» How to repair a hammer drill quickly at home
A hammer drill is in demand not only when carrying out professional construction work, but also in everyday life, when it is necessary to drill a hole in a concrete wall. If you think that a drill can cope with any task, then you are mistaken, since this tool is designed for drilling wood and metal. Even the most expensive tools do not last forever, so in case of breakdowns, every owner can repair the hammer drill with his own hands. To do this, you do not need to take the tool to a service center so that the technician can estimate the cost of a simple repair. How to repair each hammer drill unit is discussed in detail in the material.
What is a hammer drill and how does it work?
Structurally, a rotary hammer is similar to a drill, but its main difference is that it is endowed with an enhanced impact function. The impact function is needed in order not only to drill, but also to drill holes in durable materials such as concrete, reinforced concrete, brick, etc. The tool copes with its main purpose in the best possible way. Achieved through a special mechanism called impact. This impact mechanism experiences heavy loads, so the need to repair the hammer drill yourself arises depending on the frequency of its operation.
The impact mechanism is implemented through the use of a so-called “drunk bearing” in the tool’s device, which creates shocks that are transmitted to the piston. This piston, in turn, acts as an impact hammer, which hits a rod or striker connected to a working nozzle fixed in the chuck. A detailed diagram of the hammer drill device is shown in the photo below, based on which it becomes clear how the percussion system of the tool is designed.
In addition to the impact motion created by the indirect rotation of the bearing, the tool also requires rotational motion to drill holes. This option is implemented through a gear unit, presented in the form of a pair of straight gears. Rotational and impact movements are created by the rotation of the shaft of a powerful electric motor.
It is precisely due to the fact that the design of the tool uses a powerful impact mechanism, it can be used not only for drilling holes in concrete, reinforced concrete and asphalt structures, but also to perform such manipulations as chiseling, destruction, removal ceramic tiles and so on. This tool is also called destructive, but this does not make it eternal.
The time comes when the components and mechanisms of power tools break, which requires the need for repairs, the cost of which in service centers is decent. Repairing rotary hammers is not a difficult procedure, as it might initially seem, and to successfully implement it you will need not only to know the structure and design of the tool, but also the principle of operation.
Types of rotary hammers and their design differences
Before you repair a rotary hammer with your own hands, you need to understand the types of these tools. Rotary hammers are produced in two types:
If straight punchers are classified by purpose into household and professional, then barrel units are intended exclusively for performing complex work. They have a large power reserve, so they are used exclusively by professionals to perform work of any complexity.
Many do not understand how barrel units differ from direct ones, except for the location of the engines. The main difference, and it is also the main advantage, is that barrel models have a more advanced cooling and lubrication system, presented in the form of a container into which a liquid lubricant is poured. This means that barrel appliances have a longer service life, and therefore they break less often.
Barrel punchers, although more perfect, their main drawback lies in their dimensions. They not only have massive dimensions, but also weigh 2 times more than direct units. Both pistol and barrel perforators break down over time, which leads to the need for repair work. To repair the tool, there is no need to contact specialized service centers. After all, repairing a rotary hammer can be done with your own hands quickly and easily.
Operating principle of a rotary hammer
Consider the principle of operation of the units under consideration, which will simplify the troubleshooting process. For barrel and straight units, the operating principle is the same, despite their distinctive design parameters. All perforators work according to this principle:
The tool not only creates rotational movements, but also percussion, due to which heavy types of work are performed with concrete and reinforced concrete structures. Having an idea of how the punch is arranged, as well as how it works, it will not be difficult to take on its repair, which can be done at home.
What types of faults occur on rotary hammers?
If the hammer drill does not work, then you should not immediately rush to disassemble it. There is also no need to rush to buy a new power tool. You need to act in order. To begin with, it does not hurt to find out what types of malfunctions are most common on rotary hammers, which will help simplify not only repairs, but also identify the cause of the breakdown.
The most common cause of breakdowns is the wear of parts. If the parts are of high quality, then they have a long service life, and in the case of low-quality components, as on household units, you have to resort to repairing the rotary hammer with your own hands quite often. That is why it is not recommended to use household hammer drills often and for a long time, otherwise the need for repair in the near future is inevitable.
The perforator device shows that a transformation is taking place in the aggregate electrical energy into a mechanical one, which is used to perform useful actions. The tool can be conditionally divided into two parts:
- Electrical
- Mechanical
Actually, breakdowns are also divided into electrical and mechanical. Common signs of mechanical problems with rotary hammers include:
- When the start button is pressed, there are signs of motor operation, but the actuator is in place
- A working nozzle is wedged in the tool chuck - a drill, a chisel, a spatula, a crown, etc.
- Unable to install the nozzle in the chuck
- Extraneous noise occurs when the unit is turned on
- Operation modes do not switch
- Grease leaks
It is much easier to identify malfunctions of the mechanical part of the puncher than the electrical ones. This is due to the fact that the user sees signs of breakdown, which simplifies the repair procedure by 90%. TO frequent malfunctions The electrical parts of the rotary hammer include:
- When you press the “Start” button there are no signs of the motor functioning
- The sparking of the brushes increases during operation, and there are also signs of a burning sensation.
- Smoke appears when the tool is in use
- When you press the button, the motor alternately turns on and off.
In almost all cases of malfunction of the rotary hammer, in order to repair it yourself, you will need to disassemble it. This is not difficult to do, but there is no need to rush. After all, tool inoperability can often occur due to a lack of electricity in the outlet. Therefore, it is important to start repairing a rotary hammer with your own hands according to the instructions.
Repair of the electrical part of the rotary hammer, diagnostics of breakdowns and their elimination
Most often, as practice shows, hammer drill breakdowns occur in the electrical part, so this is where diagnostics should begin. If the tool works, but at the same time it crackles, buzzes or makes other sounds, then the breakdown must be looked for in the electrical part, so it is immediately recommended to skip the point on repairing the electrical part and proceed to troubleshooting the mechanics.
Diagnostics of the electrical part depends on what kind of breakdown has occurred - the device does not show signs of life or it works, but at the same time it sparks, smokes, or periodically turns off. So, in order to repair the puncher without outside help, you must follow the instructions. Let's look at the main types of breakdowns and how to fix them.
