For easier sanding of parts small size you need to use the same stationary grinding machine simple design, based on the electric motor from the old washing machine.
Today, stores offer a wide variety of woodworking and grinding machines. However, the prices for good devices are very high, and cheap ones are very unreliable.
And here the author found an option that was quite profitable in all plans - creating a grinding machine for his workshop on his own. Moreover, all the materials were ready for this - a motor in excellent condition from a Soviet washing machine, plywood and chipboard from approximately the same years.
So, the list of materials for making a grinding machine:
engine washing machine;
plywood, chipboard;
corner – 4 pcs.;
self-tapping screw;
bolt;
screw;
washer;
capacitor;
switch;
sandpaper (circle);
rubber.
List of tools:
electric jigsaw;
drill;
file;
wrenches;
screwdriver;
pliers;
ruler;
pencil.
Step-by-step description of the work
First of all, the author took a motor from a washing machine, which was once put aside until better times, cleaned it and connected it to the network to check how it works.
Then the connection was made in accordance with this diagram.
To make the machine easy to carry, an improvised handle was made.
Using a compass, the center of the motor pulley was marked, and 3 holes were drilled to install the grinding wheel.
A circle was marked on a piece of plywood, which was then cut out with an electric jigsaw along the drawn contour.
To secure the engine to the frame, the author used corners.
Connecting the motor, capacitor and switch - toggle switch.
A couple of planks were screwed to the frame.
A shelf was fixed on the obtained support points, which provides more convenient work.
Then the craftsman makes non-slip legs for the bed using rubber.
Screwed on using self-tapping screws.
As a result, we have such a nice machine.
Working on this machine is very simple and convenient. The part is placed on the shelf, turned to the desired side, and sanded. And, what is very important, the author did not spend a penny on this machine, and as a result it will last for a very long time.
Note, for those who will make such a machine, we suggest making guides, like sliders or rails. They should be parallel to the grinding disc. This way you can level the workpieces straight, which is very important.
You can use a metal brush to clean the grinding wheel. As an option, make removable discs with Velcro, so you can quickly replace a used grinding wheel.
A grinding machine is also called a grinder, which is translated from English grinder as crusher.
There are crushers for stones, crushers for meat - we have meat grinders, and there are garden crushers that produce wood chips. But if the word is used independently - simply grinder, only one thing is meant: a grinding machine in the field of metal processing.
Grinder is good and useful everywhere, including household– from proper knife sharpening high quality or tailor's scissors before grinding a complex piece of metal or other “difficult” material. In other words, the tool is needed and will be useful on the farm.
Moreover, it is quite possible to make it with your own hands. To do this it is not at all necessary to have special equipment and solid professional experience.
Of course, you will have to tinker, but you will do exactly what you need and, most importantly, you will save a serious amount of money, up to several thousand American dollars.
Do we do it with a disk or with a tape?
Grinder drawing.
In terms of the breadth of the product line, only lathes can compete with grinding machines. There are a huge number of grinders on the market – of all shapes and sizes.
The most famous and primitive one is in the form of the famous emery - a pair of grinding stone wheels with a screwed-on motor. These machines are sold with a wide variety of schemes and operating principles.
But if you are planning to make a homemade sander, it is better to stop and choose between two options: disc or belt.
- Disc grinder - a grinding layer of abrasive is applied to the disk, which rotates when turned on.
- A belt machine in which the abrasive is applied to a belt wound on rollers.
Which one is better is a matter of debate. The correct criterion would be “which one is more necessary”. The choice should depend on what exactly you are going to sand. If these are relatively simple parts made of, say, wood, homemade disc wood sanders will be more suitable for you.
If you have serious things ahead grinding work For precise finishing with complex parts, choose tape.
It is necessary to take into account the difference between a suit and a tape not only in terms of their functional features. Another important factor is drive power. If you are sanding small wooden sanders, you will have enough power in the range of 160 - 170 W.
This can easily be produced by a simple motor from a washing machine or even from an old drill.
