Cordless drill: how to secure connections

The need to tighten the screws with a hand drill or screwdriver has long since disappeared. Now, in everyday life, a cordless drill-screwdriver becomes an assistant, which is a compact and easy-to-use device. Manufacturers offer models with different specifications. Therefore, to begin with, it is important to determine the basic requirements that the device must meet, and then plan the purchase.

Why choose a cordless screwdriver: the main types of device, operating rules

Before purchasing a product, you must first determine the main goals that need to be solved with a screwdriver in industrial or domestic conditions. The main directions where the tool is used:

• mounting or dismantling of fasteners;
• more reliable tightening of self-tapping screws, dowels, anchors or other elements;
• making holes in soft or hard materials;
• threading;
• preparation of mortars requiring mixing.

A screwdriver in most cases is used to solve several problems at once. Therefore, first you should study the technical characteristics of the screwdriver. Depending on the area of ​​application, the tools are divided into 2 large groups:

• household;
• professional.

A distinctive feature of household tools is low power and a small motor resource. Considered Suitable for Soft Material Handling:

• tree;
• MDF and chipboard;
• drywall.

Important! Household screwdrivers are not intended for continuous use. The main areas of focus are furniture assembly, installation of locks, fixing of shelves, blinds, etc.

A professional tool is designed to last longer than a household tool. So, you can operate the screwdriver every day for 5-8 hours with short breaks and at the same time not be afraid that the device will fail or overheat. The tool is also used for unscrewing / screwing in, while most models are equipped with the function of drilling various materials:

• metal;
• concrete;
• wood.

You need to understand that to work with concrete, you need to purchase impact cordless screwdrivers designed for hard materials.

Which cordless screwdriver is better based on technical characteristics

By the method of receiving power, the devices are divided into 2 groups:

1. Network. They work by connecting to the mains. High efficiency is achieved thanks to constant power. Another advantage is that there is no need to constantly monitor the remaining charge.
2. Rechargeable. They differ in relatively small dimensions, but at a price a cordless screwdriver is more expensive than a network screwdriver, and it is also considered a disadvantage that the device can turn off at any time.

Helpful advice!If you want to figure out which screwdriver is better - cordless or networked, you need to take into account that the first option is mobile, so it can be used without a 220 V network, and the second works only from the outlet power supply.

An important advantage of the cordless screwdriver is that it is powered from a low voltage and does not pose a danger to the user even in the event of a breakdown. When buying, it is important to consider the type and capacity of the battery, because the duration of use without recharging will depend on this.

For convenience, you should also understand the basic concepts. So, a drill is considered a tool equipped with a drilling function. Devices are characterized by the presence of a three-jaw chuck on the spindle, installed in the foreground. It is on the qualities and technical characteristics of this element that the maximum size of the drilled hole and the durability of the device will depend. The presence of the chuck distinguishes drills from other devices, which are equipped only with a hexagonal bore.

A distinctive feature of the screwdriver is an integrated adjustable safety clutch, which is adjusted depending on the required level of fastener tightening. Another important feature is the gearbox's ability to shift gears, which allows for higher axle speed and torque.

Depending on the brand, screwdrivers with a drill function have a large number of differences, which consist in a variety of performance of secondary or main working units.

The best cordless screwdrivers depending on the type of battery used

To understand the question of which is the best cordless screwdriver for home or professional work, you need to familiarize yourself with the features of the battery. The cost of the goods and the durability of the work depend on this criterion. All models of drill / screwdrivers are equipped with one of the types of mobile batteries:

• nickel-cadmium;
• nickel metal hydride;
• lithium ion.

Most modern tools are equipped with lithium-ion rechargeable batteries, since they are characterized by the longest service life and practically have no drawbacks. Lithium batteries, unlike other types of batteries, do not lose energy efficiency at low temperatures.

