DIY screwdriver drill repair

In detail: DIY screwdriver drill repair from a real master for the site my.housecope.com.

- the screwdriver does not turn on;
- during operation, extraneous whistles and creaks are heard;
- strong runout of the chuck;
- turns are not regulated;
- reverse does not switch;
- after turning off the button, the engine continues to rotate;
- the screwdriver turns on for a split second and wedges.

About the device of the screwdriver, read the article The device of the screwdriver.

Some spare parts (motor, gearbox, switch, etc.) for the most popular models can be bought here (only it is better to buy through the online store, since the price in a regular store of this network may be higher).

The screwdriver may not turn on for three main reasons: the battery is faulty (not charged), the power button is faulty, the engine brushes are worn out, or the anchor itself has burned out (very rarely).

Battery... The battery is checked by a simple measurement at its DC voltage terminals with any tester. The output voltage of a working charged battery must correspond to that indicated on the case - 12V, 18V, etc. Otherwise, the battery must be replaced. The charger of the screwdriver may also be faulty.

Regulator of turns and reverse... The screwdriver speed controller is checked with a multimeter in continuity mode. It should be noted that if the button is fully pressed, the contacts are closed in it and the voltage is supplied to the engine (to reverse) directly, excluding the speed regulator circuit. Two wires from the battery come to the button, after which two wires are connected to the engine through the reverse contacts. The power button may still have three wires for connecting a regulating element (field-effect transistor), which is removed from the body. For continuity, the probes are connected to the input and one of the engine wires (if possible, to the reverse input contacts) alternately, then the button is pressed all the way. The device shows the presence or absence of contact, after which the second input wire is measured. We translate the reverse lever and repeat the measurements. If there is no contact, the button changes.

Video (click to play).

Do-it-yourself screwdriver button repair is possible, but only if you have certain skills. It is important to understand that after opening the case, many switching parts will simply fall out of the case. This can be prevented only by smoothly lifting the lid initially and the desired sketch of the location of the contacts and springs. If darkened contacts are found, they are cleaned with sandpaper. After assembly, repeated measurements are carried out and if the results are positive (there is a contact), the button is installed in its original place.

It should be noted right away that if, after repairing the button, the screwdriver motor starts working when the button is fully pressed, and when the button is pressed smoothly, the speed is not adjusted, then the reason should be sought in the adjustment scheme. Most screwdriver repairs in this case come down to replacing the entire button.

If there is no reverse, replace the reverse switch or try to repair it. To do this, open the switch cover and, as is the case with the button, gently lift it up. We check contacts, clean and collect. If the contacts are burnt or deformed, the reverse must be replaced. There are variants of buttons in which the reverse is assembled inside the button body, in this case the entire button is changed.

If, when the button is released, the engine continues to rotate, and before it did not rotate, in this case it is necessary to pay attention to the speed regulator, namely, to the regulating transistor. It is necessary to replace either the entire button or the transistor separately.

Electric motor... If all of the above operations have shown the health of the elements, then it is necessary to check the condition of the engine brushes. To do this, the motor is disconnected from the button, and the multimeter probes are connected to the motor wires. The absence of a small resistance in the chain indicates wear on the brushes, but an armature breakage (winding breakage) should not be ruled out, although this happens very rarely. Usually, in this case, the motor changes entirely, but if the brushes are worn out, it is possible to restore the screwdriver motor on its own. On some motors, the brushes can be replaced without disassembling the motor. For others, it is necessary to separate the rear motor cover with brushes from the motor housing.

To do this, it is necessary to bend the cover plate, but in such a way that the edges do not break off, since they will need to be returned to their place after assembly. The flexible wire of the brushes is connected to the holder using spot welding, but the wires for new brushes can be soldered, but only with refractory solder, for example, POS-60. Before assembling the motor, the brushes are removed in the brush holder with a clip made of thin wire, the cover is put in place and the wires are pulled out, thereby freeing the brushes. Next, you should go around the edges of the case in order to firmly press the back cover.

