Homemade wood sander. Grinding machine with your own hands. Design features of the machine

Grinder (English) literally - a crusher. Meat grinder is a meat grinder, rock (stone) grinder is a stone crusher; stick (wood) grinder - garden crusher of branches and rods into chips. But there is also a completely unambiguous meaning of the word grinder: in mechanical engineering and metalworking, this is a grinding machine. A useful household item. For example, it is impossible to manually guide a dull meat grinder knife on a whetstone. On a manual knife sharpener - somehow possible, with a solid working skill. And on the grinder - no problem. The same - if you need to grind a part of a complex shape without violating its profile. Or just sharpen scissors or a professional knife. All kinds of cutters for wood and metal are best corrected also on the grinder. It is quite possible to design and assemble a grinder with your own hands, without having sophisticated equipment and skills to work on it. In terms of money, this will mean savings from 50-90 thousand rubles. up to 3-6 thousand USD.

To make a grinder yourself, you will need to order a maximum of 4-5 turned parts, and it is often possible to do without turning from outside at all. For example, how to make the simplest grinder literally from trash, see the video below:

Video: do-it-yourself tape grinder from trash

Or another option, how to make the grinder stronger and more resilient from scrap metal:

Video: scrap metal grinder

Disk or tape? And drive

Almost more varieties of grinding machines are used in industry than lathes. Emery known to all craftsmen - a motor with a pair of grinding wheels (or one circle) - this is also a grinder. For yourself at home, it makes sense to make either a disc end (plate) or a belt grinder. In the first, the abrasive is applied to a rotating HDD; in the second - on an elastic tape running around a system of pulleys and rollers. Disc is more suitable for grinding simple wooden parts and coarse or medium purity - metal. On a belt grinder, it is also possible to produce precise and clean finishing of profiled parts of complex shape, incl. large, see below.

A disc grinder is very simply obtained from the same emery or a motor of suitable power, see below. It is necessary to order an adapter from the motor shaft for the shank of a cup-shaped grinding wheel on a metal base. Or under a chuck, then on the same motor it will be possible to build a mini lathe, see fig.:

A worn-out “plate” is suitable: a disc made of thin (4-6 mm) fibrous plastic is glued onto the edge of its side, and an abrasive is placed on it. How to make an end grinder, see next. video clip.

Video: homemade end grinder

The difference between a disc grinder and a belt grinder is not only in the possibilities of use. If you take ordinary home crafts, then a drive power of 250-300 W on the shaft is enough for a disk grinder. For small wooden parts - and 150-170 watts. This is a motor from an old washing machine, a straight (ordinary) drill or a screwdriver. But for a belt grinder, you need an engine from 450-500 W: three-phase with batteries of starting and operating capacitors. If it is supposed to process a large size, then the motor power is from 1-1.2 kW. Moreover, capacitor banks for both will cost a little less than the engine itself.

Note: a 100-200 W drive uses a mini belt grinder (see below) for fine dressing of knives, grinding / polishing jewelry, etc.

A drill or screwdriver as a grinder drive is also convenient in that it allows you to quickly change the speed of the abrasive (see below) with a standard speed controller. It is only necessary, firstly, to make a holder for the drill, rigidly fixing the tool. Secondly, an elastic adapter from the drill to the disc shank, because it is difficult to achieve their precise centering without special equipment, and the runout will negate the accuracy of processing and can damage the tool-drive.

Drawings of the drill holder for using it as a drive for a home metal-cutting machine are given on the left in the figure:

Since shock and irregular alternating loads on the drive in the grinder are an order of magnitude lower than, say, in lathe, the drill holder for it can be made of solid wood, plywood, chipboard, MDF, on the right in fig. The diameter of the mounting (large) hole is along the neck of the drill. It is highly desirable to use a drill without an impact mechanism and with a steel shell on the neck (for the installation of the front handle).

Coupling

For the adapter, you will need a piece of steel bar (not necessarily turned) of the same diameter as the shank of the grinder drive shaft, and a piece of reinforced PVC hose (garden irrigation) with a gap so that it is tightly pulled over the bar and shank. The length of the “free” hose (between the ends of the rod and the shank in it) is 3-5 cm. The length of the protruding part of the rod should be sufficient for a reliable clamp in the drill chuck. After assembling the coupling in place, the hose on the shank and rod is tightly tightened with clamps; can be wire. Such a coupling completely parries the misalignment of the drive and the driven shaft up to 1-1.5 mm.

