Disassembling the Bosch electric screwdriver gearbox
Every tool, regardless of model and brand, breaks down sooner or later. an electric screwdriver is no exception: individual parts and assemblies wear out over time, and without proper care or in force majeure circumstances can fail.
The main functional load during operation of the tool is distributed through the gearbox between the motor and the chuck, so if something happens to the gearbox. the work becomes. In order not to spend money for repair service, it is enough to use expert advice to restore operation of the unit by yourself.
Repair the Gearbox of a Bosch Electric Screwdriver
burns out when working under heavy load for a long time. The most common failure is distortion of the main shaft and chuck. In such a malfunction, the device begins to vibrate very much in the hands.
Another breakdown is the wear of the shaft bearing with a chuck or bearing sleeve. If only the bearing or bushing is distorted and the shaft is intact, repair
The only way to fix the gearbox of an electric screwdriver in a makeshift condition is to replace the worn element.
the motor starts for a second and then sharply stops, it means that the problem is in the gearbox. In these circumstances, in most cases, the pin fails, due to which the satellite is not able to transfer the revolutions to the main shaft. If this is the case, installing a new driver is of vital importance. If the driver is also damaged, the whole gearbox has to be exchanged. The gear teeth also have an effect on the operation of the gearbox. If the device will operate for a long time with worn gears, it leads to failure of most parts relating to the gearbox structure of an electric screwdriver. The electric screwdriver gearbox diagram
- The sun gear of the motor turns the satellites. The rotation is in the radial direction of the ring gear. From here it’s clear that the driver is spinning slower than the motor itself.
- Then the 1st driver transmits the torque to the second trinity of satellites. Transmission is through the sun gear. the other trio also rotates in a radial line of motion, and as a result, the 2nd driver gets even fewer revolutions. It is connected to the main shaft of the chuck.
This is the diagram of a two-stage gearbox. Electric screwdriver gearbox design
The only difference is the number of satellites. For example, for a 3-stage gearbox, another mechanism is added.
How to disassemble the electric screwdriver “Makita” and make repairs chuck or other parts with your own hands
In this article we will consider an electric screwdriver from a well-known brand “Makita”, will describe its technical characteristics and general device, will tell about the main problems and malfunctions that arise during the operation of the tool, as well as how to diagnose a breakdown and repair this or that element of an electric screwdriver with your own hands.
Description, general information
The company “Makita” produces a variety of power tools, among which are screwdrivers. The company’s history since the beginning of the XX century, and to this day it continues to delight consumers with its high quality products. Let’s consider the general features and characteristics of the models of this firm.
Makita screwdrivers are powerful. The average speed for different models is about 2300 rpm, which is not bad compared to other brands. The weight of most models lies within 1.5 kg.
Its small mass suggests that such a tool will be comfortable to work with. The manufacturer has taken care of convenience and work in poorly lit rooms, making the majority of models with LED backlight. Separate handle for holding the weight of these tools is worth mentioning.
As a rule, they are made rubberized, and therefore it is convenient to hold them in the hand, respectively, the work process is much easier.
The disadvantage of these screwdrivers is a strong handle vibration when working, as well as their short-lived batteries. In addition, the price of the products of this company is quite high, which is important for domestic consumers.
Diagram, structure of a Makita electric screwdriver
Consider the device of the electric screwdriver on a particular model 6271D. The scheme of this model is presented in the figure below.
- Switch lever
- Body assembly
- Rating plate
- Reverse lever
- Start button
- Contact terminal
- Quick-action chuck
- Gearbox assembly
- Electric motor
- Body assembly
- Charging unit
The modern electric screwdriver is a high-tech device. Important structural elements:
- Removable battery
- Rubberized handle
- Power motor
- Metal planetary gear
- Softstart button
- Reverse switch button
- Torque regulator
These are the basic components of an electric screwdriver and are included in the basic equipment of every electric screwdriver model.
The disassembly of a Makita electric screwdriver
To disassemble an electric screwdriver, you will need a Phillips screwdriver and some personal time. To disassemble an electric screwdriver completely, you need:
- Remove the housing screws;
- Remove the composite mechanism of the start button;
- remove the electric motor together with the reducer;
- Detach the gearbox from the motor by unscrewing the bolts that fasten them together.