For belt grinder Old household motors will not work in any way. There you will need an engine with a power of at least 400 - 500 W, and not a simple one, but a three-phase one with starting and running capacitors.
For grinding massive and large parts, higher power will be needed: up to 1200 W. Let us immediately note that purchasing capacitors for the machine will cost you not much less than the motor itself.
Selecting a feed
A machine with a tape is more versatile in terms of functionality: it does everything that disk models do, plus much more. Let us immediately note that there are a great many options for amateur models of belt sanding machines.
The point is that nature of this machine very plastic, allowing you to use a wide variety of available materials, including finds in scrap metal dumps.
The main thing is to know and adhere to three rules:
- The abrasive side of the belt must be adjusted very precisely so that only the workpiece that is being sanded touches it.
- The tape must be evenly tensioned at any time and regardless of the type of work.
- The speed of movement should be different and should depend only on one thing: the type of part and the nature of the grinding.
Construction of a homemade belt sanding machine
Grinding machine device.
The main ones are:
- A motor or motor-driven engine powered by electricity.
It is better to install the drive next to the main diameter drive roller. - Base or bed.
It is often fixed directly on the floor, sometimes this thing rides on wheels - whatever is more convenient and necessary for you. - Two tension rollers - driving and driven.
Made from metal or very durable wood with a thin layer of cushioning rubber to prevent the belt from slipping onto the rollers or drum. - Spring and lever for the belt tension system.
The spring is pressed, and the lever is attached to the base and driven roller. - Base for placing a motor with a drive.
- For abrasive tape you need to use paper or cloth.
Its width can be very different - in the range from 5 to 30 cm. Grain level - from 80. - Metal pipes with a thickness of 2 mm or more.
- Metal corners in accordance with the dimensions of the machine.
- Special magnetic stand for metal parts.
- Rail type guides.
Diagram of the grinding machine.
Stages of work:
- We make the frame of the base or bed.
– we cut the corners according to the dimensions of the bed;
– weld the frame and corners;
– we fix a chipboard board at the bottom of the frame to reduce vibration during operation. - Making a work surface.
– cut a steel sheet to size and weld it directly to the base;
– weld the rail guides to the top of the frame;
– we make a carriage from corners with wheels for moving along the guides of the bed;
- on both sides work surface we mount and fix bearing supports;
– fix the screw with the handle on the carriage; - We fix the electric motor to the working area lifting system.
- We fix the gear supports.
- We install a tape with an abrasive coating.
– cut the tape with a margin of a few centimeters at an angle of 45°;
– glue it together overlapping with glue on the sides with the abrasive washed off with water;
– dry the gluing area with a hairdryer; - We are preparing for a test launch of the machine.
– we treat all machine parts with machine oil;
– supply electrical power;
- We do a test run.
Safety precautions when working on a sanding grinder
Like any other work on any other machines, grinding on a homemade belt sanding machine is subject to fairly strict safety rules that must be strictly adhered to.
The principle of operation of the grinder.
These rules are as follows:
- It is strictly forbidden to touch anything that moves or the work surface with your hands.
- Wear safety glasses while working to protect against hot abrasive particles.
- Carefully check that the connections and fastenings of all moving parts of the grinder are tight.
- Monitor the condition of the braiding of electrical wires.
- A protective casing is a must, even though it narrows the viewing angle a bit.
The cost of a factory-made grinding machine is quite high. If you can't afford a power tool, you can try making one yourself. On such a machine it will be possible not only to grind wooden workpieces, but also to sharpen the tool. There are three types of grinding machines you can assemble with your own hands: belt, disk and drum.
To assemble a belt-type grinding machine, you will need an electric motor, a durable frame and rollers on which the belt will rotate. Be sure to have a drawing or detailed diagram indicating all components and dimensions. Example of a machine diagram with wooden frame We suggest you look at the photo. 
The following photo shows the finished design of the machine. In this embodiment, the arrangement of the three working shafts is designed so that the moving belt forms a vertical grinding plane. A belt drive is used as a drive. 
The machine design can use four rollers. One of them is the leading one and is mounted directly on the electric motor shaft. The photo shows an example of such a design. Installing four rollers allows you to get two grinding planes: horizontal and vertical. 
