Why do you need a wood grinder and how to make it yourself at home. Wood grinder: making your own hands Making a grinder with your own hands
When working with wood, the final step in processing the material will be grinding. A grinder will help you with this. There are many different models on the market, but if your budget is bursting at the seams, you can make such a machine yourself.
How to make a grinder
You can make a simple machine from your PC hard drive. To do this, you will need the hard drive itself, an abrasive, a PC power supply. It will be designed to work with small details. When disassembling the disc, stick the abrasive on a rotating plane. After that, the structure must be connected to a power supply unit (power supply), and then the entire structure must be fixed on the working plane of the table, provided with a speed controller and a switch.
DIY wood grinder
Grinding machines are represented by the following types:
- eccentric or orbital;
- vibration;
- corner;
- tape.
When making a machine, you will need:
- electric motor;
- source of power.
The power unit must be taken from household appliances, for example, from a fan, the power supply is computer, the battery is household. As a basis for the above elements, a wooden board is suitable, on which the battery with an electric motor should be fixed with screws. The start button must be attached to the base with self-tapping screws. The wire strands are fixed with staples of an industrial stapler.
The working part of the tool is a grinding wheel, which can be purchased independently. The abrasive disc will be driven by an electric motor using two bushings.
You can strengthen the design of the device if you take the motor from the washing machine as the engine. In addition to polishing discs, in this case, grinding and abrasive discs can be installed on the tool.
Homemade belt sander
An abrasive belt acts as a working element in this type of device. A do-it-yourself machine will be stationary, and have large dimensions compared to an industrial design. For the manufacture of 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 tape. A self-made design will not allow you to adjust the speed of the tape, however, you can influence the tension force by shifting the fixed axis of the tension shaft mounted on the motor shaft relative to the desktop.
The workbench for the grinder must be made of wood or metal. A sander belt can be made from abrasive paper available at a hardware store.
The working element, which is the emery belt, is set in motion with the help of a transmission and drums by a power unit. Shafts are divided into driving and driven. Drums can be made using chipboard sheets, turning them on a lathe so that the result is disks about 20 cm in diameter. One thing to keep in mind when processing is that the edges of the rollers must have a larger diameter than the central part in order to automatically hold the tape. The dimensions of the rack will depend on the width of the tape and the distance between the shafts. At the location of the shafts in the canvas, it is necessary to make slots for the smooth passage of the tape.
How to make a mini grinder with your own hands
First you need to find foam to prepare the base for the device. After that, you need to cut a hole for installing a switch in it. Then you will need electrical tape and a power source, for example, the well-known Kron battery. We fasten the battery (Krona) to the foam base with electrical tape. We take a stopper from under champagne and a core of the handle. We cut the rod to the desired length, after that we put the handle rod on the cork with a blunt end and insert the tip of the rod into the hole for the motor shaft. After that, you need to cut a strip of abrasive tape to fit the size of the cork with scissors. After you cut the tape, it should be glued to the cork around the circumference. This cork construction will be the working part of the machine. We carefully inspect all the wires and connect them with twists, isolate the connections with electrical tape. We try to start the resulting device. Now you have your own mini car. Such a device is useful for performing simple small jobs for which a conventional grinder would be too large and inconvenient. If you are an observant and patient, as well as a diligent person, it is not difficult to make a grinder with your own hands. To do this, you only need dexterous hands and a little patience.
A do-it-yourself grinder is made from really very necessary “junk” that is in every workshop or pantry. The tool is used for final processing of parts, grinding, rounding corners.
There are several types of such a device. The most common is a grinder with a vibration principle of operation. One of its main elements is a flat sole fixed on the base. It transmits movement from the motor to the abrasive surface. The harder you press the device, the more powerful the vibration movements will be. Such a machine has a low speed, it is noisy, hands get tired quickly with it, but at the same time, such a tool is cheap and compact.
A subspecies of such a device is a device with a deltoid sole, which is brought forward.
Grinding machines types and purpose
Tape devices. Such a machine works on a different principle. A tape of abrasive material (sandpaper), glued into a ring, rotates on spindles. When working with it, you do not need to apply great efforts, since the rotation of the tape is quite fast. Such machines have speed control functions, a soft start system. For more precise work, tape machines have a support frame. When working with such a tool, a lot of dust arises, so they often have a dust collector or the ability to connect to a vacuum cleaner. Various attachments can be attached to the spindles.
eccentric device. This is the most versatile type among grinders. It can process almost any surface and materials. For curved planes, such a device is ideal. It has a round platform. The rotating abrasive is fastened with special clips or Velcro. The sole of the machine performs both rotational and vibrating movements at the same time.
Angle grinders. They are electromechanical and pneumatic. They are quite versatile, they can cut, grind, clean surfaces made of stone, metals. The device is very similar to the grinder, basically it is the grinder, but with special circles.
