Choosing a grinder To make a choice, you need to clearly understand the purpose of each type of grinder. At first glance, the principle of operation of grinders is the same
Surface Grinders (Vibratory)
These machines have a mass of 1 to 3 kg, are equipped with a rectangular sole with a clamping mechanism along the edges, which fixes the sanding paper. There are models with the ability to fix the rig to the sole with Velcro.
The sole performs reciprocating movements in an annular orbit, due to this, grinding or polishing is carried out. The power of the electric motor of this tool is from 150 to 600 W. The sole is of two types: standard 100 X 200 mm, and mini miniature options with a base of about 100 X 100 mm.
The choice here is simple: mini surface grinders are suitable for narrow spaces, they are lighter and more maneuverable than standard ones.
Designed for delicate processing of large flat surfaces. They occupy an intermediate place in the cleanliness of processing parts between belt and eccentric ones. With the help of a surface grinder, they carry out finishing grinding of various surfaces: wood, plastic, stone.
Advantages: the ability to grind and polish inside corners, the availability of consumables and the reasonable cost of the grinder itself.
Disadvantages: high noise relative to orbital.
For belt sanders, the equipment, an abrasive belt glued in the form of an endless ring, moves in one direction along two end rollers, one is leading, the second rotates freely. Linear grinding and high speed of movement of the abrasive provides high productivity, but at the same time requires increased control over the grinding process. LShM weigh up to 7 kg, and the power of the electric motor varies from 500 to 1500 W.
The three main standards of belt sanders are distinguished by the length of the sanding belt: 457 mm, 533 mm, 610 mm.
Belt sanders are suitable for rough sanding of surfaces made of wood, metal, plastic, mineral building materials. Often used when removing old paint or varnish, leveling putty. Due to its high productivity, large quantities of material are quickly removed, and in combination with coarse grit, the belt sander can function as an electric planer. The quality of grinding is not the best indicator of this tool, often pits and scratches appear during processing. Effective for sanding glued panels and processing convex parts. There are models with the ability to work upside down, stationary.
This tool is not suitable for delicate sanding and requires special control during work. It can leave indentations in the material and due to the specifics of the sole, belt sanders do not grind in the corners. High noise level and frequent clogging of the dust extractor are disadvantages of this tool.
Eccentric sander (orbital)
Eccentric sanders are considered the most effective and versatile tool for polishing and sanding surfaces. In industrial production and in private use, they show the best results in terms of surface quality.
Polishing and sanding is possible thanks to the combination of rotational and eccentric movements of the sole. The sole rotates in an orbit and simultaneously rolls around its axis. This complex movement of the abrasive allows for efficient grinding with a minimum of disadvantages.
The machine weighing from 1 to 3 kg is equipped with a round sole with Velcro, to which an abrasive wheel on a felt basis is attached. The soles come in two sizes: 125 and 150 mm. Machines with 125 mm sole are lighter, designed for a smaller area and for more delicate work than sanders with 150 mm sole. Electric motors consume from 200 to 900 W and high power provides high performance.
When installing the equipment, it is important that the holes on the sole of the grinder coincide with the holes of the abrasive wheel, otherwise the process of dust removal will be difficult.
They are used for coarse or delicate sanding on large surfaces, for interlayer processing of materials and coatings, for polishing, processing large surfaces along and across the fibers. Often this type of machine is used in carpentry and car painters. With the help of ESM, volumetric, profile and curved surfaces are processed. Working with an eccentric sander is unlikely to spoil the workpiece: grind, burn the material or overdo it with the grinding depth. The noise and vibration levels are lower than other types of grinders.
The disadvantages are obvious: eccentric machines are not suitable for processing internal corners and recesses. Low performance compared to belt sanders.
Additional functions of angle grinder
Let’s talk about the controls of the angle grinder. It is important to know about them for those who strive for convenient and comfortable work, choosing a tool for themselves.
- The soft start allows the tool to be started without jerking by slowly increasing the voltage to the motor. The disc spins in a measured way, reducing gear wear.
- By adjusting the speed. Variable speed angle grinder allows you to set the speed of rotation of the cutting disc or grinding attachment.
- The automatic disk balancing system will keep the required number of revolutions during the load.
- An additional handle is needed for convenience and holding the tool.
