Do-it-yourself belt grinder for knife makers. How to make a simple polishing machine and what is needed for this? Homemade wood sander

If you need a grinder for occasional work with wood and don’t want to spend money on professional equipment, you can assemble a power tool yourself using scrap materials, as in this project.

Materials

To make a grinding machine with your own hands you will need:

suitable electric motor;
fasteners;
grinding disc;
pieces of plywood;
sandpaper;
drill;
saw;
roulette.

In this project, the basis of the tool was an old electric motor from air compressor. It is powerful enough for the finished product to work no worse than special woodworking equipment.

Step 1. Be sure to attach the purchased grinding disc to the existing engine. This will help you decide on the parameters of the pedestal for the motor.

After careful calculations, assemble the base from boards or pieces of plywood. Be sure to secure the motor to it.

Step 2. Cut out a base for the disc from plywood and carefully sand the edges of the cuts with sandpaper. Using the motor pulley, mark the holes in the center of the disc. Use a drill to drill them, and bolt the pulley and the round plywood base together.

Step 3. Basically, the grinding tool is ready, you will need to fix it on plywood base the disk itself, and you can work calmly. Or, as in this project, you can assemble a box from leftover lumber to make the power tool look nice, and also display a tool start button on its front part. Before assembling the box, be sure to make careful calculations.

You should work with the resulting tool extremely carefully and in compliance with safety rules. The rotation speed of the disc is high and the likelihood of grinding your nails or injuring your hands when processing small parts is high.

During construction and repair work Men often need to process wood, stone or metal. For quality work It is advisable to purchase a tape grinding machine. But what to do when finances do not allow you to make such a purchase? To do this, it is enough to build a belt sanding machine with your own hands.

Purpose of a belt sanding machine

Wood is widely used in a variety of production organizations. Many different parts and products are made from wood. In order to properly process a wooden blank and give it the appearance of a finished product, it is customary to use various equipment, including belt sanders.

Belt grinding equipment is typically used in the final stages of production, when parts are subjected to finishing machining. Such devices are convenient to use in the production of furniture and various consumer wood products. Depending on the material used, belt sanders work with wood or metal.

The main purposes of using wood sanding machines are to final level the surface, bring their roughness level to the required value, obtain smooth and smooth surfaces for wood products and wood material before veneering or after coating with varnish and other finishing materials, removal of local irregularities in the form of depressions and elevations, peeling off burrs and removing local deposits of varnish and primer, deburring, internal grinding and grinding of curves.

Belt grinding machines for metal work with various materials and formats that are common in metalworking: plain and alloy steel, non-ferrous metals in the form of quadrangular, round and flat workpieces. Grinding machines allow efficient and effective minimal costs time to grind round timber and large diameter pipes.

Depending on the type of processing and type of feed, belt grinding machines are intended for:

for grinding curved surfaces with a free sanding belt;
for processing a flat surface with a fixed table, manual movement of the iron and table, as well as mechanized movement of the work table and manual movement of the iron;
for processing panel and block parts, their ends and side edges;
for intermediate sanding of paintwork.

Belt Sanding Machine Design

Belt grinding machines are produced by modern foreign and domestic manufacturers in wide range. Grinding machine prices vary widely. They also differ in possible performance and design. However, they also have something in common. They are united by the fact that absolutely all machines have an abrasive belt as a working element, which is most often connected into a ring and placed between rotating drums.

One drum is the master drum and the other is the slave drum. This means that the first of them is equipped with a mechanical transmission, which is most often based on a belt drive, through which torque is transmitted to it from an electric motor. Any belt grinding machine is designed in such a way that the speed of movement of the drive drum, and therefore the speed of movement abrasive tape can be changed to provide different surface treatment modes.

The abrasive belt can be positioned vertically or horizontally. In addition, equipment modifications are available for sale in which the working element is installed at a certain angle. The abrasive belt is mounted on a frame, on which the workpieces are usually located. Workpieces can be held by the operator manually or with the help of special devices that make the work easier for consumers and make the processing procedure more efficient and safe.

The machine table is made from metal sheets or thick boards. If the design provides for the table to be made of metal, then it will be possible to sharpen more complex products. The length of the working part of the belt grinding machine and the grinding belt itself primarily depends on the length of the products that will be sanded on the machine.

If the part has a shorter length than the working surface of the machine, then it will be much more convenient to process, and the processing will be of higher quality. For example, with a sanding belt length of 4.5 meters, you can easily process wooden blanks, which are 200 centimeters long.

Belt grinding machines are divided into equipment with a fixed and movable work table and devices with a free belt. A special group is wide-belt grinding machines, in which the caterpillar-shaped table is also a feeder. For machines with tables, the belt is placed horizontally; for designs with a free belt, it is installed in different ways.

Since the grinding process inevitably generates a lot of dust, all belt sanding machines are usually equipped with special powerful hoods that remove most of it during the process. technological process. Grinding machines are powered by an electric motor, which has a power of about 2.8 kilowatts. With a high-power motor, the normal speed of the belt reaches 20 meters per second.