The engine does not turn on and shows no signs of life
The most common breakdown is when the tool does not turn on. The reasons can be various factors - from the lack of electricity in the outlet to the breakdown of the electric motor. But you need to start looking for the reason from smaller to larger, and not vice versa. It is not advisable to immediately disassemble the hammer drill if it does not show signs of life, since such types of malfunctions as described below can contribute to this.
There is no voltage in the network
It’s trite, but in 15% of cases these types of breakdowns occur for this reason. You are working, and suddenly the tool stops showing signs of life. Check availability immediately electrical voltage in room. Even if the lights in the room turn on, this does not mean that everything is working properly. Perhaps while drilling or operating a hammer drill, you hooked a wire in the wall that powers the outlet. Even with prolonged operation, the cable could overheat, and knock out the “machine” on the meter. In most cases, sockets and lighting in the premises are powered by different machines, then the sign of the presence of light in the room does not mean that everything is in order.
To make sure there is voltage in the network, you need to use an indicator screwdriver or a multimeter. It is better to pick up a multimeter, and setting it to the mode for measuring alternating voltage over 220 V, insert the probes into the holes of the socket. If there is electricity in the outlet, and its indicators correspond to the norm (not lower than 190V and not higher than 250V), then we proceed to the next stage of testing.
Damage to the power cord
The current is supplied to the electric motor of the tool through a network wire, the length of which depends on the manufacturer that produces the puncher. When working with a tool, you can damage not only the cable in the wall, but also the power cord. And this may not necessarily be the working nozzle of the tool, but also the squeezing of the wire by a door or other objects, tools and materials.
You can identify a wire malfunction in the following way - visually inspect it for defects in the form of squeezing, damage and melting. If there are no signs of defects, then it’s too early to beat the drums. The vein could become thinner, therefore, in order to determine the 100% serviceability of the network wire, you will need to ring it.
To test the network cable, you will need to disassemble the hammer drill. More precisely, it is not the entire tool that needs to be disassembled, but only its handle. After that, set the tester to the continuity mode, and touching the pin on the plug with one probe, and the second probe to the wire core (connected to the button), check. A beep means the life is OK. Carry out the same procedure for the second core. If both cores are ringing, then you will need to make a more serious repair of the puncher with your own hands.
Repairing a punch button and diagnosing its malfunction
What is a button on a hammer drill (it is also called a switch) - this is part electrical diagram, which is responsible for supplying current to the electric motor, that is, for turning the tool itself on and off. If the button on the punch is broken, then you can try to repair it. However, experience shows that repair attempts lead craftsmen to a dead end, and the result of such attempts is the same - buying a new button. Just don’t rush to buy a button for a hammer drill, as it is not always the weak link.
If mechanically it shows no signs of failure, then the probability of its malfunction is 50%. If, when you press a button, there is a feeling that it is malfunctioning, which is manifested by such signs as sticking, jamming, failure to operate, or the need to make great efforts to press it, then only a continuity test will help confirm its failure. To do this, you will also need a multimeter, which needs to be used to test the contacts.
It is worth considering that depending on the model of rotary hammers, the start buttons may differ. And the difference is not only in design, but also in functionality. Professional models of rotary hammers are equipped with start buttons without a speed controller, but with a lever for switching the direction of rotation of the cartridge - reverse. Household rotary hammers, which also often replace drills, are additionally equipped with speed controllers, which allows you to work at the appropriate rotational speed of the cartridge, for example, when you need to drill woodworking material.
Depending on the model of the puncher, the button can be disassembled and its contacts cleaned. However, if it jams, it is better to replace it immediately. To make sure that the problem of the inoperability of the tool is in the button, a multimeter set to the dialing mode will help. We turn on the dialing mode, and touch both probes to the corresponding terminals of the punch button. In this case, the trigger on the button must be pressed. If an appropriate beep is emitted when the trigger is pressed, then the button is working, and if not, then it needs to be replaced.
Below is a diagram of connecting a button on a rotary hammer with a reverse without a regulator. This circuit will be useful not only for the dialing of the button, but also for those who did not remember the location of the wires when replacing the switch.
If you have disassembled the puncher and do not know where to connect the probes for continuity, then you need to find the wires that go to power and the capacitor. It doesn’t matter what brand of hammer drill you have broken Bosch, Makita or others, in any case, the principle of verification is the same. To remove the wires from the switch contacts, on some models of punchers you will need to use a thin wire or an awl. The awl is inserted into thin hole near the contact where the wire goes in and remove it.
If you want the new button to last much longer, it is recommended to buy the original sample. The video below shows how to repair a punch button and replace it yourself.
How to repair a hammer drill when the brushes are worn out
If the graphite brushes on the hammer drill, which are designed to transmit current to the commutator connected to the armature winding, have worn out. Principle of operation electric motors is to create magnetic field stator, which helps drive the moving part - the armature or rotor.
Over time, the graphite brushes on the hammer drill wear out, which is absolutely normal. When they are abraded, the quality of contact decreases, so if strong sparking occurs, which is visible through ventilation holes in the hammer drill body, as well as if a burning smell or smoke is detected, it is necessary to replace the brushes. These items cannot be repaired as they are classified as Supplies. If they are worn out, then the motor brushes will need to be replaced. Changing the brushes is quite simple, for which you need to remove them from the brush assembly, having first unscrewed the screws, disconnect the power wires that come from the button, and then install new ones in the reverse order of removal.
The malfunction and unsuitability of brushes for further use can be determined by measuring their length of the working part. If the length of the graphite base is less than 8 mm, then the elements need to be replaced. After replacement, the hammer drill will work like new. The process of replacing brushes on an Einhell barrel hammer drill is described in the video.
Speed controller malfunctions
Not all rotary hammer models have a speed controller. This device is usually located in the design of a push-button mechanism. If the design of your tool has a chuck speed regulator that has failed, then it cannot be repaired, so it should be replaced.
A sign such as the absence of a change in the rotation speed of the cartridge will help identify a malfunction of the regulator. A malfunction of the regulator may also cause the tool to become completely inoperable.
Malfunctions of the hammer drill electric motor
The heart of any power tool is a commutator motor, which converts electrical energy into mechanical energy. If all the diagnostic and repair steps described above have been completed, but the hammer drill does not work, it means that the electric motor of the hammer drill requires repair. This is one of the most complex elements a tool that requires a special approach. Failures of this unit can be divided into two parts - faults in the rotor and stator.