Extraneous whistles and squeaks during the operation of the screwdriver can be caused by wear of the armature bushings or a detached magnet that comes into contact with the armature. In the first case, you can extend the life of the engine by dripping a drop of precision instrument oil onto the bushings, and then turning on the engine so that the oil is dispersed through the bushings themselves. This method can only extend the life of the engine, but over time you will still have to replace it.

Reducer... From the long operation of the screwdriver under heavy loads and with lateral pressure, the gearbox shaft is curved, on which the cartridge is screwed, a strong beating appears during the operation of the screwdriver. The bearing bush or bearing of this shaft can also wear out. If only the bushing or bearing is damaged and the shaft is not bent, then you can try to replace only the worn parts.

It may happen that the engine starts up for a split second and stops abruptly. Everything indicates a breakdown in the gearbox, usually a broken pin on which the satellite is attached. You can try to replace the carrier or the entire gearbox. Failure of the gearbox often occurs due to wear of the gear teeth. A detailed description of the screwdriver gearbox device can be found here.

One of the most "popular" tools of the home craftsman is a screwdriver. But, like any product, it breaks down. What to do in this case? In some types of work, an electric drill can save the situation, but only in some. You can take the tool to a service center and wait for it to be repaired. But this will take time and money, which will have to be paid to repair the instrument. But, as a rule, the third option is also available - the repair of the Makit screwdriver, and the device of the screwdriver is not so complicated.

Let's look at the main symptoms of screwdriver malfunctions and how you can fix them at home on your own.

Before proceeding directly to the malfunctions of this tool, it would be nice to briefly get acquainted with the device of the screwdriver and the purpose of its main units. Let's start with this. The photo below shows a disassembled screwdriver, on its basis and consider the purpose of the parts.

We'll start with the start button. The button has two functions: turning on the power supply circuit of the electric motor and its speed regulator.When the button is pressed all the way, the motor power circuit is closed by the button contacts to a straight line, providing maximum power and number of revolutions. The speed controller is electronic, it consists of a PWM generator located on the board. Depending on the force of pressing the button, the contact located on the button moves along the board. The degree of the generated pulse per key depends on its location along the board, the role of the key is played by a field-effect transistor (in the photo above it is designated as a "rotation speed regulator"). That is, the dependence is as follows: the harder the user presses the button, the higher the value of the pulse on the transistor and the more it opens, thereby increasing the voltage on the electric motor.

Motor rotation is reversed by reversing the polarity at the terminals. Reversal of polarity is carried out by means of changeover contacts, which are flipped by the user using the reverse handle.

Electric motor. In this tool, as a rule, single-phase DC collector motors are used. They are characterized by reliability, ease of production and maintenance. The design of such a motor is as follows: a body on which magnets, an anchor and brushes are located.

Reducer. Its purpose is to convert a large number of revolutions of the motor shaft into significantly lower revolutions of the chuck shaft. There are two types of screwdriver gearboxes: planetary and classic. The latter is very rarely used, so we will pay attention to the planetary type gearbox. The planetary gearbox consists of:

ring gear;
sun gear, which is attached to the shaft of the electric motor;
satellites and a carrier (their number depends on the number of steps, there are two or three steps).

Without going into subtleties, let's consider the principle of operation of such a gearbox. The sun gear is driven by the armature shaft, in turn, its teeth drive the satellites, which transmit the rotation of the carrier. With a two-stage gearbox, the chuck shaft is connected to the second carrier, with a three-stage gearbox - with the third.

The force regulator is designed to adjust the force that is applied to the screw. As a rule, 16 adjustment positions are used. Thus, there is a wide range of screw tightening levels, which allows you to work with very fragile materials (drywall, etc.). Its principle of operation is well illustrated in the video below.

The chuck is attached to the output shaft of the gearbox and has three cams that securely hold the part in the chuck.

Having considered the main elements of the screwdriver, let's move on to possible malfunctions and possible ways to repair the AEG screwdriver. And we'll start with the electrical part. The main signs of a malfunction of the electrical component of the screwdriver are:

the instrument does not turn on;
no reverse mode switching;
there is no adjustment of the number of revolutions.

