Reasons for frequent tool failures. We repair the drill ourselves, the main types of breakdowns and their elimination. Reasons for the failure of power tools

Each household electrical appliance is, at its core, a fairly simple piece of equipment. Without going into detail, the most common part that fails is the gearbox or engine. It is due to this that most professional builders prefer specifically power tools.

This is due to the fact that it doesn't need repairs very often, like other types of tools, however, due to its simplicity, its cost is much lower than its gasoline counterparts. Perhaps, in the case of the same saw, even a complete amateur can visually identify a broken chain or a malfunction of the saw bar, and therefore we will immediately start talking about identifying engine malfunctions and some repair principles.

If your faithful assistant does not turn on at all and also does not show other “signs of life,” then you will not be able to do without a multimeter. However, if there is no opportunity to purchase it, then it is quite possible to use an ordinary incandescent lamp for the same purpose. She can help bring your power tool back to life.

Preliminary preparation for repairs

Electrical tool repair It is recommended to start with advance preparation for it. It is easy to guess that the main preparatory step can be considered the removal of every external part that may interfere with the disassembly process. Upon completion preparatory stage connect the instrument to the network and, using the test lamp mentioned above, “ring” each connection.

It would be superfluous to cover in detail the importance of observing safety precautions.

Diagnostic progress

If all conductive paths are functioning, this means that the most unpleasant thing has happened: the engine has failed. In the vast majority of cases, it has to be immediately replaced with a new one or a serviceable one, but used. However, to rule out all possibilities, you can try to remove it and conduct a full diagnosis.

It should be noted that only a highly qualified specialist in such a situation will can bring a power tool back to life. At the same time, repairing equipment by an uninformed person leads to very sad consequences.

If we touch on the issue of identifying faults in the mechanical part, then, as already mentioned, in most cases this can be done through a routine visual inspection. As a rule, the damaged part simply becomes deformed.

Bosch brand power tool repair is especially good in this regard. The convenience of its maintenance and repair lies in the fact that in the service centers of the brand, and simply in retail trade You can always find almost any parts for it. This sets it apart from its competitors, who practically never have this.

Looking at the “insides” of a failed instrument, you can often notice that the collector has fallen into disrepair. Sometimes it may seem that there is simply no reason for such a serious breakdown. Often this outcome is caused by too much heat, which occurs due to sparking brushes. This often happens if there are any shaft defects. In addition to the brushes, due to the same faults their holders also become unusable. In this case, it is quite simple to establish the cause, since you are unlikely to need servicing of the power tool, since replacing the brushes with your own hands is not likely to be difficult.

If we touch on the issue of the engine, then, as a rule, the cause of breakdowns is various problems in the stator windings. Usually short circuits between them are detected, which almost certainly damage the power tool. Repair in such a situation will consist of replacing the motor, because rewinding it yourself is quite difficult.

How to properly operate a power tool

Now let's talk about how to use power tools correctly, so that it serves as long and efficiently as possible. To do this, we will consider the causes of standard breakdowns and methods of preventing them, we will deal with the factory warranty and other pressing issues.

Factory defects: a few words about the warranty

The more consumers use power tools, the more controversial situations arise when the tools fail.

However, there is no doubt that during the warranty period all responsibility for the instrument is clearly borne by the manufacturer. Recently, the number of citizens' appeals to courts at various levels has increased, where civil appeals about the inadequate policy of the ASC and dishonesty on the part of manufacturers are being heard. It’s good that such a common phenomenon as artificially shortening the shelf life has not yet been observed in the field of tool manufacturing.

If the device fails during the warranty period, then in any case, repairs must be made without payment! However, there are a number of restrictions that users rarely take into account, but in vain, since they are aimed at ensuring that manufacturers are responsible only for the assembly of the tool and defects in materials - that is, for a manufacturing defect. Of course, none of them will give a guarantee for equipment and parts that wear out quickly:

• platforms;
• rods;
• belts;
• canvases.

A reasoned reason for refusal of repair and maintenance may be:

• use of inappropriate lubricant or lack thereof;
• evidence of self-repair (no seal);
• low quality fuel mixture;
• mechanical defects of the armature and stator windings;
• worn out fastening mechanisms;
• belt rupture;
• damaged suction fan;
• spindle deformation;
• traces of liquids;
• heavy pollution;
• used or damaged brushes;
• worn gears;
• rust.

In fairness, we emphasize that popular manufacturing companies strive to consider in favor of the consumer. Many remove factory defects free of charge, even if they appear after the warranty period has expired.

Well-known manufacturers provide a guarantee to repair damage regardless of where the tool was purchased. The explanation for this is that image losses turn out to be many times more significant than the momentary benefit from a false “non-warranty case”. In this regard, direct consumer surveys are conducted, hotlines are organized, and service centers are monitored in every way. However, creating precedents that encourage an irresponsible user to abuse the service is also unprofitable for them.

How to avoid repair refusal

Buy equipment from popular and trusted manufacturers, which provide this guarantee and have their own ASCs.

Long-term tool overload

There can be several reasons for overloading a power tool:

• use of a tool for purposes other than its intended purpose;
• excessive pressure on the tool (this leads to destruction of the body, failure of the mechanics and motor),
• deviations from the norm in electrical power indicators

The main sign of overload is excessive heating of the device. If the cause of overheating is not eliminated in time, the process of destruction of the insulation of the motor windings begins, which results in a short circuit between turns, and this, in turn, leads to irreversible failure of the power plant.

Classes portable power tool

Portable and mobile electrical receivers

Classification of premises by danger

Dielectric carpets and insulating supports

Special dielectric footwear

Dielectric gloves

1. Before use, inspect (damage, moisture, contamination), check for punctures by twisting

2. It is not allowed to tuck the edges. It is allowed to wear canvas gloves or mittens on top

3. Periodically wash with soda or soap solution and then dry

1. Galoshes - up to 1 kV, boots - at all voltages

2. The color should be different from other rubber shoes

3. Before use, inspect for defects (detachment of parts or lining, foreign solid inclusions)

1. carpets with a thickness of 6±1 mm

width 500-8000 mm; length 500-1200 mm

2. flooring at least 500x500 (the gap between the planks is 10-30 mm)

3. not tested, examined at least once every 6 months before use

With increased danger

• dampness (more than 75%)
• conductive dust
• conductive floors
• heat
• the ability to simultaneously touch the metal structures of the building connected to the ground, technological devices on the one hand, and metal casings of electrical equipment on the other.

Particularly dangerous premises

• special dampness
• chemically active or organic medium
• 2 or more high-risk conditions simultaneously

Premises without increased danger- there are no high-risk conditions

Damp rooms- relative humidity above 75%

Particularly damp rooms-relative humidity is close to 100%

Hot rooms- temperature constantly or periodically (more than a day) exceeds 35°C

Dusty rooms- due to production conditions, process dust is released.

Room with a chemically active or organic environment- aggressive vapors, gases, liquids are constantly or for a long time contained, deposits and mold are formed.

Mobile power receiver- an electrical receiver, the design of which allows it to be moved to its intended use using vehicles or rolled manually, and connected to a power source using a flexible cable.

0 - electrical receivers that have working insulation, do not have elements for grounding and are not classified as class II or III

I- electrical receivers with working insulation and an element for grounding. The wire for connection to the power source must have a grounding conductor and a plug with a grounding contact. The designation of the grounding contact is PE or white-green stripes or the word “earth” in a circle

II- having double or reinforced insulation and not having elements for grounding. Designation - double square

III- electrical receivers for operation at safe extra-low voltage, having neither external nor internal electrical circuits, operating at a different voltage. Designation - rhombus with III

Ultra-low (low) voltage- not exceeding 50 V AC or 120 V DC voltage.