To disassemble an electric screwdriver battery, you need to unscrew the bolts that connect the case, or separate the case’s adhesive-based connections with a soldering iron. Inside the battery there are several nickel-cadmium batteries that have a certain capacity and carry a charge. If the battery is repaired, it is necessary to replace them with new ones.
The cartridge is replaced with a screwdriver and an Allen wrench. First use a screwdriver to unscrew the fastening screw in the cartridge, turning it clockwise. Then the hexagon is inserted, the reversing button is engaged, clamped, and then the chuck gives way easily.
Makita electric screwdriver malfunctions
The most common breakdowns of a Makita electric screwdriver are as follows:
- The electric screwdriver does not turn on. It’s pretty clear. The first thing to inspect is the battery, as well as contacts and connections in the housing, wiring. A multimeter will help you to check it.
- The reverse button does not work. This means that you cannot either tighten or loosen screws and bolts. Here you should check the resistance of the button with a multimeter, putting the probes on the input and output wires of the button.
- The rpm controller does not work. In this case, the speed is either permanently reduced or permanently overdriven. Here the culprit could be the regulating transistor or brushes. You need a visual inspection of the parts.
Repair of the button on a Makita electric screwdriver
The tool on/off button is a complex electronic mechanism. It consists of several elements that make it up:
When repairing the button, you must first disassemble it by unscrewing the housing screws and disconnecting the battery. After that, you should check the connections and contacts for contamination, clean them. If stripping the contacts did not help to eliminate the problem, the button should be replaced as a complete.
Bosch GSB 18V EC Chuck, Clutch, Gearbox, Speedswitch & repair
Repair the battery charger of a Makita electric screwdriver
When repairing the charger you need to unscrew the screws that fasten the housing covers. Inside is a printed circuit board with contacts. First you need to check the transformer with a tester.
To do this, you need to measure the voltage at the output. Then you need to test the cable to rule out its fracture. Then check the primary and secondary windings of the transformer and the fuse.
Assemble it in the reverse order.
Repairing the battery of a Makita electric screwdriver
When repairing the battery with a Phillips screwdriver loosen the screws that fix the housing. There are several cans inside the case. Visually inspect them to detect geometric faults such as swelling. We test the banks with a multimeter for residual charge. If it is absent, the can is replaced with a new one.
Repairing the gearbox of a Makita electric screwdriver (diagram)
To remove the gearbox you need to disassemble the housing by removing the screws with a Phillips screwdriver. Remove the start button, reverse switch button, disconnect the bolts securing the motor to the gearbox. Then it is necessary to remove the contents of the gearbox (various gears), the washer of the speed selector.
How to Disassemble the Button on a Bosch Electric Screwdriver
How to disassemble the screwdriver: chuck, battery
Innovative technologies in construction are developing every day, it has long been clear to everyone that the electric screwdriver. your assistant as an experienced specialist, as well as for novice master. Thanks to it there is a variant simply to screw various self-tapping screws and screws when assembling furniture structures, and also when carrying out repairs of appliances and apartments.
The fact that no matter what equipment has been broken for years has long been no news to us, because it is possible to disassemble the electric screwdriver and try to fix it at home. But without fanaticism, be careful when disassembling, especially such models as: Interskol sell 12er 01, Interskol and sell 18er.
How an electric screwdriver works?
What problems can be corrected at home? How to recognize a particular failure? To give some answers to these questions, we first deal with the internal mechanism of the tool. The main protruding element is the trigger. It is used to start the device and the same for the configuration of speed, direction of rotation of the working part. chuck.
The speed is adjusted thanks to an electrical device based on a transistor. The speed of rotation is directly proportional to the force of the button. Start the reverse operation by reversing the polarity on the terminals. Typically, an electric screwdriver is equipped with a single-phase motors of the collector type, which operate on a continuous current. The gearbox contains the body, magnets, armature and brushes.
The rotation from the motor goes to the gearbox. Next, he converts the highest motor speed into low cycles on the shaft, there is fixed chuck with active bits.
The gearbox used is traditional, like an ordinary drill, and including a planetary. Nowadays the traditional gearbox is practically not used, let’s not stop and move on.
Then comes the force regulator, which has sixteen positions. These positions give a particular voltage to the screw, for the possibility of not damaging the material, so they are fixed. The last component is the chuck.