Polishing machines differ from angle polishers only with polishing nozzles.
Straight grinders perform fine work with high precision. The spindle is parallel to the frame, like the shaft of a pen. Such machines are small in weight and size, they can be manipulated with one hand. Their main purpose is the grinding of corners, the processing of edges and small planes, such as planks and lintels. They look like a thick pen, they are used to engrave, cut and polish small objects.
Multifunctional grinders. They can combine several types of devices in one device, for example, a vibrating and tape machine, using replaceable nozzles.
DIY grinder video
Tools and materials for assembling a grinder
- wooden bars, metal elements for the base table;
- sheets of plywood, chipboard;
- old motor, computer hard drive, power supply;
- bolts, screws, bearings, self-tapping screws;
- screwdriver, screwdrivers, drill;
- spring, steel, metal, textolite plate;
- welding inverter, if such work will be carried out;
- abrasive tape, circle, glue.
Making a grinder from a hard drive
Now it's not a problem to get a broken hard drive from the computer (but the circle should spin up) and an old computer power supply. If there is no house, then at any repair point they will be sold for a penny.
Such a device will be oversized, for small parts. It is done simply: the disk is disassembled, an abrasive is glued onto the rotating plane, connected to the power supply - the device is ready. It must be mounted on a workbench for stability, it can be equipped with a regulator, a servo tester for speed control and a switch.
Do-it-yourself angle grinder is made from a grinder, it is enough to make the necessary nozzle-circle from an abrasive. You can, of course, make it from scratch by selecting the necessary electric motor, placing it in a casing, attaching handles. But you need to remember about the safety of working with such a tool.
Belt grinder machine. Such devices consist of:
- working body: abrasive, two drums, leading and driven. There may be more drums in the machine;
- electric motor;
- casing, machine base, frame, table.
The do-it-yourself machine is equipped with a speed change function, the tape can be placed both vertically and horizontally.
Stages of manufacturing a grinder-machine of a tape device
- preparation;
- equip the base-frame for the machine, it is rigid and stable;
- pick up the countertop, the larger it is, the larger parts can be processed;
- fix racks with tension parts and rotating drums;
- fixing the engine and drums, installing an abrasive belt.
To process large parts, they make an overall machine. To do this, they take an electric motor, which is well suited from old, sufficiently powerful household appliances, such as a washing machine.
The bed is made from a thick metal sheet.
Do not indicate the dimensions of the sheet, since in any case they come from individual preferences and the availability of materials, it can be, for example, 500x180x30 mm, more or less. A cutout for the motor is milled in the sheet, all this is attached to the bed, the necessary holes for the fasteners are drilled. All parts, and especially the engine, must be tightly fastened so that there is as little vibration as possible.
The motor can not be equipped with a gearbox if it is powerful enough. The do-it-yourself machine is created from two drums, one is firmly fixed on the shaft, the other is tensioned with it, you can adjust the degree of tension.
The frame is created from thick wooden parts, but it is possible from metal ones. If there is a suitable metal and an inverter for welding, it can be welded. The plate for the support is made from thick plywood, I take several sheets, textolite is also suitable.
The second shaft is beveled, so the tape will smoothly touch the table. For drums, several sheets of chipboard are taken, they are glued and turned to the required diameter, in the center they are made several mm thicker, so the tape will hold well. Single row ball bearings are used for drum spindles. The abrasive belt makes its movement along the frame on which it is attached.
Almost all types of work with wood are related to its finishing or preparation of wood for work, use in everyday life. For this stage of work, grinding of wooden parts is mandatory. Home crafters or professional craftsmen know how important it is to sand wood well, round off sharp corners, 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, emery is used, it is quite laborious and time consuming. Emery can be attached to a wooden block, there are also special shoe holders for it. The second method is carried out using a power tool, it is fast, with a minimum of effort. Some do-it-yourself work cannot be done as well as with grinders and machines.
Several types of such devices are made:
- Angle grinder or grinder. They are used for rough grinding of large objects - logs in baths, wooden houses. In the grinder, an emery or similar grinding wheel of different grain sizes is used.
- Vibrating grinder. Due to the reciprocating movements of the surface, the soles are polished. The sole is fastened with clips or Velcro, has a different shape, vibrations are carried out at a speed of 20,000 movements per minute.
- Orbital or eccentric machine. Its sole rotates simultaneously around its axis and in orbit.
- Belt sander. Used for rough and fine finishing of large surfaces.
Its mechanism is quite simple, these are two rollers or rollers on which an emery tape rotates. The device of the tape device of the design is the same for everyone (the appearance may differ slightly) and consists of:
- working body, this is an abrasive belt and two drums on which it rotates, one is a leader, the other is a slave;
- electric motor;
- bases of the machine (if it is stationary), bed, work table.