Abrasive belts for grinding machines

The cutting tool of belt grinding machines is sanding belt, which consists of tissue or paper base and abrasive grains that are attached to it using adhesives. Abrasive belts are manufactured using two methods: mechanical and electrical. The first method consists of uniformly pouring abrasive grains onto a base that is covered with glue, and the second method occurs in an electric field, which orients the grains upward with their sharpest edges to improve cutting properties grinding machine.

Abrasive grains are poured onto the base in a bundle tightly or sparsely. The most effective is considered to be an abrasive belt with a sparse backfill, when the grains occupy less than 70% of the area, because wood dust generated during the grinding process is not able to get clogged between their grains. Natural minerals or artificial materials, which have high hardness, for example, green and black silicon carbide, white and normal monocorundum, as well as normal electrocorundum.

For the purpose of gluing grains, synthetic resins and hide glue are used. As a base, fabric such as calico and twill, or special grade paper is used. The size of the abrasive grains is indicated by a number that corresponds to the size of the sieve cells in which these grains are retained, and is displayed in hundredths of a millimeter.

If you are interested in how to make a belt sanding machine, then you should pay attention to the following sizes of grinding powders and abrasive grains and their classification: grinding grain - from 2000 to 160 microns, grinding powders - from 125 to 40 microns; micropowders - from 60 to 14 microns, very fine micropowders - from 10 to 3 microns.

Sanding paper is supplied to woodworking enterprises in sheets or rolls. On no work surface The skins are marked with the specified characteristics of the skin and the manufacturer. For a belt sanding machine, skins are used in rolls and cut into strips of a certain length and width. The length of the cutting tool is determined depending on the method of its connection - lap or butt at an angle.

The ends are cut off when gluing end-to-end at an angle of 45 degrees and then glued onto a canvas lining with a width of 80 to 200 millimeters. At one end of the tape, when gluing with an overlap, the abrasive grains are removed hot water over a distance of 80 to 100 millimeters, then place the other end of the tape on the exposed base coated with glue. Squeeze the joined ends and dry them when using special device or size press.

Sheet sandpaper is used for combined belt-grinding machines. For grinding discs, it is customary to cut the sandpaper in the form of a circle according to a template, the diameter of which is 60 - 80 millimeters larger than the diameter of the disc. Using a rectangular template, blanks are cut for the reel. After cutting, they have smooth edges without tears. The presence of unglued ends or seals when gluing tapes can cause premature rupture of the tape.

The skin is cut into sheets using wide-belt sanding machines according to a template made of plywood or aluminum sheet. The skin is cut in such a way that the edges are smooth and the difference in the length of the side edges is no more than 1 millimeter. One of the beveled edges is cleaned, removing abrasive to a width of 20 millimeters. Cleaned edge and longitudinal edges pasted over with a strip of tracing paper, which has a width of 40 millimeters, which protrudes beyond the edge of the skin by about 10 millimeters.

Lubricate the beveled edge with tracing paper with glue and leave it in the air, depending on the viscosity and type of glue. Then the beveled edges are joined and a strip of sandpaper is applied to the joint, the joint is compressed and held in a press. Ready endless tapes It is customary to hang it on special brackets and keep it for at least a day in a dry room before installing it on a grinding machine.

Operating principle of a belt grinding machine

A belt sanding machine consists of a table top with a work table for mounting the cutting tool. This table is fixed in different positions relative to the tabletop. The material for the countertop is usually laminated chipboard 25 millimeters thick. The worktable on rollers is moved manually or laterally by a mechanical drive along round guides that are attached to supports.

Above the table there is a working belt mounted on non-drive and drive pulleys. The sanding belt is tensioned and adjusted using a screw device with a pneumatic cylinder. Double belt sanders have two identical sanding tools that are placed in series on a bed and have sanding belts that move towards each other.

Grinding is carried out by the transverse movement of the work table and the longitudinal movement of a short iron, which presses the belt to the material being processed. The sanding belts are driven by an electric motor via a belt drive. The waste generated during grinding is collected by a dust collector, which is connected to the exhaust network.

When assigning a grinding mode, it is recommended to select the grain size of the sandpaper, the feed speed and the pressing force of the belt to the product based on the specific roughness and properties of the material being processed. The grain size of the skin is usually chosen depending on the hardness of the materials being processed and the required surface roughness. The clamping force and feed speed are interdependent quantities. With little force and high feed speed, some areas of the surface may not be sanded; with high pressure and low feed, burns and blackening of the material are possible.

Before installing the tape, check the quality of its gluing. Do not use incorrectly glued or torn sanding belts with uneven edges. Using the handwheel, you can reduce the distance between the pulleys and put on the belt. The gluing area is placed so that the outer end of the seam on the abrasive side is directed against the working movement of the sanding belt.

The belt tension can be adjusted by moving the tension roller for the belt grinder or the non-drive pulley. It is not advisable to tighten the tape too much, as this will cause it to break. But the sanding belt, with low tension, slips along the pulleys and heats up very quickly. The tension force is set depending on the strength of the base of the cutting tool and is determined by the arrow of its deflection with slight pressure on it.

