DIY belt sander. Why do you need a wood sander and how to make it yourself at home. Determining the drive type





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


This is very convenient to use and the belt can be changed quickly. It is also reliable, there is practically nothing to break, such a powerful engine is difficult to overload. The machine is also easy to assemble from available materials. The most important thing is to find a suitable engine for your homemade product. So. Let's take a closer look at 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 tensioner);
- ready-made wheels (or you can carve them yourself from wood);
- dye.

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

Manufacturing process of belt sanding machine:

Step one. Base and stand
And as a base we need thick sheet steel. The metal must be strong, since this is where we will mount the engine and also 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 to screw the legs. We will need rubber legs; we fasten them with bolts and nuts, so our machine will not walk on the floor and will be firmly secured.

















Next, we prepare the blanks for making the stand. Our stand is telescopic, that is, it is a pipe of larger and smaller diameter, they fit into each other. We cut off the required pieces of pipe on a cutting machine or with a grinder. Next more wide pipe weld vertically to the base. The pipe must be welded smoothly and as tightly as possible. We use angles to weld the pipe strictly vertically. That's all, the stand is ready, let's move on.

Step two. Adjustment unit
Making the adjustment unit is the longest in this homemade product. This unit is needed to change the angle of the upper driven wheel. Thanks to this parameter, we center the belt on the wheels. This unit is made of steel plates; the process of assembly and operation of this unit 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 one steel pipe, which extends.



























Step three. Assembly
The author showed us only the main points of assembling the machine; other details were left behind the scenes. So, for example, you will need to install some kind of spring that will “pull apart” the telescope and thereby tension the sanding belt. The author uses this as a 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 working planes on the frame, this is the table itself and the thrust platform. This is all made from sheet metal of suitable thickness and there should be no problems with this.

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

For a homemade sander in household there are many possible applications. It's about not only about a private house or personal plot, but also about housing in apartment building. With its help you can treat any surface. The degree of cleaning depends on the type and abrasive materials used. Unlike industrial models, a device assembled by yourself will be favorably priced, since the design budget will depend only on the craftsman. Having plumbing skills and basic knowledge of electrical engineering, you can easily assemble the device yourself.

Without thorough knowledge of the design of grinding machines, it is impossible to assemble a high-quality device with your own hands. Before moving on to the structure, let's get acquainted with the most common types of grinders:

  1. Corner. Simply put, Bulgarian. Consumables are discs. Grinding wheels are designed for surface grinding. Pressure adjustment is carried out manually.
  2. Tape. Surface treatment is carried out with a sanding belt. Suitable for working on flat surfaces only.
  3. Delta sander. For processing products with a curved structure.
  4. Vibrating. Ideal for finishing smooth surfaces.

In addition to the above, there are several more devices that are less common:

  • straight;
  • polishing;
  • eccentric.

Regardless of whether the device is factory-made or self-assembled, the main design elements are:

  1. Drive unit. The performance of the device depends on its power. Do-it-yourself devices use a drive electric type, however, there are pneumatic homemade products powered by a compressor.
  2. Gearbox. Transmits torque from the drive to the working tool. The basic part of the gearbox is the spindle.

The gearbox is an integral part of tools such as an angle grinder or a drill. Some models, especially those assembled with your own hands, can do without it.

  1. Working platform. An abrasive material is attached to it. For this you can use circles, tapes, disks.
  2. Frame. Protects the structure from mechanical damage and dust, which is why many factory models are equipped with dust collection systems. The materials used to make a device with your own hands, as a rule, are not able to compete with high-quality polymers that are used in the production of professional tools.
  3. Control system. Includes turning off the power, as well as adjusting the abrasive speed.

Options for homemade designs

Making a grinding machine with your own hands is not difficult. The main thing is that it corresponds to the types of work that the master plans to perform. From an economic point of view, it is better to take components that are on hand. If you have to buy the components of the device, then the budget of a home-made device will be comparable to a factory model. All other things being equal, it is better to give preference to an industrial tool, because its quality is disproportionately higher.