The speed of this machine can be changed. The tape is placed both vertically and horizontally.
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Manufacturing process of grinder and machine tool by yourself
Manufacturing steps:
- select and prepare the necessary spare parts and materials (described above);
- make a stand for the machine, table, base, fix it;
- mount the countertop of the desired length (the more, the more sizes of material can be processed);
- vertical racks with a tensioner and a drum are mounted;
- install the motor and drums;
- install sanding tape.
As an example, a conventional mass-produced belt grinder is taken. You can make such a device or the like, having spare parts from broken power tools and quite affordable materials. In such a machine, the abrasive belt moves along the sole of the device with a rough plane outward.
For grinding large parts, a grinding machine is made with sufficient overall dimensions, the principle of its operation is the same as for smaller devices. It can process parts with a size of about 2m and more.
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 a speed of 20-25 m / s, the drum size is 20 cm in diameter.
The engine can be taken from a used washing machine. The bed is made of a thick iron sheet with parameters 500x180x30 mm. On the one hand, it is cut on a milling machine, a place for the motor will be mounted here. Dimensions are: 180x160x10. It is attached to the frame with three bolts, holes are drilled in it for them. Mount the engine tightly so that there is no vibration.
The design consists of two drums, one firmly fixed on the shaft, the second tension, it rotates on bearings around the axis. Grinding surface tension is adjusted by pulling it to one side. The basis for the machine is made of wooden, and preferably from metal plates. Such a base plate is made of three sheets of thick plywood, textolite. The second shaft is equipped with a bevel, providing a smooth touch of the tape to the edge of the table. Drums are made from wood board (chipboard), blanks are taken and turned on a lathe to a diameter of 20 mm. It can be done 1-2 mm more in the center, so the tape holds tighter. The wheel spindles are made from two single row ball bearings.
The emery tape is cut from canvases, 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 appliances: features
Devices of this kind are used for:
- curved planes using a free grinding surface;
- for flat planes with a fixed table or its manual mechanized movement;
- for the ends of parts, edges;
- for preparatory processing under a paint and varnish covering.
You can design a grinder, the frame of which will be made of wood. Having equipped it with three shafts, an inclined horizontal and vertical working plane is obtained. Such a device has a wooden frame, which effectively reduces vibration. Wood is used like maple, it is quite soft and durable at the same time. 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. She moves along three wooden pulleys. The upper lever with the drum is equipped with a spring, this allows you to stretch the tape. The position of the belt is adjusted by a guide pulley with two adjustable bolts.
At work, this design looks like this: A motor with a drum of 90 mm rotates another one with a size of 75 mm, and that, in turn, the third. Rotation is carried out using an abrasive belt. Thus, the device has one vertical grinding surface and one inclined.
The frame is made of six elements, it is mounted on a plywood base with a thickness of 25 mm. The bearing parts and the frame are made of wood, these are the base of the bearing supports, the rocking chairs of the table, the rear rack, the upper arm, the plane for the material being processed. Bearing supports must be placed on a sufficiently large block, on which the support is mounted on the bearings of the input shaft.
Rollers, drums and pulleys are made from 7 or 8 glued pieces of 6 mm fiberboard, sawn to the appropriate shape. They have a bearing hole. The axis on which the drum with bearings rests is made of metal. For axles, you can take shafts from broken electric motors, they are even and already polished. The same design for the two guide pulleys. Ball bearings are used, ordinary ones, they prevent the side sliding of the drums if the tape moves inaccurately.
The design may differ in the size of the parts. For the frame, you can use various materials - metal, plastic.
One of the main ways to process wood (after sawing, of course) is sanding. The manual method has been known for a long time - a wooden block is wrapped in sandpaper, and with the help of such a simple device, the workpiece is given the desired shape.
The method is unproductive, and requires a fair amount of physical effort. Masters who work with wood regularly use small-scale mechanization.
Types of grinding machines
On sale are a variety of ready-made fixtures with which you can process wooden blanks of any size. To understand the mechanism of work, consider some of them:
Based on the name, the working surface is made in the form of a disk.
The design is quite simple - a circle with good rigidity is put on the axis of the electric motor. The outer surface has a Velcro coating on which sandpaper is attached. No gearboxes or drive mechanisms are required. The grinding force is small, the rotor axis copes well with the loads.
In the transverse plane, at the level of the center of the disk, a handrest is installed. It can be hinged, which allows you to process workpieces at a fixed angle.
A feature of disk machines is the adjustment of the processing speed without changing the number of revolutions of the axis. You simply move the workpiece along the radius of the circle. With a single angular velocity, the linear velocity at the periphery is higher.