How correctly the belt runs can be checked by turning the pulley manually or briefly turning on the electric motor. When the belt slips, the pulley axis is turned with a handle to small angle and secured with a locking device. After setting up the belt grinding machine, the dust suction system is turned on, a trial processing of the parts is carried out and their quality is checked.

A manual feed belt grinder can be operated by one worker. By moving the product relative to the cutting tool in the longitudinal direction and rotating the part around its axis, the operator sequentially brings into contact with the tape all areas that form the surface to be processed. If you slow down or move carelessly, sanding may occur.

It is customary to grind individual sections of a part in several passes. Reach quality leveling is possible with proper regulation of the pressure applied to the ironing handle and the speed of movement of the table and ironing. The pressure must be reduced as you approach the edges to prevent them from being sanded off. To increase the quality and productivity of grinding, small bars are placed on the table in a row, several pieces at a time.

Belt grinding machines with mechanical feed of products are serviced by two operators. One of them places the part on the conveyor, orients it along the width of the work table and directs the product under the clamping elements of the machine. When being picked up by a conveyor, parts must not be moved laterally.

It is not allowed to feed into the machine workpieces that have unequal thickness and parts with gross surface defects. The feed rate and pressure of the clamping beam, as a rule, are not regulated during processing. The second operator receives finished parts and ensures that unacceptable edge rounding and sanding does not occur.

Making a Belt Sanding Machine

The price of belt grinding machines from an industrial manufacturer is quite high, so when they are used infrequently, craftsmen involuntarily think about whether to buy the equipment or not. An alternative to buying an expensive machine is to assemble it yourself. The main parts of the machine are the frame, rollers and engine.

The engine can be removed from the old one washing machine. Cut the frame from thick iron measuring 500 by 180 by 20 millimeters. Cut one side evenly on a metal milling machine; it is required for attaching the platform with the motor. The dimensions of the working platform are approximately 180 by 160 by 10 millimeters. Make markings and drill three holes in the end of the evenly cut frame. It is necessary to tighten the platform to the frame with three bolts.

Remember that the longer the work table is, the more options you will have when choosing a technological method for grinding and processing the product. If the length of the workpiece is less than or equal to the length of the work table, then you can achieve a perfect grind much easier than when moving a large workpiece.

The engine must be placed tightly on the frame. It should have a power of approximately 2.5-3.0 kW and a rpm of about 1500. If you choose a sanding belt speed of approximately 20 m/s, then the diameter of the drums should be about 200 millimeters. Thus, if the engine speed is sufficient, a gearbox for the grinding machine is not required.

One of the two drums will play the role of a drive drum, which should be firmly fixed to the engine shaft, and the other tension drum should rotate freely around a fixed axis on bearings. The table on the side of the driven drum should have a certain bevel, which will ensure smooth contact of the sanding belt with the surface of the work table, this is especially true for a glued joint.

You can make a tension drum and a drum that guides the sanding belt from chipboard. To do this, you need to saw blanks from the slab overall dimensions 200 by 200 millimeters and from them assemble a package of 240 millimeters. Square tiles or a package of them should be folded on an axis and machined to a diameter of about 200 millimeters.

Remember that in the center the diameter of the drum should be 2-3 millimeters larger than at the edges. With a similar surface geometry, the flexible sanding belt will be located in the middle of the drum. The optimal tape width is 200 millimeters. From a roll of emery cloth that is 1 meter wide, you can easily glue 5 similar tapes together.

The cutting tool must be glued end-to-end, with a thin, dense material, for example, a tarpaulin, placed underneath. It is recommended to use the highest quality glue you can get. Be sure to stretch rubber onto the rollers, the width of which reaches 30 millimeters. Rubber can be taken from the inner tubes of a moped or bicycle.

On a homemade belt sanding machine, in addition to grinding wooden products, for which it is actually intended, it is very convenient to sharpen tools with cutting surfaces - chisels, knives, axes, pruners. Another advantage of this grinding machine is the ability to work with parts that have a curved surface - to do this, you need to grind the workpiece with the back side of the work belt.

When work with a wooden surface comes to an end, the final sanding stage begins. To perform grinding without burrs, scratches, and to beautifully round sharp corners of any part, you need to use a wood sander. This tool will help you perform professional grinding even for a beginner who picks up the machine for the first time. If you wish, you can make a grinding machine yourself, using only available tools.

The industry produces several types of machines, differing both in design and purpose. Here are the main ones:

Eccentric or orbital, in this case the base of the tool simultaneously rotates around its axis and along a certain orbit. It turns out that each time it passes in a slightly different place, so scratches and burrs are rubbed out more and more with each pass.

