A drill is a power tool that is found in almost every home. As a rule, it is purchased for household purposes inexpensive models, which are not intended for intensive use.
Unlike professional power tools, they have a small resource and often fail.
One of the most weak points household drill - start button. During operation, the contacts of the main control element often oxidize or burn out.
If at some point the drill stopped responding to pressing the start button or it starts working every other time, do not rush to take the tool to a service center.
Replacing the button on a drill is a fairly simple procedure that even a novice master can handle. And so that no questions arise during the repair process, we have prepared simple and understandable instructions for you.
Let us note in advance that any electric drill, regardless of manufacturer and model, consists of the same elements, so the instructions below are universal.
How to replace and connect the power button on a drill - step-by-step instructions
The device of the drill button is very simple: when pressed, the button slides in a special block along the guides and the pusher closes the contacts, starting the electric motor.
During long-term operation under repair conditions (dust, moisture, etc.), dirt accumulates inside the start button block, which prevents the pusher from moving fully and blocks it.
Therefore, before buying a new button, you should try cleaning it. This defect can be eliminated very easily - you just need to open the block and remove dirt from it with a brush. If carbon deposits have formed on the contacts, they should be cleaned with fine sandpaper. If the contact burns, the entire unit must be replaced.
How to determine whether a button is working?
To do this, you will need a regular multimeter (tester) and a screwdriver.
The diagnostic process itself is carried out as follows (using the example of the common drill model DWT SBM-500):
- Remove the drill housing cover by unscrewing several fastening bolts;
- Unscrew the two screws on the power cord clamp;
- We remove the start button block, disconnect the reverse switch (it is usually attached to clips that just need to be slightly bent). The reverse itself is sold separately and can also be replaced if necessary;
- Take a multimeter and set the switch to the beep position. We close the contacts of the tester to make sure that it is working (the device should beep);
- We call the button. To do this, we place one contact of the tester in position 2 (it should be in contact with the wire), and place the second contact on the screw that presses the 220 volt wire. When you press the button all the way, the device should emit a beep. If this does not happen, the button does not work.
How to replace a button?
To do this, you will need a flat-head screwdriver and a regular pin or thin awl.
- The button replacement process itself is carried out in the following sequence (using the example of the DWT SBM-500 drill):
- Unscrew the two screws holding the power cord in place and remove it;
- We insert the awl into the hole in the wire coming from the stator, and remove the wire along with the awl.
- We carry out a similar manipulation to remove the second wire. If you are afraid of mixing up the wires when connecting a new button, we recommend drawing a schematic diagram for connecting the drill power button;
- We take a new button and connect the power cord wires to it in accordance with the drawn diagram. Then we connect the drill itself to the button block. The wires from the stator are simply inserted into the holes until they stop;
- We attach a reverse button to the block;
- Install the block in seat in the drill body, carefully lay the wires, press the power cord with two screws;
- We close the cover of the drill housing and conduct a test.
VIDEO INSTRUCTION
Connecting a drill button with a speed controller
Many modern models In addition to reverse, drills have an electric motor speed controller built into the button. This function is very useful because it allows you to set various modes tool operation.
As for replacement, the whole process is no different from that described above. It is enough to buy a new one button for drill with speed controller and replace the old one in accordance with the instructions given.
By the way, on a regular drill If desired, you can always install a button with speed control - just select a block that is suitable in shape and size, as well as corresponding to the power of the tool.
Many users of electric drills may sooner or later begin to wonder how the drill button is connected to the tool wiring. This question usually appears when a malfunction occurs in the old button, which requires connecting a new one. In this article I will tell you how it should be connected - what goes where.
I will not describe here how to disassemble the body of an electric drill to get to the insides, since I assume that since you are already asking the question of replacement, disassembling the body will not be difficult for you. I think that anyone who does not know how to disassemble the case will not even think about self-replacement anything in the instrument.
So, first you need to purchase a new button. It should match the old one in size and power characteristics, so when you go shopping, take it with you as a sample and write down the exact model of your instrument.
How to detach the old button?
To disconnect it, you will need a thin slotted (straight) screwdriver and a pin. Using a screwdriver, unscrew the existing bolts that clamp the cables coming from the power plug.