A strip of sandpaper connected in a continuous band is stretched between two shafts. 
And in the working area does not sag under the pressure of the workpiece. A persistent working plane is installed under the tape, made of a material with a low coefficient of friction. Pressing the material being processed to the plane, the operator gets an endless abrasive surface.
The quality, and the ease of processing, cannot be compared with manual fixtures. In the mass production of wooden products, such a sledge is an indispensable attribute of any workshop.
The main feature is a predictable result throughout the entire plane. You can level the ends of a sufficiently large length.
The working surface can be horizontal or vertical, as well as the direction of the tape.
Such a device can be attributed to grinding units with some stretch. The main application is the horizontal alignment of planes using the jointer method. 
The principle of operation is as follows - sandpaper is fixed on one or two drums. The most common method is spiral winding. Below, under the drum, there is a flat table. The distance between the processing surface and the table is adjustable. By setting a fixed height, you can calibrate the same type of products, aligning the thickness of the workpieces. 
Grinding machine two in one
To save space (and money), manufacturers often combine two types of fixtures in one design. 
This not only reduces acquisition costs, but also improves user experience. When processing one part, you can enjoy the advantages of two grinding units at once: disc and belt. In this case, the engine is used alone, and the load on it does not increase much.
For finishing wood, metal or stone, you can build a belt sander with your own hands. The need for such processing arises quite often. It is needed not only to obtain even and smooth surfaces. With its help, you can remove various kinds of irregularities, bulges and depressions, peel off burrs, remove local defects, remove flash formed during welding, carry out internal grinding, etc.
Manual execution of such processing is very laborious and inefficient, and the cost of industrial grinding machines is quite high. Therefore, it is necessary to invent and build home-made structures, especially since they do not differ in particular complexity.
General information about the design of belt grinders
Belt grinders, with all the apparent diversity of their designs, have common distinguishing features. An abrasive belt is used as a working tool in these designs. Most often, it is connected into a ring and placed between two rotating drums.
Usually there are two such drums: the first is the leader, and the second is the slave. The driving drum is driven by an electric motor through a mechanical transmission. Usually it is a belt drive. It is desirable to have a device that allows you to change the speed of rotation of the main drum, thereby providing a variety of processing modes.
The location of the sanding belt depends on the purpose of the sanding machine and can be any: vertical, horizontal or inclined. The tape is usually mounted on a frame, and workpieces can also be located there. In homemade designs, the blanks are usually held by hand, although there may be other options.
The length of the working part of the sanding belt depends on the size of the workpieces being processed. The grinding process is accompanied by the release of a large amount of dust, so the presence of an exhaust device is desirable. A tension roller is often used to adjust the degree of belt tension.
Depending on what the grinder will be mainly used for, it may have some design features. This applies to the diameter of the drums, the length and speed of the belt, its grain size, the design of the working table, etc. The main types of grinding are:
- grinding curved surfaces;
- leveling of flat surfaces;
- alignment of side edges or ends, as well as surfaces of bars, shields and similar parts;
- grinding of intermediate layers of paint and varnish coatings.
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Homemade belt sander
The structural prototype of a homemade grinder was a conventional industrial design in which the belt is moved by the abrasive part outward over the flat surface of the desktop. The resulting grinder is distinguished from the industrial design by increased dimensions and a stationary installation.
Since a gearbox or belt drive complicates the design, an electric motor is used, the rotor of which makes 1500 rpm. The power of the electric motor should be about 2-3 kW. With a drive shaft radius of 10 cm, the linear speed of the belt will be about 15 m/s. As already mentioned, the reducer is not needed in this case. Adjustment of the speed of rotation in such a simple design is not provided.
The drive shaft is rigidly mounted on the motor shaft, and the second shaft tensions the belt. The tension shaft rotates on bearings sitting on a fixed axle to reduce friction. This axis can be shifted relative to the desktop in one direction or another, reducing or increasing the degree of tension of the sanding belt.
The desktop can be made from improvised materials: sheet metal or wooden beams. Its dimensions are determined by the distance between the axes of the shafts and the length of the abrasive belt. Near the shafts, the surface of the table must have bevels to ensure smooth contact of the tape (especially its junction) with its plane.
Both drums are easy to make yourself. Chipboard can serve as a material for their manufacture. Squares with a side of 20 cm are cut from the original plate. Their number should be such that the total thickness of the set is about 24-25 cm. Discs with a diameter of 20 cm are made from them on a lathe. There are two options for processing them:
- You can grind each workpiece on the machine separately.
- A more preferable option is to put the workpieces on the axis, clamp and grind them all together.
The groove should be carried out in such a way that the edges of the drums are a few millimeters smaller than their middle. This is necessary so that the abrasive belt is automatically installed in the centers of the drums.