Let's look at a few handmade devices. Perhaps one of them will suit you.

Do-it-yourself grinder from an angle grinder

As the name suggests, the grinder is designed for grinding. Cleaning discs successfully cope with rough work: withdrawal old paint, removing metal deposits or traces of corrosion. For finer cleaning, special attachments made from sanding sheets of various grain sizes are sold.

Models for household use operate in one mode, and the number of revolutions reaches 15 thousand per minute with an average of 11 thousand. This speed is great for sawing materials, but it is too high for sanding work.

The grinder's motor has excess power. For polishing, 300–400 W will be enough.

A grinder made from an angle grinder will have more weight compared to a factory tool, but it is possible to adapt a homemade one for yourself, which will increase comfort when grinding.

For an angle grinder, you can make a simple attachment that will turn the device into a miniature one. In this case, work is carried out without a protective casing.

If you do not want to use devices, you can adjust the number of engine revolutions. Independent modernization of the circuit will require specialized knowledge in electrical engineering.

On professional devices, you can set the number of revolutions manually, however, their cost starts from $200.

Making a grinder from a drill

From a drill with your own hands you can assemble a productive belt grinding machine. In this case, the tool acts as a drive. The design itself is simple and does not require significant investment. To make it yourself you will need the following materials:

  • metal rods with and without threads;
  • profile pipe;
  • plywood;
  • steel sheet;
  • bearings;
  • hardware;
  • wood glue.

Care should be taken to ensure availability metalworking tools, inverter and devices for sawing metal.

Stages of work:

  1. Manufacturing of pulleys. The driving and driven pulleys are designed to transmit torque from the drill to the grinder. They are made from plywood.
  2. By changing the diameter you can obtain the desired torque. One pulley consists of several round timbers, which are connected using wood glue. In the center it is necessary to drill holes for steel rods. After the glue has dried, the workpieces are modified by making a groove that must correspond to the width of the drive belt.
  3. Manufacturing of drive and driven shafts. They are also made from plywood, similar to pulleys. More round logs should be prepared for them.
  4. Assembling the lower part. To do this you will need a profile pipe. First of all, it is necessary to make mountings for the bearings and connect them. This is the base for the working shaft.

  5. Making the top part. The tension mechanism will be attached to it.
  6. We make the thrust part from a steel sheet.
  7. Drive installation. Please note: for normal work it is better to take a powerful drill.
  8. Finishing work. All that remains is to install the pulleys, tighten the drive belt and assemble the protection. After this, the hand-assembled device needs to be coated with paint.

For small and precise work, it is better to purchase compact drum or plate type attachments, depending on the type of work.

Homemade grinder from a computer hard drive

From an old hard drive you can assemble a small grinding device, the main advantage of which will be the complete absence of investments, with the exception of the cost of abrasive wheels. The DIY manufacturing process is as follows:

  1. Open the case and remove all elements located next to the magnetic disk.
  2. According to the size of the upper part of the drive, cut out a circle of sandpaper of the desired grit.
  3. By using double sided tape We fix the paper on the surface of the disk.
  4. We make a casing that protects from dust or abrasive grain.
  5. To start the design, the hard drive must be connected to the computer's power supply.

This DIY device will allow you to do small jobs, such as grinding contacts, sharpening files or tweezers. The rotation speed depends on the factory settings. The average value is 7200 rpm.

A homemade sander will not have the attractive appearance of a factory tool, but good performance and low assembly costs compensate for this disadvantage.

Have you tried assembling a grinding machine with your own hands? What did you use as a drive? Share your invention experience in the comments.

A grinding or polishing machine is required for painting work. In tool stores and others retail outlets There are many models of such devices available. However, in some cases it is advisable to create a polishing machine yourself. This article discusses various options for such homemade devices and describes the process of their creation.