When working with class I, the following are used: gloves, boots, galoshes, mats

When connecting a class I instrument through an RCD, electrical protective equipment does not need to be used.

Personnel with electrical safety group 2 must be allowed to work with portable tools and hand-held electric machines of class I in areas with increased danger.

Before starting work with hand-held electrical machines, portable tools and lamps, you should:

1. determine the class of the machine or tool from the passport

2. check the completeness and reliability of fastening parts

3. make sure by external inspection that the cable, its protective tube and plug are in good condition

4. check the correct operation of the switch

5. perform (if extremely important) RCD testing

6. check the operation of the tool at idle speed

7. It is not allowed to use hand-held electric machines, portable tools and lamps that have defects or have not undergone periodic inspection or testing.

8. For class I machines, check the serviceability of the grounding circuit

Workers using electric tools and hand-held electric machines are not allowed to:

1. transfer machines and tools, even for a short time, to other workers

2. disassemble

3. make repairs

4. hold on to the wire

5. Touch rotating parts or remove shavings/sawdust until they come to a complete stop.

6. install working part into the tool chuck and remove it from the chuck, adjust the tool without disconnecting it from the power supply

7. work with ladders, for work at height, portable scaffolding and scaffolding must be installed

When moving a power tool from one workplace to another or taking a break from work, the tool must be disconnected from the mains with a plug. The tool should be carried by holding it only by the handle.

If a power tool or hand tool stops suddenly electric cars must be disconnected from the network.

1. Damage to the plug connection, cable or its protective tube

2. damage to the brush holder cover

3. Fuzzy operation of the switch

4. sparking of the brushes on the commutator, accompanied by the appearance of a circular fire on the surface

5. leakage of lubricant from the gearbox

6. appearance of smoke or the smell of burning insulation

7. increased noise, knocking or vibration

To maintain good condition and conduct periodic checks of portable and mobile electrical receivers, a responsible employee with Group 3 electrical safety must be appointed by order of the consumer's manager. The employee must keep a log of registration, inventory records, periodic inspection and repair of portable mobile electrical receivers.

The frequency of checking portable and mobile electrical receivers and auxiliary equipment for them is at least once every 6 months. The results of the inspection are reflected in the registration and inventory logbook, periodic inspection and repair of portable mobile electrical receivers.

Periodic inspection includes:

1. external inspection

2. Check idling for at least 5 minutes

3. Insulation resistance measurement

4. checking the serviceability of the grounding circuit

Repair of portable electrical receivers must be carried out by a specialized organization; after repair, the electrical receivers must be tested (increased voltage of industrial frequency: for an instrument with a power of up to 1 kW - 900 V, more than 1 kW - 1350 V for 1 min)

Typical malfunctions of power tools - concept and types. Classification and features of the category “Characteristic malfunctions of power tools” 2017, 2018.

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07.05.2018

• Manufacturing defects.
• Long-term overload.

Armature or stator failure.

Bearing wear.

Reverse failure.

Worn out power cable.

Broken chuck.

Worn commutator brushes.

Typical breakdowns

Notch wear.

Operating rules

How to operate an angle grinder

Typical angle grinder breakdowns

Brush wear.

Bearings wear out.

Wear of teeth in gears

1. Do not remove the protective cover;
2. Lubricate the tool.

Typical breakdowns

The air does not heat up.

Electric motor failure.

Operating rules

Typical breakdowns

Rules of operation and repair

Typical breakdowns

Sawing accuracy is impaired.

Operating rules

Typical breakdowns

• Nickel-cadmium.
• Nickel metal hydride.
• Lithium-ion.
• Lithium polymer.

Operating rules

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How to care for your power tool so it lasts a little longer

How often do you service your power tools?

Poll Options are limited because JavaScript is disabled in your browser.

Never had it serviced - everything still runs and works “like clockwork” 43%, 41 voice

Thank you very much for the article. * 30%, 29 votes

After scheduled repairs, since you’ve already disassembled it, you can add 20% lubricant, 19 votes

I disassemble, lubricate, clean regularly, after each object 7%, 7 votes

07.05.2018

I identify the following causes of breakdowns:

• Manufacturing defects. Usually it is detected during the warranty period and manufacturers do not hesitate to replace the product. By the way, in my practice, marriage was least likely to occur in such famous manufacturers, like Bosh and Makita.
• Long-term overload. The tool may be used for purposes other than its intended purpose, exceeding the permissible loads. Long-term use of power tools leads to premature failure of the mechanisms. The main rule is, if you smell it, yes, you didn’t imagine it, go have a smoke. A tool is not a person, you need to take care of it :)
• Violation of operating rules. When you use a screwdriver as a winch and use an industrial hairdryer to heat the room, you shouldn’t be surprised that the tool will soon fail.

How to operate drills and hammer drills

The main reason for the breakdown of a drill or hammer drill is intensive use and violation of operating rules, for example, using a hammer drill as a mixer. Professional power tools are designed for 40 minutes of work and 10 minutes of rest, no more than 8 hours a day. The amateur must rest every 10 minutes of work, and can be used for no more than 5 hours per week.

Major breakdowns of drills and rotary hammers

All rotary hammers have the following breakdowns:

Armature or stator failure. How to diagnose breakdowns, watch the video:

Bearing wear. To check them, grasp the shaft with one hand and rotate the outer part of the bearing with the other. If there is too much play and vibration, it is necessary to replace the bearing with a new one. Video about replacing bearings:

Reverse failure. It all comes down to replacing the button. Plastic parts usually break. After replacing the button, there are problems with proper connection. Video will be useful:

Faulty speed control button. In such cases, we immediately exchange it for a new one; reclaiming the old one is a disastrous proposition. The procedure is simple, you can do it yourself. IN service center it will cost from 500 to 700 rubles. Video about button repair:

Worn out power cable. Take it off and install a new one. Wrapping snot out of duct tape is not the best solution. Take a thicker cable, with cores 2 - 2.5 mm². Video about replacing the cable:

Broken chuck. In such cases, I advise you to change the cartridge to a new one, rather than suffer with the old one. The issue price is from 300 to 500 rubles. Repairing the old one will take longer. The cartridge is easy to change, look at the video. Video on how to replace the cartridge:

Sometimes it is enough to disassemble the old cartridge, wipe it with thick oil/lubricant, wipe it dry and reassemble it. If you decide to repair, watch the following video. The author disassembles the cartridge and talks about the reasons for the failure:

Worn commutator brushes. Brushes “run out” over time and that’s normal. As they wear out, they are tightened to prevent sparking. If the new brushes wear out quickly, then you need to check the output of the commutator. There should be no scoring, the shape of the collector is correct, cylindrical. More details in the video:

The service life of a rotary hammer depends on the intensity of use, load, and manufacturer. If you use a drill for household needs, it can serve you for decades. But with regular use, even professional models can fail within a year.

Operating rules for drills and rotary hammers

The service life of the drill can be increased by following simple rules:

• Work under favorable weather conditions (no precipitation, high humidity).
• Do not exceed the permissible operating time without interruption.
• Avoid getting chips and dust into the tool.
• After work, clean and lubricate moving parts.