Ribbon is still better.

A belt grinder allows you to do everything that a disc grinder does, and more. Therefore, further we will focus on how to make a belt sander with our own hands. Amateurs, focusing on industrial designs, sometimes make grinders very intricate, see fig.:

And this is justified: the design and kinematics of the belt grinder are very flexible, which makes it possible to successfully use improvised materials and old scrap metal. You just need to follow 3 principles:

Do not do as in the second photo from the left: the tape with the abrasive side should only touch the workpiece. Otherwise, the abrasive will eat both the bypass rollers and itself. The accuracy and cleanliness of processing during one working operation will be unpredictable;
The design of the machine must ensure uniform belt tension, regardless of the nature of the operation being performed;
The speed of the belt movement must correspond to the nature of the operation being performed.

Kinematics and design

As mentioned above, there are many designs of grinders. Thinking about what and how to build a grinder for yourself, it is better to focus on industrial designs designed for fully mechanized precision and clean grinding of large-sized profiled parts: since the propeller blade of an aircraft or wind turbine “skins” as it should, then it will cope with any other work.

Kinematic schemes of grinders for the specified purpose are given in Fig.:

Basic kinematic diagrams of belt grinders (grinders)

Pos. A - the most complex and perfect, with three rocker arms. If the length of the tensioning roller rocker is approx. 2 times less than the working one, then by adjusting the tension of the springs, it is possible to achieve a uniform tension of the tape when the working rocker moves 20-30 degrees up and down. By tilting the bypass rocker, firstly, the machine is reconfigured for belts different lengths. Secondly, in the same way, you can quickly change the belt tension for different operations. The working branch of the tape can be any, except for the one running from the drive pulley to the tension roller, i.e. a grinder with 3 rocker arms is both horizontal and vertical at the same time.

A scheme with a coaxially swinging rocker (pos. 2) is simpler, cheaper and not inferior in processing accuracy to the previous one, if the length of the rocker between the axes is at least 3 diameters of the workpiece. In order to knock down the profile by grinding, the course of the rocker arm is limited by stops within 10 degrees up and down. The clamping of the tape to the part is most often gravitational, under the weight of the rocker with a bypass pulley. It is possible to quickly change the tension of the tape within certain limits by pulling the rocker up with a weak adjustable spring, which partly compensates for its severity. The grinder of this scheme can work as a grinder for small parts from a sliding table. In this case, the rocker arm is rigidly fixed horizontally, and the running surface of the tape will be a bypass pulley. According to the scheme with a coaxial rocker arm, for example, a fairly popular BTS50 grinder was made. The disadvantages of the scheme are, firstly, the technologically complex rocker arm hinge coaxial with the drive shaft. Secondly, the need for an elastic band: if you make the bypass pulley sliding spring-loaded, the machining accuracy drops. This disadvantage when processing small parts is completely eliminated by an additional tension roller, see below.

A scheme with one misaligned rocker arm in industry is used quite rarely, because. in principle, it does not allow to achieve a uniform tension of the tape. However, it gives an accuracy that is quite sufficient at home and allows you to build a very good simple grinder.

What's good for what

Now let's see what is possible to "squeeze" out of this or that scheme from the point of view of an amateur master. And then we’ll try to figure out how to make a belt for the grinder ourselves and do without custom-made turned parts.

3 rockers

Competent amateurs build their grinders exactly according to the scheme with 3 rocker arms, on the left in fig. below. Far from all propeller blades are ground, but in this case another advantage of this scheme operates: if the grinder is used as a vertical one, then the working branch of the tape is elastic. This allows a skilled craftsman, for example, to guide cutting edges and blades with literally micron precision.

In industrial grinders for home use, the 3-rocker pattern is also widely used (in the center) for the same reasons. Repetition of them independently in most cases is quite possible. For example, drawings of the popular KMG grinder abroad can be downloaded.

The dimensions, however, are inch - an American typewriter. For the drive, in any case, it is possible to use an angle grinder drill (on the right in the figure, it is quite suitable in terms of power) with a homemade pulley and rollers, see below.