The instrument does not turn on. The first thing to look out for when repairing a Skil screwdriver is the battery. If we put it on charging, and it did not help, then we arm ourselves with a multimeter and proceed to troubleshooting. To begin with, we measure the voltage on the battery, it should more or less correspond to the one indicated on the battery case. If the voltage is too low, it is necessary to identify the faulty element: a battery or a charger.

You can determine the health of the charger with a multimeter, for this we plug it into the network and measure the voltage at idle at the terminals. It should be a couple of volts more from the nominal indicated on the device. If there is no voltage, the charging unit is faulty. For such a repair of the Interskol screwdriver, knowledge of electronics will be required, otherwise it is easier to buy a new one.

If there is a problem with the battery, then to repair the Makit screwdriver with your own hands, you need to open the block with the elements.After the unit has been disassembled, it is necessary to carefully examine all the connection points of the wires and check the quality of the soldering, whether any one has come off. If all connections are intact, we take a multimeter and measure the voltage across each element. Each element must have at least 0.9 - 1V voltage. If an element with a lower voltage is found, it must be replaced. The main thing is that the capacity and type of the cell correspond to the rest (i.e. if NiCd, then NiCd is also needed). You can learn more about the repair of batteries from the article: "Do-it-yourself screwdriver battery repair."

If the charger and the battery are in good order, and the screwdriver does not turn on, it is necessary to disassemble the screwdriver. Two wires go from the battery terminals to the button, we take a multimeter and measure the voltage at the input of the button (the battery is inserted in this case). If there is voltage at the input, then we take out the battery and with the help of the crocodile clips we short-circuit the wires from the battery. We put the device to measure resistance in ohms. Press the button all the way and measure at the exit from the button. The device should show the value of resistance tending to zero, if it is - the button is working properly, the problem is either in the brushes or in other elements of the electric motor. If the tester shows an open circuit, the button needs to be replaced or repaired. You can try to repair it yourself, as it often happens that there is no contact on the terminals due to burning, it will be enough to clean it with sandpaper and assemble it. The main thing when parsing a button is not to rush and act carefully, otherwise all the parts will fly apart, and you will have to puzzle for more than one hour how to assemble it.

Similar actions will need to be taken in the absence of reverse. We put one probe of the device on the input wire of the button, the second on the contact of the electric motor or the output of the button, this is more convenient. We switch the reverse handle. If everything is working properly, the device will fix a certain amount of resistance, if it is “silent”, the conductivity of the reverse contacts is broken. The procedure for disassembling and cleaning the contacts is the same as described above, as when repairing the Caliber screwdriver.

Is the engine running at maximum rpm and there is no rpm control? The cause of the malfunction can be both in the button itself and in the regulating transistor.

If all circuits to the electric motor are in good order, but the tool does not work, the malfunction may be associated with the brushes. Ideally, brushes should be changed when they are long, worn 40% of their original length. If the brushes are worn, replace them with new ones; if the brushes are in order, the problem is with the rest of the motor elements. To check the electric motor, you must disconnect the wires that go from the button. After disconnecting the wires, using a multimeter, we measure the resistance value at the wires fastening contacts. If the resistance value is small and tends to zero, most likely a winding break has occurred, either rewinding or a new motor is needed.

You can check the integrity of the armature windings, since the armature can be bought and changed on your own. To check the armature, it is necessary to measure the resistance on two adjacent collector plates, along the entire circumference. In this case, the normal value is "0". If during the check you find two adjacent plates, with a value other than zero, the anchor needs repair or replacement.

Signs of a malfunction of the mechanical part of the screwdriver may be the following:

during operation, the instrument emits extraneous sounds that were not previously observed;

strong vibration of the tool and chuck breakage;

the screwdriver turns on, but its further work is impossible due to jamming.

The reasons for "extraneous" sounds during the operation of the tool may be the wear of the bushings or the armature bearing. To do this, it is necessary to disassemble the electric motor and examine it for bearing integrity and the degree of bushing wear.The anchor should rotate easily, without friction and distortion. If necessary, these items can be purchased at the store and replaced by yourself.

