they use sandpaper or alcohol.
• After this, it is necessary to reassemble the tool so that all elements of the device remain in place. Then you need to check the functionality of the drill.
• Often the cause of breakdown is abrasion of the working surface under the rheostat. It’s better not to deal with it - it’s easier to buy a new one. This detail is highly complex.

Many owners electric drills with reverse, they are wondering where such a scheme can be found. First of all, you should look for it in the instructions for the tool. However, if such data is not available, you will have to ask a professional for advice or download a manual on the Internet. Instructions for many drills are available on the manufacturer's website.

Checking the electric motor

Breakage of the stator or armature of the drill can occur due to various reasons. Most likely, this was caused by non-compliance with the operating rules of the device. For example, in many cases the tool is simply overloaded, working without breaks. In this case, the engine wears out much faster.