How to repair a drill yourself? Screwdriver reasons for write-off

The lightweight version of the drill, which has been improved to work with bolts and screws, has been breaking sales records in the markets of the former Soviet Union for twenty years. Each type of tool has its own weaknesses associated with the method of implementing design solutions. The service life of units and spare parts depends on the quality of assembly, materials used and the manufacturer’s quality control system. The electric motor for a Makita screwdriver lasts much longer than motors from unknown Chinese companies.

All cordless drill malfunctions can be divided into 4 categories:

• electronic malfunctions and breaks in the electrical circuit;
• mechanical failures;
• problems with the battery and charger;
• failure of housing elements.

Why the drill does not work: main faults

Significant design differences between different drill models are the presence or absence of reverse, speed control and impact mode. Otherwise, the tool of any brand consists of the same components. Regardless of whether the Interskol, Bosch, Metabo or DeWALT drill does not work, the sources of problems will be the same, only the characteristics and parameters of the spare parts will become variables.

If the drill does not turn on at all, the main reasons for this are electrical:

• a break in the power cord, which can be easily detected with a multimeter;
• violation of contact between the cable cores and the start button terminals;
• failure of the electric motor: interturn breakdown of the armature or stator windings, their breakage, breakdown to the housing. A multimeter will help diagnose these defects, but it is impossible to eliminate them independently at home;
• when the drill turns on every once in a while or works intermittently (with a working power cable), there is a high probability of wear on the brushes, replacing which is not particularly difficult;
• heating or melting of the housing causes excessive load on the engine;
• One of the common causes of breakdown is the drill button does not work as a result of wear of the working layer of the rheostat, failure of the speed controller or reverse.

In situations where a Hitachi, DWT, Makita, etc. drill stops turning on even though the electrical part is working, defects should be looked for in the mechanical components. Most often this is:

• damage to the gears of the gearbox, accompanied by a characteristic grinding noise;
• wear of the clamping jaws of the chuck, as a result of which the reliability of fixing the drill or other tool is impaired;
• jamming or excessive play in the support bearings, which requires their complete replacement.

To prevent troubleshooting and troubleshooting on your own from taking too much effort and time, contact the “Successful Equipment Service” service center. High-quality, fast and inexpensive - the company’s main principles when repairing drills and many other types of hand tools!

Source: service.udt.ru

Critical damage

When repairs involve a serious investment of money, and the reliability of the device is questionable, it is replaced. Moreover, failures to write off a UPS are often caused by subjective reasons. That is, depending on the user:

• Obsolescence of the device, lack of spare parts for sale;
• A critical decrease in the capacity of the battery and electrolytic capacitors due to “old age”;
• Mechanical damage to the case, board or battery;

Remember: not only the safety of information, but also the integrity of household appliances, the protection of property and even life depends on the reliability of the uninterruptible power supply.

Typical malfunctions of cordless screwdrivers

1. The appearance of cartridge runout . If you encounter such a malfunction, it means that for some reason your gearbox spindle is bent or its bearing has become unusable. A ball-type device or a bronze bushing can be used as a bearing in different models of screwdrivers. In any of the above cases, you will have to change the entire screwdriver gearbox.

2. Whistling or creaking when the electric motor is running . In this case, the screwdriver motor works, but makes uncharacteristic sounds. The cause of this malfunction may be the separation of one of the motor magnets from the housing and its sticking to the rotor body. Also, the appearance of extraneous sound can cause clogging of the rotor bearing. If the design of the screwdriver allows you to disassemble the engine, then the fallen magnet can be returned to its place (if it was not damaged) and secured with suitable glue. The problem with a whistling journal bearing can be solved by lubricating it on both sides with a liquid spray lubricant, such as WD-40. It also doesn’t hurt to thoroughly lubricate the rotor shaft itself. It should be noted that rapid clogging of the bearings and the subsequent appearance of whistling sounds during rotation indicates that they are already seriously worn out. The correct thing to do would be not to wait for a more serious breakdown to occur, but to replace the entire electric motor assembly.

3. The screwdriver continues to rotate after releasing the start button . In a working screwdriver, after releasing the start button, the braking device should be activated, stopping the rotation of the gearbox. The cause of the problem is a failed thyristor of the control circuit. You can, of course, select a semiconductor device that is suitable for its parameters, but it would be wiser to replace the entire switching unit.