Despite the large number of advantages, Li-Ion screwdrivers also have certain disadvantages. The main fact is that the maximum operating voltage of one battery cell is within 3.7 V, but for the full use of the engine, a minimum of 10.8 V is required (an indicator equal to 18 V). This leads to the fact that it is necessary to use not one element, but a bunch of 3-4 batteries connected in series.

At first glance, the disadvantage is not considered significant, but in fact, such a connection method can cause uneven charging. This is explained as follows: if one battery takes on a full charge, the rest may stop charging. The problem is that the total battery capacity depends on the least charged element of the entire chain, and this mode of operation has a cumulative effect.

It is interesting! For lithium batteries to charge properly, you need to use chargers that differ in the presence of balancing contacts connected between individual battery cells in intermediate nodes chains.

The best in the rating of screwdrivers models are considered in which a controller is built into the charger, which determines the voltage in each group of batteries. Another advantage of having a controller is that it regulates the strength and voltage of the current, as a result of which, uniform charging of all internal elements is ensured. Tools with lithium batteries will cost more than, for example, tools with a nickel battery.

Nickel Cadmium and Nickel Metal Hydride Batteries: What Voltage Affects

Nickel-cadmium batteries are obsolete, but they are still used in some household screwdrivers today. The main advantages are:

• low cost;
• uninterrupted operation at low temperatures;
• the ability to recover from a complete discharge.

You need to know that an inexpensive cordless screwdriver with a nickel battery will have the following disadvantages:

• large weight and size;
• relative fragility, because the device is designed for 1000 full charge / discharge cycles;
• low specific capacity - up to 2 A / h;
• fast discharge, even in standby mode;
• environmental insecurity of the battery.

Another significant disadvantage of devices with nickel batteries is the presence of the so-called "memory effect". This suggests that the battery can be charged only after a complete discharge, because otherwise the battery capacity will decrease by the amount of underdischarge.

Tools with a NiMH battery do not have some of the disadvantages of the previous version. Firstly, they are less hazardous to the environment, and secondly, they are more compact. The devices do not have a "memory effect", and they are endowed with a sufficient specific capacity. Despite this, the products also have disadvantages:

• fragility, because the battery is designed for only 500 full charge / discharge cycles;
• high cost compared to the nickel-cadmium option;
• difficulties associated with the ability to charge the battery only after 100% discharge.

Nickel-metal hydride batteries are most commonly used in household appliances. Some craftsmen who have learned at home to restore battery performance after passing the maximum number of discharge / charge cycles, they give preference to these batteries.

Checked! Reactivating a nickel-metal hydride battery simply requires soldering a few new cells and then restoring the cell's capacity using smart charging.

Mention should be made of such characteristics as battery voltage. It is generally accepted that the greater this indicator, the higher the torque of the screwdriver and its power. It is important to consider here that some models are presented in the range from 3 to 36 V.

If you compare devices with different voltages, for example, 14 and 18 V, you can pay attention to the fact that they have the same torque is 70 N / m, and the difference is only in the number of elements that make up battery. In a device with an 18-volt battery, there are more such cells, in connection with which the battery capacity increases. This is what affects the cost of the instrument. Thus, before buying, you need to decide whether this characteristic is considered fundamental when choosing a device.

What type of motor can a cordless drill / driver be equipped with: starting system options

The DC motor is the main power element of any cordless screwdriver. Parts are of two types:

• brush;
• brushless.

About 90% of all tools are equipped with permanent magnet brush motors. Such models belong to budget screwdrivers with a simple design. The main disadvantages of this variety are:

• relatively low efficiency;
• lack of the possibility of repair;
• limited resource.

By and large, we can say that brush motors, depending on the manufacturer, can differ in varying degrees of reliability. For example, engine cooling will be better in models that have additional windows on the body. This prevents overheating and damage to the windings. If the device has a split housing, this may indicate the possibility of repair work related to maintenance of bearings and replacement of unusable brushes.

Related article:

Cordless drill / driver: universal device for screwing in and drilling

Features and varieties. Advantages and disadvantages. Tips for choosing. Rating of the best network devices. Safety precautions.