If the motor armature breaks, diagnostics and repair
You need to start diagnosing the rotor (armature) by checking the condition of the commutator - these are plates or lamellas, due to which current flows through the brushes. First you need to inspect the condition of these lamellas, which should not show signs of soot or blackening. If there is carbon deposits, then perhaps the reason for the inoperability is in it. It is recommended to clean the soot with the finest paper sandpaper. For control cleaning, you need to take cotton wool with alcohol and thoroughly clean each plate.
After cleaning the commutator and replacing the brushes, you need to check whether the hammer drill works or not. If such a hammer drill repair does not give positive results, then you will need to arm yourself with a multimeter and check the suitability of the armature.
The causes of damage to the armature of a power tool are:
- Violation of winding insulation, which leads to an increase in resistance
- Violation of the integrity of the winding or break
- Steel core delamination
The process of checking the serviceability of the electric motor armature consists of performing the following steps:
It is almost impossible to replace the armature winding with your own hands at home, so you will need the help of specialists. Practice shows that replacing the winding is advisable only if you have an expensive hammer drill, the purchase of a new armature for which will cost a tidy sum. If the hammer drill is inexpensive, then it is easier to buy a new rotor and replace it yourself than to take it to a service center for repairs. The principle of checking the serviceability of the rotor on all power tools is the same, therefore detailed description described using the example of Bulgarians.
Stator malfunctions on a rotary hammer: how to identify and eliminate them
The stator is the stationary part of the electric motor, which also consists of a steel base on which a copper winding is wound. The stator is a magnet that acts on the rotor, thereby causing it to move. To verify the serviceability or malfunction of the rotary hammer stator, you will also need to pick up a multimeter and carry out some simple manipulations:
- The presence of resistance between the stator windings and the core is checked. We touch the probe to the output of the windings, and the second to the core. The absence of resistance indicates the serviceability of the device
- Each probe must be touched in turn to the corresponding winding terminals. The resistance in each winding should be approximately the same, and with a large run-up, we can conclude that there is an insulation failure
- A visual inspection of the stator will also allow us to make a conclusion about its suitability. If there are signs of delamination of the steel plates, it will need to be replaced. If only the winding is damaged, the stator can be repaired. However, for this it will need to be handed over to a service center for rewinding.
It is also worth noting that rotary hammers are equipped with powerful electric motors with high torque, so problems with failure of the “heart” of the tool are extremely rare. If this happens, the reason for this is improper operation of the tool, for example, household hammer drills cannot be used for a long time. Another reason may be improper storage when the instrument is lying in a damp room. In any case, there are enough factors that can cause the motor to fail, so only after a specific breakdown has been identified will it be necessary to make a decision to eliminate it.
Repair of the mechanical part of the rotary hammer, diagnostics of breakdowns and their elimination
If there is a breakdown in the mechanical part of the hammer drill, you will also need to disassemble the tool to identify defects. Mechanical failures are much easier to detect, since they are audible or visible after disassembly.
In the mechanical part of the hammer drill, there are three main components that need repair:
- Gearbox - to identify a breakdown of this unit, you will need to disassemble the tool and then inspect the mechanism. If this is a barrel perforator, then you must first drain the oil. Visually, it is possible to identify such gearbox defects as licking of gear teeth, faulty bearings, or damage to the integrity of the striker. Repairing a rotary hammer gearbox, unlike an electric motor, can be done with your own hands
- The cartridge is another component that can fail if not properly maintained. Often cartridge failures are associated with clogging of its internal part. You can troubleshoot the chuck on a rotary hammer after disassembling this unit. If internal parts are damaged, the cartridge must be replaced
- The mode switch is a useful option that is designed to be able to operate the tool not only for drilling, but also for drilling
All these components break sooner or later, and in order not to take the tool to a service center, it is recommended to repair the hammer drill yourself.
Gearbox repair or if the hammer drill does not work in impact hammer mode
If the hammer drill does not drill, but drills when the percussion mode is turned on, that is, the percussion function does not work, then the reasons for this may be factors such as a malfunction of the floating bearing (destruction of the inner race) and a violation of the integrity of the rod (striker). It is impossible to detect such a breakdown from afar without dismantling the plastic case, so the hammer drill (its mechanical part) is disassembled and the internal structure of the mechanism is inspected.
How to replace a worn-out bearing on a hammer drill
If the floating bearing (on direct ones) or the crankshaft (on barrel units) fails, they should be replaced. If the reason for the inoperability of the hammer drill is a rod or striker that wears out over time, then it should also be replaced. The process of dismantling a drunken bearing is quite simple. To do this, remove the fixing U-shaped bracket using a screwdriver, after which the bearing can be removed by hand.
When replacing a floating bearing, you will need to thoroughly clean all internal parts.
How to repair a striker and put it back together
Breakage of the impact pin on rotary hammers is a common malfunction, which you can fix yourself if you know how to properly disassemble the design of the gear unit. If it is necessary to repair or replace the firing pin (also known as the firing pin), then the process of removing it from the raster tube is carried out in the following way:
As a result, we get a firing pin, which consists of some parts, including sealing collars, which are recommended to be replaced with new ones.
Often the impact bolt fails in the striker and needs to be replaced.
After replacing it, it is necessary to assemble the parts and install the mechanism in place inside the raster tube, having previously lubricated each element. The striker is secured with a locking ring, which is installed by pressing it in with a screwdriver.
How to remove and replace skew bearings and impact pins on rotary hammers is shown in detail in the video material.
In any case, if you change parts, then at the same time you need to completely replace the lubricant, cleaning the entire mechanism and the body of the mechanical part from the old work. If this is not done, then the repair will most likely have to be repeated, since the lubricant contains a lot of metal dust and fragments.
If the cartridge stops rotating, how to repair
Before you repair a hammer drill, you will first need to identify the cause of the breakdown. For example, if the working element or chuck does not rotate, then the cause may be a gear mechanism. The torque from the motor shaft to the intermediate shaft of the tool is not transmitted due to abrasion of the teeth on the gears, so the chuck does not rotate.