Note: if you are making a stationary drive, try to get a 2-3 speed asynchronous motor from a worthless washer with a horizontal tank. Its advantage is low turnover. This makes it possible to make the drive pulley of large diameter and thereby eliminate belt slippage. A slippage of the tape in the work is almost certainly a damaged part. Most washers with 2-3 speed 220 V asynchronous motors are Spanish. Shaft power - 600-1000 watts. If you come across one, do not forget about the standard phase-shifting capacitor bank.

Coaxial rocker

IN pure form amateurs do not make grinders with a coaxial rocker. The coaxial hinge is a complicated thing, you can’t make an elastic band yourself, and a purchased one is expensive. Grinders with a coaxial rocker at home are most often used in the variant for fine precision work from the table, i.e. with a rigidly fixed horizontal beam. But then the need for a yoke as such disappears.

An example is a mini grinder, the drawings of which are given in Fig.:

Its features are, firstly, an overhead bed for the tape (pos. 7), which greatly expands the possibilities of use. For example, a planer iron is straightened on this grinder with an angle stop literally by itself. In this case, the grinder works, so to speak, like a self-propelled donkey (emery bar). After removing the bed, we get a grinder with an elastic band for precise grinding / polishing of rounded small parts. Secondly, the tension shaft (pos. 12). Clamping it with a groove with nuts, we get a relatively fixed tension of the tape for working with the bed. And having released the nuts, we put the grinder into the mode of gravitational tension of the tape for fine work. The drive is not necessarily through a pulley (pos. 11). Can be screwed directly behind the drive shaft shank (pos. 16) from the drill through the adapter, see above.

A specialized tool grinder (for example, for aiming and dressing turning tools) generally loses any semblance of the original scheme. A high-speed motor is taken for it (a power of 200-300 W is enough). The drive pulley, respectively, of small diameter. The bypass pulley, on the contrary, is made larger and heavier, for inertia. All this together allows you to reduce the runout of the tape. The tension roller for the same purpose, plus for greater uniformity of the tape tension, is taken away and spring-loaded with a long, not very strong spring. How to make a cutter grinder, see the video below.

Video: cutter grinder

One rocker

In amateur practice, grinders with misaligned rocker are good because they do not need precise details at all. For example, hinges can be made from card loops. At the same time, the accuracy of processing remains sufficient for ordinary amateur requests.

The original scheme in this case is also modified: the rocker is rotated 90 degrees, carried up and spring-loaded, on the left in Fig. It turns out a simple vertical grinder. And, importantly, it works without problems with a home-made inextensible tape. Both tension spring (in the center) and compression spring can provide belt tension. Its strength is not important, as long as the tape does not bend excessively during operation. No adjustments are required during use.

Consumables and parts

The only consumable item for a belt grinder is a belt (not including grease for bearings and joints. Belt can be ordered desired length(see at the end), but you can also make it yourself from emery cloth on a textile basis. Highly desirable - flexible, unimpregnated. In general, the procedure for making a tape for a grinder with your own hands is as follows:

We cut off the workpiece - a strip of the desired length and width.
We prepare a mandrel (not necessarily round) with a length along the generatrix slightly less than the length of the tape.
We circle the mandrel with the workpiece inside out.
We bring the ends of the workpiece exactly end-to-end and securely fasten.
We put a piece of glue stick for a hot glue gun on the joint.
We heat with a building hair dryer until the glue melts.
We impose a patch of thin fabric on the joint.
We press something hard through the Teflon film until the glue hardens.

There are three significant points here. The first is to use a rough PET film with a thickness of 25-50 microns (sold) instead of fabric on the patch. It is very durable, but try running your finger over a PET bottle. Not very slippery? A rough PET film under tension cannot be stretched over polished metal. And instead of a patch, it is better to seal the wrong side of the tape with a continuous strip of PET film with an overlap of 2-3 cm. The beating of the tape will be no more than 0.05-0.1 mm. This is less than from the thinnest calico and even less than the error in the thickness of the skin-blank.

The second - fill the finished tape into the machine and grind something obscene with it without strong pressure. The hem on the seam will come together, and the tape will become no worse than the branded one.