The remaining wires are secured with a spring clip. To disconnect them, you need to insert the tip of a pin into the recess where the terminal is located. Thanks to this action, the terminal is decompressed and the wire is removed along with the pin.
When disconnecting, I advise you to leave the wires coming from the capacitor in place so as not to forget which contacts it is attached to. Since it is not attached anywhere else except to the button terminals, they can be removed together and taken in this form to the store to buy a new copy. After purchasing, the first thing to do is plug the capacitor into a new place, after which you don’t have to think about it.
Connection diagram for a drill button with speed control and reverse
Actually visual diagram connection is shown in the image below.
Let me give you a few clarifications.
- The picture shows the most common type of spare part in question. The electrical wires from the power plug are fastened to terminals that are bolted. The rest are stuck into self-clamping contacts. If your button is not like this, then it is better to make notes from the old copy of what is attached where. Also, a diagram can be drawn on the body itself, which can also be used to guide you.
- If you connected the capacitor as described above, then after connecting the wires from the plug, you will only have two contacts on the bottom of the case, where you need to plug in two cables from the stator. They usually have the same position on the stator as in the picture. Their length must be longer than the other two so that they can reach their clamps. In this case, it makes no difference which wire is plugged into which of the two contacts.
- The remaining two electrical wires from the stator, as well as cables from the brushes, are connected to the reverse terminals. In this case, the connection is made diagonally: the wires from the stator are stuck on opposite sides into diagonally located contacts; and from brushes too. At the same time, the only direction in which the cartridge will rotate at a certain position of the reverse trigger depends on where exactly the wires will be inserted. The main thing is to connect diagonally.
This is the connection diagram. I hope that you will be able to connect everything correctly and the drill will work as it should.
An impact drill is capable of performing conventional drilling only with impact. The gearbox of such devices can have either one or two speeds. As additional functions There is a reverse motion and the ability to adjust the desired idle speed.
An impact drill has two helical gears that contact when regular work drills. When hammer drilling is required, one gear moves, thus creating clearance with the gear in front. Next, the rear gear remains stationary, and the one in front begins to slide along the teeth and move the cartridge up and down. This is how shock is created in many impact drills. Moreover, the number of such strikes can be 40,000 per minute.
It is worth noting that the impact function of the drill should be used only in the most in case of emergency. If the drill is constantly used with the impact function, then very soon the impact mechanism may fail. It's all about the gears, which sooner or later wear out and the shock mode of operation disappears.
A tool such as an impact drill is an indispensable assistant in construction. For example, it can drill through brick without any problems. As for concrete, there is performance impact drill depends on the brand of concrete in which you need to drill a hole.
Let’s say with the 300th grade of concrete, from which they are usually built internal partitions rooms, an impact drill does an excellent job. But this cannot be said about the 400th grade of concrete that is used in the construction load-bearing walls. In this case, it is necessary to use a hammer drill.
An electric drill is the most popular electrical tool when carrying out any repairs, so it often breaks down due to frequent and intensive use. If you have basic skills and experience in repairing such tools, repairing a drill will not be too difficult.
Possible faults impact drill
There can be several reasons for breakdowns of this kind of tool; there is an opinion that the main reason is improper operation of the drill or the tool is not “branded”, which is why its insides consist of low-quality components. Other more technical reasons include:
Failure of the moving part of the electric motor, its stator or armature;
Bearing failure;
Broken button (speed control);
Reversing switch failure;
Wear of commutator brushes and their burning;
A broken wire in the cord, in the drill itself, or on the motor coil itself;
Failure of the gearbox or the chuck itself.
How to find what's wrong
In order to understand the cause of the breakdown, sometimes it happens that it is not immediately visible, for example, the drill simply does not rotate. The inspection begins with the power cord; often, due to intensive use, the cord is broken either in the area of the plug or somewhere else. The button and various controls are also inspected. They try to turn the cartridge.
This is where all diagnostic procedures end; the drill needs to be disassembled to gain access and inspect it from the inside. To do this, you need to unscrew (all) the screws around the perimeter of the drill body and remove the upper half of the body. When unscrewing the screws, pay attention to their length and remember in which hole the screws of what length were located; it is easier to immediately leave them in the removed part of the case.
We inspect the power cable and internal wiring for burnouts, breaks and reliability of the contact connection. In the place where the power cord enters the drill body, you can often see the outer layer of insulation damaged, broken, and the power cord itself eventually twisted.