The most common gearbox malfunctions are:

bending of the gearbox shaft;
wear of the working surface of the gears;
wear of the bearing and / or bearing sleeve of the gearbox shaft;
break in the pin on which the satellite is attached.

In all cases, it is necessary to replace defective gearbox parts. All described actions require attention and sequence in disassembling and assembling the screwdriver. Having shown these qualities, you can independently repair the Interskol screwdriver with your own hands, or any other, and only in some cases resort to the help of a service center.

The screwdriver can be safely ranked as a tool that quite often has to be used not only in everyday life, but also for work on construction sites. But, like any complex technical accessory, the product can break. We will consider how to repair a screwdriver on our own in this text. Image - DIY screwdriver drill repair

The equipment in the construction market, where screwdrivers take a separate place, is quite large. Many models have individual criteria, assembly quality and cost. However, most of the models are characterized by basic principles of operation and internal execution.

The basic elements of any screwdriver include:

the presence of an electric motor;
planetary reductor;
adjustable function button "Start";
reverse switch;
effort regulator;
power unit.

The electric motor is powered by a direct current network, structurally represented by a cylindrical shape. Inside is an anchor with brushes and magnets. The peculiarity of the electrical circuit of the motor assumes that the direction of the supply voltage flow will be directed to the brushes. When the supplied polarity changes, the motor reverses.

The planetary gearbox is an important element capable of converting the high-frequency vibrations of the electric motor shaft into the low-frequency revolutions of the chuck shaft. Typically, these parts are manufactured from wear-resistant plastic or metal. Many screwdrivers are equipped with 2 speed gearboxes. Switching to the first speed mode is necessary for working with self-tapping screws, and at the second speed you can drill into wood, plastic base or metal.

The "Start" button starts the device. It is able to control the number of revolutions, providing the ability to select the optimal rotation speed for the chuck shaft. Correspondingly, pressing forcefully will power the engine at high rpm, and as the pressing force decreases, the power criterion will weaken.

The reverse switch is required to carry out operations to change the rotational direction of the screwdriver motor. This functionality is convenient to use not only for tightening, but also for unscrewing screws.

Regarding the force regulator, we can say that it determines the speed of tightening the screws. In current models, a 16-step adjustable graduation is provided, which allows you to determine with maximum accuracy and convenience what tightening speed is relevant when working with various materials.

The power supply for the screwdriver is oversized rechargeable batteries, where the power supply voltage (depending on the model device) can vary from 9 to 18V.

If at some point you find that your screwdriver does not turn on, then most likely it has some kind of malfunction. Practical experience shows that the inoperability of a tool can be observed for two reasons:

the breakdown is associated with the electronics of the device;
breakage can be mechanical.

Understanding the objective causes of electrical breakdown, one can note its characteristic signs:

the product stops responding to switching on;
the device has ceased to regulate the speed;
the reverse operation failed.

Mechanical problems with a screwdriver include problems with wear of internal parts, for example, a characteristic ratchet of the mechanism is heard. As a rule, a faulty screwdriver will begin to make characteristic sounds, where, for example, bushings have been worn out or a bearing has collapsed. This often happens on a hummer instrument.

For example, if the tool stops turning on, then initially you need to check the health of the battery. If, when basing the device on charging, the breakdown has not disappeared, then you will have to arm yourself with a multimeter and start scanning the device in search of the root cause. First of all, take a look at the voltage value indicated on the device case and compare it with the measurements on the battery. The data should be roughly the same. If the voltage is too low, then most likely the problem is hidden in the charger or battery pack.For example, the charger can be checked using a multimeter, plugging it into the network, and taking measurements at the terminals of the device at idle. It is important that the voltage criterion is slightly higher than the nominal one. In a situation where there is no voltage, then, unambiguously, the culprit of the breakdown is the charging unit. Interskol screwdrivers "suffer" from this rather frequent problem. In general, fixing the defect will require specific knowledge of electronics or a new unit will need to be purchased.If you find a battery problem, for example, with a Makit screwdriver, you can open this block with your own hands, where the supply elements are located. As a result of opening, research of the connecting wires should be carried out and the quality of the soldering should be ensured. If no visible defects are found, then using a scanner, you should measure the voltage in each element. Values should indicate 0.9 - 1V voltage power. If a block with a low voltage indicator is found in a row, then it must be replaced.