Brushless motors are considered analogous to a full-fledged collector motor, which has a multi-phase power supply. But in this case, the motor has a rather complex design, although more advanced technologies are used in the manufacture of the drive unit itself. In such devices there is a driver - a microcircuit that regulates the power supply of the motor by applying the method of pulse width modulation (PWM). It is thanks to this that the voltage and current are monitored.

It is interesting! The PWM method makes the engine quieter, and the device itself is endowed with greater efficiency. Reliability in this case is determined not by the electrical component, but by the quality of the housing, the high level of machining of the bearing seats.

Advantages and disadvantages of different types of engines

Most often, brushless motors are found in industrial tools, although professional cordless screwdrivers Bosch, Hitachi, Hilty and others can also boast of such a motor. Another positive side of such a device is the smooth control of the rotation speed, which is provided by the electronic circuit.

In the brush motor, the joint operation of a bipolar transistor and a potentiometer built into the "Start" button, allows for a relatively smooth start with no significant current supply when turned on nutrition. If a device with a similar structure will operate at low speeds for a long time, overheating and failure of important nodal elements is possible. Most likely, you will have to change the start button.

In general, we can say that in the brush device, there is constant friction of the elements against the collector contacts, which is why they may wear out within several years after purchase. Other downsides are the constant noise of the collector motor, the likelihood of sparking and the creation of radio interference.

As for the disadvantages of brushless devices, this includes the complex electronic circuit of the microcontroller, which cannot be repaired without the necessary knowledge. Despite the fact that electronic devices are constantly getting cheaper, the cost of a brushless screwdriver still remains 2 times higher than the price of a traditional tool.

What is and why do you need a gearbox in a drill-screwdriver

The gearbox is the most reliable part of the screwdriver and is an advanced, maintenance-free design. It is thanks to this detail that it is possible to change the modes of rotation of the screwdriver shaft. The simplest gearbox is represented by one stage. In this case, the device has a monoblock structure with a motor designed to maintain a speed of 400-600 rpm. The torque in the devices is 20-30 N / m. Such gearboxes are rarely installed in battery models; they are more often used in a power tool.

Two-stage type gearboxes are equipped with an additional gear that allows the screwdriver axis to spin up to 1000-1500 rpm. At the same time, in such devices, the torque is reduced to 10-15 N / m. Do not think that the presence of a speed switch reduces the reliability of the device. The planetary transmission shifts gears using a change of engagement pairs, and an increase in the torque indicator is provided due to the blocking of the carrier, which removes rotation from the clutch ring. For this reason, the gear shifting process is absolutely painless for the gearbox itself.

It is interesting! It is the presence of the second stage that allows you to switch the device to the "drilling" mode, which is considered an integral function for a drill.

There is another type of gearboxes equipped with a third gear, which reduces the rotation speed to 150-200 rpm and increases the torque to the maximum possible. This tool is suitable for screwing in extended blowers and tapping.

The quality of the gearbox is determined by the accessories. Plastic gears are considered by many to be an indicator of an unreliable tool. But this is not at all the case. If the production used high-quality plastic of high density with the application of a special coating, this is considered an advantage, because even under heavy load, overheating does not occur elements. At the same time, the presence of plastic insides allows you to reduce the weight of the device.

What does the torque indicator affect and how it changes depending on the model of the device

If we talk about torque, it is this parameter that characterizes the potential of the electric motor, which directly rotates the chuck shaft. The higher the indicator, the denser the material can be used in work and the easier it will be to tighten the fasteners and unscrew the sour nuts. The amount of torque varies depending on the model:

• household tool for home use - 10-15 N / m;
• professional two- and three-speed devices - 130 N / m;
• semi-professional models - 50-80 N / m.

The torque indicator should be chosen based on the length and size of the fasteners with which you plan to work most often.

For greater safety, the design of the best cordless screwdrivers includes a torque limiter, which is a ring installed immediately after the chuck. In order not to break off the head of the self-tapping screw, as well as in order to preserve the bit, before starting to screw the fasteners, it is necessary to set the required value on the ring. As soon as the device reaches the desired value, the chuck stops on its own, although the engine continues to work at the same time.