The wooden frame smoothes out the vibration of a running electric motor, however, wood is short-lived. It is optimal to cut a workpiece measuring 50x18 cm from steel 2 cm thick. One edge of the frame is made perfectly flat in order to attach a platform for the electric motor to it. For the next part, you will need steel 1 cm thick. The area is cut out to a size of 18x16 cm, and then secured to the frame with a bolted connection.
A large electric motor power is not needed for such a machine. A motor from an old washing machine will do. If you need more performance grinding machine, then it is advisable to find an electric motor with a shaft speed of 1500 rpm with a power of 2.5 to 3 kW. High-quality grinding can be achieved by moving the sanding belt at a speed of 20 m/s. To achieve such parameters, working drums with a diameter of 20 cm are used. If you make the rollers thinner, you will have to reduce the speed of the motor shaft using a gearbox, which is extremely inconvenient.
The drive drum can be mounted on the motor shaft. If this option is not suitable, a separate unit is made. The drive shaft with bearings is fixed to the frame. A belt drive pulley is installed at this end, and a drive drum is installed at the other end. Then a pulley is also mounted on the electric motor shaft and a V-belt is put on. The driven rollers rotate freely on bearings.
The belt drive pulleys will have to be machined lathe, and rollers can be made from square pieces of chipboard measuring 20x20 cm. The plates are stacked on top of each other until a total thickness of 24 cm is obtained. A hole is drilled in the center of the square plates, a threaded pin is inserted and the plates are tightened tightly on both sides with nuts. The square blank is machined to form a drum with a diameter of 20 cm.
When grooving the roller, a thickening is provided in its central part. In relation to the edges of the drum, the difference should be 3 mm. Due to the thickening, the belt will not move off the rollers. Surface wooden drum covered with rubber. An old bicycle tube will do. Rubber will prevent the belt from slipping on rollers.
To make a sanding belt, cloth-based sandpaper is suitable. You can cut a solid strip of the required length, the edges of which are glued end to end. If there is no long strip of sandpaper, cut a strip of durable fabric and sew it into a ring. The sandpaper is cut into rectangles and then glued onto a strip of fabric. When making a sanding belt, it is important to choose high-quality glue so that the sandpaper does not peel off.
Manufacturing of disc grinding machine
The disk machine is considered the easiest to manufacture. The principle of its operation is reminiscent of ordinary electric emery. Assembly of the grinding machine is presented in instructions with step-by-step photos:
- The power plant of the machine is a three-phase electric motor. This choice is not accidental, since changing the phase when connecting allows you to organize reverse. The motor can be connected to a 220 V network through capacitors.
- The working disk is cut out of plywood 1.5 cm thick. Two identical blanks are glued together. The result is a disk 3 cm thick. A hole is drilled strictly in the center, the diameter of which is equal to the thickness of the electric motor shaft.
- To assemble the frame it is better to use edged board, and the guides and work table are cut out of plywood 1.5 cm thick. Wood for making the machine would be better suited than metal. Wood dampens engine vibrations.
- The working disc can be used for grinding and even sharpening. It is important to choose the right abrasive materials. They must be Velcro and fit for their purpose. If you need to grind a product made of stone or granite, stick a “Turtle” diamond wheel onto the working disc.
- To sand a wooden workpiece, glue a circle of sandpaper to the working disk.
- There are similar Velcro circles for metal. This disc can be used to sharpen knives, axes and other tools.
When designing a disc sander, it is important to consider safety. The rotating working disk is covered with a protective arch on top. An adjustable heel is provided on the work table, which serves as a stop for the workpiece. 
The tabletop of the machine should not be varnished or painted. Over time, an unevenly worn coating will create difficulties in moving the workpiece being processed.
Making a drum machine for sanding boards
For making drum machine assemble the frame. You will need timber from hard rocks tree. An electric motor with a pulley is attached to the bottom of the frame. A drum with bearings will come from a used conveyor. The sandpaper is cut into strips and wound tightly end-to-end on the work roller. Along the edges of the drum, the paper is secured with clamps.