When everything is in order with the battery and charging goes without problems, but the tool refuses to be activated, then it will check the serviceability of the device button. To do this, you will have to disassemble the device and at its terminals coming from the button, you should measure the voltage with a multimeter, which comes at the input of the button. It is necessary to carry out the operation with an active battery. If there is a signal, then the battery must be removed and its contacts must be short-circuited using the clamps. On the multimeter, you must switch to Ohm mode. The screwdriver button is clamped all the way and measures the output voltage. If the value of the resistance readings on the device tends to zero, then the button works properly. This means that the problem should be looked for in the brushes or other modules of the electric motor. If a signal break is detected, the button is recommended to be repaired, thereby returning the screwdriver to the working order of the tools.

Quite often, problems with buttons are associated with poor contact at the terminals. You can simply perform the procedure for cleaning the contacts with sandpaper and the problem will be solved. The main thing is to do everything carefully in the process of disassembling and assembling the device, without losing parts.

A broken gearbox is one of the mechanical problems with a screwdriver. Some of the most common problems with the reduction unit include:

physical curvature of the axis of the reduction shaft;
obvious defect of the working surface of the gears;
failure of the shaft support sleeve or original bearing;
breakage of the pin where the satellites are fixed.

To correct these defects, it will be necessary to physically replace the defective parts, therefore, this type of repair should be entrusted to qualified specialists who are able to correctly and accurately diagnose the breakdown and eliminate it.

One of the most sought-after tools for home craftsmen is the screwdriver. However, this device sometimes breaks, like any other. If this happens, in some cases you can replace this tool with an electric drill. If work cannot be done with an electric drill, you will need to take the screwdriver to a service center in order for specialists to repair the tool. However, this can be time-consuming and costly. Therefore, you can use another option - do it yourself repair the screwdriver.Screwdrivers are commonly used to assemble furniture both at home and in production.Before making repair work, you will need to familiarize yourself with the design of this device. In fig. 1 you can see this tool exploded.Elements that are needed in order to make a screwdriver:

multimeter;

clamps;

sandpaper;

spare parts.

Figure 1. The device of the screwdriver.The main element is the start button, which performs several functions: switching on the power supply circuit of the electric motor and the speed governor. If you press the button all the way, the motor power circuit will be closed by contacts, as a result of which the maximum power will be provided. The number of revolutions in this case will also be the maximum possible. An electronic regulator is installed in the device, which consists of a PWM generator. This element is located on the board. The contact that is placed on the button will move along the board depending on the pressure on the button. The level of the adjustable impulse per key will depend on the placement of the element. A field-effect transistor is used as a key. The principle of operation will be as follows: the more the master presses the button, the greater the value of the pulse on the transistor and the more it will open and increase the voltage on the electric motor.The reverse of the rotation of the electric motor will be carried out by changing the polarity at the terminals. This process is carried out using contacts that will be thrown by the master using the reverse handle.Charger device for cordless screwdriver.In screwdrivers, in most cases, single-phase continuous current collector motors are installed. They are reliable and easy to manufacture and maintain. An ordinary screwdriver consists of the following elements:The gear structure will convert the high speed of the electric motor shaft to the low speed of the chuck shaft. Screwdrivers can have planetary or classic gearboxes. The latter are rarely used. Planetary devices consist of the following elements:

ring gear;

sun gear;

satellites;

drove.

The sun gear works by means of the armature shaft, its teeth drive the satellites that rotate the carrier.A special regulator is used to regulate the forces that will be applied to the screw. Most often, 15 adjustment positions are used.The main signs of a malfunction in this case will be:

the screwdriver does not turn on;

it is impossible to switch the reverse mode;

it is impossible to adjust the number of revolutions.

Diagram of the gearbox of the cordless screwdriver.