But the most important thing is that in terms of elasticity, the best adhesive for gluing the grinder tape is not expensive and difficult to use thermal or assembly, but ordinary PVA. If the tape is pasted over with a lining along the entire length of the inside, then its strength for PVA is more than enough. How to glue a tape for a PVA grinder, see the video

Video: gluing the grinder tape with PVA glue

Pulley

The generatrix (lateral surface in section) of the drive pulley of the grinder must be straight. If you use a pulley-barrel, then the tape will bend like a trough along its entire length. The rollers do not allow it to slip, see below, but the pulley generatrix must be straight.

A pulley for a grinder that is not designed for particularly precise work, firstly, does not have to be turned. In the scheme with 3 rocker arms, the beating of the tape from its misalignment will go out on the rollers before it reaches the working branch. In a simple vertical grinder, the belt runout will be sufficiently damped by the tension spring. Therefore, it is quite possible to make a pulley for a grinder without a machine, see video:

Video: drive wheel on a grinder without a lathe

The second is that the pulley, rollers and, in general, all the details of a home grinder can be made from plywood. In production, this is certainly not an option, even if the plywood grinder is offered for free with an additional payment: the grinder needs a salary, and the wooden grinder in the workshop will completely wear out before it pays for itself. But you won’t drive the grinder at home day after day in 3 shifts. And no tape slips along the plywood pulley. Incl. homemade. So you can safely make a grinder pulley out of plywood:

Video: plywood grinder pulley

It is much more important to correctly calculate the diameter of the pulley according to the speed of the motor and the required speed of the belt. Too slow running belt will tear the processed material; too fast - it will be erased by itself, without really processing anything. In which case, what tape speed is needed is a special conversation, and a very difficult one. In general, the finer the abrasive and the harder the material to be processed, the faster the belt should move. How the speed of the belt depends on the diameter of the pulley and the speed of the motor, see the figure:

Fortunately, for most abrasive-material pairs, the allowable limits for belt speed are quite wide, so choosing a grinder pulley can be easier:

Video: which wheel is needed for a belt grinder

Rollers

The rollers of the grinder, oddly enough at first glance, are its most important details. It is the rollers that keep the tape from slipping and ensure its uniform tension across the width. Moreover, there can be only one video in kinematics, see, for example, the video above about the cutter grinder. Only barrel rollers will cope with this task, see below. But the “trough” of the tape after any roller should straighten out before it reaches the working area.

Rollers with flanges (sides, edges) will not hold the tape. The point here is not only and not so much with the misalignment of the axes of the rollers: the grinder belt, unlike the drive belt, must withstand, without slipping, the loads from the workpieces. If you make rollers with flanges, then, just touching something to the tape, it will crawl onto the flange. In the grinder, you need to use Type 3 barrel rollers (highlighted in red on the left in the figure).

The dimensions of Type 3 rollers are also given there. It is advisable to take the diameter of the rollers no more than 0.5 of the width of the tape (so that the “trough” does not go far), but not less than 20 mm of steel turned and not less than 35-40 mm of plywood. The tension roller (the probability of the tape slipping from it is greatest), if the working branch of the tape does not leave it, can be 0.7-1.2 in diameter of its width. Plywood rollers are made in the form of a thick shell into which the bearing is pressed; then the roller is mounted on the axle (in the center in the figure) and finished clean, see e.g. track. video:

Video: barrel roller for grinder

Not every turner can machine a profile barrel roller exactly according to GOST. Meanwhile, there is a way to make rollers for the grinder without significant difficulties. The same garden reinforced PVC hose will help out, on the right in fig. previously. On the roller blank with a straight generatrix, its segment is pulled tightly and cut off with a margin along the edges to the thickness of the hose wall. It turns out a roller with a complex generatrix profile, which holds the tape even better and gives it a smaller “trough”. Don't believe? Try to get into the graveyard of planes or missiles and dig into them. You will find rollers with exactly the same generatrix profile. It's just that the mass production of rollers of a complex profile is much more expensive than Type 3 barrels.

