Eccentric (orbital) sanders
This type of grinder is designed for high quality processing. Delicate sanding and even polishing is their element, although the performance of such machines can be no less impressive than that of vibrating machines. They will cope with any material, most often you will find ESHM at wood craftsmen, car painters. In work with profile, volumetric, curved objects, eccentric grinders have no equal, they also have no problems with planes. The only place where such a machine will fail is in the corners and shallow recesses. the “plate” simply cannot reach there.
As well as surface grinding units, “orbitals” have an eccentric and a counterweight, with the help of which a circular grinding plate performs not only movement around its axis, but also in an “orbit” with a small amplitude. Interestingly, the axial movement usually occurs by inertia, and in some models, it is forced (by means of a gear transmission. Kress 900 MPS). Such a complex movement of the working blade, coupled with the highest rotation speed, just allows you to get a surface of excellent quality, without grooves, waves and scratches.
From 200 to 900 watts. this is how much the motors of modern ESHM consume. Those that are more powerful, of course, will be more productive, they can easily pull the sole larger, up to 150 mm in diameter (for example, 400-watt Bosch GEX 125-150 AVE or Interskol EShM-150 / 600E).
Bosch GEX 125–150 AVE
Orbital vehicles also have differences in the speed of their translational motion. If we talk about rotation, then this figure can be from 4 to 14 thousand eccentric revolutions per minute for models with adjustment (Metabo SXE 425), and about 12,000 for models without it. If we talk about the concept of “fluctuation”. then these figures will be half. In fact, everything is simple here, the higher the speed, the rougher the processing will be, but the faster you can get the job done.
Metabo SXE 425
The eccentric of orbital machines may not have the same “span”. from 2 to 7 mm (Festool WTS 150/7 E-Plus). This is called the wobble amplitude. The smaller it is, the less vibration the device generates, the more compact the plate goes, the smaller the area we process, but the cleaner the grinding will be. In some ESM, the operator can set a certain amplitude, affecting the productivity and fineness of grinding.
Very nice options include a detachable power cable, an adjustable or detachable front handle, locking the start button, functional dust extraction.
Be sure to pay attention to the type of sanding pad. Firstly, if you need a particularly delicate treatment, do not chase after a large cymbal, by the way, it has a larger dead zone and an amplitude of about 5–7 mm. The slab made of metal is stable, highly durable and has excellent heat dissipation. The resilient saucer works well with curved surfaces. All of them have Velcro for fixing the emery and dust suction holes. These holes from individual manufacturers may be different in size, number and location, on this basis, you need to select the appropriate equipment.
What is the difference between an orbital sander and an eccentric sander
Understanding the types and features
To make a choice, you need to clearly understand the purpose of each type of grinder. At first glance, the principle of operation of grinding machines is the same. grinding the surface of the material using abrasive equipment. In any given task, one type of grinder will show itself brilliantly, while the other will not give the expected result. For example, eccentric machines cannot handle internal corners, but vibrating sanders can do it. Let’s analyze the types of grinders and determine the scope of each of them.
Surface grinding (vibration) machines
If we take into account the cleanliness of the processing of parts, then surface grinders occupy an intermediate position between belt and orbital. With their help, they carry out the finishing grinding of flat surfaces made of a wide variety of materials. plastic, wood, stone, metal. Due to the relatively large working plane, the PSHM is suitable for working with serious quadrature. The secret of the popularity of vibrating grinders lies in their moderate cost, accessibility of tooling elements, as well as in the absence of dead zones of processing (a flat outboard sole easily handles corners).
The main working body of a surface grinder is a plate, which, with a small amplitude, makes frequent reciprocating movements. The motor in such machines is located vertically, which makes it possible, using the “eccentric-counterweight” tandem, to translate the rotational movements of the shaft into translational movements of the platform.
Most vibration grinders traditionally boast a motor with a power of 150-300 W, they are quite maneuverable, moderately light and compact. This level of power plant is almost always sufficient. However, such a consensus among manufacturers would be at least strange. there are models with a capacity of up to 600 W (Makita 9046). They are, of course, heavier and larger, but they can work for a long time without overheating at low speeds.