The simplest polishing machine

The easiest way to make your own is a polishing machine designed to work with grinding discs. For creating of this device The following basic parts will be required:

  • electric motor;
  • power unit;
  • battery.

The electric motor can be removed from various electric tools and instruments. For example, components of a computer power supply or disk drive are suitable.

You can also use an electric motor from a fan, and a household battery is suitable to drive the electric motor.

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

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

To ensure the drive of the abrasive disk from the axis of the electric motor, two bushings will be required. The diameter of these devices is determined based on the corresponding parameter of the motor axis. It should be taken into account that different electric motors have axes different diameters. The considered grinding machine can be used for processing both wooden and metal surfaces, including during body work.

Motor and polishing discs

Remember that the functional parameters of such a homemade grinding machine are determined by the individual parts from which it is assembled. In this regard, you should use an electric motor from a fan, since the motor from a computer has less power, which may not be enough for some types of work. In addition, sanding discs made of sandpaper are not optimal devices of this type. Instead, you can purchase branded circles without large diameter, for example, for a drill.

You can create a more powerful one with your own hands stationary option grinding machine. You can use a washing machine motor for it and equip it with large diameter grinding wheels. In addition to polishing discs, such a device can be equipped with sharpening and abrasive discs.

Belt sander

The working element of machines of this type is an abrasive sanding belt. Operating principle tape devices consists of rotating an abrasive belt connected in a ring, driven by an engine through a transmission and drums. One of the drums is the leading one, and the other is the driven one. The first of them is driven by an electric motor through a transmission, usually represented by a belt drive.

Some belt sanders are equipped with a device that allows you to change the rotation speed of the drive drum, which provides different operating modes. The tape can be located on the frame vertically, obliquely or horizontally, depending on the purpose of the device. To adjust the degree of tension, a tension roller is used. Since grinding work is characterized by the release large quantity dust, it is advisable that the grinding machine be equipped with an exhaust device.

It must be taken into account that many design features grinding machine, such as, for example, the diameter of the drums, rotation speed, grain size, the dimensions of the abrasive belt, the design of the work table, which determine the main functional parameters of the device in question, are selected depending on its purpose. Classify the following options working surfaces for which grinding machines are oriented: curved, flat, edges and ends, intermediate layers of paint and varnish.

What is a grinder made of?

You can create your own belt sanding machine based on an industrial design, which involves moving the belt over the flat surface of the work table with the abrasive part outward. Wherein homemade device will differ from the branded counterpart in larger sizes and permanent installation. For these works you will need an electric motor, for example, from a washing machine, wooden or metal panel, chipboard, material for abrasive tape, glue.

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

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

You can make a work table for such a grinding machine yourself from wooden beam or sheet metal. It should be borne in mind that metal options allow you to process more complex objects. The dimensions of the working table of the tool in question are determined based on the dimensions of the belt and the distance between the axes of the shafts, as well as its purpose. Bevels should be made near the shafts in the work table in order to ensure smooth contact of the tape with it.

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

Where can I get the tape?

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

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

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

You can make a belt for a sanding machine with your own hands from sandpaper in the form of rolls, which are cut into fragments of the required size.

It should be taken into account that the length of the tape is determined by the method of fastening the ends of the cut fragment. It is possible to connect them at an angle, butt and overlap. In the first case, the ends are cut at an angle of 45° and a fabric overlay is glued under the joint. An overlap connection involves pre-cleaning a fragment of one of the ends 8-10 cm from abrasive grains with hot water. Then the cleaned area is covered with glue and the back side of the other end of the tape is placed on it and the junction is compressed. Optimal thickness abrasive belt is 200 mm. A roll of source material 1 m long is enough for 5 tapes.

You need to cut the frame yourself from a thick sheet of metal. At least one of its sides must be cut straight to accommodate the mounting of the motor platform by screwing three bolts through pre-drilled holes in the frame.