Can be used to lubricate the gearbox and tips of drills and drills. different kinds oils, litol/salidol will do. For gearboxes, I recommend lubricants from Makita and Bosh. The cost of 30 ml of Makita P-08361 lubricant is about 100 rubles.

I recommend updating the lubricant after 30-35 hours of operation. This is an average time, it all depends on working conditions. Amateur models may not see lubrication for decades, but for professional tools from a construction site this is mandatory.

How to use jigsaws

More often than not, only hamsters die from jigsaws. The instrument is capricious in itself, and will not tolerate a sloppy owner.

Typical breakdowns

Failure of the electric motor. The armature, inductor, and stator often burn out. A malfunction occurs due to overheating of the motor, aging of the insulation, hence breakdowns. Also, the notches on the shaft often wear out due to shock loads in the rod, which occurs when the saw blades are selected incorrectly. To avoid overloads, when buying a jigsaw you need to choose a model with a power reserve. I personally recommend looking at models from 580 watts minimum. Because a jigsaw up to 580 W cuts a sheet of wood no more than 80 mm thick.

Notch wear. In order to avoid such breakdowns, you need to select a saw blade in accordance with the characteristics of the material. Also, an incorrectly selected or dull file can lead to breakage of the support roller. The right file will relieve shock loads, hence a longer service life. Video on how to choose a file:

Armature worm gear wear- a common breakdown in jigsaws. It occurs due to the fact that the jigsaw begins to saw before it has yet reached the optimal speed of the blade. Therefore, let the jigsaw run for a couple of seconds at idle speed.
Modern jigsaws have a tool-free blade fixation unit. This allows you to quickly change files while working. However, this unit often breaks or begins to fix the canvas unreliably. Breakdowns are mainly caused by dust. Therefore, you should periodically clean this unit and lubricate it with a bucket (WD-40). The following video is about fixing a common breakdown - the saw blade holder wedge:

Operating rules

I advise you to follow the following rules, and your jigsaw will live a little longer.

1. There is no need to apply mechanical force when working with a jigsaw - this will lead to heating of the blade;
2. Use a wide blade for straight, long cuts.
3. Replace the blades frequently after they become dull, this will take the stress off the motor.
4. When using a jigsaw to cut metal, you need to moisten the blade with water or oil - this will make the cutting process easier and increase the service life of the saw.
5. If you are sawing a thin sheet of metal (up to 1 mm), you need to place plywood under it to prevent vibration.
6. Do not overload the tool; unplug it every 10 minutes of continuous operation.
7. Use a vacuum cleaner. Less dust will fall on the unit components.

How to operate an angle grinder

An angle grinder (angle grinder) is popularly called simply an angle grinder. The tool got its name due to the fact that the first sanders that appeared in the USSR in the early 70s were produced in Bulgaria by the Sparky company. Therefore, the people, who appreciated all the advantages of this power tool, began to affectionately call it an angle grinder.

Typical angle grinder breakdowns

Brush wear. It manifests itself in sparking, visible through the slots on the body, and stopping of the blade when the load increases.

Bearings wear out. Manifests itself in the appearance of noticeable vibration and noise
The air cooling impeller breaks, which leads to overheating of the electric motor. Video about replacing bearings:

Wear of teeth in gears, which also leads to increased noise and vibration. Video about replacing gears:

Rules of operation and repair

1. The service life of an angle grinder can be shortened due to the use of parts and accessories that do not meet the manufacturer’s requirements. Accidents often occur for the same reason;
2. Do not remove the protective cover;
3. Make sure that the wheels used will not crumble at the maximum possible speed of the angle grinder;
4. The abrasive or cutting disc must be selected in accordance with the tasks performed so as not to overload the electric motor;
5. Avoid clogging the tool, and after use, thoroughly clean it and lubricate the mechanical elements;
6. Lubricate the tool.

Video on how to lubricate an angle grinder:

Lithium or pigment greases are used for bearings. Domestic lubricants Tsiatim-221 and VNIINP-235 have proven themselves to be quite good. When choosing a lubricant for a grinder gearbox, you should be guided by the main principle - it must have a high degree of adhesion.

By the way, you can make your own lubricant for the gearbox, which in its properties is no worse than expensive foreign lubricating oils. To do this, you can take CV joint lubricant as a basis and add MS-20 wild oil to it. Mix to the desired consistency using a construction mixer. A mixture of Tsiatim-221 and TAD-17 also gives good results.

How to use construction hair dryers

A construction hair dryer is an electric tool designed to treat surfaces and various elements with a stream of hot air. Externally, a hot air dryer resembles a regular hair dryer. This tool has become an alternative to a blowtorch when solving some problems. A construction hairdryer is used to remove paint coatings With various surfaces, defrosting liquids in pipelines, bending plastic pipes, sealing plastic films, etc.

Typical breakdowns

The power button is faulty. Occurs due to wear and tear mechanical parts, or oxidation, damage to contacts. Replacing the button is similar

Opening of contacts in the wire. The main reason is a broken wire or damage to the insulation by a stream of hot air.

The air does not heat up. The reason is that the heating coil has burnt out. My colleague Alexander Brest prepared a video about replacing the filament:

Electric motor failure. Signs: sparks appear, the smell of burning plastic is felt. Symptoms and treatment methods are similar to other power tools.

Operating rules

1. Each tool model has its own operating frequency at certain temperatures and break times. Read the manufacturers' recommendations and do not overload the tool.
2. Try not to cover the openings while working. ventilation grille– this will lead to overheating of the motor. If technical hair dryer new, it needs to be allowed to work for 15 minutes without load. In the future, before each use, the hair dryer should run idle for 2-3 minutes. The same time you need to let the hairdryer work at minimum temperature and power after finishing work.
3. Keep at least the heating coil clean. Try to keep it clean by removing dust with a vacuum cleaner. It is strictly forbidden to use a technical hair dryer if there is a risk of water getting on the instrument.

How to use electric planers

A common breakdown of cheap and low-quality electric planers is a failure of the set size, as well as a rupture of the drive belt. The planes Bort, Einhell, and De Fort have such problems. Of the inexpensive tools, Interskol suits me.

Typical breakdowns

Most breakdowns occur due to excessive loads on the power tool. The following are also common causes of malfunctions:

1. The knives are not adjusted and are set to too large a grip, as a result of which overloads are possible.
2. Overload due to the wood being processed being too wet. The accumulation of chips on the outlet openings is another cause of overloads.
3. Worn or broken drive belt. You should monitor its condition to prevent rupture. Video about replacing the drive belt:
   
4. Sparking. Occurs due to a malfunction of the engine commutator or mechanical damage to the shaft.

Rules of operation and repair

• Ensure complete immobility of the workpiece before processing wooden surface. There should not be even a small amount of play, otherwise the workpiece may simply be torn out.
• Move the tool away from the surface before turning it on so that the knives do not come into contact with the wood at this moment.
• Planing begins from the end of the workpiece.
• The sole of the tool must always be parallel to the surface during operation, i.e. You can’t put a plane on your heel or nose.
• Avoid pressing hard on the tool as this may cause the motor to overheat. If you need to apply more force, set the knives a little deeper to remove less layer at a time.

The electric planer fails due to various reasons. Often, jamming of the knife drum bearing leads to a complete stop of the working tool. In this case, the bearing requires replacement and lubrication. Drive pulleys can also fail due to normal wear and tear. The drive belt often breaks as a result of excessive loads. It is imperative to monitor the condition of the knife mount on the drum.