Important! If the torque is incorrectly set, not only the head of the fastener can break off, but also it sinks too deep into the surface, which will cause wear of an expensive bit.

The limitation of the indicator is set in steps, and the divisions on the ring correspond to the mode of rotation and force. For cheap household screwdrivers, the number of steps does not exceed 10, and for a professional tool it usually reaches 20.

Important components to watch out for

The ability of a screwdriver to tighten fasteners is due to the presence of a special unit that also regulates the tightening force. Structurally, the element is a friction clutch equipped with parabolic teeth and a certain number of metal balls. The force of pressing the balls to the clutch is controlled by a spring built into the structure.

As already noted, depending on the application, the tool has 10-30 switching steps. However, it will be possible to use the regulator for its intended purpose only if the manual for operation, there is a table in which the position of the coupling is indicated in relation to the current limiting moment.

Important! When using a screwdriver, it must be borne in mind that after a while the edges of the friction clutch wear out, and this, in turn, leads to a decrease in the elasticity of the spring. This wear on the parts distorts the adjustment accuracy of the limiting clutch.

Most screwdrivers are equipped with a three-jaw keyless chuck. If you plan to work with hard material, you should select options where the chuck is made of high quality materials. In inexpensive screwdrivers, the chuck is considered a consumable part that is replaced as the gaskets wear out.

Users tend to prefer chucks with a quick-release coupling, which allows the cam head to be easily removed and replaced with a splined shank tool. This design option allows you to quickly switch from one mode of operation to another, and also minimizes wear on the shaft fit under increased load.

Experts recommend purchasing screwdrivers equipped with a shaft locking function, which allows you to conveniently fix a nozzle with a round tail of any diameter in the chuck. If you plan to work with a variety of materials and tools, it is better to immediately purchase a set of screwdrivers equipped with various additional functions, namely:

1. Reverse. The option is required when dismantling structures. Allows you to effortlessly unscrew the fasteners and get the jammed drill out of the material.
2. Hit. Mandatory function if you intend to work with concrete or brick.
3. Pulse. When this mode is turned on, the device works in jerks, as a result of which the torque increases significantly.
4. Coast brake. It makes it possible to instantly stop the motor after the power button is released, which makes it possible to exclude inertial acceleration of the cartridge.

According to the results conducting tests with a screwdriverexperts note other useful functions of devices:

• built-in backlight;
• charging indicator.

The principle of the best cordless screwdrivers for home and professional work

Cordless drills are most often small and easy-to-use devices. Depending on the manufacturer and model, the tools may differ in design, for example, the handle is often located in different places. The most common option is the handle in the middle of the tool. But for drilling it is more convenient if the handle is slightly offset to the back of the device.

An electric motor, a gearbox, a battery and a chuck are located under the housing. Drills with a brushless motor have a higher efficiency. The principle of operation of a cordless drill looks like this:

• the engine starts, as a result of which the gearbox is activated;
• the rotation of the shaft begins, which drives the chuck with the nozzle.

A toothed wrench is required to install the drill, and the sleeve in the chuck can be tightened by hand without much effort. Before starting work, it is recommended to check the amount of charge in the battery and choose a nozzle suitable for the material. After that, it is necessary to set the operating characteristics of the torque limiter.

Important! All adjustment work should be carried out only when the device is turned off.