Grinder (English) literally – crusher. Meat grinder is a meat grinder, rock (stone) grinder is a stone crusher; stick (wood) grinder – garden crusher branches and twigs into chips. But there is also a completely unambiguous meaning of the word grinder: in mechanical engineering and metalworking it is a grinding machine. A useful household item. For example, it is impossible to guide a dull meat grinder knife on a whetstone manually. On manual sharpener for knives - somehow possible, having solid working skills. And on the grinder - no problem. The same thing - if you need to polish a part complex shape without disturbing her profile. Either just sharpen the scissors or professional knife. Various kinds Wood and metal cutters are best edited on a grinder. It is quite possible to design and assemble a grinder with your own hands, without having complex equipment and skills to work with it. In terms of money, this will mean savings of 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 external turning at all. For example, how to make a simple grinder literally out of trash, see the video below:

Video: DIY belt grinder made from trash

Or another option, how to make a stronger and more durable grinder from scrap metal:

Video: scrap metal grinder

Disc or tape? And drive

There are almost more types of grinding machines used in industry than lathes. The emery known to all craftsmen - a motor with a pair of grinding wheels (or one wheel) - is also a grinder. For yourself at home, it makes sense to make either a disk end grinder (plate grinder) or a belt grinder. In the first, the abrasive is applied to a rotating HDD; in the second - on an elastic band running around a system of pulleys and rollers. The disc type is more suitable for grinding simple wooden parts and coarse or medium clean metal parts. Using a belt grinder, it is also possible to produce precise and clean finishing of profiled parts of complex shapes, incl. large-sized, see below.

A disk grinder is very easily obtained from the same emery or a motor of suitable power, see below. You need to order an adapter from the electric motor shaft to the shank of a metal-based grinding disc. Or under a clamping chuck, then on the same motor it will be possible to build a mini lathe, see figure:

A worn-out “plate” is suitable: a disk made of thin (4-6 mm) fibrous plastic is glued to 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 disk and tape grinder is not only in the possibilities of use. If we take ordinary household crafts, then for a disk grinder a drive power of 250-300 W on the shaft is enough. For small wooden parts - and 150-170 W. This is a motor from an old washing machine, a straight (ordinary) drill or a screwdriver. But for a belt grinder you will need an engine from 450-500 W: three-phase with batteries of starting and operating capacitors. If you plan to process large items, then the motor power is from 1-1.2 kW. Moreover, capacitor batteries for both will cost not much less than the engine itself.

Note: a 100-200 W drive uses a mini-belt grinder (see below) for precise knife dressing, grinding/polishing jewelry and so on.

A drill or screwdriver as a grinder drive is also convenient in that it allows you to quickly change the speed of movement of the abrasive (see below) using a standard speed controller. You just need, firstly, to make a holder for the drill that rigidly fixes the tool. Secondly, an elastic transition coupling from the drill to the disk shank, because It is difficult to achieve their precise alignment without special equipment, and runout will negate the accuracy of processing and can damage the drive tool.

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

Since shock and irregular alternating loads on the drive in a grinder are an order of magnitude lower than, say, in a lathe, the drill holder for it can be made of hard 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 advisable to use a drill without an impact mechanism and with a steel shell on the neck (for installing the front handle).

coupling

For the adapter coupling, you will need a piece of steel rod (not necessarily turned) of the same diameter as the shank of the grinder drive shaft, and a piece of PVC-reinforced hose (garden irrigation) with a clearance such that it stretches tightly over the rod 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 reliable clamping in the drill chuck. After assembling the coupling in place, the hose on the shank and rod is tightened tightly with clamps; can be wired. Such a coupling completely counteracts the misalignment of the drive and driven shaft up to 1-1.5 mm.