How to operate electric saws

There are two popular types of electric saws designed for working with wood: circular and miter saws. Of course, the leaders among manufacturers will again be Makita and Bosch. However, I purchased a good alternative, which turned out to be a couple of thousand cheaper than its famous competitors: HITACHI C7MFA. A very light circular saw, you can saw with both your left and right hands. Not noisy, angles and plane are accurately set. Even more cheap option— Interskol also makes good electric saws.

Typical breakdowns

Discrepancy of surfaces in the thrust block. Due to the divergence of the surfaces at the stop, the sawing accuracy is impaired - the workpiece on the right and left is sawed at different angles.

Sawing accuracy is impaired. Sawing accuracy decreases when the disc or flange is curvature.

Motor or gearbox failure. A sign that the engine or gearbox is faulty is a burning smell, disk jamming, unstable operation, reduced power, sparking.

Armature and stator faults. These are the most common causes of motor failure in a circular machine. This breakdown can be detected by sparking in the brush area, as well as a burning smell. If, after disassembling the tool, it turns out that the armature and stator are smoked, then they should be replaced with new ones.

Operating rules

In order for the miter saw to work for a long time and without repairs, you must follow the recommendations:

• Balancing saw blade. If it is unbalanced, play and strong vibration appear. It is necessary to avoid contact of the disc with turntable. To do this, securely and correctly fix the saw blade.
• The turntable is difficult to rotate - most likely, its movement is hampered by sawdust, please clean it.
• The disc is jammed in the cut - you need to check its sharpness, as well as its suitability for the tasks being performed.
• Cleaning the saw from falling chips and sawdust.
• Use disc blades in accordance with the thickness and hardness of the material being cut.
• Do not overload the electric motor, especially for circular motors due to the nature of their operation.
• Lubricate the saw gearbox to reduce wear on contacting parts.

How to operate a cordless power tool

Today, a huge range of cordless power tools is produced, including screwdrivers, drills, nailers, hammer drills, grinders, etc. Modern tools are supplied with four popular types of batteries: nickel-cadmium, nickel-metal hydride, lithium-ion and lithium-polymer.

Typical breakdowns

Failures of a cordless tool are associated either with a faulty charging or with the battery itself. While chargers can be easily repaired even on their own, if the battery breaks down, it usually has to be replaced with a new one.

Let's consider the problems of each type of battery:

• Nickel-cadmium. A pronounced “memory effect”. This means that the battery capacity decreases when charging a battery that is not fully discharged. It also has a lot of weight.
• Nickel metal hydride. Short term service - up to 500 charges, the ability to operate at temperatures not lower than -10 degrees, long-term charging (up to 16 hours).
• Lithium-ion. Service life is limited to 3 years, overpriced, can only be charged from “original” chargers.
• Lithium polymer. Harsh operating conditions, short service life (300-500 charges).

The main difference between professional and amateur instrument lies in battery power. Professional cordless drills and screwdrivers can last longer on a single charge and also have more motor power. This does not always lead to weight gain, so professional tool more practical and reliable.

Operating rules

1. After fully charged, disconnect the battery from the charger;
2. Avoid large and frequent overloads of the tool during operation;
3. Ni-Cd models can be operated under significant temperature changes;
4. Ni-Mh models are characterized by fast charging, but their performance deteriorates with temperature changes;
5. Li-ion batteries do not have a memory effect, so they can be charged until completely discharged. However, such models do not tolerate negative temperatures.

That's all, if you have any non-standard and interesting cases of breakdowns, write in the comments and I will definitely answer you!

Fire has been known to mankind since primitive times. Most likely, our ancestors got it as a result of natural phenomena, such as thunderstorms. Someone very observant and smart discovered that fire not only scares and burns, but also warms. Then everything went from strength to strength: people learned to preserve smoldering coals, then they figured out what exactly could burn, and which of the materials around them did not burn, even if they cracked! When primitive people moved from fireproof caves to artificial dwellings, then we had to urgently come up with the word “fire”. Fires destroyed homes, tools, and food. People died in fires. And they continue to die to this day. Now in Russia, an average of 56 people die in fires per day.

It turns out that today, when it is ridiculous to even compare our houses with the primitive dwellings of troglodytes, when ingenious means of fighting fire have been invented, when a powerful fire-fighting service exists at the expense of the state, we cannot fight the fiery element on an equal footing.

From the above, two main conclusions can be drawn. First: fire is a formidable force and second: not everyone has yet realized the danger of this threat.

In its own way physical essence combustion is a rapidly occurring chemical reaction with the release of heat and light. In a narrow sense, combustion is the process of oxidation of a combustible substance with atmospheric oxygen. Although in some cases combustion can occur in the absence of oxygen. If gases are formed as a result of combustion, the reaction is accompanied by a flame. A highly luminous flame occurs when solid particles, such as coal, are present in the combustion zone. And since carbon is an integral part of any organic compound, it is clear why you can read by the light of a fire.

During combustion, active intermediate products are released, which greatly accelerate the process. Chain reactions begin, and only two factors become of primary importance for extinguishing a fire: timeliness and sufficiency. A cigarette butt thrown into dry grass can easily be trampled. A bucket of water is enough to extinguish a small fire. But this is in the first seconds. And then the timeliness of our reaction and the sufficiency of means to extinguish the fire are expressed in the cry: “Guard, we are burning!” Even a ton of water is no longer enough, and the rate of fire spread is increasing like an avalanche.

It is in the high speed of fire spread that their insidiousness lies. No matter how highly organized the fire service is, no matter how modern and effective the fire extinguishing means are, some time passes before the fire can be fought, which turns, figuratively speaking, a simple cigarette butt into a disaster.

There are two ways to ignite a substance: from an external source and self-ignition. In the case of an external source, everything depends on the magnitude of the initial thermal impulse (cigarette butt, match, torch) and the nature of the substance being ignited. It is easy to set fire to a stack of straw with one match because the amount of heat that a single match releases is enough to start the combustion reaction of a flammable substance - straw. You won't be able to light a damp log with a match.

In the case of self-ignition, the external temperature must become such that the oxidation reaction of the substance with oxygen begins - combustion. For paper, this temperature is only 218°C. The great American science fiction writer Ray Bradbury has such a book “Fahrenheit 450”. This is the same value for the ignition temperature of paper, only on a different scale. Imagine a book forgotten by a harmless stove. The stove heats up, the book heats up. At some point, the amount of heat coming to the paper will exceed the amount of heat that the paper gives off to the environment, and the result is a household fire.

For this physical reason, it is hard to believe that primitive people obtained fire by friction. Somewhere on the equator this is quite acceptable. But try to generate so much heat by friction that in the damp and cold taiga 90% of your efforts do not disappear into the environment! But in the same taiga there may be a fragment of a bottle lying around, which will focus the rays of the modest northern sun on a very small surface of last year’s needles. This can start a forest fire. The source of trouble is still the same - man!

Our houses are built from traditional and new materials. Traditional ones include: wood, red brick, plaster, tiles, clay. Other materials - concrete, sand-lime brick, plastics, composite (consisting of different materials) building materials, metal - all these are the fruits of civilization that make it possible to build panel houses, monolithic skyscrapers, bridges, TV towers and much more.

From a fire safety point of view, all materials are divided into non-combustible, non-combustible and combustible.

Fireproof materials are considered to be those that do not ignite, smolder or char at high temperatures. Examples of fireproof materials: brick, concrete, metal, glass.

Fire-resistant are considered materials that, when exposed to high temperatures, are difficult to ignite and continue to burn and smolder only in the presence of a fire source. These materials include: composite materials (foam concrete with a heat-insulating layer, wood treated with fire retardants).