Cordless screwdrivers with drill function rating: top brands

It is not necessary to select the most expensive screwdriver for work, because there are a large number of models equipped with the necessary functions, and at the same time they have an acceptable cost. If you want the device to serve for a long time, it is recommended to give preference to trusted manufacturers that produce popular goods. If we turn to the rating of the best cordless screwdrivers, the leading positions are taken by the following companies:

1. Bosch. German company that produces models for household and professional use. Suitable for assembling furniture or installing fasteners, as well as for working in harsh conditions. Designed for active daily use.
2. AEG. Another German company that makes universal tools. Drill drivers are used for making holes of various diameters and for connecting elements with nuts or bolts. The main advantages of German screwdrivers are a high-speed chuck, a well-thought-out cooling system.
3. Makita. Japanese manufacturer producing high quality products. An important distinction of the company is the constant improvement of products. Makita's new cordless screwdrivers are improving with technological innovations.
4. DeWalt. Offers a choice of a large number of devices with different characteristics. All screwdrivers are distinguished by their high working efficiency and high-quality assembly.
5. Metabo. A well-known German manufacturer that produces power tools for even the most difficult construction and repair work. Metabo cordless screwdrivers are characterized by an excellent price-performance ratio.
6. Rioby. American firm offering garden and home tools. Screwdrivers have different power, which allows you to choose the best option for each customer.
7. Blaupunkt. A German representative renowned for its high quality technology.

Cordless screwdriver: which is the best inexpensive device

Inexpensive cordless screwdrivers are considered models costing up to 5 thousand rubles. rubles. It is these options that should be selected as the first working tool for a home or summer cottage. If the device is used occasionally, it will last at least 10 years.

The best inexpensive cordless screwdriver is the PowerMaxx BS 2014 from Metabo. Firstly, the product is lightweight - only 800 grams, which allows using the device with an uncomfortable hand position. Secondly, the tool is equipped with a powerful battery - 2.0 A / h, while the torque reaches 34 N / m. Bits and drills with a hex shank can also be installed in the device. The set includes an additional battery and a spacious suitcase. Of the shortcomings, users note that it is inconvenient to remove the cartridge. The cost of the Metabo cordless screwdriver is 4900 rubles.

The Blaupunkt BPPT-001 screwdriver weighs just over 1 kg and has a lithium-ion battery with a capacity of 1.3 A / h, the voltage of the device is 10.8 V. At idle speed, the maximum rotation speed reaches 1300 rpm. But thanks to the ability to choose one of the 17 presented modes, it will not be difficult to choose the optimal torque. Convenience of work is provided by the built-in backlight. However, you cannot work with a drill with a diameter greater than 10 mm. The cost of the model does not exceed $ 3,000. rubles.

Cordless screwdriver Interskol is characterized by a nickel-cadmium battery with a capacity of 1.5 A / h, its power is 18 V. An extra battery is included to ensure continued operation. A full charge takes place within an hour.

Due to the characteristics of the battery, the DA-13 / 18M3 model is considered the most powerful screwdriver in the budget segment. The torque indicator is 36 N / m. In this case, the device has a significant weight - 1.82 kg. Another disadvantage of the Interskol cordless screwdriver is the short battery life. The device can be operated at low temperatures, and the backlight provides convenient operation in the dark. The twisting force is adjustable in 20 positions, which allows you to adjust the tool to work with different materials. Such a number of positive aspects also affects how much the Interskol screwdriver costs. The price of the device is 5100 rubles.

Good Chinese screwdrivers are also considered inexpensive products, for example, the FIT CD-18CSP model, which is used to perform work on drilling and tightening threaded connections. The device has a high torque (at 28 N / m), which allows you to work with dense and hard materials. Additional ease of use of the Fit screwdriver provides a keyless chuck, which helps to change the equipment in a couple of seconds. Other benefits:

• ergonomic handle;
• two-speed planetary gearbox;
• increased battery capacity;
• backlight;
• torque adjustment;
• electric reverse;
• price - 4700 rubles.

The best professional cordless screwdrivers Bosch, AEG, DeWalt

The word "professional" means that the device is intended for performing serious installation and construction work. The main advantages of the models are considered to be the increased speed (at least 1300 rpm), high torque (more than 50 N / m), the presence of additional functions and built-in elements.

The GSR 180-LI 1.5AH X2 from Bosch, which is characterized by high power characteristics, is distinguished by a good package. According to reviews, the 18 volt cordless screwdriver has a two-speed motor suitable for making holes of different diameters:

• 35 mm - for wood;
• 100 mm - for metal.