4. The button for switching the direction of rotation (reverse) does not work . Almost all models of screwdrivers use a microswitch, which is mounted in the device’s switching unit, to change the direction of rotation of the chuck. Failure of the switch will require replacement of the entire screwdriver switching unit.

5. Slipping of the clutch-regulator of the gearbox . The speed of rotation of the screwdriver chuck is regulated using a special coupling, which can be represented in the form of a toothed washer. Over time, the clutch teeth wear out and it begins to slip. Outwardly, it looks like the screwdriver cannot tighten the fastening elements with the required force.

6. The screwdriver does not turn on . There may be several reasons:

• Failure of the switching unit. The problem can be treated by replacing the unit with a working one.
• Broken contact wires. Replace faulty wires and solder broken contacts.
• Electric motor combustion. The burnt out motor is replaced with a new unit.
• Critical wear of graphite brushes. Carbon brushes are a consumable item (in models with a dismountable motor), a spare set of which must be supplied with the screwdriver.
• Discharge or failure of the battery. The battery should be charged or replaced with a new one.

7. Replacing a failed cartridge . There is a left-hand threaded locking screw inside the chuck. Before unscrewing the screw, it is recommended to spray the threads with liquid spray lubricant and lightly tap the head with a screwdriver. After removing the screw, clamp the L-shaped hex key in the chuck, secure the screwdriver body and, turning the key counterclockwise, unscrew the chuck from the axle. Before you start unscrewing the chuck, you should set the screwdriver to drilling mode at first speed.

Where can I repair an electric motor?

All of the above problems (with the exception of a faulty electrical plug) can only be resolved if the equipment is disassembled.

The Federal Tax Service has updated the property tax declaration. Where in the invoice you can indicate additional information. Whether to notify the employee that he does not have a work record book.

In our example, the costs of purchasing inventory are taken into account as part of distribution costs according to accounting, since the inventory will be used in the sales department. In NU, such costs are recognized as material costs as part of indirect costs.

A machine at Vector LLC has broken down. Based on the manager’s order dated December 29, 2008, a commission was created, which, after examining the equipment, concluded that it was not suitable for use as a result of physical wear and tear and was subject to write-off.

To diagnose the severity of the problem, you need to install a long drill and check the amplitude of deviations from the central axis. Deviations of up to 1 mm are within normal limits: you can continue to use the tool. In other cases, the gearbox or cartridge will need to be replaced.

I would like to express my deep gratitude to BUKHEKSPERT for making life at work easier :), providing invaluable material and sharing professional experience.

The organization’s accounting policy for accounting and accounting regulations establishes a method for writing off materials at average cost.

The object being studied can be furniture, tools, equipment, inventory, inventory, household equipment, fixed assets, equipment, goods and everything that is on the balance sheet of the enterprise.

Screwdriver repair: main tool malfunctions

A screwdriver belongs to the category of tools that are often used not only in construction and repair work, but also in everyday life. Over time, any mechanism tends to break down, which happens with screwdrivers. If such a thing happens, then there is no need to rush to throw away the tool, since you can repair the screwdriver yourself. From this article you will learn how to repair a screwdriver without the help of specialists.

Form for writing off inventory items

A screwdriver is often used in various fields: construction, repair, decoration, and everyday life. This tool, like other electromechanical equipment, is subject to damage. However, its structure and design are not at all complicated, and the problem that has arisen can be dealt with independently without the help of specialists. Common screwdriver breakdowns and reasons for their occurrence.

Management materials can be immediately written off as expenses (Dt 26 - Kt 60) without being reflected on account 10. To do this, you need to approve the procedure for classifying materials as management in the accounting policy.

This is important, because the tax office may be interested in why the balance does not add up and materials disappear in an unknown direction. They are withdrawn from accounts according to an algorithm that is predetermined and cannot be violated. It is on the basis of the executed papers that the accountant will work, so the company’s employees cannot simply throw anything away, everything must be formalized.

When all the data is entered into the act, everyone who certified the defectiveness of the product must sign. This confirms the accuracy of all recorded points.

If everything is indicated and calculated correctly, then this is documentation with legal status. Let's figure out what this is about the write-off act.