What other design possibilities are there?
The following additional functions are also distinguished, the presence of which is due to the price of the instrument.
- Keyed or keyless spindle. The latter is found on professional angle grinders. Removable by hand, without tools.
- Adjustment of the protective casing for budget models is carried out using a screwdriver or hexagon. In more expensive models, manufacturers install a button under the casing.
- Some angle grinders have speed control.
- Overload protection system that reacts to temperature, turning off the power at 180-200 degrees.
- Anti-jamming protection that turns off the motor almost instantly.
- The anti-vibration system is installed not only on the handles, but also in the case of two-handed models. It is necessary to reduce vibration and stress on the hands.
- Protection against unintentional activation of the angle grinder.
- Dust protection in the form of a casing to which a vacuum cleaner can be connected.
- The cordless angle grinder is weaker in cutting speed than the mains-powered angle grinder. Equipped with replaceable batteries. Cordless angle grinders are used for auxiliary and minor work: mount something on site, cut a pipe, corner, etc.
How to choose an angle grinder for your home? Household angle grinder
Angle grinder or angle grinder is a kind of power grinding tools. Unlike its counterparts, the axis of the cutting disc is directed at an angle of 90 degrees to the engine.
The principle of operation consists in transferring the rotational speed from the engine to the driving spindle, on which the cutting or grinding disc is installed.
Due to its wide possibilities, it has gained immense popularity in construction. A large selection of consumables allows you to use the angle grinder for cutting and grinding metal, concrete, brick, stone, wood and plastic.
Grinder: vibrating or eccentric
To get a flat and perfectly smooth surface when sanding, I always recommend that craftsmen use two sanders. One for the primary, rough roughing, the other for the final cleaning.
If everything is clear with the primary processing. Here you need to take a belt sander, then when bringing the surface to perfection, you can use one of two types:
- Vibrating (another name is surface grinding, or abbreviated. PShM);
- Eccentric (ESM, another name for orbital).
Both are designed for sanding substrates at completion. Which of these machines is better in which situation. Vibration or eccentric sander? I’ll cover it today in this article.
You will find out what their main differences are, how their design determines the capabilities of each device, what are their strengths and weaknesses.
The information provided will give you the necessary knowledge on how to grind surfaces of different shapes using these aggregates, and which one is more suitable for you.
Pay attention to the parameters when choosing a grinder
It should be noted that both of these grinders mostly perform finishing work and if you have the task of performing work on a large scale, then the wrong choice will bring you not only monetary losses, but also wasted time.
Vibratory or eccentric grinders can be of different purposes:
- For household use;
- Professional scope.
When choosing a grinder, you should pay attention to the following technical characteristics:
- Platform stroke amplitude. This is one of the main characteristics of grinders. Average vibration value. 2-3 mm. The higher the amplitude, the higher the performance of the grinder, but the grinding becomes much coarser. That is, if you need a grinder for primary processing, pay attention to models with a high amplitude. For the finishing one. On the contrary, machines with an amplitude of 2 mm or less;
- Sole size. PSHM and ESHM soles come in different sizes and shapes, although there are generally accepted standards. For eccentric diameter 122 and 150 mm, for PShM 187×90, 115×230, 114×105 mm. Models with small soles will help when working in hard-to-reach places;
- Speed control. Thanks to this function, you can customize the operation of the machine. Initial or finishing, as well as choose the optimal speed for grinding a particular material. For example, if we are sanding soft wood or plywood, then it is recommended to choose medium speed, and if we are sanding hard wood. High;
- Power. The power consumption of the machines can range from 130 to 900 watts. But, as a rule, for most jobs, a power of 200-300 W is quite enough, because such models are light and compact, conveniently controlled, and work with them is more comfortable;
- Attachment of sanding paper. For a surface grinder, manufacturers have provided 2 types of fastening: a clip (similar to a regular latch with a spring, which is on most household-grade grinders) and Velcro (with less of a hassle, since you do not have to cut the paper, it has a standard size, but the cost of such machines , like the consumable, above).
- Additional handle. For PSHM and ESHM, the additional handle is either cast or removable. If it is removable, it reduces the size of the device and allows you to work with the tool in one hand. This is useful when sanding small parts.