The chuck may also not rotate due to jamming of the gear unit. If part of a gear tooth breaks off, it could become trapped inside the rotating elements, resulting in jamming. If the gearbox is jammed, you will hear it. The engine will hum, but the tool will not work. Disassembling the tool and removing stuck parts will help eliminate such damage.
If the drill does not hold in the chuck and constantly falls out
If, when installing a drill or other attachments into the tool chuck, they fall out, then the reason for this is non-compliance with the operating rules of the unit. Working with a tool that does not hold the drill and other attachments is not only difficult, but also dangerous.
If the cartridge does not hold, then the reason for this is its wear or breakage. To eliminate this type of failure, you will need to disassemble the cartridge and identify the cause. The reasons may be the following factors:
- Deformation of the fixing balls for rotary hammers with chuck type SDS plus and rollers for SDS max
- Development of the restrictive ring
- Sagging of the retaining spring
By replacing the worn part, the cartridge begins to work properly again. How to disassemble a hammer drill chuck and repair it is shown using the example of a DIOLD sds max brand tool in the video below.
The cartridge does not hold in the hammer drill: causes and repairs
In addition to the fact that the chuck does not hold the attachments, there are situations when the drill flies off along with the chuck. This is also not a pleasant phenomenon, which has its own explanation. The cause of such a breakdown is wear of the housing fastening that secures the element. The cartridge body is secured by a locking ring mounted on the end of the raster sleeve.
As soon as the integrity of the locking ring is broken, the entire cartridge with all component parts- protective cover, balls, rollers, springs, etc. It is not difficult to repair a hammer drill with your own hands if the cartridge falls off. To do this, you need to place all the elements in their places, and then secure everything with a new locking ring. To install the retaining ring you will need to use special devices- round pliers.
How to replace bearings on a rotary hammer and lubricate them
The hammer drill has not only a “drunk” bearing, but also ordinary ball bearings on which the electric motor armature is centered. The bearings that allow the armature shaft to rotate require regular lubrication. The skew bearing must also be lubricated, otherwise it may accelerate its wear. When installing drills and other attachments, you need to lubricate their shanks, which will extend their service life. components cartridge, among which there are also fixing balls or rollers, depending on the type of cartridge.
To remove bearings to replace them, you will need to use a special tool called a puller. Installing new bearings is done by using the appropriate size tube and hammer. When installing new devices, one factor must also be taken into account - they should not be skewed relative to the rotor shaft. How a drunken bearing changes is already known. On barrel hammer drills, instead of a dead bearing, a crankshaft can be installed, which has a longer service life compared to its counterpart on direct units.
This is interesting! If we compare the cost of barrel models with impact mechanisms - a drunk bearing and a crankshaft, then the latter are more expensive, which is due to their efficiency and reliability. However, this does not mean that models with floating bearings are not effective. They have a slightly shorter resource, but also have high impact efficiency.
How to properly disassemble the gearbox on a hammer drill and repair it
To diagnose the gearbox, as well as repair it on a hammer drill, you will first need to disassemble it. Let's look at how to do this correctly below. Initially, you need to unscrew all the screws holding plastic cover housing, and also dismantle the cartridge. After this, the gearbox and housing are moved apart in different directions until a gap appears between them. To remove the mode switch, it must first be set to “impact with drilling” mode and then removed. To do this, you need to press the switch against the body and move it slightly below the impact mode with drilling, and then pull it towards you.
Following the switch, you can remove the plastic housing cover, under which the gearbox is located, or remove the mechanism from the base of the housing. It all depends on the model of the hammer drill being repaired. After repairing the gearbox on the hammer drill, you will need to assemble it into place, having previously treated it with lubricants. Lubricant must be in sufficient quantity to eliminate the possibility of the mechanism operating in conditions without lubricants.
How to repair a barrel perforator
Disassembling a hammer drill does not present any difficulties, but the dismantling process differs depending on the type of tool. For example, repair barrel perforator begins with draining the oil from a special container, while there are no such devices on pistol devices.
The process of disassembling a barrel perforator begins with the removal of the plastic cover, which is located on top. To access the electrical part, you will need to remove the plastic cover at the bottom. The principle of repairing the electrical and mechanical parts of a barrel-type hammer drill is similar to direct devices.
On barrel perforators, instead of skewed bearings, crank mechanisms are used. However, the design of such units uses sliding bearings located on the wheel cam together with the eccentric. All these mechanisms operate in liquid lubricant, the amount of which must be sufficient. If there is not enough lubricant or it has not been changed for a long time, the likelihood of failure of the crank mechanism of the hammer drill increases.
If the firing pin on a barrel perforator is broken, that is, the impact mode does not work or it is noticed that the impact force has weakened significantly, then it is necessary to repair or replace it. The principle of repairing a barrel perforator to replace the striker is as follows:
If it is working properly, as in the photo, then it is necessary to replace the seals and lubricate it. If it is damaged, then it should be completely replaced.
This is interesting! Barrel units do not have a drilling function in the design of the mechanism, as is typical for pistol devices. This means that professional barrel units are used exclusively for heavy work such as slotting and drilling. In addition, in the design of such units, only cartridges for attachments with the type of shanks are usedSDS-max.
How to properly use and care for a hammer drill so as not to have to repair it often
How long a power tool will last depends on how it is properly maintained and stored. Even if this is a professional tool of the popular brands DeWalt, Makita, Metabo, Bosch, Hitachi and others, this does not mean at all that they can be loaded to the fullest. Any even the most high-quality and expensive tool has its own specific resource, which largely depends on the nature of operation and storage.
If you want to extend the life of the newly purchased puncher, then from the very first days you need to follow a number of the following recommendations:
- Before using the tool, it is necessary to check its technical condition visually.
- Use the unit only for the work for which it is intended. If there is no drilling option in the assignment, then you should not try to drill a hole with an impact function in metal or wood, since you will not only fail, but the tool will also break
- Before installing the drill and other nozzles in the cartridge, it is imperative to apply lubricant to the tail section. This will extend the service life of not only the tool, but also the attachments used.