How to Disassemble an Electric Screwdriver
There are unpleasant situations when in the midst of work breaks down an electric tool, such as an electric screwdriver. There is no time to go to a workshop or supermarket to buy a new one, so you have to repair it yourself. How to disassemble an electric screwdriver for repair we will consider below.
- How it is built
- How to disassemble an electric screwdriver in general
- Disassembling the battery of an electric screwdriver
- How to disassemble the chuck of an electric screwdriver
- How the chuck is fitted
- Determining how the manufacturer secured the chuck
- Dismantle the cartridge
- Construction of the planetary gearbox
- How the 2 speed gear works
The nuances of removing, disassembling and replacing heads on screwdrivers of different manufacturers
The design of the electric screwdriver chuck is such that the procedure of its removal, disassembly and replacement, in general, is the same and standard for all models. Differences only in subtleties for each company.
Home tools from this manufacturer are often equipped with a plastic head. It should be removed carefully, because the risk of damage is greater than with a metal sleeve. Quick-clamping devices on Makita screwdrivers, as a rule, are single-fingered.
The cylinders in Bosch wrenches are made in the same way as for Makita, they can be separated and disassembled in the same way. The only difference is that Bosch has a fixing screw in the cylinder. It must be unscrewed clockwise.
To change the chuck, unscrew it clockwise from the shaft.
The removal of the head on the screwdriver models Interskol, Hitachi, DeWalt, Metabo, Vortex is not diverse. The procedure is as follows:
- Unscrew the fixing screw with a Phillips screwdriver. Before unscrewing element it is recommended to slightly smear it with WD-40. This will not only loosen the strong clamp, but also dissolve the rust, if any.
- Clamp an L-x wrench 10mm or more into the socket with the short side.
- It is necessary to hit the long side of the hexagon with a hammer one accent stroke in clockwise direction. it is necessary to hit exactly on the hexagon, but not on the cylinder itself: you can both break the clamping device and deform the shaft of the electric screwdriver.
- Can be unscrewed by hand after impact.
inside a cordless drill (with schematic & gearbox autopsy)
Battery life for an electric screwdriver
The battery can last about three to four years if used and stored properly. In practice, this period is sometimes reduced to two years. It is very expensive to constantly change the tool, so it is better to choose the best option for a particular purpose at once.
There are 3 different types of batteries:
- Nickel-cadmium. The most affordable, but short-lived, especially with frequent work in cold weather conditions.
- Nickel-metal hydride. A small device that does not have a long life.
- Lithium-ion. The most in demand, long able not to discharge, but have a higher cost than the above options.
Regardless of battery type, battery life depends on how many charges are used and how they are stored. That is, the more you work, the faster it runs out of power. Downtime” has a negative effect on the life of the tool, especially if the tool is stored in a condition where it has sat down.
The main causes of malfunction
Screwdrivers can be cordless or cordless. Their basic faults are virtually the same, and the differences are related to the type of power.
Electric power screwdriver
If the device does not start, first check the condition of the socket, and then, if it is serviceable, inspect the plug. Often an electric screwdriver won’t start because the contacts are burned out. If both units are intact, you should inspect the cable to make sure it is intact, not kinked or overkinked. Also a faulty trigger, worn brushes or blown motor winding can be possible causes.
If the technique sparks, you need to look for a defect in the armature, electric brushes or the collector of the motor.
Self-starting electric screwdriver tells you if the trigger is broken.
If the chuck has a backlash, the gearbox shaft is defective. If the chuck is jammed and you can’t remove the drill bit or bit, the jaws are jammed. It is caused by lack of lubrication or internal chuck components breakage. If the ratchet turns, the gearbox is defective.
If the ratchet is defective, examine its locking paddles, spring and pins.
Cordless electric screwdriver
If the technique does not turn on, check the charger and the serviceability of the battery. If it discharges quickly, its condition can be diagnosed with a special tester.
Other malfunctions of a cordless-type electric screwdriver are similar to mains-operated equipment.
Electric screwdriver repair with their own hands: the main aspects
One of the most popular and popular tools of home craftsmen is an electric screwdriver. Thanks to its mobility, power and versatility it can handle all kinds of drilling and assembling screws and self-tapping screws.
Despite its obvious advantages, in the event of malfunction, you can repair an electric screwdriver with your own hands or send it to specialized centers. For most users, the first option (with the study of some nuances) will be more acceptable, because it allows to avoid costs and save time.
