One of the most versatile power tools is a screwdriver. It is used for unscrewing and tightening screws, bolts, and self-tapping screws. It has also found its application when drilling holes in hard materials. On sale today you can find different types of screwdrivers, among which we should highlight:
- household;
- professional;
- semi-professional.
Household ones are used to perform a wide range of tasks. With their help you can replace a lock, assemble furniture and hang a picture. The torque of such models does not exceed 15 Nm, and the rotation speed will be equal to 500 rpm maximum. Such units are not suitable for frequent use.
The same cannot be said about professional devices. In addition to screwing, they have a drilling function. The torque in this case reaches 130 Nm. This equipment is suitable for frequent use, and the rotation speed of different devices can vary from 1200 to 1300 rpm. Among other things, screwdrivers can be cordless or corded. Among others, the market offers models of the Interskol brand, which will be discussed below.
Device Features
In the design of a screwdriver, one of the main components is the motor. Its execution is mostly standard. It is a cylinder with magnets inside. The armature of the motor is held on supports that are made of brass or other material. The motor windings are placed in the armature slots. They are made of material with high magnetic permeability.
The armature body material is steel. Through an equal number of turns, the winding has access to the collector plates. To press the brushes, spring-loaded plates are used, which do not allow structural elements to move out of their places. Once you understand the DC motor circuit, you can understand that voltage is supplied to the brushes themselves. The direction of rotation of the motor will depend on the polarity of the applied voltage.
The Interskol screwdriver also has a planetary gearbox, which is one of the important mechanisms. It is carried out in a separate housing and consists of several parts, including:
- carrier;
- gear;
- sun gear;
- satellites.
During operation, four components may fail. Not all gearboxes are made the same. They may have their own characteristics. To repair the unit, the location of each element should be clarified.
The main part is the ring gear, which has a cylindrical shape. Along the circumference there are teeth along which the satellites move. They are installed on the carrier pins. Between the satellites there is a sun gear.
A fairly simple scheme is used to control the speed of the Interskol screwdriver. This unit involves a key and a pulse-width controller. The first is made on the basis of a field-effect transistor. The control uses a variable resistor. Its resistance and rotation speed will depend on the force of pressing the power button. It is sometimes called the trigger.
The Interskol cordless screwdriver uses a constant voltage power supply. It is usually small in size, which reduces weight for ease of use. A battery is a device of several power elements fastened together. Their connection is carried out in series. They are located in a single building. For home household models, the supply voltage usually starts at 9 volts. The range of these parameters is quite wide and can reach 19 volts. This applies to professional units.
Looking at Interskol screwdrivers, you will be able to discover that with an increase in the supply voltage, the equipment becomes more powerful. The design also usually includes a rubberized handle, a reverse switch and an engine cooling system. If you want to make your work more comfortable, you should choose a device with a soft start. The gear housing is usually made of metal. The switch is rubber coated.
Diagnostics and troubleshooting of the electrical part of the screwdriver
If you have a battery-powered device, then the first thing you need to do is check the batteries in the battery pack by disassembling it. There are collapsible and non-dismountable blocks. In the second case, you will need to carefully insert a screwdriver into the place where the walls of the block are glued and, slowly, separate them.
Next, you need to measure the voltage on all “banks”. The voltage rating is indicated on the body of each battery. The voltage should be slightly lower than specified, but the same on working batteries. Faulty batteries will differ significantly from the rest in the voltage they produce - they will need to be replaced. New batteries can be purchased online.
It is important to solder them correctly, that is, in series: the plus of one battery is connected to the minus of the other, and the plus of the second to the minus of the next, etc.
If you are the owner of a networked screwdriver, then the verification algorithm is slightly different. First, you will need to unscrew the body of the device and remove one half of it. Take a tester and “ring” the power cord for a break. If the cord is working, you need to check the start button. With the button pressed, check whether there is a circuit at its output contacts. If the button is faulty, it will need to be replaced or repaired. How to do this will be discussed further. If the button is working properly, the problem may lie in the electric brushes or the motor.
Button repair
Below is an electrical diagram of a cordless screwdriver.
From the diagram you can see that 2 wires from the battery go to the button, and 2 wires come out of it to the engine. Also, 3 wires from the transistor responsible for adjusting the speed are connected to the button. To understand the structure of the screwdriver button, it must be disassembled. All wires going to this part do not need to be soldered. They will not interfere with disassembly.