The most important indicator of the PSHM is the amplitude of the sole stroke. In different models, it can vary, although it is invariably a relatively small value. On average in the class, the platform moves by 1–3 mm, in more mobile models, figures of 5–6 mm may appear (Festool RS 100). A large amplitude helps to sand the surface faster, but this treatment will also be coarser.
Another nuance is the stroke rate of the sole. At high speeds, the machine quickly removes a relatively thicker layer, while at lower speeds it is easier to achieve a precise finish sanding. Some manufacturers make the platform movement frequency variable, exceeding 20,000 strokes per minute (Bosch GSS 280 AE L-BOXX), which allows you to adapt to the processing of various types of materials, to the characteristics of specific surfaces.
Bosch GSS 280 AVE
When choosing a vibratory sander, special attention must be paid to the platform. With its dimensions, everything is quite simple, there are two options: a kind of “standard” and “mini” models. the area of the plate is about 100 mm 2 (Makita BO4557, Sparky MP 250). Toddlers are good for tight, tight spaces. Obviously, the sole must be of high quality, perfectly flat, with clear geometric shapes. Budget cars are equipped with a platform made of steel or high-strength plastic, and more expensive analogs are equipped with cast platforms made of alloys with m aluminum or magnesium (Festool RS 100). A good sole is characterized by accurate balancing, which is easily determined by low vibration when working without load (idle). It is important what the pad is made of, the most suitable option is a porous polymer, it is better than rubber, it “holds” the plane.
Vibrating grinders with a deltoid platform are distinguished into a separate class; they are popularly called “iron” (Hitachi SV12SH, Makita BO4565). Due to their miniature size and good “cross-country ability” they are used for processing objects with small details and complex surfaces, such as furniture, woodwork, elements of stairs, car body. Their triangular platforms are rotatable. you can continue to work with an uneven “eaten” emery petal (Festool Deltex DX 93E) or removable (with a quick installation of another type of platform. for concave / convex surfaces, for structuring, polishing, rubbing).
Festool Deltex DX 93E
Emery can be attached to the site in different ways. It is more convenient when the paper is fixed with Velcro, but special equipment is relatively expensive. The version with spring-loaded clamps is somewhat more complicated, but you can use inexpensive sanding paper, cut with your own hands (you just have to make holes in the right places for dust extraction).
Dealing with fine dust, which inevitably forms when using a sander, poses many challenges for developers. They have to work hard to protect all mechanisms. In this case, a special sealing of the motor, protected bearings and switches, an impermeable housing, a system of channels with a forced dust extraction are used. So that dust is removed from the working area and does not saturate the air, it is sent to a collection bag or filter, in most cases a vacuum cleaner can be connected to the nozzle. this is the most effective method of protection.
Rating of the best models
Summing up the review of the varieties of polishing and grinding equipment, we can confidently say that they are very diverse. Still, there are a number of models that deserve close attention. Among the inexpensive versions, it is worth mentioning the Sturm AG1014P. This device, although marked with the logo of the German brand, is assembled in China. The designers were able to create an excellent mechanism capable of removing dirt and unnecessary coating, as well as artificially aging wood.
An electric motor with a power of 1400 W rotates at a speed of up to 3000 turns per minute. The total weight of the tool is only 3.35 kg. Options for soft start and latching of the start key are provided. The rotational speed in the loaded mode is maintained at a stable level. advanced (professional) option. Bosch GSI 14 CE.
A significant amount of money will need to be paid for the Makita BO6040. With this apparatus, you can remove rust and polish various flat surfaces. BO6040 is considered the ideal option for car paintwork. The determination of the number of vibrations and the rate of rotation of the shaft is carried out using an electronic system. Thanks to the smooth start-up, the processing is carried out in a gentle manner.
- Most modern grinders are equipped with a dust extraction system: a construction vacuum cleaner is connected through a special pipe or there is a dust collection bag in the kit. This makes the work process cleaner, the tool itself is better controlled, and the consumption of abrasive equipment is reduced.
- By the type of power supply, the machines are divided into network and battery. The advantages and disadvantages of cordless sanders are obvious. mobility and independence from the mains, but the operating time is limited by the battery charge.