Vibration model. Here the working sole carries out reciprocating movements with a frequency of about 20,000 movements per minute. It is through these movements that grinding occurs.
An angle grinder, which is popularly called a “grinder”. Using this tool, rough processing of parts, large logs, etc. is carried out. Abrasive wheels of the required grain size are used for processing.
A belt sander typically used for large surface jobs. Structurally, it consists of rollers driven by an electric motor, on which sanding tape is worn.

Making a belt sander with your own hands + (Video)

Making a belt sander yourself is not at all difficult; you need to complete the following steps:

select suitable materials and parts;
do solid foundation for securing the tool;
install a suitable tabletop;
secure the vertical posts with tensioner and drum;
mount the motor and drums;
secure with sanding tape.

To process fairly large parts and elements, it is necessary to make a large copy of a serial grinder. For example, if you take an electric motor with a power of 2 kW or more powerful with a rotor speed of 1500 rpm, then you don’t need to install a gearbox. The power of such an engine is quite enough to rotate a drum about 20 cm in diameter and process parts of about 2 m.

You can also use an electric motor from an old one washing machine. In this case, the frame is made from a thick sheet of iron, preparing a place for installing the motor and carefully securing it with bolts to eliminate vibration. The design of such a machine consists of 2 drums, one of which is fixed, and the second can be tensioned and rotates on bearings around an axis. It is advisable to make the base for the machine from metal or several sheets of thick plywood. Drums are made by lathe from chipboard. The tape is cut from sandpaper sheets about 20 cm wide and secured to the frame. The larger the table size, the larger the parts can be stacked and processed in the future. Blueprints finished products can be found on the web.

https://youtu.be/vDs1gBM_MW4

Making a grinder from a grinder

Many may say that the “grinder” is the same as an angle grinder, but there are some subtleties hidden here. It should be borne in mind that the angle grinder has very high speeds and often quite a decent weight. To polish a surface with a grinder, you need to have considerable experience in this matter and use special polishing discs and circles. The grinder has much lower engine speed and weight. To operate a factory grinding machine, no specific experience or skill is required.

You can independently make a good grinder from a grinder, which is not inferior in its parameters to a factory machine, only by modifying it electrical diagram, by installing the regulator at lower speeds and by using special grinding attachments.

Making a grinder from a drill

To turn ordinary, household electric drill The grinding machine must be equipped with a special attachment - a working drum or a special support plate, depending on the task at hand.

The support or sanding pad is a plastic or rubber base with sandpaper glued on and a shank for clamping into the drill chuck. Discs with a flexible shaft are suitable for working with a loose drill, while those with a rigid shaft are best used only for a well-secured drill.

Sanding drums for a household drill are structurally a regular cylinder, a shank and sandpaper glued to the cylinder. When using drums, the working surface of the grinder is parallel to the axis of rotation.

Making an orbital sander

Currently, you can only make an orbital machine with your own hands from a broken orbital machine. This is due to a complex device for rotating the working disk, which is quite problematic to replicate on your own. You should also keep in mind that a machine manufactured by a specialized company will not cost too much, but making it yourself will be very difficult and will take a lot of time.

Making a grinder from a computer hard drive + (Video)

Any old hard drive can be converted into a miniature grinding machine. To do this you need to follow these steps:

completely disassemble the hard drive and remove from the case everything that is located to the left of the magnetic disks;
cut out a working circle from sandpaper, make a hole in the center of the circle for the spindle;
stick several strips of double-sided tape onto the rotating disk of the hard drive and secure it with sandpaper;
do protective screen, protecting the eyes from possible flight of the manufactured sanding disc;
to plug finished design to the power supply from the computer and use it.

Of course, this design does not have high power, but it is quite possible to sharpen a small knife or scissors.

Hand-held power tools have become so widespread these days that not a single craftsman can do without them. However, sometimes even this toolkit is not enough, and there is a need for serious equipment for your workshop. So in my practice, a period came when a belt grinding machine became necessary, allowing me to process the surfaces of large parts.

Industrial copies of grinding machines are too expensive. So I had to come up with something myself. An ordinary manual belt machine, in which a continuous sanding belt moves along a straight surface of the soleplate with the abrasive side outward, seemed to me the ideal structural prototype for a homemade machine. Naturally, my machine will be much larger in size, and it will be installed permanently.

It so happened that I needed to process a large number of parts about two meters long. This determined the dimensions of the table and the future machine itself. (photo 1).

There was no need to choose an electric motor. I installed the motor I have on the machine with a power of 2.5-3.0 kW and a speed of 1500 per minute. If the belt speed is chosen to be about 20 m/s, then the diameter of the drums should be close to 200 mm. Thus, it turned out that at the speed of our engine, the machine does not require a gearbox.

Of the two reels, one plays the role of the leader. It should sit rigidly on the motor shaft, and the other - the tension one - should rotate freely on bearings around a fixed axis. To regulate the tension of the tape, it is enough to shift this axis along the desktop in one direction or another (photo 2). I built the table from thick pine timber, but now I think it should have been made from sheet metal. "

It is quite obvious that the distance between the shafts and the length of the sanding belt depend on the length of the table. The size of the entire platform on which the machine parts are mounted (electric motor with drive drum, work table, driven drum with tension device) is also decisive. On the side of the driven drum, the table must have a bevel (photo 3). ensuring a smooth touch of the tape (especially its glued joint) to the surface of the desktop.