And another option

All critical parts of the grinder - one-piece belt, non-slip coated pulleys, rollers - can be purchased separately. They will cost not so cheap, but still not in thousands of foreign and not in dozens of native "leather jackets". The remaining parts of the grinder, either flat or from professional pipes, are made using a conventional bench drill or drill. Here is where you can order grinder parts:

//www.cora.ru/products.asp?id=4091 - tape. Do lengths and widths at the request of the customer. Advise on abrasives and processing modes. The prices are acceptable. Delivery time - questions to Ruspost.
//www.equipment.rilkom.ru/01kmpt.htm - spare parts (accessories) for grinding machines. There is everything, the prices are divine. Delivery - see prev.
//www.ridgid.spb.ru/goodscat/good/listAll/104434/ - the same, but foreign-made. Prices are higher, delivery is the same.
//www.pk-m.ru/kolesa_i_roliki/privodnye_kolesa/ - drive wheels. You can find suitable for the grinder.
//dyplex.by.ru/bader.html, //www.syndic.ru/index.php?option=com_content&task=view&id=36&Itemid=36 – spare parts for grinders. Ribbons are not made to order - choose from the catalog. Rollers without axles; axles are sold separately. The quality is impeccable, but everything is very expensive. Sending - within 2 weeks to the border. Then - their customs, our customs, Ruspost. Total ok. 2 months It may not reach if some local bureaucrat considers the goods to be sanctions. In this case, there are no problems with the return of the payment due to the complete absence of real opportunities for an ordinary citizen to receive one.

5,00

Everyone who was engaged in the repair, reconstruction, manufacture of parts and fixtures, faced with finishing work. Performing them manually is very difficult and time consuming, the process can take several hours or even days. The grinder will do the job just fine. There are devices for various purposes - from stripping to polishing. If it is not possible to buy a tool, it is made by hand.

Grinders - types and features of units

There are 3 types of grinders, which differ in specialization and functionality:

tape remove large layers from large areas;
surface grinding is used for finishing;
eccentric work on the verge of polishing.

Many craftsmen who are professionally engaged in grinding have the entire set of these tools in their arsenal. The overwhelming majority of devices operate from 220 V. They are heavy and overheat. A pneumatic machine is lighter than an electric one, but a source of compressed air is required. Such units are produced by a few companies, the most famous being Bosch.

Tape machines - "tanks" among similar devices

Such a grinding unit with its working body in the form of an endless ring resembles a caterpillar machine, and is similar in shape. It is relatively powerful, its design is simple but reliable. From the engine, the skin belt is driven through a gearbox and a V-belt drive.

Works with all kinds of materials: wood, metal, polymers, minerals. Removes a few millimeters from the plane, performs rounding, edges. The quality is not the best - an orbital (eccentric) or surface grinder (vibration) machine is required for finishing.

Performance directly depends on the power of the motor. LSHM have engines of 0.5–1.2 kW. Another important indicator in technical specification of these units is the speed. A fast machine will do more, but it will not be possible to press it down due to the high torque. In addition, in this case, there is not enough power. For responsible manufacturers, the indicators are as balanced as possible, often the possibilities are regulated by electronics.

Fast machines are usually low power. If they are still given strength, it will be difficult to manage, the cost will increase significantly, with inept use it is easy to spoil the part. High-speed lightweight machines can easily process large areas in a short time. If the upcoming load on the grinder is unknown, professionals recommend for the home to choose a lower speed that can be pressed down (the usual range of devices is 150-550 m / min.). Even more convenient is the tape version with pre-set speed, for example, Dewalt DW433.

Surface grinders - the importance of the platform in the design

The devices occupy an intermediate place between tape and orbital tools in terms of processing cleanliness. They are popular due to their affordable cost, the availability of additional equipment, and the ability to finish fairly large areas, including corners. The motor is usually 150-300 watts, but there is enough power.

The main thing in such an ESHM is a plate moving in a forward-reverse direction with a high frequency. The most important characteristics:

1. The amplitude of the sole, which is mainly 1-3 mm. There are models where it reaches 5-6 mm. An increase in the indicator leads to faster processing, but less quality.
2. The frequency of the platform. A thicker layer is removed at high rates, but when they are lower, sanding is more accurate. Some devices, for example, Bosch GSS AEL-BOXX, have a speed of 20 thousand moves per minute.
3. Plate material and dimensions. According to the latter indicator, there are standard and mini (100 mm2). Budget models have a steel or plastic platform. Better from porous polymer with low vibration.

