Do-it-yourself metal grinder. Belt grinder from angle grinder

Often there is a need to perform various kinds of finishing work on the surface of wood.

The use of such a unique tool as a wood grinder helps to significantly speed up the execution of this kind, as well as improve their quality.

It is quite popular among buyers. That is why I would like to dwell in more detail on the features of this tool, as well as its varieties.

The popularity of such equipment is due to its rather wide area. By using a grinder for woodworking, you can perform the following types of work:

• Curved plane polishing
• Leveling a flat surface that is on a fixed work table or by manually moving it mechanically
• Edge processing of various parts or their ends
• Carrying out the preparation of a wooden surface for painting, etc.

All these and other types of work often have to be performed in a country or private residential building.

In addition, a wood grinder is simply an indispensable tool for craftsmen who work with wooden surfaces and blanks.

In addition, when choosing equipment, it is necessary to pay attention to such an indicator as the grain size of the abrasive belt. In order to be able to perform different types of work, experts recommend that when buying a machine, take several types of tape at once with a different grain size.

Vibrating

The design of this type of equipment consists of a body and an abrasive element, which is attached with strong clamps.

Grinding is performed as a result of frequent oscillatory movement of the worker.

The master can set the amplitude of movement independently in manual mode.

This indicator fluctuates in the range of 1 - 5 mm.

The smaller the amplitude, the more accurate and finer the processing of the working surface will be.

delta grinder

A distinctive feature of this is the presence in its design of the working sole, the shape of which resembles an iron. Using this equipment, the master has the ability to work with all types of surfaces.

Equally important is the presence of a small acute angle in its body. Thanks to this, by using this tool, it is possible to process such surfaces or parts that consist of one or more hard-to-reach corners.

Different models of the machine have different speeds. Significantly increases the popularity of such a tool among buyers and the fact that its working surface can be rotated in different directions as needed, as well as to replace different nozzles. Thanks to this, the use of equipment increases several times.

Eccentric

The main difference between this type of tool and others is that it is designed to perform jewelry processing of the working surface. The abrasive surface has a round shape.

The master can independently choose the degree of graininess of the surface. The subtlety of the work performed depends on this indicator. The sole of the equipment is equipped with small holes through which dust is removed.

Thanks to this, working with such a tool ensures the safety of the master. It is also of great importance that the master can choose the speed at which the sole of the machine with the abrasive surface attached to it will rotate.

Renovator

This tool is used by craftsmen as an analogue of a grinder. Its distinguishing feature is its versatility.

By using a renovator, you can perform the following types of work:

• Make cuts of different diameters and shapes in the work surface
• Clean the back of tile or any floor covering
• Trim different communication lines

Such a variety of functions has become possible thanks to the many attachments that are included in the equipment.

The wide variety of wood sanders greatly increases the range of jobs that can be done with them. In addition, the masters have the opportunity to choose the most optimal equipment, which is designed to perform a certain type of work.

Making a grinder with your own hands

It's no secret that it is quite difficult for a home craftsman to do without such unique equipment as a wood grinder.

Despite the apparent complexity of the device, a do-it-yourself wood grinder is a reality.

It is possible to simply make a tool from a conventional computer power supply that has already failed.

First you need to prepare all the parts and tools necessary for work:

• Power Supply
• Old computer disk
• abrasive surface
• Bolts or screws
• Speed ​​controller
• Switch

The build sequence is:

• Disassemble the power supply so that only its twisting part remains.
• Attach a computer disk with an abrasive surface attached to it with glue (abrasive material can be fixed permanently, or small clamps can be made. Thanks to this, the master will be able to change the surface as it wears out)
• Connect power supply and speed controller.

This is how you can make a simple grinder them at home. With its help, you can work with small work surfaces.

Such equipment can also be made from a simple grinder. It is enough to simply change the abrasive wheel. But it should be borne in mind that the rotation speed of the abrasive element of such a machine will be quite high.

Therefore, it is worth paying special attention to the observance of safety measures when working with such a tool.

Often, craftsmen adapt a conventional drill in such a way that it can be used as a grinder. To do this, you need to use a special nozzle.

