How to Choose a Home Sander
Creating an ideal surface for varnish or paint is impossible without a grinding machine. Today, for these purposes, on the market you can find several different types of grinders, each of which is good in its own way. So, for example, even a high-quality and expensive belt sander will not be able to provide an ideal surface for varnishing or under a stain, unlike an eccentric, which was created just for this. In how to choose an eccentric sander, there are no special difficulties, even despite the huge assortment from various brands. The main thing, before choosing an eccentric type grinder, is to determine for yourself what it should be in terms of basic parameters and additional functions.
For those who are going to grind the surface for the first time using an eccentric grinder, the following should be clarified. Eccentric sander is meant for polishing, rough and fine grinding. In practice, in most cases, it is used only for polishing and fine processing with further varnishing or painting of the surface. Such a narrow orientation of the machine is due to the peculiarity of its work. The principle of operation is a reciprocating circular movement of the grinding wheel, which is achieved high-quality processing.
Key parameters of the eccentric sander
When choosing an eccentric sander (ESM), you will immediately have to decide how often it will be used. If from time to time and for short-term work, then when buying, you can take the budget option. But if the loads on this tool are frequent and quite large, then you can safely take a professional ESM. Of course, if the tool is purchased for yourself and so that it serves for a long time, then you can without hesitation look after a professional ESM. True, the price for a professional eccentric grinder will be much higher than for a regular one.
Having determined whether this will be a regular or professional grinder, it remains to figure out the characteristics of the ESM itself. Without this, it will not be possible to determine which best grinder of the entire possible assortment you need. All characteristics can be divided into two categories. The first category is the performance characteristics that determine the quality and efficiency of work with a particular eccentric sander. These include power, vibration amplitude, rotation speed, diameter of the abrasive wheel, weight and power tool option. The second category is the additional functions of the machine, which provide the convenience and comfort of working with the tool. Additional functions include speed control, a dust collector option, the ability to connect to a vacuum cleaner, a second handle, inrush current limitation, and a pressure indicator.
The main characteristic of any power tool is its power. And eccentric grinders are no exception. It is her first and foremost to be considered when choosing a grinder. High power ESM allows you to use the tool longer and with greater efficiency. In addition, the quality of the work performed, the speed of rotation of the grinding plate, as well as the weight of the machine, depend on this parameter.
The power range of eccentric grinders is from 160 W to 900 W. But low-power and high-power ESM can be listed on the fingers. The most common grinders with power from 300 watts to 600 watts. Especially popular segment ESHM with a power of 300. 600 watts uses an eccentric sander Bosch. When choosing, you should pay attention to ESM with high power indicators. Over, if the difference in power is 20. 50 W, then there will be no special differences in the quality of processing. But if the difference is 100 W or more, then a preference should be given to a more powerful tool. The quality of work, their duration and the life of the ESM will be high.
Various sources of energy are used to operate the ESM, depending on this, there are several types of eccentric grinders. This can be an electric machine powered by an electrical outlet or a battery, or it can be a grinder using compressed air. This diversity allows the use of ESM in places where there is electricity, and where it is not. Choosing this or that option, it is necessary to clearly understand why and where ESM will be used.
If with electric grinders it is more or less clear, then a little should be said about pneumatic. The pneumatic eccentric grinding machine is mainly used on an industrial scale, since it requires the installation of additional equipment in the form of a compressor or compressed air cylinders. These ESMs perfectly serve in a garage, service station or in a furniture production workshop. Their main advantages are low weight, it is only from 600 g to 1000 g. And also a small number of moving parts. Since, using compressed air, there was no need for an electric motor, accordingly there were fewer parts. This affected both weight and lifetime. To all this, the light weight allows for a longer and more comfortable use of the tool itself. One of the manufacturers of such ESMs is Dynabrade, with its eccentric grinders Dynorbital.
Esm rotation speed
This parameter of the eccentric sander is directly related to its power. The quality of work performed and the convenience of work depend precisely on the speed of rotation. But there is one important point. When buying, they usually try to choose a machine with high RPMs, believing that the higher, the better for work. But this only relates more to productivity than to quality of work. Very high ESM speeds are suitable for roughing the surface, but low speeds are required for perfect grinding.
Another feature that should be taken into account is related to the rotation speed. It lies in the fact that the rotation speed will be the lower, the higher the power of the machine. For example, an eccentric sander bo6040 the company Makita It has a power of 750 W, and at the same time its rotation speed is only 1600. 5800 rpm. At the same time, eccentric sander Bosch GEX 125-1 AE It has a power of 250 W and a rotation speed of 7500. 12000 rpm. When choosing an ESM, you must remember this feature and focus on what purpose the machine will be used for. It will be a high-speed grinder for rough grinding or a low-speed grinder for finishing grinding.
Esm oscillation amplitude
The next parameter that affects the quality of surface treatment and depends on the speed of rotation is the amplitude of the vibrations, or as it is also called the eccentric stroke of the grinding machine. As noted above, ESM performs reciprocating circular motions. And if the rotation speed to a greater extent affects productivity, then the amplitude of movement of the grinding plate is responsible precisely for the quality of processing.
In fact, the amplitude of the oscillation and the speed of rotation are interconnected. It is the combination of these two movements that allows you to perform high-quality grinding. On the market are models with an amplitude of 2 mm to 5 mm. The smallest amplitude is possessed by DVT grinders. The presented photo demonstrates the movements of the grinding plate of an eccentric sander, it can be seen how the quality of the surface treatment changes depending on the amplitude of the vibration.
Important! It should be noted that for some pneumatic ESMs, reciprocating movements are created using special nozzle levers. Depending on which lever is installed, this will be the diameter of the orbit for grinding.