Emery is attached differently. Velcro is more convenient, but they are more expensive. Spring-loaded clips are more complex, but you can use paper cut by yourself.

Eccentric (orbital) machines - a guarantee of high-quality processing

They work both with a flat surface, and with a profile, volume, curvilinear, except for the angular one. The design is similar to the PCM, but the plate moves not only along the axis, but also orbitally with a small amplitude, which is set by the eccentric. Difficult movement and high speed provide high-quality surface treatment. Motors are usually 200–900 W: the more powerful, the more the sole is pulled.

Velocities (amplitude and orbital) are also different. The same rule applies here as for other types of aggregates: higher speed mode - more processing area per unit of time, but worse quality. An eccentric sander is rich in electronics, which is used to perform various functions: frequency support, brake, limiting starting currents.

The simplest grinders based on low-power electric motors

Somewhere in the far corners of the garage, a weak motor can be stored, which was forgotten as unnecessary. And it can be turned into a small section. device, which is useful in some cases. Alteration is simple, the main thing is the grinding wheel. In its role, they use the factory one, adapted to the device, or they are made independently from a suitable material.

Winchester from the computer in an unusual role

The old obsolete PC, which is covered with dust as unnecessary, now does not surprise anyone. But it has a node that will still serve in the household - this is a hard drive. It is equipped with an electric drive, which is used to manufacture the simplest ESHM.

Hard drive grinder - installation sequence

Actions are simple:

1. Disassemble the device, remove the cover and remove everything that is on the left side of the disks.
2. Draw a circle of 9 cm on abrasive paper, cut it off. Where the leg of the compass stood, a hole is made according to the size of the spindle. Stick double-sided tape on the pancake of the hard drive, fix the sandpaper.
3. An aluminum can shield is installed to protect the operator's eyes. Connect to the computer's power supply.

The design will not surprise you with its power, but you can sharpen a knife with a small drill.

Polishing device from a car electric motor

Fan motors can be found in the garage. It can be used to do redecorating in the car and for other economic purposes. A neat little sander will eliminate the need to buy an expensive orbital machine to smooth out a small scratch or chip with your own hands, then paint.

There is a power source in the garage - this is car battery. Requires stranded copper wiring long enough to reach anywhere in the machine. The engine is powered by throwing alligator clips onto the battery terminals or through the cigarette lighter socket. A toggle switch is screwed to the motor with electrical tape to control the device.

A car electric motor is useful for a small ESHM

The working body is a circle. It is better to use ready-made with Velcro, which is sold for grinders. Only the mount needs to be done differently. There are many options, but in any case, it is necessary to machine the sleeve. Its inner diameter must correspond to the size of the motor shaft, and the interface must be the same - key or thread.

When it is planned to use the device not only in the garage, they make a portable option. A household battery is used as a power source. Both the motor and the switch are fixed on a piece of plywood, the wires are fixed with staples from a stapler. This machine can grind wood and metal surface to perform body work.

Reworking a household power tool

Almost every owner has a grinder. It can be used for rough finishing - to clean metal from rust, walls before plastering. For delicate work, for example, body work, it is not suitable - too high speed. One careless move - and a hole in the car. If you equip it with a voltage regulator, which is on professional models, then delicate grinding will become possible for household angle grinders.

Anyone who is at least a little versed in radio engineering will assemble the device with their own hands. You will need running parts that are easy to buy or solder from old products. Those who can read wiring diagrams do not need explanations.

Scheme of a homemade speed controller for a grinder

The order of work is as follows:

solder using printed circuit board or hanging installation;
thyristors are mounted on radiators;
test with a 40–60 W light bulb (it should smoothly change brightness when turning the tuning resistor);
after a successful test, the device is mounted under the tool casing.

The proposed scheme is simple, it is connected to the mains supply of the angle grinder.

Belt grinder from a grinder - device ideas

A small angle grinder is used as a drive, which costs a little, and almost everyone has it. The manufacturing work is simple: you need to make a frame for attaching the tool. They are different, so the bed in each case will be different. Other important components: the drive shaft and sandpaper wheels are all made from waste materials, no turning work is needed. It takes a little profile pipes, sheet metal, welding machine and grinder.