Tape is still better

A belt grinder allows you to do everything a disk grinder can do, and much more. Therefore, next we will focus on how to make a belt sanding machine with your own hands. Amateurs, focusing on industrial designs, sometimes make very intricate grinders, see figure:

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

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

Kinematics and design

As mentioned above, there are many designs of grinders. When considering what and how to build a grinder for yourself, it is better to focus on industrial designs designed to be fully mechanized for precise and clean grinding of large-sized profiled parts: once it “sands” the blade of an airplane propeller or wind turbine properly, it can handle any other work.

Kinematic diagrams of grinders specified purpose are given in the figure:

Basic kinematic diagrams of belt grinding machines (grinders)

Pos. A is the most complex and perfect, with three rocker arms. If the length of the tension roller rocker arm is approx. 2 times less than the working one, then by adjusting the tension of the springs, it is possible to achieve 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 of different lengths. Secondly, in the same way you can quickly change the belt tension for different operations. The working branch of the belt 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.

The scheme with a coaxially swinging rocker arm (item 2) is simpler, cheaper and in terms of processing accuracy is not inferior to the previous one, if the length of the rocker arm between the axes is at least 3 diameters of the workpiece. To reduce the profile by grinding, the stroke of the rocker arm is limited by stops within 10 degrees up and down. The pressure of the belt to the part is most often gravitational, under the weight of a rocker arm with a bypass pulley. The tension of the belt can be quickly changed within certain limits by pulling the rocker up with a weak adjustable spring, partly compensating for its heaviness. 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 working surface of the belt will run around the bypass pulley. For example, the fairly popular BTS50 grinder is made using a coaxial rocker design. The disadvantages of the scheme are, firstly, the technologically complex rocker arm joint, which is coaxial with the drive shaft. Secondly, the need for an elastic band: if you make the idler pulley sliding and spring-loaded, the processing accuracy decreases. This drawback when processing small parts is completely eliminated by an additional tension roller, see below.

The scheme with one misaligned rocker arm is used quite rarely in industry, because in principle, it does not allow achieving uniform tape tension. However, it gives 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 circuit from the point of view of an amateur master. And then we’ll try to figure out how to make a grinder belt ourselves and do without custom-made turned parts.

3 rocker arms

Competent amateurs build their grinders exactly according to the scheme with 3 rocker arms, on the left in Fig. below. Not all propeller blades can be ground, but in this case another advantage of this scheme applies: if the grinder is used as a vertical grinder, then the working branch of the belt is elastic. This allows a skilled craftsman, for example, to direct cutting edges and blades with literally micron precision.

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

The dimensions are, however, inch - the machine is American. For the drive, in any case, it is possible to use an angle drill-grinder (on the right in the figure, 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 an asynchronous motor at 2-3 speeds from an unusable washing machine with a horizontal tank. Its advantage is low speed. This makes it possible to make a large-diameter drive pulley and thereby eliminate belt slippage. A belt slip during operation is almost certainly a damaged part. Most washing machines with 2-3 speed asynchronous motors for 220 V are Spanish. Shaft power – 600-1000 W. If you come across one, don't forget about the standard phase-shifting capacitor bank.

Coaxial rocker

Amateurs do not make pure grinders with a coaxial rocker arm. A coaxial hinge is a complicated thing; you can’t make an elastic band yourself, and store-bought ones are expensive. Grinders with a coaxial rocker are most often used at home in the version for small precision work from a table, i.e. with a rigidly fixed horizontal rocker arm. But then the need for a rocker arm as such disappears.

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

Its features are, firstly, an overhead bed for the tape (item 7), which significantly expands the possibilities of use. For example, the plane iron is straightened on this grinder with an angular stop literally by itself. In this case, the grinder works, so to speak, like a self-propelled whetstone (emery block). Having removed the bed, we get a grinder with an elastic band for precise grinding/polishing of rounded small parts. Secondly, the tension shaft (item 12). By clamping it to the groove with nuts, we get a relatively fixed tension of the tape for working with the bed. And after releasing the nuts, we switch the grinder to the gravitational belt tension mode for fine work. Drive - not necessarily through a pulley (pos. 11). You can screw it directly onto the drive shaft shank (item 16) from the drill through the adapter coupling, see above.