Above, we inadvertently called the belt sander heavy artillery, in fact, it would be more appropriate to say “tank”. The working element of this highly recognizable tool is an abrasive belt, glued together in the form of an endless ring, which moves along two end rollers and clearly resembles a tracked vehicle track. Such units are relatively powerful, they have a relatively simple, reliable design (bevel gear plus V-belt transmission), a low center of gravity, and a solid speed of movement of the abrasive material. With a belt sander, you can easily remove a layer of material a few millimeters, make an edge or rounding on a workpiece, remove old paintwork or rust. She is subject to: wood, metal, polymers, mineral building materials. Clean the floors from paint. yes, correct the planed timber. please, align the plastered wall with the marriage. no problem. However, it should be understood that high performance is not the best friend of quality, there will certainly be scratches and sinks. For finishing sanding it will be necessary to use an orbital or surface sander.
It is no secret that the power consumption of its motor directly affects the performance of an electric tool. the higher it is, the more we can squeeze out of a particular unit. In the case of LSHM, the consumer has the opportunity to choose from models with a motor from 0.5 to 1.2 kW (Skil Masters 7660MA. 1200 W).
Skil Masters 7660MA
Please note that the instrument of Chinese brands is often declared with overestimated engine power ratings, or, if there are indeed sounded watts, then they are not balanced with the rest of the device’s characteristics. Record power is praised by those manufacturers who have nothing more to show, except perhaps the great weight and bulkiness of the “unique” product.
The next characteristic that is important for a belt sander is speed. Obviously, it also needs to be considered to determine the capabilities of the instrument. A fast car will do more, but you won’t be able to pin it down unless the outstanding speed is backed up by extra power. It’s all to blame for the notorious torque, which says that the more speed the tool has, the less power remains for it. A responsible manufacturer carefully balances these characteristics, makes them mutually mutable, which is sometimes the responsibility of smart electronics. The speed of the belt in these grinders can be in the range of 150-550 meters per minute (Fiolent MShL1-100. 550 m / min.).
The question may arise, why even produce nimble, but relatively weak-powered LSM? It’s just that a super-productive (fast and at the same time strong) car is more difficult to control, it is heavier, larger, more expensive. With excessive pressure, it is easy to spoil the workpiece with it. In turn, maneuverable high-speed light weights are convenient in a short time, often “on site”, to process a large surface area. If you do not yet know what loads await the grinder, choose a slower model that you can apply a little pressure on, so it will be more versatile. Even more versatile are LSMs with the ability to preset the speed mode (Sparky MBS 976, DeWalt DW433). Among them there are options with smooth or step adjustments.
It’s time to say about the electronic systems that help in the work of belt sanders. These machines are not rich in electronic stuffing, compared to other types of electrical tools. This is usually limited to adjusting the belt speed. The switch responsible for this function is performed in the form of a slider or a wheel with divisions. There are models with overheating protection (Metabo BAE 75). With some stretch, this includes the function of fixing the start button in the on position.
Much more interesting is the case with mechanical “bells and whistles”. The kit may include a stand or special clamps designed for stationary fastening of the tool (very convenient for processing small parts). The sanding frame serves as a kind of stop that helps to avoid damage to the workpiece. A rip fence or miter fence is useful for a precise bevel or flat, parallel surface. The thin front roller in some LShM (BlackDecker KA88) has a small diameter, which minimizes the dead zone in the inner corners. Automatic centering of the belt (the tricky barrel shape of one of the rollers) does not allow the latter to treacherously slide at the most inopportune moment. An additional handle with a variable inclination or removable will significantly increase the functionality of the machine in “clamped” places. sometimes noticeably.
Special attention should be paid to the dimensions of the working plane. the sole, respectively, the length and width of the tape. Wide soles (100 mm) are characteristic of powerful professional shoes, making them more stable and productive. The hobby class is usually limited to 75 millimeters. The long and wide sole of expensive LSHM has a complex structure, consisting of a substrate and an elastic plate, which allows you to have constant uniform contact of emery with the part, such a tool “holds the plane well”. It is necessary to mention the “ribbons” with narrow accessories. these are the so-called “electric files”, which do not differ in great power and versatility, but experts appreciate them for their unprecedented compactness (for example, Makita 9032 with a tape only 9 mm wide).