Remove the push mechanism (red) from its seat. Do this with gentle rotational movements, while simultaneously pulling the part in the direction opposite to the button, making sure that the joke does not break.
Next, remove the button cover. In the places indicated by arrows in the figure, use a knife and a screwdriver to pry and push out the latches, and then remove the cover.
After removing the cover, you will see the reverse compartment. But the button mechanism will still be unavailable. Using a soldering iron, separate the 2 elements (indicated by an arrow in the following figure).
Carefully pull out element number 1, then remove the cover that covers the compartment with the device’s activation mechanism.
Holding the return spring, remove the mechanism from the housing.
In the faulty button you will see erased contact pads.
The contact pads wear out quickly due to the poor quality of the metal. Fine metal dust from actuated contacts accumulates between them and shorts out the pads. As a result, the device starts spontaneously.
Use cotton wool soaked in alcohol to remove metal dust. If this fails, you can scrape it off with a knife. After these steps, the spontaneous startup of the device will stop.
If the speed controller does not work, it means the transistor has burned out and needs to be replaced.
Replacing brushes
To check the condition of the brushes, it is necessary to disassemble the engine by bending the “antennae” located at the end of the housing.
Next, lightly tap the motor shaft with a hammer to knock the rotor out of the housing.
In this case, the cover in which the electric brushes are located will first be removed.
The next photo shows that the collector is black. This means that it will become contaminated with dust from the brushes. As a result of contamination of the commutator, as well as the grooves between its plates, engine power drops and the brushes spark. It is necessary to wipe the collector with cotton wool soaked in alcohol and clean the grooves with a needle.
The following photo shows what a clean manifold looks like.
If the brushes are worn out, they will need to be replaced. It is difficult to find original brushes on sale for some models of screwdrivers. But you can find brushes that are suitable in size, then use a sharpening machine to trim them and connect (solder) them to the brush holders.
Sometimes, to replace the brushes, you will need to cut a groove into them. It depends on the way they are attached.
To better understand how brushes are replaced, you can use the following video.
Engine brake repair
The engine brake is a device that stops the rotation of the armature when the start button is released. In screwdrivers, this function is implemented by closing the plus and minus of the motor when the button is released. As a result, a large self-induction occurs, and the spindle locks (with large sparks from under the brushes). If engine braking does not work, then the control transistor or start button will need to be replaced.
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Review of the cordless screwdriver model DA-12ER-01 434.0.1.40
This device is a battery-powered unit for use in a home workshop. The design assumes a two-speed gearbox, so the screwdriver can be used as a drill. At the first speed, you can drive screws even into a hard surface, but by switching the equipment to the second speed, you can drill holes in different materials. If you have to work without power sources, this model of screwdriver is perfect, because it runs on a battery.
History of the device
A screwdriver is a power tool. Its main purpose, as the name suggests, is to tighten or unscrew a fastener. After the electric drill was invented in 1868, the development of power tools became widespread. Founding companies DeWalt, Bosch, Black & Decker, Makita and Hitachi developed the industry by creating new devices.
The introduction of the Phillips head screw in 1934 created a demand for electric tools to tighten them. It was especially in demand in mechanical engineering. The first device of this kind was called a wrench. With the advent of batteries, the device gained mobility, and the name screwdriver came into use. Its mass production began in the early 80s .
Modern devices are constantly improving, but to a greater extent this relates to the method of autonomy and control. The design of the device remains unchanged.
Model specifications
The Interskol screwdriver described above has a quick-release chuck. The device operates using a brush motor. The equipment has reverse. The spindle speed can vary from 0 to 1400 rpm. The unit weighs 0.96 kg. The size of the cartridge used varies from 0.8 to 10 mm. The overall dimensions of this model are 180 x 52 x 185 mm. Charging time is 1 hour.
The maximum drilling diameter in metal and wood is 10 and 20 mm, respectively. This Interskol screwdriver uses a lithium-ion battery.
Repair of the electrical part of the tool - battery
A common failure in the operation of the Interskol Da-18ER screwdriver is battery failure. It is very easy to identify this malfunction. If you put both screwdriver batteries on charge, and one of them charges, but the other does not, and testing the charger shows no deviations, then the reason is in the power source itself.
It is necessary to open the battery case and remove the battery of galvanic cells from it. After this, you need to check the voltage on each bank. It should be 1.2–1.4 volts. If there is no voltage on at least one element, or it is below this value, it must be replaced. Since the battery banks are connected in series, the increased resistance of the damaged cell prevents the others from charging.
