Belt grinder, abbreviated as LSM, is one of the most popular carpentry tools. The device is widely used both at the household and professional level, is characterized by ease of use, processing efficiency and reasonable price.
Features and Application
The belt grinder is an electromechanical tool that is used for grinding wooden, concrete and metal substrates, while ensuring their absolute smoothness and uniformity. Using the device, you can efficiently and quickly remove the old paintwork from metal and wood , as well as perform rough processing of non-planed boards and timber. LSHM is able to process sections of any area, as well as to carry out primary and intermediate grinding on them with the removal of a thick layer of wood.
Moreover, belt models can perfectly prepare the work surface for fine grinding performed by eccentric or vibration grinders. And also with the help of LSM it is possible to give roundness and other non-standard shapes to wooden blanks.
In addition, some models are equipped with clamps that allow you to fix the tool in an upside down position, that is, the work surface up. This allows grinding miniature parts, sharpen planers, knives and axes, as well as grind and fine-tune the edges and edges of products. However, such work should be done with special care, moving in the direction of movement of the tape abrasive and not touching it with your fingers. But also many machines are equipped with a restrictive frame that controls the depth of grinding. This function is very convenient for beginners and does not allow to grind material larger than the required thickness.
Another important feature of the devices is their ability to grind and clean surfaces close to the wall. This is due to the design feature of the LSM, which consists of flat sidewalls, the absence of protruding elements and the presence of additional rollers that allow you to process dead zones. For high processing efficiency, which consists in removing the layers in turn, and the ability to work in hard-to-reach places, tape machines are often compared with planers. However, unlike the latter, tape units require a minimum of labor, as they cope with the task much faster. This is due to the center of gravity displaced downward, which makes working with LSM easy, without requiring a lot of physical effort.
Principle of operation
All modifications of belt sanders have a similar design, which is why they work on the same principle. The main driving force of the tool is an electric motor. It is he who creates the torque and transfers it to the roller mechanism, on which, in turn, the abrasive belt is looped. As a result of rotation of the rollers, the tape also begins to cyclically move and grind the work surface.
Belt abrasives are available in a wide range of sizes , which allows you to quickly replace them and treat the base with different skins in width and grain size. At the beginning of processing, a coarse-grained tape is installed, then in the process it is changed several times to finely abrasive samples.
Usually, as a result of using three or four numbers of grinding skins, the treated surface is ideally smooth.
Classification of belt grinders is made according to a number of signs. The main criterion is the scope of the models. According to this parameter, household and professional tools are distinguished. The former process mainly straight surfaces, while the latter are designed to form complex arbitrary shapes and to grind curved and convex bases. Professional models are often equipped with a figured sole, which, if necessary, can be advanced. In addition, the working life of the professional units is much higher than that of inexpensive household appliances. Therefore, if regular use of the machine is expected, it is preferable to choose a more functional device.
Among the professional models, highly specialized units are distinguished for cleaning and grinding pipes , joining seams and any other rounded elements made of wood or metal. Such units differ from traditional models in the arrangement of a tension mechanism and the absence of a sole. And another type of professional equipment is represented by stationary type machines. Such samples are characterized by increased power and are often equipped with a grinding disc.
As for the design features, stationary samples consist of the same units as manual units, and differ only in size and work surface area. Their advantage over mobile products is their special processing accuracy, high productivity and safety of use.
The next criterion for the classification of mechanisms is the tension of the sanding belt. On this basis, two types of devices are distinguished: with two and three rollers. The latter are equipped with a movable part with a third roller mounted on it. Such a device allows the blade to bend and capture a large area of the surface to be treated, thereby providing more accurate and high-quality grinding. The first ones do not have such advantages, representing traditional household models designed for simple processing of flat surfaces.
Another sign of machine classification is the type of motor power. It distinguishes between electric, pneumatic and battery models. The former are completely volatile and require a 220 V power supply in the immediate vicinity. The latter are powered by an air compressor, are characterized by high power and performance, and can be used in the field. Battery devices include pipe grinding machines with batteries with a capacity of more than 4 A. h and weighing about 3 kg.
The determining operating parameters of belt grinders include their power, rotation speed and abrasive width, as well as the mass of the device.