The dust removal system is available in all draw frames, but not all of them work equally effectively. The fight against dust is carried out either with the help of a vacuum cleaner connected through the branch pipe, or by collecting it in a bag, built-in filter. Of course, a vacuum cleaner is preferable, especially when sanding mineral substrates. In super-cheap models, the impeller, which is responsible for air intake, cannot cope with its function, the channels quickly become clogged, a lot of harmful “flour” remains in the air.
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 other 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 during processing cavities and scratches appear. Effective for sanding glued panels and processing convex parts. Models available with the ability to work upside down, stationary.
This tool is not suitable for delicate sanding and requires special control when working. 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 levels and frequent clogging of the dust extractor are the disadvantages of this tool.
There are special purpose belt sanders, the so-called belt files or electric files. Often used for deburring weld seams and sanding materials in hard-to-reach areas.
Only certain accessories are suitable for electric files, with a width of 9 to 30 mm.
Such belt sanders weigh much lighter than conventional ones. 1-2 kg.
Still polishing with a rotary? THIS could change your mind!
Pay attention to the parameters when choosing a grinder
It should be noted that both of these grinders for the most part 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:
- Amplitude of the platform stroke. This is one of the main characteristics of grinders. Average vibration value. 2-3 mm. The higher the amplitude, the better 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. conversely, 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;
- Fastening 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 (it is less hassle with it, 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 instrument in one hand. Convenient when sanding small parts.
Basic principles of grinding
These two types of grinders differ significantly in the principle of grinding. First, let’s review the vibrating tool. The mechanism of operation is quite simple, for cleaning the surface, reciprocating movements are used with an amplitude of 1-3 (low-power) to 5-8 mm (powerful). This allows you to cope well with a metal surface or plastic, in contrast to ESM. However, PShM leaves traces on the tree and will not be suitable for opening with varnish, but only for coating with paint.
The principle of operation of ESM is that with the help of a round sole, not only vibration occurs, but also rotation around its own axis. Thanks to such a double movement, ESHM perfectly prepares the surface for varnishing. In the process of work, it does not leave traces of grinding at all. Models of this type ideally create the effect of abrasive grinding. Widely used for furniture restoration or decoration.
Structural difference between the two machines
Both machines are capable of delicately sanding the surface with emery cloths. In fact, they do the same work, but there is a difference between them. They differ in both form and principle of operation. In FSHM, the 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 quietly sanded with PSHM, thanks to the angular sole, you can reach any corner.
The eccentric clipper is used for working with both flat surfaces and radii, as well as wooden parts of various shapes. Orbital and eccentric grinders 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 (plasterboard). But she does it a little roughly, unlike ESM. In turn, the orbital sander will perform this entire list of works more delicately due to the fact that it has the function of additional rotation, which helps to hide the traces of grinding.
Grinder: vibrating or eccentric
category expert “Power tool”
To get a smooth and perfectly smooth surface when sanding, I always recommend that craftsmen use two sanders. One is for primary, rough roughing, the other is for 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);
Both are designed for sanding substrates at the completion of work. Which of these machines is better in which situation. vibration or eccentric sander? I will cover 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.
Advantages of eccentric sanders:
- Cleaner surface sanding;
- Ability to grind curved surfaces;
- Polishing capability.
- Corner surfaces cannot be machined because the sole is round.
Pros of vibration grinders:
- Effective sanding of wood, stone, primer, metal;
- There is a wide selection of outsole sizes and shapes. rectangle or delta;
- It copes well with corner surfaces, leaves no frayed areas at the edges, close to the edging, in narrow places.
The minuses of PSHM include:
The Difference between Orbital Sander & Random Orbit Sander | Bosch Power Tools Sanding Solutions
- Not such a high quality of grinding as that of ESHM. Often scratches wood.
If we talk about surface cleaning, then for more delicate sanding, it is better to choose and use eccentric machines. They do better in the finishing phase and are designed for perfect sanding. Although their performance is much lower than that of vibration ones. However, the orbital instrument is indispensable on volumetric surfaces with curved and profiled details.
On a large area, it is better to use a vibratory sander, as its power and performance are much better. If you need to process a surface with corners, then you cannot do without a vibration machine. Thanks to the rectangular shape of the sole, corners and hard-to-reach places, as well as the edges of the product, are easily processed.