Make a leading sanding belt (photo 4) and tension (photo 5) drums can be made of chipboard. To do this, it is enough to cut blanks measuring 200x200 mm from the slab and assemble a 240 mm package from them. Square tiles - each separately or (if the lathe allows) together, placing the blanks on an axis - grind to a diameter of 200 mm. The latter option is preferable, since the drum can be made in one installation. It should be borne in mind that the diameter of the drum in the center should be 2-3 mm larger than at the edges. It is known that with such a surface geometry, the flexible tape will be held in the middle of the drum. In my opinion, the optimal tape width is 200 mm. From one roll of emery cloth 1 m wide you can easily glue 5 such tapes.

If at the very beginning I expected to process exclusively wooden blanks (photo 6-10), then during operation I discovered the ability to quickly and efficiently sharpen special tools, for example, various profile fully assembled cutters.

It turned out that the longer the work table, the greater the opportunity for imagination when choosing a technological method for processing a product. Personally, I had to work with a tape of about 4.5 m, while the length of the processed parts reached 2 m. This does not mean that the length of the workpieces cannot be even greater. Under certain conditions, the length of the workpieces being sanded may not matter. If they are narrow, then any of them is the machine's capabilities. Now I don’t have to go to specialized workshops to sharpen cutting tools: planes, jointers, surface planers, etc. (photo 11-13). Such quality of ax sharpening (photo 14), knives, chisels and various chisels I could not achieve before on any universal sharpening equipment. And if you remove wooden table and make it from iron, it will be easy, you can put it on an abrasive belt (photo 15). But when the length of the workpiece is equal to or less than the length of the table, then achieving perfect grinding of the entire surface is much easier than when moving a large workpiece.

Belt is used in cases where it is necessary to perform finishing processing of parts, that is, as equipment for carrying out finishing technological operations. Most often, such machines are used in the furniture industry; they are used to process parts made of wood. various breeds. But you can also use a belt grinder to process metal parts, for which a tape with an appropriate abrasive material is used.

Application areas of the machine

The main tasks performed by the belt grinding machine are: final leveling of the surface being processed, bringing the level of surface roughness to the required level, bringing the processed surfaces to the level of smoothness before covering them with varnish and other finishing materials. The belt machine is also used to eliminate minor defects of the processed surface: depressions, elevations and burrs, processing the finishing coating: removing sagging primer and varnish, burr, grinding internal surfaces, processing roundings on the surface of the part.

A factory-produced option, the drawings of which can be used to create a similar homemade device.

The band saw can be used to process parts made from various materials: wood, plain and non-ferrous metals. What’s convenient is that you can process parts that have different shape: quadrangular, round and flat. Using such equipment, it is possible to process round and tubular parts with a large cross-sectional diameter.

Design features of the machine

The working tool of any belt is a belt on the surface of which abrasive powder is applied. It is made in the form of a ring and is placed between two rotating drums, one of which is the leading one and the second is the driven one.

Rotation on drive shaft band press transmitted from an electric motor, which is connected to it using a belt drive. The speed of movement of the belt mechanism can be adjusted, thereby changing the processing modes of parts. The belt of a surface grinding machine can be positioned horizontally or vertically, as well as at a certain angle, which is allowed by some models of equipment in this category.

When choosing a belt sanding machine model for processing a particular part, it is important to consider the length of the surface that needs to be sanded. It is much more convenient to process parts on such machines whose surface length is shorter than the length of the abrasive belt and work table. If such conditions are met, the quality of processing will be much higher.

The belt grinding machine can have different 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 work table, which is also a feed element, is made in the shape of a caterpillar. In those equipment models that have a work table in their design, the abrasive belt is located in a horizontal plane, and in equipment with a free belt that does not have a work table, it can have a different spatial position.

A mandatory structural element of any belt sanding machine, including a tabletop one, is an exhaust device, which is necessary to remove dust generated in large quantities during the processing process. Both a professional and any homemade grinding machine used in a home workshop or garage are powered by an electric motor.

Principle of operation

The main operating parameters of a belt sanding machine include the feed speed and the force with which the belt is pressed against the workpiece. Parameters such as the degree of grain size of the abrasive belt should be selected depending on the material from which the workpiece is made, as well as the degree of roughness that the surface of the machined product should have.

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

Another variation of the machine - view from the working surface of the belt

The results of grinding are also influenced by how well the abrasive tape is glued together. In order to obtain high quality processing and not encounter malfunctions in the operation of the belt machine, you should not use abrasive belts that are glued incorrectly or have torn edges. When putting the tape on the equipment shafts, it should be positioned so that the overlapping end of the seam does not ride up against the surface of the workpiece, but slides along it. Learn more about gluing tape in the video below.