After identifying the weak point, the battery needs to be assembled and tested under load. Re-checking will help ensure that the decision was made correctly. The ideal solution would be to replace individual elements or the battery assembly with a new, original one. The cost of a screwdriver battery is quite high, so it’s worth trying practical ways to restore the functionality of “old” elements.
First of all, the damaged can must be briefly exposed to high current. This will restore its former tightness and stop the processes of drying and evaporation of the electrolyte.
The second option for restoring functionality to a faulty can is to slightly compress it or slightly deform the element body. Such actions will allow the battery to work for some more time.
If there are several used batteries available, then you can assemble a new one from them by selecting and soldering suitable elements. In doing so, you need to remember two things. The assembled battery must have a voltage 1.5–2.5 volts higher than the nominal value, and the so-called memory effect must be eliminated. To do this, it is charged and completely discharged several times. In this case, you need to ensure that the screwdriver does not overheat.
Another reason for the battery not working may be the thermal switch. It is installed on the battery of galvanic cells and connected to the control contacts. Its mission is difficult to overestimate. During the charging process, the sensor monitors the temperature level of the galvanic cells and, if the nominal values are exceeded, interrupts the circuit, thereby protecting them from destruction. Its failure will trigger irreversible processes in banks, and this will lead to their destruction.
Consumer Reviews
Consumers emphasize that the screwdriver model described above is popular because it has many advantages. For example, the device provides a battery charge level indicator. The handle has a soft non-slip coating, which ensures maximum comfortable operation.
Consumers also like the fact that it will be possible to remove the drill from the material thanks to the reverse. The torque has 18 positions, which allows you to select and fix the tightening torque. For ease of storage and transportation, the manufacturer has included suitcases, which is very popular with craftsmen who are used to working outside the home.
Review of the DA-18 ER screwdriver
You can purchase this model of screwdriver, which can also be used as a drill, for 6,500 rubles. It is a tool that is popular not only among home craftsmen, but also among professionals. You can screw screws and install fasteners using this model.
The tool can be used in difficult conditions; it will work for a long time without additional charging. The equipment is powered by an 18-volt battery, which allows the use of large drills for wood and steel. In the first and second cases, the hole diameter can reach 18 and 10 mm, respectively.
Elimination of mechanical breakdowns
Mechanical breakdowns of a screwdriver include malfunctions of the ratchet, gearbox and chuck of the device.
Ratchet repair
If the ratchet on the screwdriver does not work, you will need to disconnect it from the gearbox to troubleshoot. Sometimes special rods are installed in the coupling, which regulate the force, and in some devices, instead of rods, 2 balls are installed in each hole. They are pressed by a spring, which, when the adjusting ring is tightened, presses on the balls.
In most cases, repairing a screwdriver ratchet consists of cleaning its components from dirt and applying new lubricant.
Screwdriver gear repair
If unusual noises are heard in the gearbox, or the spindle rotates jerkily, with slipping, then the fault may be faulty gears of the mechanism, ground off teeth on its body.
Gears most often break if they are made of plastic (used in cheap devices). If this happens, they must be replaced.
In the next photo you can see the gearbox structure.
The reason that the spindle does not rotate when the engine is running may be wear of the plastic teeth inside the gearbox housing.
To restore the functionality of the mechanism, it is necessary to disassemble the gearbox (it is better to photograph the disassembly process) and screw in a small bolt ground to the required size in place of the worn teeth. The place where you will install the bolt must be marked. It should be located strictly opposite the plastic tooth located on the inside of the case.
Make the same markings on the back side of the case, opposite the first.
Next, drill holes in the marked places.
Screw bolts of the required length into these holes, first grinding them down so that they are flush with the other plastic teeth. After adjusting the bolts, you can assemble the gearbox by applying the required amount of lubricant to the gears. At this point, the repair of the screwdriver gearbox can be considered complete.
Keyless chuck repair
To begin repairing this unit, you must first remove the chuck from the screwdriver. To do this, complete disassembly of the screwdriver is not required. How to unscrew the quick-release chuck was described above.
Frequent chuck malfunctions include incomplete exit of one of the jaws, as shown in the following photo.
The cause of the malfunction may be a worn thread on the nut that clamps the cams, or worn teeth on the cams themselves. To verify this, you will need to disassemble the cartridge.