The work roller is attached to the frame from above. The machine table top will be located under it. A pulley is mounted on the drum shaft and a belt drive with a motor is created. The tabletop is made adjustable with screws so that you can sand boards of different thicknesses. To avoid vibrations of the machine, it is advisable to fix the legs of the bed to the floor.
If you try and make an effort, then any unit considered will work no worse than a factory-made grinding machine.
A belt grinding machine is used to perform the final processing of parts - their final grinding. The main area of use of the tool is the furniture industry, processing wooden parts. But they can also be processed metal elements using appropriate abrasive material.
Using a belt-type grinding machine, the surfaces to be treated are leveled and their roughness is brought to the required level before applying coatings. They also eliminate minor defects: depressions, burrs, raised surfaces, varnish deposits, primers. The tool can be used to round corners. It is suitable for processing round and tube parts.
The working tool in a grinding machine is a belt with abrasive powder applied to its surface. It is made endless, placed on two rotating drums - the master and the slave.
The drive drum is driven by an electric motor, which transmits rotation to it through a belt drive. The tape can be positioned vertically, horizontally, or at an angle. The machine has a device for regulating the speed of the belt.
Having decided to make a belt sanding machine yourself, you need to decide: maximum length the processed surface in detail; what kind of table to make (movable, fixed) or give preference to a free tape and refuse to make a table. The design of the machine must include an exhaust device for removing large quantity dust that is generated during its operation.
The main parts of a belt-type grinding machine that will have to be prepared or made are: frame, electric motor, rollers. The motor, for example, comes from a washing machine that has already reached the end of its service life.
The bed of the future machine can be made of sheet metal - its dimensions can be, for example, 50x18x2 cm. One side of the plate is made flat - this is necessary because a platform with an electric motor is attached to it. The platform for the motor is made of metal in the form of a plate measuring 18x16x1 cm and secured to the frame with several bolts.
The electric motor used has a power of 2.5...3 kW and is capable of providing a rotation speed of 1500 rpm. The speed of the belt when grinding should be 20 m/s. Based on this, the diameter of the pulleys is made equal to approximately 20 cm. Under such conditions, there is no need to install a gearbox in the craft, which makes it cheaper.
The drive drum and shaft shafts are directly connected; the slave is allowed to rotate freely, placing it on bearings.
Pulleys for a homemade belt-type grinding machine can be made from square pieces of chipboard. Central holes are drilled into them, combined, gluing, to a thickness of 24 cm. Then the package is machined, giving it a cylindrical surface with a diameter of 20 cm. In this case, the central part of the pulleys is made convex, increasing the diameter by 2...3 mm when turning.
A simple, homemade, DIY belt sanding machine: photo step-by-step production with description.
With this band press, you can easily and quickly grind, form bevels on knives, sharpen axes and many other tools. You can make such a device with your own hands, we suggest you take a look step by step photos for the manufacture of a grinding machine.
Materials for production:
- — electric motor 220 V, 2 kW, 2800 rpm;
- - square steel pipes;
- — sheet steel;
- — bearings;
- — nuts and bolts;
- - spring;
- — car trunk lid shock absorber;
- - wheels (you can carve them yourself from wood).
The base of the machine will be made of thick sheet steel.
The following shows the process of making a telescopic stand; it will be made of two square pipes. We cut the required pieces of pipe into cutting machine or Bulgarian. Next, we weld the wider pipe vertically to the base. We use angles to weld the pipe strictly vertically.
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 the blanks, drill holes, cut threads where required.
This adjustment unit is then assembled on a long steel plate, which is welded horizontally to the post.
We install and fasten the electric motor onto the base. This design uses a shock absorber from the trunk of a car as a tensioner for the sanding belt.
Next, we install the wheels; you can turn them out of wood yourself on a very simple lathe. The drive wheel is fixed to the motor shaft, and the driven wheel rotates on a bearing. You should also install auxiliary plates under the sanding tape, one plate is attached vertically, the second horizontally.