Any, including a manual grinding machine, must provide the ability to adjust the belt tension, which is ensured by moving a movable shaft that is not driven. Belt tension is very important parameter, when choosing which you should be guided by the “golden mean” rule. If the sanding machine belt is pulled too tightly, this can lead to its rupture during operation, and if its tension is too weak, it will cause slippage and, as a result, excessive heating. The main characteristic for determining the degree of tension of the tape is its deflection, which is measured by lightly pressing on its surface in a tense state.

A manual belt grinding machine can be serviced by one operator, who moves the work table with the workpiece and rotates it so as to bring all areas of its surface under the abrasive belt.

How to make a belt sander

Many home craftsmen and professionals are wondering how to make a grinding machine with their own hands. The reason for this question is quite simple: high price serial grinding equipment, which not everyone can pay for if not used regularly. In order to make such equipment, you will need several main components: an electric motor, rollers and a reliable frame. Naturally, drawings of such a device or a photo of it would 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 grinding equipment is not difficult to find; it can be removed from an old washing machine. You will have to make the frame yourself; for this you can use a sheet of metal with dimensions 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 180x160x10 mm. Such a platform must be secured to the frame very securely using several bolts.

Another version of the bed

The efficiency of a belt sanding machine directly depends on the characteristics of the electric motor that is installed on it. If you are planning 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 for the sanding belt to move at a speed of 20 m/s when using such a motor, the drums must have a diameter of about 200 mm. What’s convenient is that if you choose an engine with these characteristics, you won’t need to make a gearbox for your grinding machine.

The drive shaft is connected directly to the electric motor shaft, and the second - driven - must rotate freely on an axis, which is installed in bearing units. In order for the abrasive belt to touch the surface of the workpiece more smoothly, the section of the frame on which the driven shaft is installed should be slightly beveled.

You can make shafts for a belt grinding machine with minimal financial costs from chipboards. Simply cut square blanks of 200x200 mm in size from such a plate, drill central holes in them and place them on the axle with a package with a total thickness of 240 mm. After this, all you have to do is grind the resulting package and make it into a round shaft with a diameter of about 200 mm.

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

Wood belt sander (click to enlarge)

Table tilt adjustment mechanism Plate block Belt tensioner Machine assembly

The industry produces several types of machines, differing both in design and purpose. Here are the main ones:

Eccentric or orbital, in this case the base of the tool simultaneously rotates around its axis and along a certain orbit. It turns out that each time it passes in a slightly different place, so scratches and burrs are rubbed out more and more with each pass.

Vibration model. Here the working sole carries out reciprocating movements with a frequency of about 20,000 movements per minute. It is through these movements that grinding occurs.
An angle grinder, which is popularly called a “grinder”. Using this tool, rough processing of parts, large logs, etc. is carried out. Abrasive wheels of the required grain size are used for processing.
A belt sander typically used for large surface jobs. Structurally, it consists of rollers driven by an electric motor, on which sanding tape is worn.

Making a belt sander with your own hands + (Video)

Making a belt sander yourself is not at all difficult; you need to complete the following steps:

select suitable materials and parts;
create a reliable basis for securing the tool;
install a suitable tabletop;
secure the vertical posts with tensioner and drum;
mount the motor and drums;
secure with sanding tape.

You can also use an electric motor from an old washing machine. In this case, the frame is made from a thick sheet of iron, preparing a place for installing the motor and carefully securing it with bolts to eliminate vibration. The design of such a machine consists of 2 drums, one of which is fixed, and the second can be tensioned and rotates on bearings around an axis. It is advisable to make the base for the machine from metal or several sheets of thick plywood. The drums are made on a lathe from chipboard. The tape is cut from sandpaper sheets about 20 cm wide and secured to the frame. The larger the table size, the larger the parts can be stacked and processed in the future. Drawings of finished products can be found online.

https://youtu.be/vDs1gBM_MW4

Making a grinder from a grinder

You can independently make a good grinder from a grinder, which is not inferior in its parameters to a factory machine, only by modifying its electrical circuit, by installing the regulator at lower speeds and by using special grinding attachments.

Making a grinder from a drill

To turn an ordinary household electric drill into a grinding machine, you need to equip it with a special attachment - a working drum or a special support plate, depending on the task at hand.

Making an orbital sander

Making a grinder from a computer hard drive + (Video)

Any old hard drive can be converted into a miniature grinding machine. To do this you need to follow these steps:

completely disassemble the hard drive and remove from the case everything that is located to the left of the magnetic disks;
cut out a working circle from sandpaper, make a hole in the center of the circle for the spindle;
stick several strips of double-sided tape onto the rotating disk of the hard drive and secure it with sandpaper;
make a protective screen to protect the eyes from the possible ejection of the manufactured sanding disc;
connect the finished design to the power supply from the computer and use it.

Of course, this design does not have high power, but it is quite possible to sharpen a small knife or scissors.

Grinding machines from the manufacturer are expensive and therefore if they are used infrequently, then you involuntarily think about whether to buy it or not.

And if, in addition, there is no free money, then you have to make something with your own hands. This is what happened with this homemade grinding machine.