Disassembling and repairing the screwdriver chuck is done as follows.
- It is necessary to hit the part protruding in its center with a hammer. In order not to deform this part, you can lay a small piece of wood.
- Separating the top will not be sufficient and further disassembly of the cartridge will be required. To do this, you need to lightly clamp the bolt into your fists and hit it with a hammer.
- When the inside of the cartridge falls out, its disassembly is considered complete. You will see a nut consisting of 2 halves. Most often, malfunctions in the cartridge occur due to this part. The thread on it wears out and the cams slip when tightened. Therefore, incorrect alignment of the latter occurs.
Also, the threads can be worn out on the cams, which, like the nut, need to be replaced. But if you do not find the necessary parts to change them, you will need to completely replace the cartridge. When assembling the cartridge, the cams must be installed at the same level, in a compressed state, after which a nut consisting of 2 halves is put on, and after that the entire structure is placed in the housing. When the problem is fixed, you can assemble the screwdriver.
In practice, finding spare parts for a cartridge is a troublesome task. It’s easier to buy a new chuck, since its price is not so high, around 300 rubles.
A screwdriver belongs to the category of tools that are often used not only in construction and repair work, but also in everyday life. Over time, any mechanism tends to break down, which happens with screwdrivers. If such a thing happens, then there is no need to rush to throw away the tool, since you can repair the screwdriver yourself. From this article you will learn how to repair a screwdriver without the help of specialists.
Specifications
The described Interskol cordless screwdriver has outstanding technical characteristics. For example, the battery capacity is 1.5 Ah. The maximum diameter of the screw used is 6 mm. The spindle rotation speed per minute can vary from 0 to 1100 revolutions.
The cartridge dimensions reach 10 mm. The kit comes with two batteries. Charging time is 1 hour. The device weighs 1.9 kg. It does not have a spindle lock function. Having considered the characteristics of the Interskol screwdriver, you may be inclined to choose another model, because this one does not have a backlight. The battery used is nickel-cadmium.
Reviews about the model
Before making your final choice, experts recommend reading reviews. As for the above-described model, it has many advantages, for example, it is capable of working in any mode, has a thoughtful design, and provides a quick change of nozzle. The kit comes with a fairly powerful battery.
You can take advantage of two stages of spindle rotation. At the first speed, the speed can reach 400 per minute, at the second - 1100 per minute. By reading the review of the Interskol screwdriver, you can find out that on a cordless drill you can set 1 of 16 torque options. You can also use the drilling mode, which will depend on the task being performed. The design of the case is well thought out; it has a special compartment where you can store additional attachments.
Operating principle and main components
Before you start repairing a screwdriver with your own hands, you need to understand the principle of its operation and what parts it consists of. The main difference between a screwdriver and other power tools is the use of a mechanism that stops the rotation of the working part of the device. This happens when the maximum resistance configured for the instrument is reached. This value is not constant and can be adjusted. There are two types of device:
- operating from a 220 volt network;
- using a rechargeable battery.
Regardless of the type of device, their operating principle is the same and is based on the transmission of torque. It determines which fastening tool the screwdriver can tighten. To increase torque, devices use gearboxes with a large gear ratio, but the rotation speed is reduced. For screwdrivers operating on AC power, the torque value is related to the power consumption of the tool. The main parts underlying the device of a screwdriver, be it Makita, Hitachi or Bison, are as follows:
- electric motor;
- push button;
- speed controller with reverse;
- chuck;
- the electronic unit;
- gearbox
The electric motor rotates the spindle at a set speed using a planetary gearbox. The torque is controlled by a clutch, and a chuck or hex holder is placed on the spindle. A replaceable device called a “bit” is installed in this cartridge. The screwdriver is controlled by an electronic circuit and reverse switching .
Reverse occurs by changing the polarity of the power supply. The motor is a single-phase continuous current commutator motor. This motor is designed to be connected to an alternating current network. The field winding is connected in series with the armature winding and is divided into two parts. One turns on before the anchor, and the other after it.
The tool uses a planetary type gearbox. The gearbox includes sun and ring gears, satellites, and carrier. The electric motor shaft rotates the sun gear, which transmits torque to the satellites, and they directly affect the carrier.
The gearbox is available in one- and two-stage types. In the second case, a double carrier connected to the shaft is used. The design of two carriers and satellites is located in the middle of the ring gear. It is fixed through special grooves on the body. Along the entire perimeter, the lugs of the ring gear rest against spring-loaded balls through the ring. The load control mechanism acts on the ring through a controlled spring, the force of which is changed by moving the regulator.
