What is a belt sander for?

A grinder is a tool that cannot be dispensed with during the repair of various rooms. With the help of such equipment it is possible to efficiently and quickly grind a variety of surfaces. An eccentric sander is a popular unit in a group of similar devices.


The eccentric grinder is designed to prepare a wide variety of surfaces for coating with varnish, primer or paint.

What is a belt sander for?

Materials that can be processed with this device:

The technique works on the principle of rotation of a circle with two pulses: orbital and radial. Esm makes it possible to polish planes of various degrees of curvature and slope.

There are various types of units, each of which is designed for a certain type of work. For example, a tape machine is not able to polish a plane intended for varnish, and an eccentric machine can do this job without any difficulty.

When choosing a grinding machine (popularly referred to as the “orbiter”), it is important to pay attention to a number of important characteristics.

  • The power of the unit depends on the energy that is consumed.
  • Rotation frequency. The standard speed is 12,000 rpm. However, this indicator can vary from 2,000 to 20,000 rpm. Many devices have electronic stabilization, which reliably controls the number of revolutions.
  • Platform stroke parameter (it ranges from 2 to 7 mm). The lower this indicator, the more accurate the processing will be.
  • Weight. Often it is necessary to work with this device at a height, keeping the device on weight, so the weight of the machine is important.
  • Diameter of discs (115, 125, 150 mm).

Device and principle of operation

Before you start working with an eccentric sander, you should familiarize yourself with how it is arranged, as well as with the modes of its operation. Esms are designed for both coarse and filigree polishing of a wide variety of materials. To do this, the rotating abrasive wheel performs translational and reciprocal circular movements.

A similar tool works on a simple principle: the drive is attached to the base (sole), a removable working circle is mounted on it. The circle rotates and simultaneously oscillates (this impulse is possible due to the presence of an eccentric in the form of an ellipse). The rotation speed can reach 20,000 rpm. With these indicators, using abrasive materials, you can process any materials.

Esm generates increased vibration, so the presence of one or more handles on the instrument often has a decisive value. For small jobs, models with a pistol grip may be the best choice. Such a device has classic parameters and fits comfortably in the palm of your hand. It is especially convenient to work with such ESMs on hard-to-reach elements that are often found in the repair of machines.

The presence of a stopper is of great importance during the operation of the units. It allows you to automatically keep the unit in operation.


When choosing an ESM, you should know exactly its purpose, as well as how often it will be used. If the device is operated once a month (or even less often), then it is wise to purchase an inexpensive grinding machine. In the case of professional use of ESM (for example, for construction), it is recommended to look at more expensive models.

The quality of the machine depends on such indicators:

  • Power;
  • Amplitude;
  • Rotational speed;
  • Machine weight;
  • Source of power;
  • Diameter of a circle nozzle;
  • Rpm
  • Current adjustment, etc.

Esm power is one of the main indicators. Power fluctuates from 165 watts to 950 watts. In everyday life, units are used that have a power of 300 to 600 watts. The machine can be powered by a power plant or from a network of 220 volts. If you have to work at a distance from stationary energy sources, it is better to use the battery option.

On production sites (for walls and ceilings, for work on plaster), a pneumatic eccentric machine is most often used. Such units are easy to use: they have a minimum of dynamic nodes, do not need power from an electric motor or a battery device. One of the best manufacturers of such equipment is Dynabrade, which manufactures Dynorbital machines.

An important point to keep in mind when choosing an ESM is that the rotation speed decreases with increasing unit power. The oscillation amplitude is responsible for the quality of surface treatment. There are models with an amplitude of oscillations from 2 to 5 millimeters. On some models, you can install additional nozzles that will adjust the reciprocating motion. Such additional devices change the dimensions of the “orbit” necessary for grinding.

It is also important to consider the diameter of the grinding “plate” itself: the larger the size, the larger the area you can process in one go. Typically, this figure varies in the range from 120 to 155 mm, however, there are other sizes: 75 mm, 95 mm. Small diameters of the “plates” make it possible to work with corner joints.

Small diameter devices are exclusive products. Such aggregates are produced by only a few companies: Rupes, Metabo.

There are special ESHM horizontal layout engine, which forced rotation is present.

Such machines are designed for combined work, so they are most often used by professional builders.

Esms are classified according to several criteria:

  • Machines with which you can work on wood or metal;
  • Esms that operate from the mains or from batteries;
  • Professional models and devices for domestic use;
  • Miniature units with speed control and large pneumatic ESM.

Esms can make surfaces perfectly smooth. The quality of the “orbitalka” is achieved by using the movement of the dull-rotational nature of the canvas itself. At high speeds (more than 10,000 thousand per minute) there is a large amount of energy that is transmitted to vibration. It is transformed into a power impulse, due to which the polishing process takes place. The eccentric needs a counterweight, which is necessary to smooth out excess vibration.

Consider the most popular manufacturers of ESM.

  • Metabo Company produces inexpensive and compact units.
  • “Boch” produces models of large (more than 650 watts.) and medium power. The company’s products are of good quality and many different additional options (speed adjustment, speed, etc.). This technique is most often acquired by professionals. It is quite expensive, but it is very reliable, and also has a long resource in terms of operation.
  • Eshm from the Makita company in quality they are not inferior to German units from Boch. Devices are ideally suited for work in service stations and garages. Particularly effective on models mounted dust removal system. Each model has its own design features. Some ESMs are equipped with a speed controller (up to 6 positions).

Now let’s look at some of the distinguishing details and features of the devices.

  • Orbiters for professionals are equipped with special relays that control the constant speed during operation. In this case, the torque automatically switches to afterburner mode, while the engine’s reserve power is used.
  • The starting current limitation block is used for several reasons: when it is necessary to reduce the load, and also to avoid crashing when starting the engine. This device is found exclusively on professional models.
  • Sole brake adjustment is necessary for operational stop.
  • A 90% ESM has a bell, which allows you to connect a vacuum cleaner (sometimes a vacuum cleaner replaces a special capacity from a PVC bag or paper bag).
  • A professional tool is often equipped with a casing around the eccentric assembly.
  • D-lever makes it possible to work more comfortably.
  • The switch, in which the latch is present, is most often found in expensive professional models.

It is important to note that the ESM does not have the ability to work in hard-to-reach places, since the sole of the tools has a round configuration (in such cases, a surface grinding unit is used).

Also ESM cannot be installed permanently. This is usually necessary when you need to work with small format products. If there are volumetric depressions or depressions on the workpiece, then the ESM will not penetrate there, there is also the possibility of damage to the edges by the rotating element of the machine.