The first step is to check the screwdriver's battery. If the tool was put on charge, but this did not help, then you will need to prepare a multimeter and try to find the malfunction with it. First you need to measure the voltage on the battery. This value should approximately correspond to the one indicated on the case. If there is an underestimated voltage, then it will be necessary to identify the faulty element: a battery or a charging device. To do this, you will need to use a multimeter.This device must be plugged into the network, and then measure the no-load voltage at the terminals. It should be several V more than that indicated on the structure. If there is no voltage, then it will be necessary to repair the charging unit. If there is no knowledge in the field of electronics, then it is recommended to purchase a new one.

If the battery is faulty, then you will need to disassemble the unit, inspect all the places where the wires are fastened and check their quality. If there are no damaged connections, you need to measure the voltage on all elements with a multimeter. The voltage should be 0.9-1 V or more. If there is a part with a lower voltage, then it will need to be replaced. The capacity and type of the element must necessarily correspond to the installed parts.

Diagram of the internal structure of the screwdriver.

If the charger and the rechargeable battery are in good working order, but the screwdriver does not work, then this device should be disassembled. Several wires go from the battery terminals, you need to take a multimeter and measure the voltage at the input of the button. If voltage is present, then you need to remove the battery, use the clamps to short-circuit the wires from the battery. The device should show a resistance value that tends to zero. In this case, the element is OK, the problem lies in the brushes or other parts. If the resistance is different, then the button will need to be replaced. To repair the button, in some cases, it is enough just to clean the contacts on the terminals with sandpaper.

In the same way, you will need to check the reverse element. Repair is carried out by cleaning the contacts.

If the electric motor operates at high speeds, and the speed cannot be adjusted, then the problem may be in the button or transistor that is used for adjustment.

The device of the gears of the screwdriver reducer.

If the chains to the engine are in good order, but the screwdriver does not work, then the problem is in the brushes. If these elements are worn out, they will need to be replaced.

The problem may be directly in the engine. To test the electric motor, you will need to disconnect the wires that are connected to the button. Next, using the same tool, you need to measure the resistance value at the wires fixing contacts. If the value tends to zero, then the winding has broken. In this case, you will need to rewind or install a new motor.

You will need to check the condition of the armature windings, since this element can be purchased and changed by yourself. To check the anchor, it will be necessary to measure the resistance on the adjacent collector plates, along the entire perimeter. The value should tend to zero. If, during the check, plates with a resistance that differs from zero are found, then it will be necessary to repair the armature or replace it.

Mechanical problems can be identified as follows:

In the process of work, the screwdriver makes extraneous sounds that were not there before.
The tool vibrates strongly during operation.
Fight of the chuck for the clamp.
The tool turns on, but it is not possible to use it due to jamming.

If during operation the device emits extraneous sounds, this means that the bushings or the bearing are worn out. To fix this, you will need to disassemble the electric motor, and then check the integrity of the bearing and the level of wear of the sleeve. The anchor should rotate freely, there should not be any friction or distortion. These devices can be bought at a construction supermarket and replaced by yourself.The most common failures of the gear structure include the following:

shaft malfunction;

abrasion of the working base of the gears;

break of the pin on which the satellite is fixed.

The top section will not be enough and further chuck disassembly will be required. To do this, lightly clamp the bolt into the cams and hit it with a hammer.

When the inside of the cartridge falls out, its analysis is complete. You will see nut consisting of 2 halves... Most often, malfunctions in the chuck arise from this part. The thread on it wears out and the cams slip when tightened. Therefore, there is an incorrect centering of the latter.

Also, the thread can be worn on the cams, which, like the nut, must be replaced. But if you do not find the necessary parts to change them, then you will need complete replacement of the cartridge... When assembling the cartridge, the cams must be installed at the same level, in a compressed state, after which a nut consisting of 2 halves is put on, and after that the whole structure is placed in the body. When the malfunction is eliminated, you can assemble the screwdriver.

In practice, finding spare parts for a cartridge is troublesome. It is easier to buy a new chuck, since its price is not so high, within 300 rubles.

Video (click to play).