- After finishing work, clean the hammer drill from dust and debris, and even better, using a compressor and a blow gun, clean the tool with compressed air
- Do not store the tool in damp rooms, as moisture accumulates in the design of the working mechanisms, which not only destroys the metal, but can also cause a short circuit when the tool is plugged into an outlet
These are the simplest rules that will help extend the life of the tool to 5-10 years, depending on the frequency of its use. In addition to electric ones, there are also battery models of rotary hammers, the repair of which is almost the same. Structurally, battery devices are similar to barrel units, only they are additionally equipped with autonomous batteries.
In general, it should be noted that if the design of the device and the principle of operation are known, then any repair of a hammer drill of different brands with your own hands will not be difficult. Difficulties only arise mainly in the electrical part, however, using the above material, any breakdowns can be easily and quickly eliminated. How a screwdriver works and the design of the tool -... Learning to take measurements different types micrometers [Total votes: 2 Average: 5/5]
A rotary hammer always works under difficult conditions and may fail after a while. You can buy a cheap fake again, but you can’t just throw away a branded model. In order not to pay a “round” sum for repairs, you can repair the rotary hammer yourself. But for this you need to understand what components the tool consists of, the order of its disassembly and possible replacement certain details.
TOOLS AND MATERIALS REQUIRED
Screwdrivers Tweezers Pliers
ExpandHow does a hammer drill work?
Any electromechanical device becomes unusable over time. If you have certain skills, then you can try to do the repairs yourself. To do this, you need to know the operating principle and structure of rotary hammers, which are divided into two types:
- The engine is installed horizontally.
- The motor stands vertically.
For repairs this does not matter much. All other details are almost identical. Any device consists of two main parts:
- Electric:
- power cable;
- elements that dampen interference (capacitor, chokes);
- switch;
- engine control device (ECD);
- commutator motor (armature, brushes).
In some models, the switch is combined with a control device.
- Mechanical:
- reducer (gear) on the motor shaft;
- clutch;
- impact-translational mechanism pneumatic (piston) or mechanical;
- clamping chuck.
In expensive devices, auxiliary mechanisms are installed for convenience and safety:
- depth limit;
- vacuum cleaner;
- mode switch;
- bit fixation
- others.
How to repair a rotary hammer with your own hands?
Many people who are ignorant of technology, when bringing a tool for repair, always describe the breakdown with the words “the hammer drill stopped hammering” or “it won’t turn on.” And only upon meticulous questioning do they remember that they put a lot of pressure on it, did not lubricate it, and worked when the network fluctuated (during operation, the “light blinked”). All this causes device failure and damage, which is divided into:
- Electrical:
- the device does not turn on;
- sparks are visible in the housing;
- speed does not change;
- there is smoke coming from the body;
- When turned on, the plugs are knocked out (automatically).
- Mechanical:
- the hammer drill does not hammer;
- a grinding or cracking sound is heard;
- modes do not switch;
- During operation, liquid leaks from the device.
Correct disassembly of a rotary hammer
To repair a particular malfunction, any electromechanical device must be disassembled. Each model has its own nuances in execution. And although the bodies of almost all tools are made of two halves, the disassembly method of one brand may not work with the model of another.
The cases of many models are made of a front and a rear half, when viewed from the chuck side. The screws that tighten the body are located parallel to the slotting axis, and if the caliber of the cartridge is smaller than the diameter of the body, then it is easy to unscrew them. But on many devices the diameters are the same. Therefore, you must first remove the cartridge and then disassemble the rest.
For other models, the body is disassembled from the side. We unscrew the screws, remove half of the body and all the mechanics at a glance. You can begin the inspection immediately. True, to repair the electrical part you will need to unscrew the handle, but this is not so difficult. The main points of disassembly and assembly can be found on the Internet on the “YOUTUBE” service. Therefore, let's move directly to the repair.
Electrical faults and their elimination
- The device does not turn on for the following reasons:
- Broken cord (usually near the handle). The cord should be replaced or shortened, cleaned, carefully threaded into the rubber shock absorber seal on the handle and soldered in the appropriate places.
- Poor contact in the switch (eg oxidation).
- Breakage (combustion) of extinguishing elements. They should be replaced. For a while (if there are no such elements), you can connect the engine “directly” to the control unit. Please note - this method can lead to rapid wear of the motor.
- Combustion of the UUD itself. Replace with a new one.
- Winding breakage or burnout. You need to take it to a workshop or a friend to rewind it.
Advice: Check the breakage of the cord or windings, non-contact of the switch and combustion of the extinguishing elements with a tester.
- Sparks are visible inside the housing. They are called:
- Poor fit of the brushes to the armature due to wear. It is necessary to change the brushes or sharpen them with a file (fine “sandpaper”).
- Oxidation of the anchor. To be cleaned with a student's eraser or alcohol.
- The speed does not change due to a malfunction of the control unit. It needs to be replaced, but you can get by with it for a while.
- Smoke comes from faulty windings, brushes or other elements. For example, due to “sticking” of the motor, the windings begin to heat up and smoke. Visual inspection required
- A short circuit in the cord (insulation breakdown) or switch can cause the plugs to be knocked out.
Mechanical malfunctions and their elimination
There is no clear answer to the natural question of why a hammer drill does not chisel. This may happen due to the reasons given below:
- The main function is not performed (does not hammer).
- Breakage of any of the metal parts located inside many models in this sequence.
After inspection and identification of a malfunction, the unusable part is replaced.
- Liquid leakage from the cylinder due to damage to the gaskets. Change the gasket.
- Dirt getting inside. Clean the tool.
- Solidification of the lubricant. Remove old grease and apply a new coat.
- Reducer gears are damaged. Once identified, replace it.
- Bearing failure. Replace
- A grinding or cracking sound is heard due to the following reasons:
- Bad lubrication. Be sure to replace it with the same one. It is prohibited to use grease and other lubricants of this type.
- Cracked bearings or gears. Change.
- The details worked out. For example, the fingers of the mode switch. change switch
- Modes do not switch due to the following:
- worn out or broken switch fingers.
The switch needs to be replaced, but for a while you can turn the worn pin 180 o.
- breakdown seats. Be sure to change the switch.
- breakage of fixing covers. Replace.
Spontaneous mode changes occur due to a broken latch. Some people continue to work in this mode, but the best option is to replace the retainer.
- Liquid may leak due to deformation (rupture) of the gearbox or cylinder gaskets. Once a faulty gasket is identified, it should be replaced.