If your button or reverse switch is faulty, it’s easier to replace it with a new one. You can, of course, disassemble it and clean the contacts, but it will be troublesome to assemble, there are a lot of small spare parts and springs that all tend to jump out.
One of the most common types of breakdown is wear of the motor brushes; you can easily replace them yourself at home. Sometimes, brushes can be replaced without disassembling the drill body, if the design allows it.
For some models, it is enough to unscrew the plugs from the installation windows and install new brushes. For other models, replacement requires disassembling the housing; in this case, you must carefully remove the brush holders and remove the worn brushes from them.
A characteristic sign of a problem with electric brushes is strong sparking and no stable work electric motor when it operates intermittently or jerkily. What happens from intermittent electrical contact between the brushes and the plates on the commutator.
You should also not allow the brushes to wear out until minimum size. This is dangerous because the gap between the brush and the collector plates may increase. As a result, increased sparking occurs, the collector plates become very hot and can “move away” from the base of the collector, which will lead to the need to replace the armature.
It is necessary to regularly clean the commutator plates from carbon deposits and constantly check the tightness of the brushes to the commutator drum. Other electrical faults may manifest themselves as a lack of rotation of the drill motor, when there is no sign of the motor turning on (no humming is heard).
If the drill does not turn on and its chuck is easily turned with normal force, then we can most likely assume that the electrical part is faulty.
The specificity of the cause is checked when available; the power cord, speed control button, starting capacitor and motor windings are checked; everything is simply checked with a multimeter in resistance mode.
Among electrical faults you can note the breakage of the anchor. Breakage of the armature or stator occurs for two reasons - improper operation and poor-quality winding wire. Top world-famous manufacturers use high-quality wire with double insulation and heat-resistant varnish, which significantly increases the reliability of motors and can significantly extend the life of your drill. Cheap models cannot withstand prolonged and intense work with overheating.
Armature failure (coil malfunction) can be diagnosed by a characteristic smell and an increase in spark formation during operation. And upon inspection, you can see burnt wire windings. But you can also observe a drop in engine power, which will indicate that the windings have begun to burn out, their resistance has already changed as a result of this, which can be seen with the help of a tester.
You can observe the following breakdowns of the armature and stator: interturn electrical breakdown, breakdown to the “case” (magnetic circuit) and winding breakage. A breakdown to the housing can be determined using a megger (multimeter) by touching any winding output and magnetic circuit with probes. A resistance of more than 500 MΩ indicates no breakdown.
You should know that ideally measurements should be made with a professional megger with a measuring voltage of at least 100 volts. By taking measurements with a simple multimeter, it is impossible to accurately determine that there is definitely no breakdown, but you can determine that there is definitely a breakdown. Another sample can be measured simple method, using a light bulb connected with one terminal to a 220 volt network, and the second terminals to the housing and collector plates.
The interturn breakdown of the armature will be a little more difficult to determine. To do this, you can use a special transformer, which has only a primary winding and a break in the magnetic circuit in the form of a trench for installing an armature into it. In this case, the armature with its core becomes a secondary winding.
Rotating the armature so that the windings alternate in operation, we apply a thin metal plate to the armature core. If the winding is short-circuited, the plate begins to rattle strongly, and the winding heats up noticeably.
Often, an interturn short circuit can be seen during normal inspection; the turns can be bent or wrinkled. You can try to fix it yourself by bending closed or bent turns of wire to the sides.
To find a break in the armature winding, you can connect a milliammeter to the adjacent armature plates and slowly turn the armature. In intact windings, a certain identical current will appear; a broken winding will show either an increase in current or its complete absence.
Using the comparison method, you can find the faulty one or make sure it is working properly if all windings produce same values on the multimeter.
A break in the stator windings is determined by connecting an ohmmeter to the disconnected ends of the windings; the absence of resistance indicates a complete break. IN in this case make repairs with your own hands, by rewinding the armature or stator, without special devices impossible.
When rewinding the windings, the following conditions must be met: the windings are wound in one direction, the beginning of the winding is marked at the coil, the wire is wound clockwise, after which the end of the output is marked. The second winding is wound in the same direction, with the terminals marked beginning and ending.