- Power is one of the most important technical characteristics and directly affects a number of operational capabilities of the device. The engine speed, power consumption, the mass of the unit and the time of its continuous operation depend on power. Modern cars have power from 500 W to 1.7 kW. The Makita 9032 mini-device has the lowest power, for its modest size, called the electric file. The model is equipped with a very narrow ribbon and is able to work effectively in hard-to-reach places. Most household appliances are available with motors from 0.8 to 1 kW, while for intensive work it is better to use 1.2 kW models. Professional stationary machines have a power of 1.7 or more kW, and are characterized by high energy consumption.
- The speed of rotation of the abrasive belt is the second most important technical parameter, it depends entirely on the engine power, having a great influence on the grinding speed and the overall quality of processing. In addition to power, the width of the tapes themselves also affects the speed of rotation. So, higher-speed units are designed for narrow abrasives, and wider samples are installed on machines with low speed. The modern market represents LSM with speeds from 75 to 2000 m / min, but most household models operate at a speed of 300-500 m / min, which is the optimal value for use in home workshops. In a minute, such an aggregate is capable of removing from 12 to 15 g of material from the working surface, which compares favorably with the LSM from surface grinding and eccentric grinders capable of removing from 1 to 5 g of material.
For working with small parts, as well as a tool for beginners, a device with a speed of 200 to 360 m / min is suitable. Such a machine will not remove material more than required, and will produce grinding more slowly and smoothly.
High-speed copies with a speed of over 1000 m / min are designed for professional use and work in hard-to-reach places. Such models have a thinner abrasive tape and are capable of removing over 20 g of material per minute.
- The weight of the machine is also an important factor affecting the usability of the machine and the quality of grinding. Weight characteristics are especially important when performing vertical processing of doors, window frames and slopes, when the device has to be kept on weight for a long time. The mass of the unit directly depends on the engine power, and the more powerful the motor is installed on the LSM, the heavier the product. So, medium-power household models usually weigh in the range of 2.7-4 kg, while the weight of serious professional samples often reaches 7 kg. When working with heavy equipment, you must be extremely careful: when starting up, a machine standing on a horizontal surface can abruptly jerk out of its hands and injure the operator. In this regard, the unit must first be started, and only then put on a working base.
- The width of the belt is interconnected with the motor power and rotation speed: the greater the width of the abrasive, the higher the power and the lower the speed, and vice versa. The most common are ribbons with a length of 45.7 and 53.2 cm and a width of 7.7, 10 and 11.5 cm. The step of the multiplicity of length is 0.5 cm. However, there are also models with a non-standard length, which causes certain difficulties when choosing consumables materials.
Rating of the best models
The modern market offers a huge number of LSH models of different brands. Among them there are both expensive professional appliances, and very low-cost household samples. Below is an overview of the tools for several categories that are most interesting to the reader, having become familiar with which, it will be much easier to make the choice of the right model.
The rating of economy class cars is headed by the BBS-801N model of the Chinese company Bort , equipped with an 800 W electric motor. The device is designed for a tape measuring 76x457 mm and is capable of working with a belt speed of 260 m / min. The unit can be used in combination with a vacuum cleaner. It is also equipped with a speed controller. The model has a power button lock and is equipped with an electric cable 3 m long. The design features are the ability to quickly change the tape and the presence of a knob adjuster. A dust collector, an abrasive belt and an additional handle are included in the basic package. The weight of the device is 3.1 kg, the cost is 2,945 rubles. Warranty period is 60 months.
Second place in the ranking of low-cost devices belongs to the domestic model "Caliber LSHM-1000UE" , which has an engine with a power of 1 kW and a belt rotation speed of 120 to 360 m / min. The abrasive is well fixed on the roller mechanism, without slipping during grinding, and the unit is equipped with a handle with a lever that provides a comfortable grip, and two additional carbon brushes.
The width of the tape is 76 mm, the weight of the device is 3.6 kg. The consumers have no particular complaints about the tool, however, there is a need for periodic shutdown arising from overheating of the tape. The cost of the product is 3,200 rubles.