Prevention at work
The impact-forward device and the gearbox of the device are subject to heavy loads. The components heat up during operation, the seals rub against moving parts and wear out. All this leads to malfunctions. To avoid premature failure of the device, the following instructions must be observed:
- change the gearbox lubricant completely every six months;
- Once every 6 months, remove the brushes, inspect and replace them if necessary;
- after work, blow out the insides with a vacuum cleaner;
- Before work, do not forget to lubricate the rear end of the drill (chisel). If this is not done, the firing pin and seals will quickly wear out.
Advice: Do not apply pressure to the instrument. When pressure is applied, the stroke of the striker decreases and it begins to strike faster. Because of this, the striker and seals become unusable.
A hammer drill is a tool without which today it is difficult to imagine the bulk of repair and construction work. That is why today every person involved in repair and construction strives to get their hands on this tool. A video about repairing a rotary hammer with your own hands will be of interest to anyone who wants to independently learn how to identify and repair breakdowns of this tool.
Finding out the cause of the breakdown
In order to know what exactly needs to be repaired, you need to understand the reasons for the malfunction of the rotary hammer. This video will help you do this.
Replacing a bearing in a hammer drill
In those cases when, while operating the hammer drill, you began to hear a rustling noise uncharacteristic of normal operation or suddenly felt that the drill began to slip, then it is time to change the bearing. Watch how to do this in this video.
Disassembling the rotary hammer gearbox
A gearbox in a rotary hammer is necessary to transmit rotational motion from the engine to the chuck. It is he who activates the impact mechanism. In order to lubricate the parts or replace them, the gearbox must be disassembled. Watch how to do this in this video.
Another video about disassembling the gearbox.
Hammer lubrication
To ensure that the hammer drill does not fail, it is necessary to properly care for it. One of the main conditions proper care– regular lubrication of the tool. And in order to lubricate the device, it must be disassembled. You will find out how to do this if you watch this video.
If you need a rotary hammer repair, this means, at a minimum, that you already have one. Although it is quite possible that you are still just studying, at the same time, the weak points of its design, and which components could theoretically fail in it.
Well, let's try to help you. In this article we will explore:
- Device of perforators.
- The most loaded parts and components of the tool.
- Disassembly and assembly.
- Measures to extend the life of impact drilling power tools.
Device of rotary hammers
Studying the principle of operation of a hammer drilling tool will not only expand your technical horizons, but first of all will allow you to competently produce it Maintenance and, if necessary, repairs. To facilitate understanding of the processes occurring during drilling hard materials(and this tool is designed to perform exactly such work), take the time to watch these two short videos. The first clearly shows the operation of a rotary hammer with a longitudinal engine.
The second video demonstrates the design of a rotary hammer with a transverse engine.
So, let's start with the most important thing: the tool destroys concrete, brick, stone shock wave, which occurs at the moment of very short contact of the striker with the end of the drill (through the striker). The energy of the shock wave is transmitted through a drill (impact drill) and destroys the bonds (forms microcracks) between the grains of minerals that make up the stone (concrete, brick). The spiral grooves of the rotating drill serve to remove loose particles of material from the hole.
(The conclusion follows: there is no need to press hard with a hammer drill on concrete wall, he won’t drill faster - you’ll just get tired, and the tool will break faster.)
The hammer is made of high-strength steel and moves quite freely inside the piston cylinder. The rubber O-ring seals the gap, preventing air from freely passing into the gap between the cylinder and the firing pin.
The outer race of the rolling bearing, mounted at an angle on the shaft rotated by the electric motor, performs reciprocating movements, causing the piston cylinder to move back and forth. When the cylinder moves forward (towards the drill), the hammer remains in place by inertia, there is air between the hammer and back wall the cylinder compresses and pushes the hammer to meet the end of the drill.
In fact, this air serves as a damping element that prevents deformation and destruction of the hammer cylinder. In a tool with a transverse engine, the cylinder is stationary, and the vacuum and compression of the air behind the striker is created by a piston driven by a crank mechanism.
The most loaded parts and components of a hammer drill
Based on the foregoing, the impact mechanism and gearbox are in the process of long work experiences maximum loads. Part of the kinetic energy of the striker goes into thermal energy, and heats the entire assembly. The O-ring continuously rubs against inner surface the cylinder and with a lack of lubrication wears out, leaking more and more air from the working area over time.
The energy of compressed air is becoming less and less - the impact drill no longer chisels as needed. At self-repair For a hammer drill, sometimes it’s enough just to replace the lubricant in the gearbox, the piston cylinder and the rubber sealing ring on the hammer.
During prolonged continuous operation or during normal drilling under high load, the electric motor can easily overheat and burn out. Although the latest models of the tool have an electronic control unit that includes motor overload protection. If you wish, you can read about the power cord, electronics and power button in the previous article.
Disassembling and assembling a hammer drill
When trying to repair a rotary hammer with your own hands, first of all, you need to disassemble it. To do this, remove the rubber tip, the ring spring, and the casing of the drill fixing coupling. The fixing steel ball is removed. By turning the operating mode switch to its extreme position and pressing the locking button on it, the switch handle is removed.
The rear cover on the handle is removed, and the motor brushes are removed. Unscrew 4 screws (from the drill side) and remove the entire front part of the tool (gearbox housing), containing the barrel, gearbox, impact mechanism and operating mode switch.
The engine rotor is removed. Unscrew the two screws securing the stator. 4 terminals are removed from the stator contacts, then it is removed from the housing. The switch (button + reverse switch), brush holder, noise filter and power cord are removed.
If it is necessary to repair the hammer drill in terms of the impact mechanism and gearbox, unscrew 4 screws from the end of the gearbox housing, then remove the outer plastic casing. It is better to do this in a vertical position. Then in the inner case all the parts will remain in their places.
After replacing the faulty part, assembly is carried out in the reverse order. Parts that turn out to be “extra” should be wiped dry and taken to a repair shop along with the hammer drill.
Activities that extend the "life" of the perforator
All activities are as follows:
- Please read the user manual and operating instructions for the instrument carefully.
- Strictly follow the instructions given in the instructions.
- Change gear and impact mechanism lubricant regularly. Exactly replace, since there is no point in adding new lubricant to the used old one - metal dust serves as an excellent abrasive, “eating” everything in its path.