Speed control is performed using a pulse circuit assembled on a pulse-width modulation (PWM) chip. The controller controls a field-effect transistor operating in switch mode. The pulse frequency is changed using a variable resistor. The resistance value of the resistor depends on the force applied to the button.
The screwdriver clutch is a ratchet. If the load on the cartridge exceeds the permissible value, the load regulator is activated. The spring force becomes insufficient to hold the ring gear, and it comes off the balls. The electric motor begins to rotate the gear idle. When switching to electric drill mode, this gear is turned off and does not participate in the work .
A rechargeable battery with a voltage of 12 V or 18 V is most often used as a power source. It characterizes the power of the device.
The battery consists of several elements installed in one housing and connected in series. The case has a special latch that allows you to quickly remove the battery.
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Review of network model DSh-10/320E2 220.1.1.00
If you are thinking about the best Interskol screwdriver to choose, you should also consider network models that are not tied to operating time. You don't have to keep an eye on the battery charge indicator without fear that the charge will run out before you finish working.
The Interskol corded screwdriver mentioned in the subtitle will cost the consumer 2,900 rubles. It is used for drilling holes and driving as well as loosening screws and screws. Using a torque control clutch, you can set the tightening torque for a specific material.
Specifications
The power of the above model is 320 W. The maximum diameter of the screw used is 6 mm. The diameter of the cartridge used is 10 mm. This model does not have a function for adjusting the screw depth. The equipment weighs 1.4 kg. You can make holes in wood and metal with a maximum diameter of 25 and 10 mm, respectively.
The overall dimensions of this Interskol corded screwdriver are 250 x 70 x 200 mm. The models have reverse. The spindle rotation speed per minute can vary from 0 to 1800 revolutions. The size of the cartridge used is within the range of 0.8 to 10 mm. Before purchasing the model described, you should evaluate whether you need a backlight, a shock function, and how much torque you need. The equipment does not have the first two options, but the torque is 35 Nm.
Reviews about the model
Reviews of the Interskol screwdriver, which was described above, say that this model has many advantages. Firstly, it ensures quick replacement of equipment. Secondly, according to consumers, the equipment is universal. Thirdly, it is convenient to use. According to home craftsmen, the brushes are easy to access.
Reviews about the Interskol screwdriver will allow you to make the right choice. After reading them, you can find out that among the additional benefits:
- reverse;
- quite impressive operating temperature range;
- presence of a two-speed gearbox.
Cost of spare parts
No matter how high-quality the equipment is, over time it will require replacement of some components. Because of this, you should know their cost. For example, a speed switch key costs the consumer 10 rubles. The spring is also inexpensive - 12 rubles. But the locking spring will cost 18 rubles.
The engine will cost more, it costs 790 rubles. and has a counter gear. You can purchase the gearbox for 1600 rubles. It is better to purchase spare parts for the Interskol screwdriver from the manufacturer. This way you can ensure longer operation of the tool.
Disassembling the Interskol screwdriver
During operation, the Interskol DA 18 ER screwdriver sometimes breaks. This may be due to the failure of various electrical elements or wear and tear of the main mechanical components. Therefore, to identify the cause of the breakdown and eliminate it, the faulty tool is fully charged.
The Interskol DA 18ER screwdriver is disassembled. in the following order:
- The battery is disconnected.
- The cartridge is removed from the spring, after which the rotary cone is removed. This must be done carefully so that the balls do not get lost.
- The screws connecting the two parts of the case are unscrewed.
- The start button is disconnected.
- The speed switch is removed.
- The adjusting sleeve is removed.
- The electric motor is disconnected. If the malfunction is related to the electrical part, then the battery and motor are checked. If the gearbox malfunctions, the disassembly process continues.
- The shift bracket is removed.
- The guide is dismantled and the gearbox itself is disassembled.
To disassemble the gearbox screwdriver Interskol DA 18ER you need to:
- The iron plate is snapped out and the elements of the first stage are taken out.
- The connecting bolts are unscrewed, after which the gearbox is divided into 2 parts.
- The second stage gears are removed from the housing.
- The condition of all parts is assessed for the presence of defects, after which they are eliminated or the entire assembly is replaced.
- After completing the repair work, the screwdriver is assembled.