Esm plate diameter
The performance of an eccentric sander, in addition to power, also depends on the diameter of the grinding pad. Everything is simple here. The large area of the plate allows you to quickly process a large area at a time. The most common sizes are diameters 125 mm and 150 mm. But you can also meet non-standard sizes of 50 mm, 80 mm, 90 mm or 115 mm. Although the eccentric sander is designed to process only smooth surfaces, the small diameters of the sole allow grinding of corner joints.
Custom sizes of the grinding pad are a rarity. Only a few companies produce them and among the entire range of eccentric grinding machines on the market you can find only a few copies. Bright representatives of EShM with a small diameter of a plate are the grinder Rupes TA 50 and Metabo SXE 400.
When purchasing an ESM, in many cases it is enough to look at the name of the model to determine the diameter of the plate. Most manufacturers indicate the size there. For example, eccentric sander Interskol EShM-150 / 600E. Looking at the marking, you can immediately determine that the diameter of the plate is 150 mm, and the power of the machine is 600 watts. But it will not be superfluous to look into the passport or ask the seller. Since the eccentric sander Makita BO5031 in its name does not contain such data.
As previously noted, the weight of the eccentric sander directly depends on its power. The point is only in the engine. The more powerful it is, the heavier the machine. Weight does not directly affect the quality or productivity of work. But this parameter is important for the comfortable work of the wizard. So ESM with a lot of weight will be more difficult to process vertical surfaces, as well as the ceiling. For processing horizontal surfaces, this parameter weakly affects the comfort of working with it.
Additional functions of the random orbit sander
In contrast to the above-described characteristics of eccentric grinders, additional ones to a lesser extent affect the productivity and quality of work. But the presence of certain additional functions allows you to make the work more comfortable.
Today, manufacturers are trying to provide their ESM with the most useful functionality. These functions include speed control, various dust collector options, the ability to connect to a vacuum cleaner or adapter for it, a second handle, inrush current limitation (soft start), and pressure indicator. Let us consider each of them in more detail, since when choosing some of these functions can play a decisive role.
Today, almost any power tool has this function and ESM is no exception. Even in pneumatic ESMs, there is the possibility of speed adjustment, implemented in the form of pressure levers. For eccentric grinders, the possibility of adjusting the speed makes it possible to use the tool for both coarse and fine grinding. Which in turn allows you to save on the purchase of several grinders.
Dust collector option
The result of the grinding machine is not only a flat and smooth surface, but a rather large amount of fine dust. Of course, manufacturers took care of having a dust bag for her. But everyone has his own and not always convenient.
So, for example, Makita the eccentric sander is equipped with three types of dust collectors. Plastic, rag and paper. And here are the grinders Bosch only with plastic dust collectors with the possibility of replacing them with a vacuum cleaner. When buying an ESM, it is always worth considering a dust collector option that will be convenient for everyone in particular. The dust collector itself, of course, does not affect the quality of work, but even when cleaning it, you don’t want to bother too much.
Possibility of connecting to a vacuum cleaner
As already noted, the removal of dust from various models and manufacturers of ESM is carried out both in a separate dust collector and with a vacuum cleaner. This approach is justified. After all, the dust collector has small dimensions and is not enough for a long time, and it is often necessary to carry out cleaning, breaking away from work. Therefore, some manufacturers have provided the ability to connect a vacuum cleaner. Unfortunately, not all eccentric sander models have this capability. But professional ESMs like grinders Bosch, Rupez or Makita, connection to a vacuum cleaner is mandatory.
Of course, there is also another option for connecting to a vacuum cleaner, this is a special adapter. Other ESM manufacturers, realizing the importance of connecting, decided to leave their models of grinders unchanged and began to produce special adapters. Therefore, when buying an eccentric machine, realizing that it will have to work a lot and for a long time, you should ask the seller about the possibility of connection.
The specifics of working with an eccentric machine provides for pressure on it from above. Even the form of the tool itself is completely directed towards it. But quite often, the starting mechanism and the electric motor are somewhat away from the center, which creates certain difficulties during operation. In this regard, ESM manufacturers have added an additional handle that compensates for pressure on the other hand and makes it easier to work with the machine. The handle itself can be removable or stationary. It all depends on the model. For example, sander Makita BO5040 / 5041 has a removable handle, at the same time Bosch PEX 400 AE equipped with a stationary additional handle. Grinders should be highlighted. Dwt. They equipped their ESM with side handles, which provides additional convenience when working with vertical surfaces.
Inrush Current Limit
The result of the grinder should be a flat and smooth surface. But from the moment of launch to the start of work, the master does not always have time to adjust and make the necessary effort. As a result, the surface can be damaged, leaving unwanted furrows that will have to be sanded. Therefore, many manufacturers equip their grinders with a soft start system. This approach is justified, especially if the wood sander is eccentric. It’s all about vibration that occurs immediately after turning on the machine. The presence of a soft start allows the ESM to gradually reach working revolutions and adapt to them to the master.
One of the additional functions useful for the beginner is the indicator of the force of pressing. This is especially useful for those who have not yet learned to feel their power of pressing the tool. This indicator in case of excessive or insufficient pressure will allow you to adjust it to perform grinding properly. This feature will be useful for professionals. It will allow you to assess the degree of your skill in working with ESM and facilitate the grinding process itself.
Abrasive Mount Option
During grinding work more than once there is a need to sweep the abrasive due to its wear or in order to reduce grain size for smoother grinding. To prevent this simple operation from taking up too much time, manufacturers have developed several different methods for attaching the abrasive to the grinding pad. The most common is ordinary Velcro. Besides her, there is still quick fit system providing modular replacement, but it is less popular. When choosing an ESM of one or another manufacturer, it is necessary to familiarize yourself with how the abrasive will be fixed so that during operation there will be no hitch with a replacement.