- Lubricate the drill shank before work.
- Inspect motor brushes regularly and replace as necessary.
- Clean the outside of the tool every day after finishing work.
- Try not to work in clouds of dust - it is harmful not only for the hammer drill, but also for your lungs. Ventilate workplace by opening all the windows.
- Don’t go into something you understand absolutely nothing about - entrust the maintenance to a professional, or, if you’ve already decided to repair the rotary hammer yourself, then do it slowly, remembering well where you put it.
We wish you success!
For drilling holes in various materials, breaking walls, drilling rocks and roads, a hammer drill is designed. The tool is used under heavy loads and malfunctions occur over time. You can replace a failed rotary hammer with an inexpensive Chinese model. But if you have a branded instrument, then it’s a shame to throw it away. In order not to pay half the cost of a hammer drill for troubleshooting, you can do it yourself. No repair is complete without studying the structure of the tool and the procedure for disassembling it.
Types of rotary hammers
Rotary hammers have several classifications. This is due to the various areas of application of the tool.
The number of modes can be from one to three:
drilling The hammer drill operates in drill mode;
hammer drilling. You can make holes in brick and concrete;
jackhammer, that is, impact without drilling.
Types of hammer drill drives:
Classification by weight:
- heavy. More than 5 kg. Over 1200 W. In construction.
lungs. 2–4 kg. Power 400–700 W. Used in everyday life;
average. About 5 kg. Power 700–1200 W. Professional;
Types of cartridges used in hammer drills:
SDS+ is installed on light and medium hammer drills for working with drills up to 20 mm;
SDS max is used for drills larger than 20 mm, therefore they are installed on heavy rotary hammers with high power.
Classification by engine location:
Perforator device
Regardless of function and design, rotary hammers have similar basic elements.
The device of a simple hammer drill with a network drive
Power cord.
Power button.
Engine.
Gearbox.
A barrel perforator has the same main components.
Device of a barrel perforator with a network drive
The impact mechanism of the hammer drill can be made in two versions:
A swinging bearing is also called a drunk bearing. This mechanism is used in light and medium hammer drills.
Impact mechanism with drunk bearing
The crank mechanism is used in heavy hammer drills.
Crank impact mechanism of a hammer drill
How to disassemble a hammer drill
Disassemble the hammer drill sequentially. Inspect all details carefully. Even if you are looking for a problem in one unit, you may find damaged parts in other units. When disassembling the tool, the body should be cleaned of dust and dirty grease.
How to disassemble a cartridge and remove stuck equipment
Start by disassembling the cartridge so that it does not interfere with the removal of the gearbox housing.
If a drill or other equipment cannot be pulled out of the chuck, there are two options for solving this problem:
- Clamp the tool in a vice. Slightly shake the hammer drill and pull it towards you;
- Clamp the hammer drill in a vice through the rubber gaskets so as not to damage the plastic housing. Clamp the end of the equipment with a gas wrench. Tap the key with a hammer in the direction of the axis of the tool.
The second option is used in as a last resort. If after several blows the drill or chisel cannot be pulled out, stop. You may damage the hammer drill. Disassemble the cartridge and gearbox. Try to knock out the equipment with a drift. After this procedure, the raster sleeve will most likely need to be replaced. To avoid this problem in the future, lubricate the end of the equipment.
How to remove a stuck drill bit from a hammer drill chuck
How to remove the mode switch
In some models of rotary hammers, the switch is removed by turning it to the extreme right, in others - to the extreme left. Consider the extreme right position.
Disassembly of the electrical part of the hammer drill
Analysis of the mechanical part of the hammer drill
- Remove the plastic gear housing. You will see an aluminum housing with a fixed bearing, an intermediate shaft, and a raster bushing inserted into it.
- Carefully clean the plastic housing of the gearbox, because pieces from the collapsed bearing remain in it. Take a magnet and go through all the holes to remove all the balls and metal shards. Clean out the grease completely. There may be pieces of plastic separator left in it.
- Remove the intermediate shaft from the worn bearing.
- To remove the helical gear, remove the retaining ring and bearing using a special puller.
- To dismantle the spur gear, you need to remove the retaining ring and spring at the other end of the shaft.
- Remove the bushing from the sleeve.
- Remove the sleeve from aluminum body.
- There is a firing pin inside the cartridge case. It is pulled out with a bent rigid wire.
How to assemble a hammer drill
Assembly is carried out in blocks. First, collect small parts into blocks, and then connect them.
- Insert a bearing with a groove and a sleeve into the aluminum gear housing.
- Place a rubber band on the body. It prevents lubricant from leaking out.
- Connect the raster sleeve to the sleeve.
- Liberally lubricate the outside of the bearing and gears.
- Place the plastic gear housing on the assembled unit.
- Insert the rotor into the gearbox.
- Install the stator and air intake into the electrical housing. Connect the two halves of the hammer drill body.
- Insert a screwdriver into the hole in the raster sleeve and twist. It should rotate easily. Screw the housing bolts.
- Put the brushes back in place.
- Insert the button and all wires into the grooves. Make sure there is nothing in the way and put it on back cover. Screw it on.
- Before installing the switch button, use a screwdriver to move the switch bracket in the hammer housing. So that the pin that is on the switch fits between the two metal guides of the bracket.
- Place the mode switch just below the impact, push it down and turn it up until it clicks.
- Reassemble the cartridge in reverse order.
How to assemble a hammer drill
Hammer diagnostics
Take a multimeter, put it in dial mode and start testing with the power cord.
- Connect one probe to the end of the plug, the other to the contacts on the other end of the wire. When connecting to one of the contacts there should be a sound signal. Do the same with the other end of the fork.
- Check the power button on the contacts with the power cord and with the stator. Press the button trigger.
- Check reverse contacts.
- Connect the probes to the brushes to check the contact through the armature.
- Connect the probes to the stator wires and test them.
- If the contacts of the stator or brushes do not ring, and the buttons and power cord are working, proceed to diagnosing the commutator and motor windings.
Diagnostics of wires and buttons of a rotary hammer with a multimeter
At the armature, first inspect the commutator and winding. If the wiring is melted, the burnt insulating varnish will leave black marks or a specific smell. You may see bent or crumpled coils or conductive particles, such as solder residue. These particles cause short circuits between turns. Commutator damage: raised, worn or burnt plates.
