Grinder or ushm: what is it, types, explanation and how to choose

To make a grinder from a drill, you first need to decide on the power of the tool, that is, figure out what kind of metal you are going to cut. Of course, this option is far from the best for regular use, but if you need to go to any site to perform small work, then such a universal tool can easily fit in a bag or backpack. Based on this, we can come to the conclusion: it is possible to make an angle grinder out of a drill, but only for use in special cases.

The shaft for the disk is clamped in the chuck and if you remove it, you will be left with a full-fledged screw Source tehnika.expert

Bulgarian or ushm decoding and what it is

Among both home tools and at any enterprise there is almost always an angle grinder, meaning an angle grinder. The second, more common name is “grinder”.

The grinder is intended for cutting and cleaning surfaces made of metal, concrete, tiles, bricks and other hard materials, and sanding wood. Areas of application: construction, home renovation, mechanical engineering and metalworking, automotive services. There are cases when experienced specialists can work with it for purposes other than its intended purpose - cutting boards or slate, but in terms of safety precautions such work is not reliable. Grinding and metal cutting work is optimal.

The low cost, good maintainability, high versatility and wide capabilities of the angle grinder have made it one of the most common tools.

Why is the tool called an angle grinder?

An angle grinder is an angle grinder; the working force is applied at an angle to the body. The name “angular” is based on the design of the device: the entire device is placed in a housing, the working element of which extends at a right angle. This is the difference from straight grinding.

The angle connection imposes some limitations on functionality, so the straight grinder is more versatile. The grinder can only perform cutting, grinding and creating a polished surface; her colleague can also perform drilling and engraving.

The body is cylindrical and contains an electric motor. The motor shaft is connected to the working axis through a gear drive. The output torque is directly dependent on the power and diameter of the disk.

The external design consists of a handle with control buttons on the body itself and a screw-on handle for holding, as well as a power cord. The handle is screwed into the head of the tool without additional devices.

Package

For review, I chose a 400 Watt mini drill + flexible shaft. It was packaged in two different bags, but wrapped with courier tape and collected in one parcel.

The mini-drill was additionally packaged in a plastic bag with air sections.

Lesser known names of ushm

There are other names for angle grinders.

The device was invented in Germany back in the 1920s. Years later, in 1954, the same inventors released production samples.

The unofficial “grinder” came into use after its appearance in the USSR in the early 1970s. Then in Bulgaria they began to produce devices that were supplied to neighbors for construction work. By the way, nowhere in the world except in the countries of the former USSR is this word used in relation to the Bulgarian. In our country it is also called as follows:

1. “monkey” - there were rumors among working people that constant use of the machine lengthens the arms and makes a person look like this animal - as a result, the joke was almost forgotten;
2. “turbine” - the sound produced by an angle grinder is very similar to that produced by a real turbine or car;
3. “Fortune” - when the first manual machines with this name appeared in the USSR. The working masses appreciated their convenience, the name became a household word.

Types of grinders (ushm)

There are a whole range of varieties and types of grinders. Some are better suited for certain conditions, while some can do more than just cut metal, and the technical characteristics can vary greatly. There are varieties that are strictly connected to a compressed air network, and there are mobile ones - battery-powered or motorized (options such as moto are not shown - they are too exotic). For the job, you can choose a powerful saw or even a long drill. The main types and types can be identified as follows.

Mini grinder

The small (mini) grinder is a small version with a light weight. Its distinctive features are work with a circle with a diameter of up to 125 mm and the absence of a side handle.

The main purpose is operations in confined spaces and hard-to-reach places. The low weight does not tire the hand, so working with the mini machine lasts longer and is more efficient.

Due to the low power (up to 1 kW), the number of revolutions is not significant, so the design does not have a gearbox. Thanks to this same feature, the vibration is weak, so the work is more accurate. This makes it easy to polish.

The functionality of the machine is enhanced by the fact that the body itself is a handle: by setting the button to permanent operation, you can very easily grind surfaces and simultaneously hold or perform related operations. Due to its small size, it is convenient to perform gating at a considerable height.

Big grinder

The large grinder is a regular version with dimensions and power that allow you to work with a circle with a diameter of up to 230 mm and requires two-handed operation.

The most common type, equipped with a protective shield, a side handle (installation in several positions is possible) and requires removal of the working disk with a special key. The work is done in the largest circles. Therefore, depending on the manufacturer and configuration, there may be built-in speed control, and the gearbox is made of durable materials. Power is supplied from the general power supply, so when choosing, you should pay attention to the length of the cord. Regardless of power supply, cutting with water supply is possible. There are also vacuum cleaners for grinders.