Emery is attached to its working part. And on the opposite side, a small shank is inserted.

It will be necessary in order to be able to connect this nozzle and the drill chuck. With the help of such a tool, it is possible to process rather large surfaces not only from wood, but also from metal or plastic.

How to choose the right equipment

In order for the wood grinder to work with full efficiency, it is necessary to pay special attention to the following indicators when buying it:

• The type of work being done. Different types and models of equipment are designed to perform various operations, as well as to work with different work surfaces. These indicators can be found in the technical data sheet of the tool, which is included in its kit.
• centering mechanism. This element is designed to fine-tune the abrasive surface. If the design of the machine has such a mechanism, it means that it will be much easier to work with it, and the quality of the operation will increase by several points.
• Speed ​​controller. Thanks to this mechanism, the master can independently adjust the speed of the tool. This is especially important if there is no necessary work experience or if the work surface https://www.youtube.com/watch?v=eE7j2vOW8gg is uneven.
• Grain size of the abrasive. This is the indicator that affects the quality of the work performed. If precise surface treatment is planned, the grain index should be very small. For routine cleaning of tiles or linoleum, a coarse-grained abrasive surface is also suitable.

Wood sanders are a unique type of tool, without which it is impossible to do in the household. On the market of tools you can find several types of such equipment.

In addition, a grinder can be made and, and how to do it from a fan is shown in the video:

The rotation on the drive shaft of the tape machine is transmitted from the electric motor, which is connected to it by means of a belt drive. The speed of the belt mechanism can be adjusted, thereby changing the modes of processing parts. The belt of a surface grinder can be located horizontally or vertically, as well as at a certain angle, which is allowed by some models of equipment in this category.

When choosing a model of a belt grinder for processing a particular part, it is important to consider the length of the surface that needs to be grinded. It is much more convenient to process parts on such machines, the surface length of which is less than the length of the abrasive belt and the desktop. Under such conditions, the quality of processing will be much higher.

The belt sander can be of various designs: with a movable and fixed work table, with a free belt. A separate category includes wide-belt equipment, the peculiarity of which is that their desktop, which is also a feed element, is made in the form of a caterpillar. In those models of equipment that have a working table in their design, the abrasive belt is located in a horizontal plane, and in equipment with a free belt, in which a working table is not provided, it can have a different spatial position.

An obligatory structural element of any belt grinder, including a desktop one, is an exhaust device, which is necessary to remove dust, which is formed in large quantities during processing. Both professional and any homemade grinder used in a home workshop or garage is powered by an electric motor.

Principle of operation

The main parameters of the belt grinder are the feed rate and the force with which the belt is pressed against the workpiece. Parameters such as the degree of grit of the abrasive belt should be selected depending on what material the workpiece is made of, as well as the degree of roughness that the surface of the machined product should have.

The characteristics of the material to be processed, in particular its hardness, primarily influence the grit size of the abrasive belt. The processing modes that are directly related to each other are the feed speed and the belt pressure. So, if grinding is carried out at high speed, but with a slight pressing force of the abrasive belt, then some parts of the surface of the part may turn out to be untreated. If, on the contrary, you increase the pressing force and reduce the feed rate, then you may encounter the fact that burns and blackening of the material may appear in certain areas of the treated surface.

Another variation of the machine is a view from the side of the working surface of the tape

The results of grinding are also influenced by how well the abrasive tape is glued together. In order to obtain a high quality finish and not to experience a malfunction of the band machine, do not use abrasive belts that are not glued correctly or have torn edges. When putting on the tape on the shafts of the equipment, it should be positioned so that the end of the seam, which is overlapping, does not lift up on the surface of the workpiece, but slips along it. Learn more about gluing the tape in the video below.

Any, including a manual grinding machine, should provide for the possibility of adjusting the belt tension, which is ensured by moving a movable shaft that is not driven. Tape tension is a very important parameter, the choice of which should be guided by the "golden mean" rule. If the belt of the grinder is too tight, then this can lead to its breakage during operation, and too little tension will cause slippage and, as a result, its excessive heating. The main characteristic for determining the degree of tension of the tape is the arrow of its deflection, which is measured by lightly pressing on its surface in a taut state.