Combustible materials are those materials that ignite at high temperatures and continue to burn and smolder even when the source of fire is removed. This group, of course, includes wood and composite materials based on it (chipboards, fiberboards, plywood). This also includes materials made of rubber, plastic, leather, linoleum, rolled roofing materials(roofing felt, roofing felt).

The main physical characteristics important for understanding the properties of materials and their ability to withstand fire are:

· strength;

· specific gravity;

· porosity;

· thermal conductivity;

· fire resistance;

· water absorption.

Strength is the ability of a material to resist destruction under the influence of external load.

Specific gravity- the ratio of body weight to its volume. Numerically equal to density. Measured in g/cm3.

Porosity- a property due to the structure of the substance, the presence of empty spaces between individual grains. Measured as a percentage.

Thermal conductivity- the ability of materials to transfer heat through thickness from one surface to another.

Fire resistance— the ability of materials to withstand high temperatures during fires without destruction.

Water absorption- the ability of materials to absorb and retain water. It is measured as a percentage as the ratio of the volume of water absorbed to the volume of the sample.

Having familiarized ourselves with the physical characteristics of materials that interest us from the point of view of fire safety, we can comment on them as follows:

Strength is the main quality of a building material. Monolithic reinforced concrete and metal have no equal here. The steel Eiffel Tower stands in Paris, having its own weight of 9 thousand tons! There are giant reinforced concrete skyscrapers in Dubai, Mexico City, New York and Sydney. The Ostankino Tower stands.

Specific gravity is important for creating a safety margin. That is, the structure is capable of resisting heavy loads when its strength is not spent on combating own weight. This means that lightweight materials make it possible to count on greater stability.

Porosity is a wonderful quality. The most good heat insulator is air. The more pores filled with air in a material, the lower its thermal conductivity and the more preferable it is for building houses. The leaders here are foam concrete, expanded clay concrete, mineral wool and polyurethane foam.

Thermal conductivity is an extremely important concept, since not only depends on the ability to transfer heat through the thickness of the material Fire safety material, but also the speed of fire spread. Metal conducts heat well. And cold. Try licking a piece of iron in the cold. No, better not! Take my word for it - your tongue will freeze right away. And you can lick a piece of wood for your own pleasure without harmful consequences. A great illustration of the concept of thermal conductivity! Materials with a high degree of porosity, as a rule, also have low thermal conductivity, which is very good.

Water absorption is the ability of a material to resist fire by absorbing water. There is such a fire term - “spill”. It probably came from “heavy rain.” During pouring, smoldering fires are destroyed and surfaces are cooled. In order to turn 1 g of water into steam, you need to spend 80 kcal. So the fire spends its energy on steam generation, which is what we actually wanted. This leads to another important observation: water is an excellent means of fighting fire.

Getting acquainted with water as a fire extinguishing agent should begin not with the “Cat House”, but much earlier. Back in 200 BC, the first fire water pump was invented. The first fire department appeared in Russia in 1803, and in 1853 there were fire departments in 450 cities. The respected profession of firefighter (axeman) and the honorable position of fireman (fireman) appeared. Over time, the horse-drawn water barrel was replaced by a tank truck. The manual rocker pump was replaced by high-performance pumps. But the principles of fire extinguishing remain the same, since the enemy - fire - has not changed at all over time.

Continuing to talk about water, it is worth noting that the speed and effectiveness of fire extinguishing is proportional to the amount of water supplied to the fire. Pumps (pumps) mounted on fire trucks are capable of providing a capacity of 30 l/sec or more, and mobile fire modules - up to 400 l/sec. Water with its physical properties - density, viscosity, fluidity; in accordance with the laws of hydrodynamics, the possibilities of transmission over a distance are far from unlimited. Friction against the walls of pipelines, curvatures, and narrowings cause difficulties in the transfer of water and reduce productivity. From bottom to top, a powerful pump can supply water under pressure to a height of 100 m, but the laws of physics will not allow sucking up water using a vacuum from a depth of more than 7 m.

Water is supplied from the pump using flexible fabric hoses, at the ends of which there are connecting heads (locks) that allow the hoses to be connected to each other. Quick release connections, bayonet type. This type of bayonets (bayonets) were once attached to guns. Fire hoses come in a variety of diameters, but they can be easily differentiated by the diameter of the matching connection heads.

To connect several hoses or hoses of different diameters to the pump, there are branches, each branch (stroke) of which has its own valve. The branches are made of aluminum alloys for ease of handling.

To supply water to the fire, a barrel is attached to the end of the hose, which allows water to be supplied as a stream or sprayed.

When working with hoses, you should not forget that overloads occur at the breaks, which can lead to rupture of the hose, and in this case the water supply stops. With good pressure, it is extremely difficult for one person to hold the sleeve and point the barrel in the desired direction. He usually needs the help of one or two other people.

There are also large fire monitors, but only professional firefighters work with them.

In addition to water, compositions that increase the effectiveness of extinguishing are supplied to the fire flames - foams, powders, emulsions. This is especially important in cases where flammable liquids are burning - oil, gasoline, etc. Water is no help here, since these liquids have a density lower than that of water, float to the surface and continue to burn.

Fires in which live electrical installations are located are extinguished using compressed air. carbon dioxide, which is not a conductor of electricity.

Burning chemicals are extinguished with special compounds that react with the burning substance to release carbon dioxide.

Local fires are extinguished with fire extinguishers. Fire extinguishers are divided into foam, carbon dioxide, powder, emulsion.

Before using a fire extinguisher, you must read the text printed on its body. The fact is that the wide variety of brands and designs of fire extinguishers and extinguishing materials does not allow us to confidently judge the purpose of the device. For example, the newest emulsion fire extinguishers are marked: “Suitable for extinguishing electrical installations up to 1000 V.” Such information cannot be neglected, as well as the following: “Not suitable for extinguishing live electrical installations.”

Portable pulse fire extinguishing systems “Igla” and “Igla-2” began to appear in rescue services. Their use sharply reduces water consumption when extinguishing local fires, eliminating such an unpleasant procedure as pouring, in which something that has not had time to burn gets wet through and through. Working with Igla is especially effective in apartments where the use traditional ways fire extinguishing leads to large material losses not because of fire, but because of water.

In general, fire extinguishing is the job of professionals. Rescuers who have not completed a special training course and are not certified to work as part of a combat crew are left with two important areas: fire reconnaissance and human rescue.

The basic principles of fire reconnaissance are purposefulness, activity, timeliness and reliability of the data obtained. Reconnaissance is the most important type of support for firefighters. And very dangerous.

That part of the reconnaissance that includes clarifying the internal structure of a burning object, the possible number of people inside, the presence and quantity hazardous substances(all this is clarified through interviews with specialists, residents, workers and knowledgeable persons) requires speed, intelligence and efficiency. But, as a rule, it does not pose any particular danger. This type of reconnaissance is possible for one person.

Much more dangerous and responsible is reconnaissance, which is carried out inside a burning object, in conditions of smoke, the release of toxic gases, darkness, the danger of collapse of structures and the occurrence of fire whirlwinds. Such reconnaissance is carried out in groups of two people, and in cases of using self-contained breathing apparatus - in groups of three people.

Any person can enter a burning object possible ways- through window openings, along ladders and assault ladders, using hydraulic lifts, ropes, free climbing on structures. This is when our ability to work safely at height can come in handy.