Unlike the small one, it is often used as a wall chaser. High power when cutting allows you to quickly obtain a high-quality result - the grooves will be even. However, it should be borne in mind that the mass of the tool can be considerable, so it will not be easy to ditch at high altitudes. As for the diameter of the circle, with its large size, cutting the wall can stop in front of the inner corner near the floor.

When cutting rolled products with such a powerful machine, it is optimal to place the metal in a stand - on racks or in a miter box.

Wireless grinder

The wireless one is powered by a battery, so its dimensions and weight speak for themselves. Working with such a machine has maximum mobility and does not require meters of extension cord.

The working part is not fundamentally different from the usual one, but the rear part is significantly different: there are connectors for attaching and connecting the battery. The kit fits into a case.

There are also changes in the motor: power from the mains is suitable for an AC motor, and the battery motor is suitable for DC. The difference is in power; a DC motor produces less power for an angle grinder.

In this regard, the purpose of a cordless machine is the accuracy of the operation performed. It is most effective to accurately and quickly cut fairly durable materials - from granite to cast iron (even such small models are enough to cut a cast iron battery). Portability makes it best for car repairs.

Grinder straight

A straight angle grinder is different in appearance: the working body is a continuation of the body, usually there is no additional handle. The work can be done with one hand. The second hand is used to correct or hold material, or to stay in space under difficult conditions.

Its purpose is to work in hard-to-reach and miniature places and an extended list of operations. For this purpose, an extension cord or an adapter for an angle grinder is supplied in the kit or separately.

The design is convenient for polishing work. To treat the surface, you can use not only discs, but also cylindrical and conical nozzles of abrasive and petal types (to remove the height of the concrete floor in the corners), drills (this way you get a grinder-drill). Adapters are available for attachments. The end installation of the circle is convenient in its own way.

The number of revolutions per minute is up to 30,000 thousand. Usually a soft start system and overload protection are installed.

Ushm pneumatic

The operation of a pneumatic angle grinder is based on the supply of air under pressure to the working part. To do this, connect to the compressed air system - there is a special connector for this purpose.

The compressed air is started by pressing the trigger. After entering the internal cavity of the machine, the air spins the rotor, which in turn, through the gearbox, creates rotation of the working circles.

Like other options, the pneumatic angle grinder comes with a protective shield and an additional handle. Compared to others, it has a longer service life and quite high power. Such a tool can be used in a polluted environment. The housing is sealed and durable due to pressure work.

However, due to air escaping from the case, it is often impossible to work without dust. However, it is possible to install a dust removal system (as on other models). Polishing is often done to prevent too much dust. And the air suspension accelerates from the supply hose.

Brushless grinder

Like any other electrical device, an angle grinder includes such an element as brushes - removable sliding-type electrical contacts. The design of the brushes is developed, but quite unified (although each manufacturer produces their own).

As a mechanical element operating under dynamic conditions with constant friction, brushes often fail. The brushless motor is the next step in the development of electrical engineering. It requires less repair due to the absence of brushes, makes less noise and does not produce sparks. This allows us to consider this model more fireproof. A brushless angle grinder works quietly in very dusty air - it has no equal in repairs and construction. The question is how to grind a concrete floor (if it is not possible to install a dust extractor).

The price is a little more expensive than the classic model, but the advantages outweigh the cost of regularly replacing the brushes.

Editor's Choice

Makita GA5030 (from 3.4 thousand rubles)

Makita GA5030.
Photo: yandex.market.ru The device is in great demand, and you can find it on the shelves of most large hardware stores and equipment centers. Manufacturer from Japan, but production is in China. Sometimes there are models from Romania. Famous for its mid-price instruments. Largely thanks to its good price, it managed to win the lion's share of the market. This angle grinder is used for cleaning and grinding surfaces, as well as cutting various parts and materials. The 720 W engine here is not a record figure, but in everyday life and when renovating a house it will cut off anything. There is a side handle - an essential attribute for precision work. The diameter of the case can safely be called compact. There is a spindle lock - when you press a button, the mechanism stops and the disk can be replaced without disconnecting the device from the network. The manufacturer has added a lock for the power button, which means that there is no need to constantly squeeze it during operation. The advantages include a bearing protection system to prevent construction waste from becoming clogged, and double insulation of the housing for the sake of safety.