To replace the rotor or stator, it is necessary to disassemble the housing, disconnect the wires, brushes, remove the drive gear if necessary, and remove the entire motor along with the support bearings. Buy a replacement and put everything back.
If you suspect that the button (speed control) is broken, you must make sure that there is voltage at the input and output terminals of the button. If, when you press the button, no voltage appears at the output, you need to disassemble the button body and inspect all contacts.
As a rule, burning or sticking of contacts is determined visually. All contacts must be thoroughly wiped with alcohol and sanded with sandpaper. Then check the voltage again. Do-it-yourself button repair is only possible if you have certain skills.
It is important to understand that after opening the case, many switching parts will simply fall out of the case. This can only be prevented by smoothly and carefully lifting the lid initially.
When replacing a button with a new one, you need to make sure that the new button is designed for the power of a specific drill. For example, for a 750-watt drill, the regulator must have a current of at least 3.4 amperes.
The reverse button is checked in the same way sequentially. The reverse mechanism is based on a system of normally open and closed contacts. Its prevention is carried out similarly to the start button.
The reason for the electric motor not working can also be the failure of the starting capacitor. Usually, the non-working state of the capacitor can be noticed by a change in color. But it is more reliable to measure its capacity and compare it with the nominal value.
Drill mechanical repair
In the mechanical part of the impact drill, there may also be various breakdowns, for example, jamming of the drill shaft. If the cartridge cannot be turned by hand, and the engine hums when turned on, then the reason is most likely a breakdown of the gearbox or bearings. A common cause of malfunction can be observed in the destruction of support bearings.
Gearbox failure can also occur when the chuck is turned by hand and the electric motor is running, but rotation is not transmitted to the main shaft. All faults in the mechanical part can cause periodic stops and failures during operation, humming, grinding and insufficient shaft rotation speed.
The operating principle of an impact drill is based on forward movement two ratchets that repel each other as the motor spindle rotates. During impact drilling, the motor drives the spindle.
From the motor spindle, rotational movements are transmitted further to the large gear of the gearbox to which the ratchet is rigidly attached.
Diagram of a "planetary" gearbox:
The wavy surface of the ratchet of the large gear slides along the wavy surface of the second ratchet, rigidly fixed to the gearbox housing, thereby performing impact actions.
Over time, during long-term and intensive use of the drill in impact drilling mode, the wavy surfaces of the ratchets wear out, the impact becomes weaker and weaker or does not occur at all. It is necessary to inspect worn gearbox parts and, if necessary, replace them with new ones.
If the chuck jams or there is an audible grinding noise, first of all, you need to disassemble the drill body and inspect the condition of the gears in the gearbox. Wear of the fastening splines or damaged gear teeth indicate failure of the part. This gear needs to be replaced.
The gears are inspected along the entire circumference, smoothly turning the shafts by hand. Bearings can be checked by turning the shaft in them. If the shaft runs too hard, you should start by lubricating the bearings. If this does not help, then they are removed from the axle using a special puller.
The bearing race is turned by hand. If movement is difficult or extraneous sounds are heard, the bearing should be replaced. A bearing replaced at the wrong time will lead to jamming of the armature, or, in best cases, the bearing will simply turn in its seat.
To get to the drill bearings, it is necessary to completely remove the motor along with the gearbox, first removing the brushes so as not to break them and so that they do not jump out.
Before removing the insides of the drill, carefully examine what was located where, so that during assembly, as is often the case with “experienced” craftsmen, there is not a bunch of unnecessary elements left, the use of which is difficult to find. Do not lose the ball, which is located at the end of the shaft of the drill chuck; it is responsible for the drilling mode with and without impact.
If necessary and the drill chuck is heavily worn, unscrew the fixing screw located inside the chuck. After this, unscrew the cartridge with the left-hand thread and remove it from the shaft. The cartridge is replaced with a new one.
Often, a drill breaks down during serious work, during an undertaking repair, or in other conditions, so as not to waste time and so that this does not become a problem for you, you should remember how to repair a drill yourself. You should know the design of the drill you are using and easily and quickly determine the cause of the malfunction and eliminate it.
An electric drill is one of the most common tools in household. And it’s very bad when it suddenly stops working. In such cases, you really want to repair the drill yourself.