And in third place is the MILITARY BS600 with a power of 600 W and a tape speed of 170-250 m / min. The device is designed for abrasive size 75h457 mm and is equipped with a function of electronic adjustment of belt speed. The model has a built-in dust extraction system and two clamps, which allow to securely fix it in the desired position. The weight of the device is 3.2 kg, which allows it to be used for processing vertical surfaces. The model is characterized by an ergonomic case and a convenient system for replacing abrasive tape, which is produced in a keyless way using a lever. During continuous operation, the start button can be locked. The cost of the model is 3,600 rubles.
The leader in this category of machines is the Japanese Makita 9404 with an abrasive size of 10x61 cm. The model is equipped with a dust collector and belt speed controller. Motor power is 1.01 kW, rotation speed is from 210 to 440 m / min. The machine weighs 4.7 kg, costs 15 500 rubles. The second place is occupied by the lightweight Swiss-made unit Bosch GBS 75 AE worth 16 648 rubles. The device is equipped with a fabric-based sanding belt, a bag filter and a graphite plate. Engine power is 410 watts, belt speed - up to 330 m / min, product weight - 3 kg.
And in third place is the serious stationary combination tape and disk model Einhell TC-US 400 . The unit is designed for small woodworking workshops and has a low noise level. The speed of rotation of the tape reaches 276 m / min, size - 10x91.5 cm. In addition to belt abrasive, the device is equipped with a grinding disk with a speed of 1450 rpm. The weight of the device is 12.9 kg, the cost is 11,000 rubles.
According to this criterion, it is rather difficult to objectively evaluate models. Each product has both strengths and weaknesses, so it is difficult to choose a unique leader. Therefore, it will be fairer only to designate some models, the positive reviews of which are most common. Such devices include the Black Decker KA 88 car worth 4,299 rubles. The device is characterized by an optimal ratio of price and quality, and as a result of the reduced size of the front roller, it is able to perform effective grinding in hard-to-reach places.
The second place can be conditionally given to the Skil 1215 LA unit at a cost of 4,300 rubles. Consumers position the device as a very reliable and durable device, equipped with an automatic centering of the abrasive. The weight of the device is 2.9 kg, speed - 300 m / min. The third place is occupied by the domestic Interskol LShM-100 / 1200E worth 6,300 rubles. The model is equipped with a 1.2 kW engine, capable of working with metal and stone, and also has a long service life in harsh conditions. The machine is capable of sharpening a cutting tool, has a dust collector and weighs 5.6 kg.
In addition to the basic functions, many LSMs are equipped with various options and useful devices that facilitate the operation process and make working with the device much more convenient.
- Soft start tape. Thanks to this option, the abrasive does not begin to move jerkily, but translationally, eliminating operator injury.
- An additional handle allows grinding more accurately.
- Depth gauge will not allow to remove excess millimeters beyond what was planned.
- Stationary fasteners make it possible to fix the machine on a hard surface, turning it into a grinding machine.
- The keyless abrasive change option allows you to change the tape with a single movement of the lever.
- The automatic centering function of the abrasive prevents the tape from sliding sideways during operation.
Which one to choose?
When choosing an LSM, it is necessary to pay attention to such parameters as power, belt speed and mass of the unit. If you plan to use the machine in a workshop, it is better to purchase a desktop stationary model or a model with the function of attaching to the table. This eliminates the need to keep the device on weight and allows you to process small parts.
If it is planned to work with a professional model in the field or on the road, then the determining factor, along with the motor resource, should be weight. When buying an instrument for processing pipes, it is better to choose a model on the battery.
Such devices are independent of electrical power sources, have a low weight and a special tape tension loop designed to work with pipes.
When working with LSM, some recommendations must be observed.
- For effective grinding of wood, the dead weight of the device is enough, therefore, it is not necessary to put pressure on it during operation.
- You need to start polishing the tree with an abrasive with a grit of 80, and finish - 120 units.
- The first movements when grinding wood should be performed at a certain angle to the direction of the wood fiber. Next, you need to move along the structure of the tree, or carry out circular movements.
- It is necessary to monitor the position of the electric cord. If it interferes, it is better to hang it on a bracket or throw it over your shoulder.
When sanding any surfaces, be sure to wear gloves and safety glasses.
In the next video you will find an overview of the Interskol LSHM-76/900 belt sander.