The simplest hand-held sander was taken as a sample (read about how to choose an eccentric sander). In such a sander, the abrasive belt moves along the surface of the sole, with the rough side outward (abrasive).

That is, in the future belt grinding machine I laid down the same principles in advance, changing only the dimensions in the plans - I need a large machine so that it can be used to process parts of at least 1.9-2 meters by grinding, and it must be installed permanently.

The entire design of the grinding machine is based on an electric motor with a power of 2.8 kilowatts and a speed of 1500; I already had it, so I didn’t have to buy anything.

There was no need to install a gearbox, because with an electric motor of such power, in order to achieve a normal belt speed (which will be quite enough for grinding) of 20 meters per second, the diameter of the drum should be only about 20 centimeters.

The design has 2 drums: one, rigidly fixed to the shaft - the driving one. The second is tension, it rotates around an axis on bearings.

To tighten or loosen the sanding belt, just adjust this axis in either of the 2 directions.

The machine table is made of thick boards, if possible in the future I will remake it and make it from metal sheets.

The length of the working part of the machine, as well as the grinding belt itself, depends, first of all, on the length of the working surface of the table. The second shaft is equipped with a bevel as shown in photo No. 3, this is necessary to ensure that the tape touches the edge of the table as smoothly as possible.

Both drums can be made from ordinary chipboard. To do this, file square tiles 20 by 20 centimeters and assemble a workpiece of 24 cm from them and then grind them on a lathe to a diameter of 20 centimeters. When making a drum, take into account the fact that the tape will stick to it better if it is a couple of millimeters larger in diameter at its center.

About the sanding belt. Through trial and error in practice, I found that the best width of the sanding belt is 20 centimeters - with this width you can perform all the tasks facing the machine and, moreover, cut 5 such belts from a meter roll of sandpaper, without any residue.

Besides sanding wooden parts, for which it was originally intended, on such a homemade machine it is very convenient and quick to sharpen any tools with cutting surfaces - knives, chisels, axes, knives, pruners, etc. The sharpening quality is excellent.

In principle, if the design provides for the manufacture of a table not from wood, but from metal, then it is possible to sharpen more complex ones, special tools, which no universal device can handle sharpening.

Let me emphasize once again that in this machine a lot depends on the length of the table. It is this that gives you scope for possibilities, because when a part is shorter than the length of the working surface of the machine, it is much more convenient to process it and the processing will be of higher quality. For example, with a sanding belt length of four and a half meters, you can easily process wooden workpieces 200 cm long.

Another advantage of such a do-it-yourself grinding machine is that with some skill you can also work with parts that have curved surfaces (as shown in photo 16) - to do this, just remove the wooden table and, placing the workpiece on the bed, grind the part the reverse, bottom side of the working tape.

DIY belt grinding machine: photo

Below are other entries on the topic “How to do it yourself - for a homeowner!”

How to make a homemade grinding machine Recently...

For wood - a highly efficient device for processing material planes. Using such units, you can quickly and efficiently process wood, obtaining perfectly smooth surfaces.

Classification

A wood sander is used at the final stage of wood processing. During the work, special rough circles, tapes, and powdered pastes are used.

Currently, based on their purpose, the following units are distinguished:

Automatic cylindrical grinding devices.
Devices designed for processing the internal surfaces of parts and workpieces.
Surface grinding machines.
Specialized models that are used to implement narrowly focused tasks.

Areas of application

The areas in which a wood sander can be used are extremely varied. The latest advances in the field of carpentry processing of parts make it possible to replace large turning units with more convenient to use mobile devices.

Such common solutions as drum and belt sanders for wood can be successfully used for:

Rough abrading of workpiece surfaces.
Precise processing of wood planes.
Obtaining refined surfaces.
Cleaning of timber and panel parts, their side and end edges.
Intermediate sanding of paint and varnish coatings.

Thanks to its wide range of uses, a wood sanding machine is one of the most popular units among professional carpenters. Manufacturers are constantly improving popular models and offering consumers a whole host of additional tools to perform complex, specific tasks.

How to assemble a wood sanding machine with your own hands

We propose to consider the features of self-assembly of a drum device for processing the external surface of wood. This will require several functional design elements. Some of them can be found in the household.

Engine

To assemble a wood sander, the easiest way is to remove the motor from an old washing machine. Fortunately, Soviet-made models gather dust idle in many closets. From here you can get belts, pulleys and electrical parts.

However, for assembling the grinding unit Any will do motor with power from 200 to 300 W. It is desirable that its design be compact in size.

If it is necessary to obtain maximum efficiency indicators, you will have to find asynchronous motor, capable of delivering 1500-3000 rpm.

Drum

This structural element can be made using all kinds of leftovers building materials. Sometimes, to assemble a drum sanding machine for wood, it is enough to take a pipe covered with old linoleum, rubber rings glued together or cylindrical bars mounted on a metal axis. Let's look at the first of these options.