Good productivity is ensured by a high torque of 54 N / m. With regard to the shortcomings, it is worth knowing that after six months of intensive operation, many users note the appearance of beating, which affects the accuracy of the hole being made, which is especially critical when working with tree. The price of a Bosch screwdriver 18 volts is 7340 rubles.

The BS 18G2 LI-152C model of the German company AEG, which occupies an honorable place in the rating of professional devices, is characterized by high torque. The first thing that makes the AEG cordless screwdriver stand out is the good torque (50 Nm). The second important advantage is competent ergonomics. A special socket is thought out in the body of the tool, which allows you to always keep the necessary bits at hand.

In order not to increase the weight of the device, experts do not recommend storing more than 2-3 of the most frequently used bits inside. Convenience of work is provided by the keyless chuck, spot illumination and the ability to adjust the torque. The main disadvantages are the large weight (1.8 kg) and the cost, which is more than 10 thousand. rub.

The Dewalt DCD791D2 cordless screwdriver has the highest spindle torque of 70 N / m, which meets the requirements of any professional user. Despite the high performance and increased dimensions of individual units, the device weighs only 1.5 kg, and it can accelerate to 2000 rpm. This allows you to work with viscous and difficult-to-pliable materials. An important advantage of the model is the brushless motor, which provides an increased working life. Cost - 17.6 thousand. rub.

The best Makita cordless screwdrivers of different power

The Makita 6271DWAE cordless drill features a 12-volt motor and a 2 Ah battery. The maximum torque is 30 N / m, while the rotation speed reaches 1300 rpm. Convenience of operation is ensured by electronic speed control. In addition, the tool is additionally equipped with a spindle locking system and a reverse. Other advantages of the Makita cordless drill-driver:

• light weight - 1.5 kg;
• optimal balancing;
• comfortable handle for work in shock mode;
• availability of a spare battery;
• reverse function;
• self-locking shaft.

Among the disadvantages of the Makita 12 volt screwdriver, one can single out a plastic gearbox, a wreath for switching speeds, as well as the high cost of the tool at the level of 8 thousand rubles. rub.

The Makita screwdriver of 14 volts (model BDF343SHE) is equipped with a 1.3 A / h lithium battery. An important advantage of the battery is fast charging within 30 minutes. Maximum torque - 36 N / m, rotation speed - 1300 rpm. The functions of reversing, fixing the shaft and adjusting the speed are available, and among the advantages of a 14 volt screwdriver it is worth noting:

• light weight - 1.2 kg;
• attractive design;
• the ability to work with self-tapping screws 200 mm;
• additional battery included;
• the ability to work on a single charge up to 1.5 hours.

Of the minuses, a certain backlash of the cartridge and the absence of a battery charge level indicator stand out. Some users note that the plastic gearbox breaks down over time.

The Makita 18-volt screwdriver (model 6347DWAE), equipped with a nickel-cadmium battery, has very good reviews. The torque reaches 80 N / m, although the rotation speed does not exceed 1300 rpm. The speed is regulated by an electronic sensor, it is easy to dismantle the structures using the reverse function. The weight of the device is only 1.5 kg. Other advantages of the Makita 18V screwdriver:

• easy replacement of brushes in the engine;
• high torque;
• the presence of two batteries in the kit;
• convenient start button;
• the ability to use the battery for a whole day of work.

A significant disadvantage is that, unlike the 18-volt Makita screwdrivers equipped with lithium batteries, the data batteries have a "memory effect", which, firstly, complicates charging, and secondly, significantly increases the time recharging. In general, the tool is recommended for those who need to work with a large variety of fasteners.

When buying a cordless tool, you should always remember that any, even the most expensive, battery is not designed to last more than 5 years. However, in most cases it is much more convenient to operate the device without a cord. To choose the right model, it is important to determine in advance what the requirements are for a screwdriver and compare the characteristics of similar devices.