The task of reconnaissance is to determine the size and direction of the spread of the fire, the condition of the object (danger of collapse, explosion, etc.) and, most importantly, whether there are people blocked by the fire or injured by the fire. This leads to the continuation of the scout’s actions: to find ways to save people and determine methods of evacuation.

Scouts should always have flashlights, ropes, crowbars or hatchets for opening doors, and self-contained breathing apparatus at the ready.

If for closed door and something is burning with the partition - and this can be determined by streams of smoke from under the door, cracking paint, a burning smell, a heated door or partition, a change in the color of the paint or plaster - then you need to open this door very carefully while being under the protection of the partition or panel doors (if the door opens in your direction), since the influx of fresh air to the source of a possible fire can cause a sharp increase in the flame - a fire whirlwind, the culprit of severe burns and the death of many firefighters.

When entering a room, you need to leave the door behind you, and when leaving, close it. And be sure to try to remember your path. If along the way there are local sources of ignition that pose a danger of fire spread or threaten people, they should be extinguished immediately - this is where the portable “Igla” comes in handy.

In dark or smoky rooms, where flashlights are ineffective, you need to move around the perimeter, along the right wall, without losing contact with it. This reduces the risk of getting lost in passages, branches and winding corridors. If smoke spreads across the floor, you need to move at full height. If smoke rushes upward, you need to move bent over, and sometimes even crawl. The group moves one at a time, without leaving each other. If at least one scout feels unwell, the group stops reconnaissance, helps a friend get out into the fresh air and provides assistance to him.

Victims found during reconnaissance must immediately begin to evacuate, requesting help by radio. Moreover, you need to check all the premises, not trusting the information of strangers that there are no people in the room or cannot be. They stop checking the premises only after personally verifying that there are really no people in the room who need help. A useful observation is made by the famous survivalist Jacek Palkiewicz: “It should be remembered that children, frightened by a fire, can hide in the most secluded places, for example under the bed, and almost always do not respond to unfamiliar voices.”

Rescue operations are carried out simultaneously with fire extinguishing. This relieves the burden on firefighters and creates a field of activity for rescuers. If joint actions are insufficient or ineffective, all firefighters are involved in rescuing people, using all available ways and means to evacuate people.

The rescue procedure is determined depending on the degree of threat from fire, smoke, explosion, or collapse. Children are rescued first, then the sick, the elderly and women. Ways to save people include:

· independent exit of people along the routes indicated to them;

· removal of people accompanied by firefighters or rescuers;

· removal of children and persons unable to move independently;

· evacuation of people using retractable and extension ladders, lifts, rescue hoses, slip-evacuators, ropes.

Particular attention is paid to those people who are afraid of evacuating from a height, are in an excited state, and lose their composure. In these cases, rescuers carry out evacuation with escort and arranging additional insurance. Not least important is the behavior of the rescuers themselves: calmness, confidence and goodwill will help relieve stress and take control of the situation.

It is especially difficult to organize rescue operations in places where there are large concentrations of people - in discos, theaters, hospitals, kindergartens, etc. It is true that the primary responsibility for the evacuation of people in these institutions lies with their management, but one should not overly expect that this will be:

· carried out in a qualified manner;

· in a timely manner;

· don't panic;

· no casualties;

carried out at all.

The initiative to prevent panic and organized evacuation should be in the hands of rescuers until the last person is removed from the danger zone. Rescuers and firefighters are placed along the evacuation route to regulate the flow of people, curb panic, and help those in need.

In hospitals, schools, and kindergartens, evacuation is carried out together with service personnel. The priority, order and methods of evacuation are determined by doctors and educators. During the cold season, special care must be taken to ensure that children and the sick are dressed or wrapped in blankets.

In all cases when rescue operations are underway during a fire, you should call an ambulance.

Most often, rescuers are called upon to extinguish forest fires. Here, the forces of professional firefighters alone are clearly not enough. Therefore, our qualified assistance comes in handy here.

The rarest case is a forest fire caused by lightning. In this case, several unfavorable factors must overlap each other at once: prolonged drought, high temperature and low air humidity, lightning striking a tall dead tree, strong wind. It is clear that a forest fire caused by a thunderstorm is exotic. But a forest fire due to an anthropogenic (human) cause is an outrageously ordinary and sad event.

Forest fires are usually divided into grassroots, top And underground.

In a ground fire, the fire spreads through dry grass, fallen leaves, and undergrowth. At the beginning of summer, as a rule, such fires do not cause much harm, since the forest floor has not yet dried out enough. In the middle of summer or during a long drought, a ground fire damages the undergrowth and roots and causes much more damage.

A crown fire is much more dangerous due to the fact that the crowns and branches of trees ignite, the fire spreads at high speed, “jumps” from tree to tree, even remote from the burning massif. The high temperature of the fire forms its own ascending air currents, into which air is sucked from the periphery - a source of additional oxygen. The fire covers large areas and is very difficult to extinguish.

The food for underground fires is peat, which lies under the forest. The thickness of the peat layer can reach tens of meters, and the peat can smolder in the depths for years.

They try to surround ground fires and start extinguishing them from all sides at once. The edge of the fire is spilled with water, covered with branches, and covered with soil. Depending on the strength and direction of the wind, as well as depending on the type of tree, density of undergrowth, and air temperature, choose best option extinguishing tactics: from the front of the fire, from the rear, along the entire perimeter, or with a retreat to a new line and the creation of a fire protection zone.

The undergrowth in it is cut down, the pine needles, and the leaves are covered with earth. The loosened soil is moistened if possible. The main tools here are an ax and a shovel. Backpack portable sprayers are low-productive. Let's remember kind words"Igloo"

Raised fires are much more difficult to extinguish. Of course, everyone is not excluded here listed methods combating ground fires, but for large crown fires more effective measures are needed.

These methods include annealing. When annealing along the front of a crown fire, that is, from the direction where the wind blows and where the fire spreads, a strip 20-100 meters wide is burned. This method of stopping a fire requires special skill and careful observation, since here they stop fire with fire, which is far from safe.

The rate of crown fire spread decreases at night. Therefore, the optimal time to fight fire is late evening and early morning hours.

An underground fire is extinguished using a large amount of water pumped into the fireplace. There is a special technique for this. Underground fires are delineated by ditches that are filled with water.

The work of rescuers at such fires usually comes down to helping fell trees. All trees adjacent to the ditches on the side of the fire fall with their tops towards the fire. In order to place trees with a branched crown or inclined in the other direction exactly in a given direction, guy ropes made from climbing ropes are used. Guys are attached to the tree as high as possible and, if there are no other trees or stumps in the direction of felling, the rope is pulled manually. In this case, the length of the rope must be at least one and a half times the height of the tree. Using a chainsaw, make a double cut (like a slice of watermelon) in the direction of the felling to a depth slightly less than half the diameter. Pull the guy on the opposite side and make one horizontal cut, located 10-20 cm higher than the previous one.

Of course, if you have a rope attachment point, you can use a chain hoist, which will be more reliable, but, unfortunately, this does not happen often.

Climbing crampons with horizontal front teeth are used for tree climbing. The belay is organized using a piece of the main rope, one end of which is attached to the ISS belt, the second is looped around the trunk with slack and secured to the ISS on the other side of the belt.

One of the main tools used in construction and repair is an electric drill. Even children know what it is, but few owners of this instrument know how to repair it. Breakdowns happen with all tools, and if a drill breaks, you can repair it yourself with your own hands. A step-by-step description of not only repairs, but also diagnostics of the drill is described in the material.