Carry out diagnostics with a multimeter:
set the resistance mode to 200 ohms. Connect the probes of the device to the ends of one winding. One means an open circuit, and zero means a short circuit between the turns. If it shows resistance of more than 1.5 ohms, then check the second winding. Both windings should have approximately the same resistance;
check that there is no breakdown to ground, that is, a short circuit between the winding and the metal stator housing. Set the multimeter to maximum resistance mode. Connect one probe to the end of the winding, the other probe to the metal stator housing. A unit indicates the absence of a breakdown.
- does not turn on. Check the electrical circuit;
- The hammer drill doesn't hit. Damage to the impact mechanism;
- The tool does not turn or drill. Reasons: armature bearings, armature gear, gearbox;
- the drill flies out and doesn't stay in place. Faulty cartridge or raster bushing;
- sparking in the electrical housing. Reasons: violation of armature winding insulation, wear of brushes, commutator, clogging of brush holders;
- sparking in the area of the power button. Faulty button contacts or wires;
- The hammer drill is heating up. The reason is worn brushes, short circuit of winding turns, poor lubrication of the gearbox;
- puncher does not hold a cartridge. Snap ring or locking washer broken.
- To replace the button, just unscrew the screws of the contacts. But there may be buttons without screws. Here, next to the contacts, there are holes into which a needle or thin awl is inserted. Poke into the hole, push in and pull out the wire. Do not pull the wire, you may damage the button.
- Wires must be stripped and tinned.
- Take an old button and buy a similar one.
- On the new button, insert the awl into the hole, apply light pressure and insert the wire. It will automatically be clamped by the contacts.
- Remove the stator from the electrical housing. Put a new one in its place.
- Screw in the mounting bolts.
- Install the air intake.
- Proceed to connect the windings. Connect the two ends of different windings to each other and connect to the nearest brush. Connect the other two connected ends to the start button. Also connect the wire from the second brush to the button.
set the resistance to 200 ohms. Connect the probes of the device to two adjacent collector plates. If the resistance is the same between all adjacent plates, then the winding is working. If the resistance is less than 1 ohm and very close to zero, there is a short circuit between the turns. If the resistance is two or more times higher than average, then there is a break in the winding turns. Sometimes when there is a break, the resistance is so great that the device goes off scale. On an analog multimeter, the arrow will go all the way to the right. But digital won’t show anything;
determination of breakdown to ground. Set the device scale to maximum resistance. Depending on the tester, it can be from 2 MOhm to 200 MOhm. Connect one probe to the shaft, and the other to each plate in turn. If there are no faults, the resistance should be zero;
The anchor can be saved if the balance is not disturbed. If during operation of the device you hear an intermittent hum and there is strong vibration, then this is an imbalance. This anchor must be replaced. And the winding and commutator can be repaired. Small short circuits are eliminated. If a significant part of the winding is damaged, it can be rewound. Worn and badly damaged lamellas should be sharpened, extended or soldered. In addition, you should not undertake anchor repairs if you are unsure of your capabilities. It is better to replace it or take it to a workshop for repairs.
Checking the performance of the stator with a multimeter:
Malfunctions and their causes
Frequent hammer drill malfunctions:
DIY repair
When disassembling the assembly, carefully inspect the parts for cracks and chips.
Replacing the power button
Before replacing, mark the wires and contacts of the button so as not to confuse the connection order.
Replacing a button using an awl
Brushes must be checked periodically. If one is worn by 40%, replace both. Also, clean the brush holders.
Replacing and connecting the stator
Replacing bearings
There are several bearings in a hammer drill. To dismantle them you will need a puller. In some cases it is necessary to remove the retaining ring. If there is no puller, hang the shaft with the bearing and knock it out with a piece of wood. The bearing is seated using a polypropylene tube adapter by tapping it with a hammer.
Replacing the cartridge
The cartridges in rotary hammers are very easy to change. Remove the rubber boot, retaining ring, plastic boot, washer pressing the balls, fixing plates, spring. IN different models The number of rings and plates is different. Put a new set in their place.
Drunk bearing repair
Prepare a flathead screwdriver, a clean rag and the gearbox lubricant recommended in the instructions.
Repair of raster bushing and impact bolt
To disassemble the raster bushing, you need to compress the spring, remove the retaining ring and gear.
Raster bushing assembled and without gear
The impact bolt is repaired by replacing parts or replaced completely if it has fallen apart.
Replacing the sleeve
The sleeve wears out less frequently than the raster sleeve, but if the tool frequently overheats, it also fails. Remove the grid sleeve and sleeve from the aluminum gear housing. Put a new one in its place.
Worn and new sleeve with striker
Features of barrel puncher repair
Repair of a barrel puncher has the same principles as a simple one. The main difference is in the design and number of elements.
Replacing the brushes on a barrel puncher
Impact mechanism and gearbox repair
The main difference between a barrel puncher and a gearbox that is simple in design. Some models have an impact mechanism with a drunken bearing.
Barrel puncher with screwed bearing
But most rotary hammers have a crank-and-rod impact mechanism.
Barrel perforator with crank percussion mechanism
All gears and bearings must be inspected and lubricated. Change worn ones. To disassemble such a structure, you need to unscrew the bolts on the body. The barrel is knocked out of the body rubber mallet. The bearings are removed with a puller.
How to remove the firing pin and raster sleeve from a barrel perforator
Due to a faulty striker, the hammer stops hitting.
Drum perforator repair
Proper operation and care of the hammer drill
To ensure that the hammer drill works for a long time, you should follow some recommendations:
Before fastening the equipment, lubricate the shank with the product specified in the instructions;
after work, clean the chuck and equipment;
when working with concrete, remove the drill every 2 cm;
if you need to drill big hole, use drills of different diameters so as not to drill with the largest drill at once;
When doing a large amount of work, take breaks to allow the equipment to cool down. During breaks, you can clean the cartridge;
spend regularly full analysis cleaning and lubrication tools.
If the hammer drill has any malfunction, read the instructions. Inspect the instrument carefully. If you don’t doubt yourself, then do the repairs yourself.