The design of a drill or hammer drill is quite simple. Various models tools generally differ only in the difference in the arrangement of parts and the quality of their manufacture. The versatility of the operating principle and designs used allows us to produce do-it-yourself repair drills in most cases of malfunctions.
Design features of the drill
Any electric drill consists of a housing in which the electrical and mechanical parts are located, and a chuck in which the drill is mounted on the main shaft of the drill. The electrical part usually contains:
- electric motor;
- contact brushes fixed in the brush holder;
- start button (switch);
- engine speed controller;
- reverse device;
- starting capacitor;
- power cord (cable).
In turn, a two-phase electric motor alternating current consists of a stator and a rotor (armature) with a commutator.
The mechanical part includes a gearbox and a bearing system. The gearbox transmits the rotation of the electric motor to the drill shaft, reducing the rotation speed. A more complex mechanical part in an impact drill (hammer). The rotary hammer reducer provides shock-translational and rotational movement drill (drill). Its design, in addition to the gear, includes pistons (impact and flying), a ram and a firing pin.
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Types of faults in the electrical and mechanical parts of the drill
A malfunction of the electrical part manifests itself in the form of a lack of engine rotation, i.e. when there is no sign of the engine turning on (humming, vibration, etc.). If the impact drill does not turn on, and the chuck is easily turned by hand, then we can safely say that the electrical part is faulty. The same can be said if there is no speed control or reverse rotation. This indicates an expected malfunction in the electrical part. Temporary interruptions in the operation of the drill, extraneous noise may also indicate an electrical circuit.
Most often, a malfunction in the electrical part is due to wear on the contact brushes. If they are drained by 40%, then sparking and malfunctions may occur. If the brushes wear out more, the electric motor simply does not turn on. The following procedure for determining the culprit of an electrical fault is recommended (as available). First, the tester determines the integrity of the cord (cable). Then the operation of the start button (switch) and the integrity of the start capacitor are checked. Then the contact buttons are removed and checked. At the end, the integrity of the motor windings is determined.
A clear sign of a mechanical problem is a jammed drill shaft. If you cannot turn the cartridge by hand, and you can hear the hum of the electric motor when you turn it on, then the reason lies in the failure of the gearbox or bearing. Most common cause Failure in the mechanical part results in destruction of the support bearings. Gearbox failure can also occur when the chuck is turned by hand and the electric motor is running, but rotation is not transmitted to the main shaft. A mechanical malfunction can cause the drill to intermittently malfunction (temporarily stop), humming, grinding, and insufficient shaft rotation speed. In rotary hammers, a mechanical failure can eliminate the drill's impact motion.
Finally, the fault may appear in the drill chuck. Thus, difficulties may arise in removing the drill when the jaws do not move apart due to a breakdown in the engagement inside the chuck. Sometimes the malfunction manifests itself in the form of the chuck spinning relative to the drill shaft. In this case, the malfunction occurred in the area where the chuck is attached to the shaft.
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Drill repair: replacing contact brushes
One of the most common causes of malfunction is wear or burning of the contact brushes. The first signs of brush wear appear in the form of sparking in the contact area of the brushes with the armature of the electric motor and minor malfunctions in the operation of the drill when the load increases.
Many drill models have simplified access to the brushes, and changing them is not difficult, and some drills require disassembling the body and removing the brush holder. The brushes must be replaced with new ones, equal in size to the failed brushes.
They should fit tightly in the brush holder. The electrical contact of the supply wire must be tightened well. The brush contact with the armature commutator must be reliable. It is necessary to check the action of the spring.
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Motor fault
Electric motor failure is the second most common cause of drill malfunction. This is due to damage to the stator or armature winding. Such damage occurs due to a manufacturing defect in the windings or improper operation of the drill ( long work without interruptions, load exceeding permissible when the drill jams, etc.). As a rule, electrical breakdown of the winding is easily determined visually or by the characteristic burning smell. If there are no visible manifestations, then the motor windings should be checked with a tester, ohmmeter and megger for resistance value. There are three types of wire damage possible: short circuit between turns, breakdown of a turn on the body or wire break. Repair of the stator or armature is not carried out independently.
To replace the elements of the electric motor, the drill body is disassembled, the contact brushes and supply wires are disconnected, and the electric motor is removed along with the support bearings.
If necessary, remove the drive gear. The faulty electric motor element is disconnected and replaced with a new one, or the old one is installed after repair (rewinding) by professionals.