The Supreme Arbitration Court of the Russian Federation dated February 28, 2011 No. VAS-17332/10 refused to transfer the case to the Presidium of the Supreme Arbitration Court of the Russian Federation for review in the manner of supervision), the court recognized it as legitimate to record expensive spare parts on account 10 “Materials” and write them off as expenses at a time at the time of release into production on the basis of acts of write-off of material assets and acts of consumption of materials.

If the property has fallen into disrepair before the end of its useful life (prematurely), the persons responsible for this are determined. In addition, members of the commission find out whether individual components, parts, and materials of the disposed object can be used in the future, monitor the withdrawal of non-ferrous and precious metals, and determine their weight.

The repair technology in these cases is almost the same. Careful opening of the case is required. If you lack experience, you can make notes on the location of the springs and contacts. After this, the state of the switch or button contacts is determined, and the darkened elements are cleaned with sandpaper. The presence of contact after cleaning is determined by an avometer or other device.

Screwdriver and its design features

You should start repairing a screwdriver yourself by becoming familiar with its design. The main element of a screwdriver is an electric motor. Screwdrivers come in both corded and cordless types. The use of a corded screwdriver is used less frequently, due to such a disadvantage as the need to connect the tool to a 220V network. Battery-type tools are more popular, as they allow you to carry out not only repair work at home, but also outside it.

The main components of a cordless screwdriver are:

1. Frame. Typically, all screwdrivers are made of durable plastic.
2. Start button. It is designed in such a way that the number of revolutions of the cartridge depends on the force of pressing it.
3. Electric motor. Battery-powered tools use single-phase commutator-type and DC motors. The motor consists of a rotor, a stator in the form of magnets, and a brush assembly.
4. Gearbox.
5. Force regulator.
6. Reverse switch.
7. Battery. As a rule, it is removable and is often supplied with the product in duplicate.
8. Cartridge. As a rule, quick-release chucks are used.

Some models are additionally equipped with LED backlights, as well as battery charging indicators. Returning to the problems with the screwdriver, it should be noted that any of the above elements can cause the tool to malfunction. What is needed for repairs? The first step is to find the cause of the breakdown, and then make the appropriate decision to eliminate it. The tool can be divided into two parts: electrical and mechanical. Initially, you need to find out what the problem is with the screwdriver not working: mechanical or electrical. This won’t be difficult to do, so let’s look at the breakdowns in more detail.

Mechanical faults

Mechanical malfunctions of screwdrivers can be identified by such a sign as the audibility of the operation of the electric motor. When you press the start button, you can hear signs of the electric motor running, but the tool chuck does not rotate or characteristic sounds of a malfunction are heard when rotating.

What determines the service life of the battery?

The battery life depends on its design, intensity of use, and conditions in which it is used. Practice has shown that in road transport the average working life of a battery does not exceed 2.5 years. And if the mileage is more than 70 thousand kilometers per year, the service life will already be reduced to one and a half years.

If we talk about batteries used in uninterruptible power supply sources, they usually last no more than 3–5 years. This indicator depends on the frequency of switching to autonomous power supply and correct maintenance.

Mechanical breakdowns

Mechanical breakdowns of the instrument are often indicated by extraneous sounds that appear during operation. Inspecting a squeaking or grinding screwdriver may reveal damaged bearings or bushings that should be replaced.

• Jamming of the rotating mechanism often indicates failure of gearbox parts - deformation of the shaft, damage to the pin for attaching the satellite, wear of gear teeth.
• Chuck runout, among other reasons, can be caused by significant wear of the bearings or deformation of the gearbox shaft.

All listed parts cannot be restored and must be replaced.

If it is impossible to tighten the cartridge well, you should inspect the couplings - when their teeth wear out, “slippage” is observed. Clutches with worn teeth must also be replaced.

How to write off a battery: timing, malfunctions, reasons, standards, instructions

Failure of the support roller. In the process of operations on various materials, the saw blade is considered the main working element of the jigsaw, performing its useful functions. This element is attached to the support roller of the tool, which bears the maximum load during operation.

We inspect the power cable and internal wiring for burnouts, breaks and reliability of the contact connection.

During maintenance or DIY repairs of a Bosch drill, you may notice wear on some parts. Of course, they need timely replacement. Many craftsmen warn that it is necessary to use only original components.