Characteristics:

Advantages and disadvantages:

Compact design that can be held with one hand

To change the position of the casing you need a screwdriver

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Bort BWS-905-R (from 2.2 thousand rubles)

Bort BWS-905-R. Photo: yandex.market.ru

Despite the fairly affordable price of this grinder for the home, it has a lever for adjusting the rotation speed. In 2022, manufacturers of more expensive models often save on this function, but the German company did not skimp on the additional mechanism. The angle grinder differs from its competitors in its thin body - only 19 centimeters. In reviews, buyers praise the device for this characteristic. It weighs a little less than two kilograms and, compared to others, seems like fluff. Like other sanders of this class, it will take wood, ceramics and metal. The main thing is to choose a disk. Among the advantages, we highlight the spindle lock for high-speed changing of equipment, a comfortable grip and a casing to protect the operator. However, it is still better to wear glasses. By the way, unlike the previous participant in our best rating, here the casing is adjustable without a key. There are several ventilation holes on the case, through which heat is dissipated. Judging by the reviews, the thing is necessary, but not completely improved, because there are many complaints about overheating during prolonged work. The declared power of 900 W is a decent indicator.

Characteristics:

Advantages and disadvantages:

Lightweight and powerful grinder

Heats up during continuous operation for 10-15 minutes

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Sturm! AG9012TE (from 2.4 thousand rubles)

Sturm! AG9012TE. Photo: yandex.market.ru

For some reason, angle grinder manufacturers fell in love with the sea green color, so our rating again includes a device in this range. This time from another German tool manufacturer. The sample has all the qualities of a good grinder: quick change of discs due to the locking mechanism, an additional handle, which can also be located on the left and right. By the way, you can insert a marking tool into it, the so-called scriber. You'll have to buy it separately though. You can lock the power button so you don't have to hold your finger on it. The mechanism includes integrated units that are responsible for a smooth start - an important nuance for angle grinders, which was not previously presented in the mentioned samples. The electronic components of this device are generally praised: in case of abnormal operating situations, it will simply turn off and then calmly resume operation. The RPM is adjustable to suit different materials. The casing rotates with the wave of your fingers, without the need to use a screwdriver.

Characteristics:

Advantages and disadvantages:

Sophisticated electrical “filling”

The wire is short and stiff

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How to choose an angle grinder or an angle grinder

To select the right angle grinder, you should consider the following parameters and capabilities:

1. Power - it all depends on the scope of application: for home a range from 600 to 900 W will be enough, for professionals 1500 W is optimal;
2. A smooth start will eliminate jerks when starting, which is good when continuing to work in the old cut, and your hands will get less tired;
3. Speed ​​in revolutions: the ideal option is with a speed setting, but for fixed revolutions up to 12,000 per minute is enough for disk diameters up to 125 mm and up to 7,000 for 180 mm; It is important to remember that circles of different diameters move at different angular speeds at the same rotation speed - there is a limit at which the destruction of the disk begins (usually 80 m/s), so it is impossible to install a circle that is too large on a small model;
4. The presence of a side handle with installation in different positions;
5. The locking button will help with long-term work (such as stripping);
6. The presence of dust protection (when working with dust-emitting materials, the closed gearbox and varnish coating of the stator with the rotor are useful), a dust removal system (when working with concrete, an angle grinder with a vacuum cleaner helps, for which there may be a connection point);
7. The ability to replace a disk without a key speaks for itself if you have to use it often;
8. Operating mode - the break period plays a role due to the need for the angle grinder to cool down under heavy load or long-term operation (if the housing or gearbox overheats, it may fail).

Step-by-step assembly and selection of parts

So, if you are planning to make a grinder out of a drill, then decide what you intend to cut, that is, will it be sheet metal or fittings, and how thick will they be? For a steel rod, if this is, of course, one-time cutting work, the power of a cordless drill (screwdriver) is quite sufficient, as shown in the top photo. Only for thick metal - from one millimeter or more, you will need a corded drill with a power of at least 700-750 W. The fact is that a corded power tool has a more powerful motor than a screwdriver and with the latter it will be difficult for you to even cut off the fiftieth corner.

If we talk about a screwdriver, then a drill-grinder will cause problems here not only because it has a low-speed engine, but also because the battery will discharge very quickly under heavy loads. The best batteries from models such as Makita or Bosch are also not a panacea for long-term use. For example, if a Makita can be used in normal mode on site without recharging for a whole day, then as an angle grinder it will last no more than a couple of hours. But it’s up to you to decide, and we’ll talk about the device for fixing the saw blade.