Circuit diagram and operation

The emery belt in the device moves on rollers, which are transmitted by rotation from an electric motor. In this case, the grinder acts as a drive, but you can just as well use a drill or any suitable motor. They are attached to the frame with reliable fasteners.

The principle of the tape device

To prevent the belt from sagging, a tensioning mechanism with a spring is used, which is pulled over one of the rollers. The stationary one differs from the manual unit by a table for fixing the workpieces. Safety is ensured by a transparent acrylic screen.

Industrial model

There are factory-made tape attachments for angle grinders on sale. They give the impression of being solid, heavy-duty designs, but users complain about poor fastening, an excessively long belt that requires powerful engine. So for purely practical reasons, and not just because of high cost many people prefer to make the prefix themselves.

Homemade car ideas

There are many original variants recycling of household power tools in order to expand the functionality. How to make a belt grinder from a grinder is shown in the drawing below.

The implementation of the second idea is more difficult. It is required first to make a bracket for the drive - the shape and dimensions may be different. Measure the tool, think over how to fix it. For manufacturing, steel plates are used, which are bent with the letter "P". Details are welded. The main task of this knot is to securely hold the grinder.

The bracket is hinged to the frame

The following photo shows a general view of the product. Here it is important to pay attention to 2 details that serve to adjust the tool. This is a spring between the base and the bracket, which is used to tension the working tape. There are also bolts in the mount. They are needed to change the angle of the angle grinder. This is necessary in order to achieve a position where the abrasive belt will be in the center of the drive wheel and will not fly off it.

Then they make driven rollers - there are two of them. Closed bearings are taken, which are put on a bolt of suitable diameter and length, fixed with a nut. From above they are closed with a piece of plastic pipe. A bicycle stand is used as a leader, which is installed to perform various tricks.

Lead Roller

The following photo shows a general view of the product. In front - a table made of a piece of sheet iron, welded to the base. Processing of parts is carried out with fixation on it.

stretch, but stay whole.

The sizes of the factory emery tape can be larger, but for a home-made device you should not take longer than 1230 mm. Otherwise, the dimensions of the product increase significantly, and these are unnecessary problems.

Self-manufacturing of a grinding machine is quite possible. The implementation of the options is not particularly difficult, the main thing is to choose the right drive.

You can make a very convenient, manual belt grinder from a grinder with your own hands. With the help of such a tool it is good to sharpen an ax, knives, etc. Treat the surface at any angle, giving it a flat plane. In general, those who work with iron or wood will appreciate this mini machine.
Sharpening the cutting edge of the ax:

With such sharpening, the corner will not float away.

How to make a belt grinder from a grinder

The mount for the girth of the grinder will be made of a piece of thick steel, about 10 mm thick. We drill a hole for the neck of the angle grinder.

We cut a wide slot.

We cut the mount with a grinder.

Next, we clean and grind so that everything has a beautiful and safe appearance.

We drill a hole from the legs of the clamping device.

Then we cut the thread in the wide side.

As a result, this mount can be easily put on the grinder and clamped so that everything is held tightly.

Trying on.

Now you need to make a roller that will rotate the sandpaper tape. We take a chipboard and, using nozzles of large diameters, we cut round pieces. To get a wide round roller, glue them together.
Then, with a pen drill, we drill a hole in all at once.

Then we clamp it in a vise and with a triangular file we make an internal hole for the hexagon.

Like this.

We take a wide nut and make notches on the planes with a file.

They are needed to keep the nut in the tree better.

We breed two-component adhesive on an epoxy basis and glue the knurled nut into the wooden roller.

After the glue dries, we clamp the roller into the lathe.

We sew under an ellipse. This is necessary so that the tape does not fly off. Then sand with sandpaper until smooth.

It's time for the second video. It is made of three bearings pressed on vl.

Let's make two such ears.

Let's dress on the edges of the protruding shaft.

Let's make a plate. The result is a U-shaped part holding the roller.

So that the shaft does not fly out, we fix it by welding

Now let's make a frame. You will need two steel pipes different diameter so that one enters the other.
A flat overlay is welded onto a pipe of a larger diameter. It is needed in order to press on the tape during grinding.