The manual belt grinding machine of the group can be operated by one operator, who moves the desktop with the workpiece and rotates it so as to bring all parts of its surface under the abrasive belt.

How to make a belt sander

Many home craftsmen and professionals are wondering how to make a grinder with their own hands. The reason for this question is quite simple: the high cost of mass-produced grinding equipment, which, with irregular use, not everyone can recoup. In order to make such equipment, you will need several basic components: an electric motor, rollers and a reliable frame. Naturally, the drawings of such a device or its photo will not be superfluous. Also at the end of the article you can watch videos on assembling a tape machine on your own.

The motor for belt sanding equipment is easy to find, it can be removed from a used washing machine. The bed will have to be made independently, for this you can use a sheet of metal with dimensions of 500x180x20 mm. One side of the frame should be cut very evenly, since it will be necessary to attach the platform on which the electric motor will be mounted to it. The platform for the electric motor should also be made of a sheet of metal with dimensions of 180x160x10 mm. Such a platform must be fixed to the bed very securely with a few bolts.

Another version of the bed

The efficiency of a belt grinder directly depends on the characteristics of the electric motor that is installed on it. If you are going to make a grinding machine with your own hands, then an electric motor with a power of 2.5–3 kW, developing about 1500 rpm, is quite suitable for you. In order to use such a motor to move the sanding belt at a speed of 20 m/s, the drums must have a diameter of about 200 mm. Which is convenient, if you choose an engine with such characteristics, then you do not need to make a gearbox for your grinding machine.

The drive shaft is connected directly to the motor shaft, and the second - the driven one - must rotate freely on the axis, which is installed in the bearing units. In order for the abrasive belt to more smoothly touch the surface of the workpiece, the section of the bed on which the driven shaft is installed should be made with a slight bevel.

It is possible to make shafts for a belt grinder with minimal financial costs from a chipboard plate. You simply cut square blanks 200x200 mm in size from such a plate, drill central holes in them and put them on the axle with a package with a total thickness of 240 mm. After that, you just have to grind the resulting package and make a round shaft out of it with a diameter of about 200 mm.

Drawings and a detailed analysis of some parts of a machine made of wood.

Wood belt sander (click to enlarge)

Table Tilt Adjustment Mechanism Plate Unit Belt Tensioner

For finishing wood, metal or stone, you can build a belt sander with your own hands. The need for such processing arises quite often. It is needed not only to obtain even and smooth surfaces. With its help, you can remove various kinds of irregularities, bulges and depressions, peel off burrs, remove local defects, remove flash formed during welding, carry out internal grinding, etc.

Manual execution of such processing is very laborious and inefficient, and the cost of industrial grinding machines is quite high. Therefore, it is necessary to invent and build home-made structures, especially since they do not differ in particular complexity.

General information about the design of belt grinders

Belt grinders, with all the apparent diversity of their designs, have common distinguishing features. An abrasive belt is used as a working tool in these designs. Most often, it is connected into a ring and placed between two rotating drums.

Usually there are two such drums: the first is the leader, and the second is the slave. The driving drum is driven by an electric motor through a mechanical transmission. Usually it is a belt drive. It is desirable to have a device that allows you to change the speed of rotation of the main drum, thereby providing a variety of processing modes.

The location of the sanding belt depends on the purpose of the sanding machine and can be any: vertical, horizontal or inclined. The tape is usually mounted on a frame, and workpieces can also be located there. In homemade designs, the blanks are usually held by hand, although there may be other options.

The length of the working part of the sanding belt depends on the size of the workpieces being processed. The grinding process is accompanied by the release of a large amount of dust, so the presence of an exhaust device is desirable. A tension roller is often used to adjust the degree of belt tension.

Depending on what the grinder will be mainly used for, it may have some design features. This applies to the diameter of the drums, the length and speed of the belt, its grain size, the design of the working table, etc. The main types of grinding are:

• grinding curved surfaces;
• leveling flat surfaces;
• alignment of side edges or ends, as well as surfaces of bars, shields and similar parts;
• grinding of intermediate layers of paint and varnish coatings.