Structural difference between the two machines
Both machines are capable of delicately sanding the surface with emery cloths. In fact, they do the same job, but there is a difference between them. They differ in both form and principle of operation. The FSHM surface is often rectangular (but it can be deltoid and square). And the eccentric one. The sole is round. Therefore, depending on the complexity of the grinding work and the shape of the workpieces, you choose a machine with a comfortable sole shape. For example, steps or shelves are easily sanded with PSHM, thanks to the angular sole, you can reach any corner.
The eccentric machine is used for working with both flat surfaces and radii, as well as wood parts of various shapes. Orbital and eccentric sanders are used in construction workshops, in car services they perform not only finishing work for grinding wood, but are also convenient for all kinds of finishing work. But still, their main purpose is to ideally prepare the surface for painting or to give the details the required shape.
In fact, these are two identical instruments, however, there is some difference. The surface grinder (vibration) grinder will cope with any surface: wood, plastic, metal, walls (drywall). But she does it a little roughly, unlike ESM. In turn, the orbital sander will perform this entire list of work more delicately due to the fact that it has an additional rotation function, which helps to hide the traces of grinding.
Which sander is best for wood
There are several types of wood sanders. The design and principle of operation determine their purpose and the ability to perform certain types of work.
- Belt sanders are designed for rough sanding and fitting of parts. Surface treatment takes place with an abrasive belt stretched over rotating shafts.
- Vibration (surface grinders) machines. They have a flat sole, often of a rectangular shape, to which a sheet of abrasive material is attached. Suitable for large flat surfaces.
- Vibrating with deltoid sole. Vibration type angle grinders. They are used to work in hard-to-reach places and to process parts with complex configurations.
- Eccentric (orbital) grinders. They have a round sole with replaceable abrasive pads. Designed for finishing and fine sanding.
- Brush grinders. They differ from the rest in that a brush with metal or synthetic bristles acts as a working consumable. Such a tool is not intended for fine grinding. Its main function is the removal of paintwork and rough surface preparation.
Depending on the type of the proposed work, one or another type of tool is used. Professional craftsmen usually have at least two grinding devices in their arsenal for coarse and fine processing.
Wood floor sanders
This is a separate niche for highly specialized power tools, designed exclusively for working with wooden floors and natural wood flooring. The devices have a specific design that simplifies the processing of large areas. High power provides sufficient performance.
The principle of operation of such machines is similar to manual options for grinding tools. The most commonly used types of equipment are:
- Drum type: the working principle is the same as that of the brush machines. Instead of a cylinder with bristles, a drum with an abrasive belt is used. The device is used mainly for stripping old coatings (scraping) or for preliminary rough grinding and eliminating differences at the joints.
- Belt: differ from the manual version in power and use of a wider blade. They cope with both scraping and finishing.
- Disc: grind the surface with an abrasive material attached to one or more rotating discs.
- Eccentric (orbital): the round sole rotates and simultaneously performs back-and-forth movements in the horizontal plane. An emery cloth is used as a consumable.
- Vibrating: devices with a flat working sole of a rectangular shape. The mechanics are driven by a vibration drive or a motor with an eccentric attached to the shaft. In this case, the sole does not rotate, but makes short horizontal movements with high frequency.
Most of these machines are rather bulky, so all parts and assemblies are located on a movable frame. Power and performance don’t come out of thin air either. These units are powered mainly from the 380 V.
Professional wood sander
Any professional tool differs from a domestic one in that it is capable of withstanding heavy loads and is designed for long-term operation in large volumes. Endurance and reliability depend on quality and specifications.
Models of hand grinders for professional use, depending on the type and purpose, can have a power of over 1000 watts. For example, the average power of orbital-type devices is about 350-450 W. Belt type machines consume from 500 to 1200 watts. There are also more powerful models.
An important indicator for the professional segment is functionality. Some models provide for the use of special equipment: interchangeable soles, guides, attachment devices, etc. This expands the capabilities of the instrument and improves its accuracy.
Equipping with options is typical: smooth speed control, various operating modes, automatic centering of the belt, the presence of a dust collector or the ability to connect to external devices for collecting dust.
All special grinders are professional. A special place is occupied by multifunctional devices. Usually these are small portable machines for grinding and polishing wooden parts.