Before identifying faults and their elimination, it is necessary to read in detail the operational documentation, as well as pay attention to the design features of the specific model of the device.
Almost all the screwdriver models on the market have a similar design.
- Electric motor. Is the actuating and main organ that converts electrical energy into rotational energy.
- Planetary mechanism. Allows you to change the direction of rotation of the tool chuck.
- Pulse width control. Allows you to adjust the speed when you change the force on the trigger.
- Chuck. Represents a mechanical assembly for securing bits, drills and other tools.
- housing. It is an injection-moulded plastic body that serves as a framework for the assembly of all the actuating elements of an electric screwdriver. There is a rubberized handle on the housing as an aesthetic addition.
- Force regulator (ratchet). Fits between the planetary mechanism and the chuck. Limits the tightening torque to prevent the bit from slipping in the screw and consequently damaging the mounted material. Each digit on the ratchet represents a tightening torque that increases as the digits increase.
Basic screwdriver malfunctions and troubleshooting
Troubleshooting for the electric screwdriver
because of the similarity in the design of the whole screwdriver range, the failure modes are pretty much always the same.
Changing the brushes on an electric screwdriver
One of the reasons that the electric screwdriver has stopped working is because the brushes are very worn out. All electric motors have a collector-brush node to transfer energy to the armature windings, as such special contacts are used. They are made of graphite or carbon, which do not create a high friction force with the metal and therefore minimize heat.
If the tool fails, do not start disassembling the electric screwdriver, because it can often be caused by a faulty battery or a complete discharge. If there is no change in the operation after the battery replacement, the cause is probably just the brushes wear. The first thing to do is to measure the resistance between them.
if its value is near 0, we can say that the fault lies not in the collector unit. But if the reading on the multimeter shows a broken circuit, gently squeeze the brush holder and twist the chuck. Unchanged numbers on the tester necessarily indicates that the contact is not restored.
Therefore, it is necessary to make a repair of the electric screwdriver motor, and in particular, the replacement of brushes.
On a traditional serviced motor everything is very simple: you remove the worn out set of brushes and install a new one.
The maintenance-free models are a bit more complicated, because to disassemble them, you need to bend the crimped holders with pliers.
After removing the cover, using a high-powered soldering iron, solder and paste, you need to tin the three necessary points. Then pre-cut wiring, remove the old and solder new brushes.
Repair of the electric screwdriver chuck
Despite the large variety of models, almost all of them are equipped with the usual quick-change chucks. A small set of locksmith’s tools is needed for repair.
The dismantling of this assembly begins with the unscrewing of the central screw with a left-hand thread that fastens the cartridge to the drive shaft.
Next, switch the button to change the direction of rotation of the shaft and with a strong counterclockwise jerk remove the assembly from the cone.
Since a chuck of an electric screwdriver is a rather complicated mechanism with a lot of small parts, its repair with the replacement of individual parts is problematic due to the lack of repair kits readily available. Therefore, at home you can make the disassembly and installation of a new chuck, and the repair of the electric screwdriver chuck is best left to professionals of the service center.
Repair of the power button
In most cases, it is not easy to find a suitable power button for an electric screwdriver, because you have to make an order at a service center and wait for an indefinite amount of time. For many users, therefore, an excellent solution is to repair their own electric screwdriver with their own hands. First of all we disassemble the tool and dismantle the pressure mechanism.
On most models, the button is usually red or orange, but it depends on the manufacturer. Then remove the protective housing with a knife or flat-blade screwdriver.
Working carefully in a circular motion loosen the plastic tabs and release the reversing mechanism. In the next step release the switching element by means of a soldering iron.
Warm up the soldering points and separate the housing into two parts.
Holding the spring, remove the trigger mechanism and examine the contact pads, which are subjected to abrasion during the operation. In most cases, the reason for their wear and tear is the poor quality of metal. This is often the reason for the failure of the pushbutton mechanism.
You can eliminate the problem by cleaning these areas with sandpaper and absorbent cotton. After restoring the properties of the contacts, reassemble the electric screwdriver trigger in the reverse order of disassembly.
Disassembling and repairing the gearbox
One of the most critical components of an electric screwdriver is the reducer, which significantly increases the torque of the output end of the motor shaft.