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Homemade belt sander

The structural prototype of a homemade grinder was a conventional industrial design in which the belt is moved by the abrasive part outward over the flat surface of the desktop. The resulting grinder is distinguished from the industrial design by increased dimensions and a stationary installation.

Since a gearbox or belt drive complicates the design, an electric motor is used, the rotor of which makes 1500 rpm. The power of the electric motor should be about 2-3 kW. With a drive shaft radius of 10 cm, the linear speed of the belt will be about 15 m/s. As already mentioned, the reducer is not needed in this case. Adjustment of the speed of rotation in such a simple design is not provided.

The drive shaft is rigidly mounted on the motor shaft, and the second shaft tensions the belt. The tension shaft rotates on bearings sitting on a fixed axle to reduce friction. This axis can be shifted relative to the desktop in one direction or another, reducing or increasing the degree of tension of the sanding belt.

The desktop can be made from improvised materials: sheet metal or wooden beams. Its dimensions are determined by the distance between the axes of the shafts and the length of the abrasive belt. Near the shafts, the surface of the table must have bevels to ensure smooth contact of the tape (especially its junction) with its plane.

Both drums are easy to make yourself. Chipboard can serve as a material for their manufacture. Squares with a side of 20 cm are cut from the original plate. Their number should be such that the total thickness of the set is about 24-25 cm. Discs with a diameter of 20 cm are made from them on a lathe. There are two options for processing them:

1. You can grind each workpiece on the machine separately.
2. A more preferable option is to put the workpieces on the axis, clamp and grind them all together.

The groove should be carried out in such a way that the edges of the drums are a few millimeters smaller than their middle. This is necessary so that the abrasive belt is automatically installed in the centers of the drums.

A sander or polisher is required for painting work. There are many models of such devices in tool stores and other outlets. However, in some cases it is advisable to create a polishing machine with your own hands. This article discusses various options for such home-made devices and describes the process of their creation.

The simplest polishing machine

The easiest way to do it yourself is a polishing machine designed to work with grinding discs. To create this device, you will need the following main parts:

• electric motor;
• power unit;
• battery.

The electric motor can be extracted from various electrical tools and appliances. So, for example, components of a computer power supply or a drive are suitable.

You can also use an electric motor from a fan, and a household battery is suitable for driving an electric motor.

In addition to these components, you will need a board, it needs to be sanded with sandpaper. Next, the battery and the electric motor are fixed with screws on the board and connected with wires. It is also necessary to install a switch in this electrical circuit, fixing it on the board. The wires should be fixed with a stapler to prevent loosening.

The working element of the considered design is represented by a circle. You can use branded products or you can make your own sandpaper sanding disc. To do this, you need to cut out two sectors from a fragment of the source material and fasten them together with their back sides, gluing them together.

To ensure the drive of the abrasive disc from the axis of the electric motor, two bushings are required. The diameter of these fixtures is determined based on the corresponding motor axis parameter. It must be taken into account that different electric motors have axles of different diameters. The considered grinder can be used for processing both wooden and metal surfaces, including body work.

Motor and polishing discs

Remember that the functional parameters of such a homemade grinder are determined by the individual parts from which it is assembled. In this regard, you should use an electric motor from a fan, since the engine from a computer has less power, which may not be enough for some types of work. In addition, sandpaper discs are not optimal devices of this type. Instead, you can purchase branded circles of small diameter, for example, for a drill.

You can create with your own hands and a more powerful stationary version of the grinder. For it, you can use the engine from the washing machine and equip it with large diameter grinding wheels. In addition to polishing, grinding and abrasive discs can be installed on such a device.

The working element of machines of this type is an abrasive grinding belt. The principle of operation of belt devices is the rotation of an abrasive belt connected into a ring, driven by an engine through a transmission and drums. One of the drums is the leader and the other is the slave. The first of them is driven by an electric motor through a transmission, usually represented by a belt drive.

Some belt grinders are equipped with a device that allows you to change the speed of rotation of the main drum, which provides a variety of operating modes. The tape can be located on the frame vertically, obliquely or horizontally, depending on the purpose of the device. To adjust the degree of its tension is a tension roller. Since grinding operations are characterized by the release of a large amount of dust, it is desirable that the grinder be equipped with an exhaust device.