A specialized tool grinder (for example, for guiding and straightening turning tools) generally loses any semblance of the original design. A high-speed motor is used for it (200-300 W is enough power). The drive pulley is, accordingly, of small diameter. The bypass pulley, on the contrary, is made larger and heavier for inertia. All this together helps reduce tape runout. The tension roller for the same purpose, plus for greater uniformity of belt tension, is moved further away and spring-loaded with a long, not very strong spring. How to make a grinder for processing incisors, see the video below.

Video: grinder for making cutters


One rocker

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

In this case, the original scheme is also modified: the rocker arm is turned 90 degrees, moved up and spring-loaded, on the left in Fig. It turns out to be a simple vertical grinder. And, importantly, it works without problems with homemade non-stretchable tape. A tension spring (in the center) or a compression spring can provide tension to the tape. Its strength is not so important, as long as the tape does not bend excessively during operation. No adjustments are required during use.

Consumables and parts

The only one consumables for a belt grinder - tape (not including lubricant for bearings and hinges. The tape can be ordered required length(see at the end), but you can make it yourself from sandpaper on a textile basis. It is highly desirable - flexible, unimpregnated. In general, the procedure for making a grinder belt with your own hands is as follows:

  • We cut the workpiece - a strip of the required 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 outline the mandrel with the workpiece inside out.
  • We bring the ends of the workpiece exactly end to end and securely fasten them.
  • Place a piece of glue stick for a hot glue gun on the joint.
  • Heat with a construction hairdryer until the glue melts.
  • We apply a patch of thin fabric to the joint.
  • Press with 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 for the patch. It is very durable, but just try running your finger across a PET bottle. Not very slippery? Rough PET film cannot be stretched under tension even over polished metal. And instead of a patch, it is better to seal the back of the tape with a continuous strip of PET film with an overlap of 2-3 cm. The runout 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 blank skin.

Second - finished tape put something indecent into the machine and grind it without strong pressure. The scar on the seam will be sealed, 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 grinder tape is not expensive and difficult to use, thermal or assembly, but ordinary PVA. If the tape is covered with a lining along the entire length of the back, then its PVA strength will be more than enough. How to glue PVA grinder tape, see video

Video: gluing grinder tape with PVA glue

Pulley

Formative ( side surface cross-section) of the grinder drive pulley should be straight. If you use a barrel pulley, the belt will bend like a trough along its entire length. The rollers prevent it from slipping, see below, but the generatrix of the pulley must be straight.

A pulley for a grinder that is not intended for particularly precise work, firstly, does not have to be turned. In a scheme with 3 rocker arms, the beating of the belt from its misalignment will go out on the rollers before it reaches the working branch. In a simple vertical grinder, the beating of the belt 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

Secondly, the pulley, rollers and, in general, all the parts of a home grinder can be made from plywood. In production, this is certainly not an option, even if a 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 it and itself. But you won’t be running a grinder at home every day in 3 shifts. And no tape slips along the plywood pulley. Incl. homemade. So you can safely make a grinder pulley from plywood:

Video: pulley for grinder made of plywood


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

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

Video: what wheel is needed for a belt grinder

Rollers

The rollers of the grinder, oddly enough at first glance, are its most important parts. 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 grinder for incisors. Only barrel rollers can cope with this task, see below. But the “trough” of the belt after any roller must straighten before it reaches the working area.