To make a drum, it is enough to use a piece of PVC pipe, a metal rod, a strong board, screws, glue and linoleum. Plugs are cut out of wood corresponding to the cross-section of the existing tube, in which holes are drilled for the rod. Such locking elements are inserted into the pipe and secured with screws.

A metal rod is passed through the plugs and seated on epoxy glue. A layer of dense linoleum is glued on top of the polyvinyl chloride pipe. As alternative option You can use rough rubber. This shell will act as the basis for securing the sandpaper. You can fix the latter on the finished drum using double-sided tape or staples for a stapler.

Frame

To make the case where the homemade wood sanding machine will be placed, ordinary plywood is suitable. You can make a design of a rather unassuming structure. All you need to do is install the side panels, work table and additional reinforcement struts. If desired, you can make a metal shell.

Installation

The engine is securely mounted on a statically installed base. The rotating axis is threaded through a pre-prepared hole in the housing wall. Sanding drum is installed in the upper part and rests on bearings in cages that are fixed to the side walls of the structure.

Pulleys are attached to the axis of the drum and engine. The drive belt is being tensioned. Wiring and switches are connected. Clamping bolts are screwed into the sides of the housing, and adjustment bolts are screwed into the lower part.

To give the structure a complete and attractive look, you can treat the surfaces with paint. Naturally, it is necessary to undertake such work before assembling and installing the unit. To increase safety during operation of the device, the design can be supplemented protective casing, placed above the drum.

Finally

Thus, we tried to consider the main classes of grinding machines, their areas of application, and also gave an example of self-assembly of a drum-type unit. Ultimately, the decision to purchase a factory device or assemble it from existing materials depends on the size of the budget, goals, available funds and the needs of each individual user.

When working with wood, the final stage of processing the material will be sanding. A grinding machine will help you with this. There are many on the market various models, but if your budget is bursting at the seams, you can make such a machine yourself.

How to make a sander

Do a simple typewriter possible from hard drive your PC. To do this, you will need the hard drive itself, an abrasive, and a PC power supply. It will be intended to work with small details. When disassembling the disc, stick the abrasive onto the rotating plane. After this, the structure must be connected to the PSU (power supply), and then the entire structure must be secured on the working surface of the table, equipped with a speed controller and a switch.

DIY wood sander

Grinding machines are presented in the following types:

eccentric or orbital;
vibration;
corner;
tape

When making a machine you will need:

electric motor;
power supply.

The power unit must be taken from household appliances, for example, from a fan, a computer power supply, a household battery. As a basis for the above elements a board will do made of wood, onto which a battery with an electric motor should be secured with screws. The “start” button must be attached to the base with self-tapping screws. The wire strands are fixed using industrial staplers.
The working part of the tool is grinding wheel, which you can purchase yourself. The abrasive disk will be driven by an electric motor using two bushings.
You can strengthen the design of the device if you use a motor from a washing machine as a motor. In addition to polishing discs, in this case, sharpening and abrasive discs can be installed on the tool.

Homemade belt sander

The working element in this type of device is an abrasive sanding belt. A self-made machine will be stationary and have larger dimensions compared to an industrial model. To make a sample, it is best to use a power unit with a power of 2–3 kW and a rotor speed of 1500 rpm.
The radius of the drive drum directly affects the speed of the belt. The larger it is, the higher the speed of the belt. Homemade design will not allow you to regulate the speed of the belt, however, you can influence the tension force by shifting the fixed axis of the tension shaft mounted on the motor shaft relative to the work table.
The workbench for the grinding machine should be made of wood or metal. The sander belt can be made from abrasive paper, available at a hardware store.
The working element, which is the sanding belt, is driven by a transmission and drums by a power unit. Shafts are divided into driving and driven. Drums can be made using chipboard sheets, processing them on a lathe so that the processing results in disks about 20 cm in diameter. One thing to consider when processing is that the edges of the rollers must have a larger diameter than the central part to automatically hold the tape. The dimensions of the rack will depend on the width of the belt and the distance between the shafts. At the location of the shafts in the web, it is necessary to make slots for smooth passage of the tape.

How to make a mini grinder with your own hands

First, you need to find some foam to prepare the base for the device. After this, you need to cut a hole to install the switch in it. Then you will need electrical tape and a power source, for example, the well-known Krohn battery. We tape the battery (Crown) to the foam base with electrical tape. Take a champagne cork and a pen refill. We cut the rod to the required length, then put the handle rod on the plug with the blunt end and insert the tip of the rod into the hole for the motor shaft. After this, you need to use scissors to cut a strip of abrasive tape to fit the size of the cork. After you have cut out the tape, it should be glued to the cork around the circumference. This cork construction will be working part cars. We carefully inspect all the wires and connect them with twists, insulating the connections with electrical tape. Let's try to launch the resulting device. Now you have your own mini car. This device is useful for performing simple tasks. minor works, for which a conventional grinding machine will be too large and inconvenient. If you are an observant and patient, as well as diligent person, making your own sanding machine is not at all difficult. To do this, you only need deft hands and a little patience.