It should be taken into account that many design features of the grinding machine, such as, for example, the diameter of the drums, the speed of rotation, the grain size, the size of the abrasive belt, the design of the desktop, which determine the main functional parameters of the device in question, are selected depending on its purpose. The following variants of working surfaces are classified, for the processing of which grinders are oriented: curved, flat, edges and ends, intermediate layers of paintwork.

You can create a do-it-yourself belt grinder based on an industrial design, which provides for the movement of the belt over the flat surface of the desktop with the abrasive part out. In this case, a home-made device will differ from the branded counterpart in large sizes and a stationary installation. For these works, you will need an electric motor, for example, from a washing machine, a wooden or metal panel, chipboard, abrasive tape material, glue.

Since the transmission in the form of a gearbox or belt drive significantly complicates the design of the tool in question, they try not to use it on home-made models. To do this, you can equip the device with an electric motor with a power of 2-3 kW with a rotor speed of 1500 rpm.

In this case, with a drive shaft radius of 10 cm, the belt will move at a speed of about 15 m/s. It should be borne in mind that the design in question does not provide for the adjustment of the belt rotation speed. However, it is possible to adjust the degree of its tension due to the fact that the tension shaft, which rotates on bearings to reduce friction, is fixed on a fixed axis, which can be shifted relative to the working table. The drive shaft is fixed on the motor shaft.

The desktop for such a grinder can be made with your own hands from a wooden beam or sheet metal. It should be borne in mind that metal options allow you to process more complex objects. The dimensions of the working table of the tool in question are determined on the basis of the dimensions of the tape and the distance between the axes of the shafts, as well as its purpose. Bevels should be made near the rollers in the working table in order to ensure smooth contact of the tape with it.

Drums can also be made by hand. Chipboard can be used as the starting material for these elements. Squares with side lengths of 20 cm are cut out of the slab in such an amount that their total thickness when superimposed on each other is about 25 cm. Then these blanks must be turned into disks with a diameter of 20 cm by processing on a lathe. You can process the cut fragments separately, but it is more convenient to grind them all at once, putting them on the axis and holding them. In this case, it should be taken into account that the drums must have edges of a larger diameter compared to the central part in order to automatically hold the tape.

The sanding belt can be made by hand on the basis of paper or fabric. The second option is considered more preferable. The fabric can be represented by coarse calico or twill. It should also be taken into account that the rare filling of the belt with abrasive grains, which is less than 70%, makes it possible to reduce the degree of filling it with dust during operation.

The main characteristic of the abrasive belt is the grain size. This parameter is determined based on the number of sieves through which they can leak. According to the grain size, abrasive belts are divided into coarse-grained (12-80), medium-grained (80-160), fine-grained (160-4000).

Abrasive grains can be represented by artificial materials or minerals with high hardness, such as, for example, silicon carbide, corundum. They are fixed to the base by gluing or electrically. In the first case, the grains are evenly poured onto the base surface, previously coated with an adhesive in the form of synthetic resins or skin glue. An electric field is used to orient the abrasive grains with sharp edges upwards, which increases the functionality of the belt.

The belt for the grinder can be made by hand from sandpaper in the form of rolls, which are cut into fragments of the required size.

In this case, it should be borne in mind that the length of the tape is determined by the method of fastening the ends of the cut fragment. It is possible to connect them at an angle, butt and overlap. In the first case, the ends are cut at an angle of 45 ° and a linen overlay is glued under the joint. The overlap connection involves preliminary cleaning with hot water of a fragment of one of the ends 8-10 cm from abrasive grains. Then the cleaned area is covered with glue and the back side of the other end of the tape is applied to it and the junction is compressed. The optimal thickness of the abrasive belt is 200 mm. A 1 m long roll of raw material is enough for 5 tapes.

The bed must be cut with your own hands from a thick sheet of metal. At least one of its sides must be evenly cut to secure the platform with the electric motor by screwing it with three bolts through the holes pre-drilled in the frame.