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Checking electrical components
The switch (start button) and the rotation speed regulator in the drill are usually combined. The speed is adjusted by pressing the button with different force. First, you should check the presence of voltage at the input and output terminals of the button. If there is no signal, then you need to carefully remove the button housing and inspect all contacts. As a rule, burning or sticking of contacts is determined visually. All contacts must be thoroughly wiped with alcohol and sanded with sandpaper. After this, you should check again for the presence of voltage. If there is no signal, the button should be replaced with a new one. The cause may be a violation of electrical contact with the wire. In this case, the wire should be soldered.
The reverse rotation mechanism is based on a system of normally open and closed contacts. Its prevention is carried out similarly to the start button. In addition, you should check all the mechanism wires going to the brushes and the motor stator.
The reason for the inability to start the electric motor may be the failure of the starting capacitor. Usually the non-working state of the capacitor is noticeable by a change in color. But it is more reliable to measure its capacity and compare it with the nominal value.
Checking the electrical part begins with determining the integrity of the power cord (cable) using a tester or ohmmeter.
The resistance between the contacts of the plug is measured (determining the short circuit of the wires) and the resistance of each core.
Repairing an electric drill can be done on your own. To do this you need to know certain types breakdowns and methods for restoring units. Special attention requires a wiring diagram for the electric drill button. Malfunctions associated with its operation should also be considered. If you know the intricacies of your instrument, it will be easy to repair it at any time. Before repairing, you should find out which drill button connection diagram is used in a particular model.
Possible faults
If the drill's performance begins to deteriorate, it is worth having it diagnosed. First you need to check the drive for various damages. Also, first of all, the presence of voltage in the network from which the device is powered is checked.
Battery models can be diagnosed using a special device - a tester. The voltage specified by the manufacturer must correspond to the value given by the testing device.
If the voltage is lower, replace battery. The most common drill malfunctions:
- problems arising when the button mechanism malfunctions;
- engine breakdown;
- brush wear.
If you know how to connect the tool button, you can easily deal with damage associated with this part. It should also be remembered that many problems that arise when operating a drill are associated with dustiness of the device. It should be cleaned after each use. Otherwise, the tool will last much less.
Connection diagram
To check the functionality of a tool, using only a tester is not enough. The main part of the device buttons is equipped with a smooth speed control mechanism. This is why the tester can produce incorrect values. In this case, you should familiarize yourself with the specific button connection diagram.
Often in electric drills there is only 1 wire going to the terminal. Due to this, when the contact is closed by the button, the terminals are tested. In this case, the blinking light means that everything is in order with the button. In the case of a faulty mechanism, the tester will not respond.
When replacing a button, it should be taken into account that the circuit may have a fairly simple structure, or it may be made in reverse. Due to this, each process associated with replacing a tool button must be carried out in accordance with the diagram. Nothing can be added. For example, the size of the new part must be appropriate. Drills with reverse will have to be checked for malfunctions a little longer than simple models.
Connecting a button
Despite the complexity of the process of replacing the button, you can do it yourself. At the same time, it is important to comply certain rules. For example, you must remember that careless opening of the case often results in some parts falling out. If this is not avoided, assembling the device will be quite difficult.
To open the drill, you need to very smoothly lift the lid and then mark the location points various elements devices on paper. Repairing the button is carried out as follows:
- First you need to pick up the casing clamps and tighten them.
- Each terminal that has carbon deposits or rust must be cleaned. For this purpose they use sandpaper or alcohol.
- After this, it is necessary to reassemble the tool so that all elements of the device remain in place. Then you need to check the functionality of the drill.
- Often the cause of failure is abrasion. work surface under the rheostat. It’s better not to deal with it - it’s easier to buy a new one. This detail is highly complex.
Many owners electric drills with reverse, they are wondering where such a scheme can be found. First of all, you should look for it in the instructions for the tool. However, if such data is not available, you will have to ask a professional for advice or download a manual on the Internet. Instructions for many drills are available on the manufacturer's website.
Checking the electric motor
Breakage of the stator or armature of a drill can happen for various reasons. Most likely, this was caused by non-compliance with the operating rules of the device. For example, in many cases the tool is simply overloaded, working without breaks. In this case, the engine wears out much faster.