Rollers with flanges (sides, edges) will not hold the tape. The issue here is not only and not so much with the misalignment of the roller axes: the grinder belt, unlike the drive belt, must withstand the loads from the parts being processed without slipping. If you make videos with flanges, then if you barely touch the tape with something, it will creep 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 for turned steel and not less than 35-40 mm for plywood. The tension roller (the probability of the tape slipping from it is greatest), if the working branch of the tape does not come off it, can have a diameter of 0.7-1.2 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 processed cleanly, see e.g. track. video:

Video: barrel roller for grinder


Not every turner can turn a profile roller barrel exactly according to GOST even on a machine. Meanwhile, there is a way to make videos for the grinder without significant difficulties. The same PVC-reinforced garden hose will help out, on the right in Fig. previously. A section of it is pulled tightly onto a roller blank with a straight generatrix and cut off with a margin along the edges to the thickness of the hose wall. The result is a roller with a complex profile of the generatrix, which holds the tape even better and gives it a smaller “trough”. Don't believe me? Try to get to an airplane or missile graveyard and dig around in them. You will find rollers with exactly the same generatrix profile. Just mass production of rollers complex profile much more expensive than Type 3 barrels.

And another option

All critical parts of the grinder - a solid belt, pulleys with a coating that prevents it from slipping, rollers - can be purchased separately. They won’t be that cheap, but still not thousands of foreign ones and not dozens of native leather jackets. The remaining parts of the grinder, either flat or from corrugated pipes, are made using a regular tabletop drill or drill. Here's where you can order parts for the grinder:

  • //www.cora.ru/products.asp?id=4091 – tape. Lengths and widths are made according to the customer's wishes. Consult on abrasives and processing modes. Prices are reasonable. Delivery time - questions to Ruposhta.
  • //www.equipment.rilkom.ru/01kmpt.htm – spare parts (components) for grinding machines. There is everything, the prices are divine. Delivery - see previous page.
  • //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 ones suitable for grinding.
  • //dyplex.by.ru/bader.html, //www.syndic.ru/index.php?option=com_content&task=view&id=36&Itemid=36 – spare parts for grinders. They do not make ribbons to order - choose from the catalogue. Rollers without axles; axles sold separately. The quality is impeccable, but everything is very expensive. Dispatch - within 2 weeks to the border. Then - their customs, our customs, Rusposhta. Total approx. 2 months It may not arrive if some local bureaucrat considers the product sanctioned. In this case, there are no problems with the return of payment, completely absent for the average citizen real possibilities get one.
    • (2 ratings, average: 5,00 out of 5)

Almost all types of work with wood are associated with its finishing or preparing wood for work or household use. For this stage of work, sanding of wooden parts is mandatory. Those who love to make things at home or professional craftsmen They know how important it is to sand the wood well, round off sharp corners, and remove extra millimeters and burrs. A wood sander is a great tool for this kind of work.

Wood sanding work

There are two methods - manual and mechanical. For the first one, emery is used, which is quite labor-intensive and time-consuming. Emery can be attached to wooden block, there are also special holders-pads for it. The second method is carried out using a power tool, it is quick and requires a minimum of effort. Some DIY work cannot be done as efficiently as grinding machines and cars.

Several types of such devices are made:

  1. Angle grinder or grinder. Used for rough grinding large objects- logs in the baths, wooden houses. The grinder uses an emery or similar grinding wheel of different grits.
  2. Grinding machine with vibration principle actions. Due to the reciprocating movements of the surface and the sole, grinding occurs. The sole is attached with clips or Velcro and has different shapes, vibrations are carried out at a speed of 20,000 movements per minute.
  3. Orbital or eccentric machine. Its sole rotates simultaneously around its axis and in orbit.
  4. Belt sander. Used for rough and finishing large surfaces.

Its mechanism is quite simple; it consists of two rollers or rollers on which an emery belt rotates. The design of the tape device is the same for all ( external view may differ slightly) and consists of:

  • the working body is an abrasive belt and two drums on which it rotates, one is the drive, the other is the driven;
  • electric motor;
  • the basics of the machine (if it is stationary), bed, work table.

The speed of such a machine can be changed. The tape is placed both vertically and horizontally.