Electric drill - remember the design of the tool

An electric drill is a type of tool that is designed for drilling different types materials, including concrete and reinforced concrete. Only for this you will need to use a tool with an impact drilling function or an impact drill. You can find out how the tool works if you take it apart. A brief description of the design of Soviet and foreign-made electric drills is described below.

It should be noted that the design of modern drills of domestic and foreign production differs from the design of Soviet tools. Only these are minor differences, which consist in the absence of reverse on an electric drill, as well as impact drilling. So, structurally, an electric drill consists of two main parts - electrical and mechanical. The mechanical part is based on the following: structural elements:

1. Gearbox - a set of gears, due to which the speed decreases and the torque from the electric motor shaft increases
2. The cartridge is an executive body that is designed to secure working attachments
3. Bearings are supporting mechanisms for shafts and axes that ensure their rotation.
4. Impact mechanism - in electric impact drills this device is part of the gearbox

The electrical component of any corded electric drill consists of the following elements:

• A commutator type motor consisting of a stator (fixed part), rotor or armature (moving part) and a collector (copper plates or lamellas through which current is supplied to the armature winding)
• Graphite or carbon brushes are a transmission device through which current is transmitted to the rotor winding. Brushes are consumables, and when, this indicates their wear
• Start button - depending on the model of the electric drill, the switches can be regular or with a built-in speed controller
• Reverse button - Soviet drills do not have such devices. This is a polarity reversal mechanism through which the direction of rotation of the tool chuck changes. Installed separately or integrated into the start button
• A ferrite ring is an element (filter) through which noise in the network is smoothed out
• A capacitor is a filter element that prevents interference from entering the network
• The network cable is the connecting link between electrical outlet and tool

The photo above shows the design of the drill with the main components. Sooner or later, it becomes necessary to repair the drill due to the failure of its individual components and mechanisms. To do this, you first need to inspect the tool, identify the cause of the malfunction, and eliminate it. More details about what types of drill breakdowns there are, how to identify and fix them, are described in the material.

This is interesting! Old Soviet drills do not have a reverse mechanism or an electronic speed controller. Instead of an electronic regulator, a mechanical one consisting of gears is used different diameters and number of teeth. This method of adjustment is more reliable, since reducing the speed does not affect the power. However, this method of speed control is expensive, as it requires the additional use of a pair of gears. If one pair of gears wears out, you can continue to use the tool. Below are photos showing the design of the mechanical speed controller of an old Soviet drill.

What you need to diagnose electric drill breakdowns

Where should you start troubleshooting an electric drill? Of course, from the first signs, by which it becomes clear where the breakdown is hidden and which part needs repair. It is easy to identify mechanical problems with a drill, but with the electrical part everything is much more complicated. Here you will need appropriate tools from which you can draw conclusions about the malfunction of certain components, parts and mechanisms of the tool. To identify breakdowns in the electrical part of the electric drill, you will need to prepare the following tools:

• Voltmeter or multimeter. Preference should be given to the second option, as it is more effective and multifunctional
• Device for measuring turn-to-turn short circuit at anchor

To diagnose the mechanical part, you will need to perform the following manipulations:

1. See what specific function the drill does not perform
2. Inspect the integrity of the gearbox by first disassembling the tool body
3. Inspect the serviceability of the bearings, as these devices often fail in the absence of lubricant
4. Determine if the mode switch is working properly. If the device jams or fails, the tool will only work in one mode

In a drill, like any other type of power tool, various parts and mechanisms fail. The entire drill cannot break down completely, but in any case, even when the mode switch is faulty, the operator will not be able to use the tool to its full potential. That is why you need to learn how to repair a drill yourself. This is not at all difficult to do, even if you have no experience. Therefore, you should not buy a new tool at the first malfunction, since the malfunction is sometimes easy to fix even without the need to replace parts. What types of breakdowns occur, how to fix them and what needs to be done for this are described in detail in the publication.

Where to look for a breakdown in the electrical part, the most common faults and their elimination

Electrical faults are the most difficult not only to identify, but also to eliminate. This is due to the fact that it is impossible to see the principle of the flow of electric current, but you can understand how the drill works. Based on the operating principle of the electrical part, appropriate conclusions can be drawn about possible malfunctions. The operating principle of the electric part of the drill is as follows:

• When the plug is connected to a socket, voltage is supplied to the electric motor.
• The presence of a button in the design eliminates automatic start when the plug is connected to an outlet
• For the tool to start working, you must press the start button
• At the same time, the contact closes and current is supplied to the stator and rotor windings. The wires are connected to the stator directly, and to the rotor through brushes and a commutator assembly
• If we describe the principle of operation of a commutator AC motor, it lies in the fact that the stator winding acts as a permanent electromagnet, due to which the armature is repelled. The armature will not rotate just like that, so it is also necessary to apply biased current to its winding

The rotor begins to rotate at a certain speed. This speed depends on the voltage. To reduce speed, regulators are used that work on the principle of increasing resistance. The greater the resistance, the lower the voltage, and accordingly the lower the rotation speed. Knowing the principle of operation of the electrical part of the drill, we will consider the main types of breakdowns and their elimination.

The drill does not turn on, what should I do?

When connected to the network, there are no signs of life of the instrument. Experienced craftsmen have had to deal with this phenomenon more than once, but what to do if such a phenomenon happens for the first time? Disassemble, diagnose and repair the drill. Troubleshooting when the drill does not turn on begins with identifying the presence of voltage in the network. It’s trite, but true - often the reason for a tool’s inoperability is the lack of voltage in the network. The reasons for this may be scheduled repairs at the transformer substation, tripping circuit breakers or the power cord of the outlet is damaged. Take a multimeter and measure the voltage in the network.

If the socket is working, then the next suspect for a malfunction is network cable. Yes, it also does not last forever, and can be damaged during the use of the tool. Do not try to find a breakdown visually, as this will be a waste of time. Take the tester and turn on the dialing mode, check the integrity of both wires. To do this, you need to disassemble the case and alternately touch one probe to the contact on the plug, and the second to the wire connected to the button. The cores are in good working order when the device “beeps”.

How to perform a simple repair of a drill button with a speed controller

If a preliminary check shows that the power cord is in good condition, then it is necessary to continue searching for the fault along the current flow circuit. The next element in the queue for troubleshooting is the button. On Soviet drills, such buttons are a simple mechanism through which contacts are closed. On modern tools, the trigger design includes a round regulator in the form of a washer with resistors, with the help of which the speed of rotation of the cartridge is regulated.

If the drill button does not have a regulator, then identifying and eliminating malfunctions is quite simple. To do this, you should disassemble it, inspect the integrity of the contacts and clean it with fine-grained paper sandpaper.

If an additional reverse switch is connected to the button, it must also be checked by testing. If it is determined that the breakdown is related to a malfunction of the button, then it is easier to replace it than to look for the malfunction and try to fix it.

Drill button why a capacitor is needed and how to check its serviceability

If you disassemble the button, you will find that in addition to this part a capacitor is connected (a yellow or black block). Could this unit cause the power tool to malfunction or not work? No, the capacitor is used to smooth out noise that occurs in the network. It serves as a filter element. If you disconnect it, the drill and other types of power tools will work as before. However, it is not recommended to operate the tool without a capacitor, since its absence (or malfunction) leads to the failure of semiconductor elements.

There is an opinion that the capacitor is designed to create a phase-shifting effect. This is an erroneous opinion, since this element does not affect the operation of the tool in any way, but only prevents radio interference from getting back into the network.

