Long time operations with metal and wood in hard to reach places caused many problems, difficulties and inconsistencies. Acceptable results using traditional methods it didn’t work and the manufacturers went to all kinds of tricks. Exactly their result was the birth of the angle grinder, which Japanese company Makita invented in the late fifties last century. Since then a lot of water has flowed, the angle grinders have bristled new components and assemblies that expand its functionality, however, their principle of operation has remained unchanged. In our country, these devices are well known by another name – grinder.
What are the grinders – types
All on sale models of grinders can be divided into two conditional categories. Conditional – because depending on technical features and applied solutions of a particular model can be attributed to two classes simultaneously:
Compact one-handed angle grinder. They are also often called household, since it is in everyday life that they find their main application. Characterized by the presence of a low power electric motor (up to 1.2-1.5 kW), and use a disk as a working tool diameter up to 150 mm .;
Professional grinders with a two-handed design. Powerful devices designed for long-term routine work. Their power can reach 3 kilowatts, and the diameter installed disk can be 250-300 millimeters. Devices of this class are perfect for working with all without exception, materials and types of surfaces;
The main criteria for choosing a grinder
There are a number of technical nuances that should be addressed. attention when choosing a grinder for specific purposes.
The disc is a removable cutting wheel that is fixed to the stem grinders and makes direct contact with the processed surface. The diameter of the cutting wheel varies from 110 up to 260 millimeters, and the larger the disk, the heavier and more powerful it will be Bulgarian.
We recommend reading the article how to choose a drive for a grinder.
By this parameter, almost always mean power installed on the device of the electric motor, and with it – the functionality of a particular grinder. Available for sale meet a large number of different patterns – starting compact low-power models (300-400 W) and ending power professional machines whose power exceeds the above 7-8 times. The more powerful the angle grinder is, the more universal it is, and also the bigger, harder and therefore more expensive.
Disk rotation speed
In this situation, the most direct impact initial diameter of the used disk. Models designed for work with compact discs with a diameter of 110-130 millimeters, can develop up to 10-11 thousand revolutions per minute, while more large machines equipped with larger discs, practically They are never faster than 6.5-7 thousand revolutions per minute. At exceeding this threshold almost always appears parasitic vibrations that lead to the destruction of the disk. The compromise option is the use of angle grinders equipped with the ability to adjust the speed depending on the type installed disk, but almost always such machines are quite expensive.
What functions can be equipped with a angle grinder
The possibility of a smooth start, eliminating the increased load on rotor, and the same smooth braking device – when turned off the power spindle rotates by inertia for some time;
The protective mechanism excluding jamming of a circle during cutting. Measures deviation of angular velocity of rotation of a circle relative to the original option, and if any reaches critical value – the grinder is automatically turned off;
Preventing secondary startup of the device. very useful function that prevents the device from spontaneously starting after of how the voltage in the working network disappeared. To turn on the grinder, you must press the start button again;
Speed controller and speed synchronizer. Quite popular features that significantly expand the range the use of grinders. The first allows you to adjust the speed devices and adjust them to the type of disk used, second serves to maintain sensitively tuned speeds in any mode operation;
Customization of controls. Location, length, stick out, as well as many other settings – all this does work with a grinder as convenient as possible;
Ease of use and weight of the power tool
In order for the grinder to be as comfortable as possible and functional, it is necessary to pay special attention to it weight and size characteristics, as well as such a parameter as balance. The weight of household grinders is almost always limited to the mark 1.5-2 kilograms, while professional models can weigh twice or even three times as much. But even with such a rather big You can use angle grinders with a sufficient degree of comfort. All, what is necessary for this purpose is to adjust the balance of the device so so that during operation she does not outweigh either back.
What nozzles (discs) are the grinders equipped with
As noted above, the main cutting element of any grinder – This is a special high-strength removable disk. It is he in contact with the treated surface and transfers energy electric motor on it. However, universal drives are not exists, and on sale you can find various models suitable to work with a variety of materials. It depends this parameter and you should select one or another disk.
High strength diamond wheels. Used for stone processing, marble, granite, and also for metal cutting.
Brushes – special nozzles, the basis of which is hard metal wire. Used to clean metal from plaque, corrosion and oxides;
Petal circles – special soft disks designed for working with wooden surfaces – like processing and grinding, and for the final stage of processing – polishing.
In the next article, our experts tell you how to choose a hammer drill.
Video of the choice of the grinder
Attention! This material is subjective opinion of the authors of the project and is not a buying guide.