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The process of making a grinding machine and machine yourself

Manufacturing stages:

  • select and prepare the necessary spare parts and materials (described above);
  • make a stand for the machine, table, base, secure it;
  • install a tabletop of the required length (the longer, the more more sizes material can be processed);
  • are mounted vertical racks with tensioner and drum;
  • install the motor and drums;
  • install sanding tape.

As an example, a conventional mass-produced belt sander is taken. You can make such a device or a similar one if you have spare parts from broken power tools and quite available materials. In such a machine, the abrasive belt moves along the base of the device with the rough plane outward.

For grinding large parts, a grinding machine is made sufficiently overall dimensions, the principle of its operation is the same as for smaller devices. It can process parts measuring around 2m or larger.

To assemble such a device, you need an electric motor with a power of approximately 2 kW or more, the number of revolutions is 1500. You can do without a gearbox, since such a motor easily reaches speeds of 20-25 m/s; the drum size in diameter is 20 cm.

The engine can be taken from a used washing machine. The frame is made of thick iron sheet with parameters 500x180x30 mm. On the one hand it is cut into milling machine, a place for the motor will be mounted here. The dimensions are: 180x160x10. It is attached to the frame with three bolts; holes are drilled in it for them. The engine must be secured tightly to prevent vibration.

The design consists of two drums, one firmly fixed on the shaft, the second tensioning, it rotates on bearings around an axis. The tension of the grinding surface is adjusted by pulling it to one side. The base for the machine is made of wooden, or better yet, metal plates. This base plate is made from three sheets of thick plywood, textolite. The second shaft is equipped with a bevel, ensuring a smooth touch of the tape to the edge of the table. The drums are made from wood board (chipboard), the blanks are taken and turned on a lathe to a diameter of 20 mm. It can be made 1-2 mm larger in the center, so the tape holds tighter. The spindles of the circles are made of two single row ball bearings.

The emery tape is cut from sheets, its optimal width is 20 cm. It is mounted on a frame (sole) along which it moves. This machine is also used for sharpening tools. The length of the table on which such a machine is mounted determines the size of the parts that can be processed on it, so the longer it is, the better for different sizes of material.

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Using devices: features

Devices of this kind are used for:

  • curved planes using a free grinding surface;
  • for flat surfaces with a stationary table or manual mechanized movement;
  • for the ends of parts, edges;
  • for preparatory treatment for paintwork.

You can design a grinder, the frame of which will be made of wood. By equipping it with three shafts, an inclined horizontal and vertical working plane is obtained. This device has a wooden frame, which effectively reduces vibration. The wood is used like maple; it is quite soft and at the same time durable. The working surface is lined with plastic, but it can be made entirely of wood. It is made so that it can be tilted. The length and dimensions of the tape are selected according to the size. It moves along three wooden pulleys. The upper lever with the drum is equipped with a spring, this allows you to tension the tape. The position of the belt is adjusted by a guide pulley with two adjustable bolts.

In operation, this design looks like this: A motor with a 90 mm drum rotates another one measuring 75 mm, and that, in turn, rotates a third. Rotation is carried out using an abrasive belt. Thus, the device has one vertical grinding surface and one inclined one.

The frame is made of six elements, it is attached to a base made of plywood 25 mm thick. The supporting parts and frame are made of wood, these are the base of the bearing supports, the table rockers, the rear pillar, the upper arm, and the plane for the material being processed. Bearing supports must be placed sufficiently big block, a support is mounted on it on the bearings of the drive shaft.

Rollers, drums and pulleys are made from 7 or 8 glued pieces of 6 mm thick fiberboard, cut to the appropriate shape. They have a hole for bearings. The axis on which the drum with bearings rests is made of metal. For the axles, you can take shafts from broken electric motors; they are smooth and already polished. The two guide pulleys have the same design. Ball bearings are used, ordinary ones, they prevent lateral sliding of the drums if the belt does not move accurately.

The design may differ in the size of the parts. For the frame you can use various materials– metal, plastic.

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