We weld a roller from bearings to a thin pipe.

We take a ring of sandpaper (sold in hardware stores), insert the pipe into the pipe and estimate the approximate size of the entire fixture.

We saw off the long ends of the pipes. We make a wide groove in a thin pipe, and a hole in a thick one.

Weld a nut to the hole.

If you need a grinder for occasional woodworking and do not 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 grinder 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 to make the finished product work as well as 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.

The base, after carefully making calculations, assemble from boards or pieces of plywood. Be sure to mount the motor on it.

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

Step 3. In fact, grinding tool ready, you will need to fix the disc itself on the plywood base, and you can work in peace. Or you can, as in this project, assemble a box from the remnants of lumber so that the power tool looks nice on the outside, and also display the tool start button on its front part. Before assembling the box, be sure to make careful calculations.

Work with the received tool should be extremely careful and in compliance with safety rules. The speed of rotation of the disc is high and the probability of grinding off nails or injuring hands during processing of small parts is high.

I welcome all those who work with metal and not only, I present to your attention a simple, convenient, powerful grinding machine. With this tool, you can easily and quickly form bevels on knives, sharpen axes and many other tools, perform grinding, and so on. As a power unit, a 220V engine with a power of 2 kW is used, the revolutions of which are 2800 per minute.
The belt on the machine is set with dimensions 1000x50, and the speed is 20 m/s.

This is very convenient to use, it quickly changes the belt. It is also reliable, there is practically nothing to break, such a powerful engine is difficult to overload. The machine is also assembled easily from available materials. The most important thing is to find a suitable engine for homemade. So. Let us consider in more detail how to assemble such a machine.

Materials and tools used by the author:

List of materials:
- motor 220V, 2 kW, 2800 rpm;
- square steel pipes;
- Sheet steel;
- wires;
- nuts and bolts;
- shock absorber (will work as a tension);
- finished wheels (or you can carve them yourself out of wood);
- dye.

List of tools:
- cutting machine or grinder;
- drilling machine;
- Bulgarian;
- vice;
- welding machine;
- chisel, hammers, spanners other.

Manufacturing process of belt sander:

Step one. Base and stand
And as a basis, we need thick sheet steel. The metal must be strong, because here we will mount the engine, as well as weld the rack. We select a suitable piece of metal and mark it. The author drills holes in the corners of the sheet, they are needed in order to screw the legs. The legs will need rubber, we fasten them with bolts and nuts, so our machine will not walk on the floor and will be securely fixed.

Next, we prepare the blanks for the manufacture of the rack. Our stand is telescopic, that is, it is a pipe of a larger and smaller diameter, they go into each other. Cut off the pieces of pipe you need. cutting machine or Bulgarian. Next, we weld a wider pipe vertically to the base. The pipe must be welded evenly and as tightly as possible. We use the corners to weld the pipe strictly vertically. That's all, the rack is ready, let's move on.

Step two. Adjusting node
The manufacture of the adjusting unit is the longest in this homemade product. This node is needed in order to change the angle of the upper driven wheel. Thanks to this parameter, we center the belt on the wheels. This assembly is made of steel plates, the process of assembly and operation of this assembly is shown in more detail in the photo. There is nothing complicated in manufacturing, we cut blanks, drill holes, cut threads where required.

Then this adjusting unit is assembled on a long steel plate, which is welded horizontally to a thinner steel pipe, which is pulled out.

Step three. Assembly
The author showed us only the main points on the assembly of the machine, other details were behind the scenes. So, for example, you will need to install some kind of spring that will “push apart” the telescope and thereby stretch the sanding belt. The author has this shock absorber, something similar can be found in some washing machines. You can also adapt an old Soviet aluminum pump for this by installing a spring inside.

You will also need to install work planes on the frame, this is the table itself and the thrust platform. This is all done from sheet metal of suitable thickness and should not be a problem.

As for the wheels, you can carve them yourself from wood, plywood is suitable as a material, several layers need to be glued together to obtain the desired thickness. We grind the wheels on a lathe or on the engine that you found for the grinder. The drive wheel is fixed on the motor shaft, and the driven wheel rotates on the bearing.