How to connect the drill button

Experience shows that drill malfunction in 60% of cases is associated with a malfunction of the shutdown button. Often, an attempt to replace this element leads to all the wires getting tangled, and the question arises - what should be connected where in order to connect everything correctly. This is precisely what is worth understanding so that wires connected at random do not lead to a short circuit.

It should be noted right away that the buttons on drills can have different designs, however, there are three types of their devices:

• Conventional ones without a regulator - when you press the trigger, the electric motor starts at full power. Typically, such buttons were used on old Soviet drills
• Button with speed control - there is a washer on the trigger, the movement of which increases or decreases resistance. The greater the resistance, the lower the rotation speed of the cartridge
• Buttons with speed control and reverse - the device is additionally equipped with a plate with a lever for switching the direction of rotation of the cartridge. Reversal is realized by changing the polarity of the voltage supply to the rotor and stator windings

One of the most difficult connection schemes is the last option. However, if you look at it, there is nothing difficult about connecting all types of buttons. The following diagrams for connecting the buttons of different drills - Bosch, Interskol and others will help you figure this out.

This scheme is also found in another design, as shown in the photo below.

The difference between these circuits is in the connection of wires from the reverse to the rotor and stator. Both options are correct and will work. It all depends on the model of the tool. By following the sequence of connecting the drill buttons, it will not be difficult to restore the functionality of the tool. Below is a diagram in the form of an illustration of connecting a drill button to an AC brushed motor.

It is worth noting that the drill button fails not only due to burnt-out contacts, but also due to wear of the expansion spring. With a large output, the spring breaks, which ultimately leads to jamming of the device.

How to identify a faulty brush assembly

Drill brushes, which are a consumable item, fail. The brushes are made of graphite, and with their help, current is transferred to the rotor through the commutator unit. During operation, brushes wear out, burn out, wear out and require replacement. The service life of brushes depends on various factors:

• Quality
• Collector serviceability

A brush malfunction can be identified by signs such as excessive sparking. If, before the drill stopped starting, there was excessive sparking with signs of carbon deposits, then it is highly likely that the carbon brushes need to be replaced. To replace, you need to remove the elements from the brush holders, remove the worn parts and install new ones in their place.

In addition to the malfunction of the brushes, it is necessary to pay attention to the condition of the copper lamellas of the commutator. If there are signs of soot on the copper base, as well as chips and other defects, then all this should be eliminated. If you cannot fix it yourself, then you should replace the anchor. The cause of carbon deposits on copper plates is excessive sparking of the power tool. In addition, when the collector is severely worn, a connection (short circuit) between the plates occurs, which is also unacceptable.

If the electric motor is faulty, when should it be replaced?

The commutator-type electric motor on a drill and any other tool is the heart of the equipment, which costs 60% of the total cost of the device. If the malfunction is related to the electric motor, then there are two ways to repair the drill malfunction - replace the entire motor or carry out diagnostics, identify the malfunction and eliminate it. It should be noted right away that you can do the diagnostics yourself, but you won’t be able to fix the faults yourself. Here you will need to take the faulty unit to a specialized workshop, but practice shows that it is easier to buy a new rotor or stator than to repair them.

Let's consider the principle of checking the serviceability of the stator and rotor of an electric drill motor with your own hands:

1. Using a multimeter in resistance measurement mode, the value between the armature windings and the metal core is measured. The presence of resistance indicates a violation of the integrity of the insulation
2. We use a marker to indicate the plate from which the check begins. Use the probes of the tool to touch the plates one by one and record the resistance value. In this case, the value between the plates should be approximately the same. A resistance difference of more than 10% is unacceptable and indicates the presence of a break
3. Checking interturn short circuit. A special device can be used to measure the presence of an interturn short circuit. It makes no sense to buy such a device specifically, since if there is no breakdown of the insulation on the body or a short circuit between the plates, then with a high degree of probability it can be assumed that the armature is working
4. After this, you should check the serviceability of the rotor. Similarly, the absence of resistance between the winding and the core is checked
5. Check the resistance between the windings. The absence of resistance indicates complete damage to the winding, and if it great importance it can be assumed that there is a breakdown. The video description below explains in detail how it is carried out. step by step check serviceability of the commutator motor

Malfunctions of the stator are less common than the rotor, but in any case, if the drill has recently been operating under high load, then the motor will fail. If it is determined that the motor on the drill is faulty, then it is easier to replace it than to repair it, and sometimes it is better to buy a new drill. The video below describes in detail how to find and fix electrical problems with a drill.

Failure of the mechanical part of the instrument

If electrical faults are difficult to identify, then dealing with mechanical breakdowns is much easier and cheaper. Mechanical defects can be identified even without the need to disassemble the instrument. If the drill cracks or the chuck does not rotate, but the characteristic sound of the engine is heard, it means there is a breakdown in the gearbox. When the attachment does not hold in the drill, there is a malfunction in the clamping jaws. Bearings may also fail and cannot be repaired and require comprehensive replacement..

Let's consider each type of malfunction, and the features of their identification and subsequent elimination.

1. The bearings have failed. Typically, bearings last quite a long time, and the main reason for their rapid failure is the lack of lubrication or its depletion. There are two types of failures in bearings - complete destruction of the balls or wear. If completely destroyed, the part must be replaced. There are no difficulties when replacing bearings, so be sure to check their serviceability
2. Jamming of the gear unit - here breakdowns are associated with licking of the driven or driving gear. Even during operation, a tooth may break off, which will ultimately lead not only to a decrease in productivity, but also to the occurrence of a complete jamming of the transmission mechanism. If the gearbox malfunctions, the gears must be replaced. It should be taken into account that on household tools the gearbox can be made of plastic gears. They must be replaced with similar ones, otherwise installing metal gears will lead to accelerated engine wear.
3. Repair of the impact mechanism of a drill - unlike a hammer drill, this mechanism on a drill has a primitive design.

4. Malfunction of the actuator - cartridge. Drills use key type chucks, which are characterized by increased reliability and efficiency. The clamping jaw on this part may fail and should be replaced. Detailed instructions on how to remove, repair and

Bearings and cartridges are considered minor mechanical failures, and failure requires an appropriate approach. Even if diagnostics have shown that the gearbox does not need repair or replacement of parts, it must be dismantled, washed in gasoline and new lubricant applied. Such manipulations must be performed regularly, depending on the frequency of use of the power tool. Detailed description how to repair impact mechanism drill, described in the video report.

Learning to extend the life of a power tool from the moment of purchase

In order for the purchased power tool to serve for a long time and not fail at the most inopportune moment, it is necessary to ensure proper care from the very first day of purchase. This care includes doing the following:

• Store the tool exclusively in a dry and warm room. Exposure to moisture and low temperatures will lead to the formation of condensation and failure of the electrical parts of the tool
• Do not use the tool for a long time under heavy loads, as this will lead to overheating of the windings and failure of the electric motor.
• The presence of an impact mode does not mean that you can drill holes in concrete and reinforced concrete with a drill every day. The impact drilling function is auxiliary and is intended for infrequent use. For such purposes it is necessary to use
• If the brushes spark strongly, it is necessary to replace them without waiting until the tool stops turning on altogether.

When purchasing, keep in mind that drills are available for household and professional purposes. If you choose a cheap household option, then you need to understand that such a tool is intended only for infrequent home use. Any repairs in the house using a household drill will cause the tool to fail. If you need a drill to make repairs in your home, then you need to choose only professional options.