Making a machine for sharpening knives with your own hands. DIY grinder DIY grinder

The sharpening machine is designed for straightening the cutting edge of knives, drills, scissors, saws, chisels. As a sharpener, a diamond or abrasive surface is used. To work on a modern grinding machine, special skills are not required, but such devices are not cheap. But homemade machine will cost a penny.

Types and device of machines

There is specialized and universal. Specialized designed to work with a specific type of cutting tool, such as hairdressing and nail scissors, chains or cutters. Universal equipment is used for sharpening any kind of cutters.

Sharpening machines can belong to the household or professional category. The latter are very reliable, withstand continuous work during the working day, the road. household small size, light and inexpensive. Professional, as a rule, are mounted directly on the floor, household - desktop.

Each machine consists of:

grounds;
electric motor;
grinding wheel (maybe several);
handpieces and other devices for the correct supply of the tool being sharpened.

Specifications:

electric motor power;
mains voltage;
grinding disc diameter;
rotational speed abrasive disc;
landing size of the abrasive disc;
machine dimensions and weight.

Additional options

Professional machines differ from household and home-made ones, including the presence of additional devices that facilitate the work:

automatic adjustment of the feed angle of the sharpened part;
automatic adjustment of the rotation speed of the grinding wheel.

Universal grinder

On such a machine, you can sharpen any cutting tool, so it is most often done by hand. A simple device consists of a motor whose shaft exits from two sides. Two abrasive discs of different grain sizes are put on the shaft. First, the tool is processed on a coarser disk, after which fine grinding is carried out on a fine one. Factory models are equipped with a support bar for the part to be sharpened and a transparent protective cover against flying sparks.

The main indicators of homemade or factory grinders- engine power and disk rotation speed. The higher the characteristics, the cleaner and more accurate the sharpening. A number of models have the possibility of stepless switching of speeds.

Homemade sharpening machine

Protozoa homemade model desktop type. Do-it-yourself manufacturing will take a couple of hours of time and a minimum of materials:

cable ties;
thick plywood No. 10;
two bolts with nuts;
self-tapping screws;
jigsaw;
screwdriver

Work progress:

from plywood with our own hands we cut out a rectangular base, 4 parts for racks and one part under the tool stop;
at the top of the body grinder make holes for cable ties;
we turn the car over and with our own hands we pull it to the base through the prepared holes;
in the details of construction sites we will make holes for bolts;
attach the lower parts to the base with self-tapping screws;
we attach the upper parts of the racks to the stop, connect them to the rack bolts and the home-made sharpening machine is ready.

Homemade universal sharpening machine

To do it yourself, you will need:

electric motor not more powerful than 1000 W;
shaft and two bearings;
two pulleys;
strip of metal 2 mm thick;
Plexiglas plate;
electric wire;
steel corners.

Work progress:

we weld the frame with our own hands from a steel corner;
we install the shaft and pulleys on the engine, fasten them to the bolts and nuts. Engravers are used so that the nuts do not unwind;
we put abrasive wheels on pulleys on both sides of the engine. If the inner diameter of the circle is larger than the shaft, additional washers and bushings are used. The put on circles are fixed with fixing nuts.
as a stand for the tool during sharpening, we assemble a swivel bar from the corner;
cut and weld a protective box from a metal sheet;
we hang a Plexiglas sash on the upper part of the protective casing;
the engine is connected to the power supply using a piece of wire that is connected to the start button and from it to the electrical network.

This model of a homemade machine can also be used for sharpening drills: one of abrasive wheels we remove it with our own hands and attach it instead collet from an electric drill.

When everything is ready, you need to do a test run. Pay attention to the vibration and beating of the stone - they should be minimal. Between the edge of the abrasive disc and the base of the machine, a distance of more than 1.5 cm is maintained.

Videos about simple machine for sharpening without electric drive and factory model JET:

An electric grinder or, as the people say, emery, a great variety of everything that falls under the arm is collected, often they are made from engines from washing machines.

I also decided to make myself a homemade machine for sharpening drills, knives, etc. I have a Chinese sharpener, but its quality 😥 well, you understand...

Making such a machine turned out to be one of the easiest things 🙂

Because:

I had an extra motor at 1370 rpm and 370 watts.
I did not order a nozzle for planting a grindstone on a shaft from a turner, such nozzles are sold on our market - it is enough to know the diameter of the motor shaft and you can purchase a nozzle for only 250 rubles + 200 rubles. for the grindstone.

Making a grinding machine with your own hands step 1

I installed an electrical box on the engine, placed a capacitor in it to start the engine, a toggle switch and a power supply for the lamp.

I used the toggle switch from a Soviet tube TV - it turns out to be a reliable thing, first I installed a modern beautiful Chinese toggle switch - when using it, the machine "stuttered" (worked with some jerks), and replacing the toggle switch with another of the same brand did not help until I installed the Soviet toggle switch.

For the sake of interest, I then installed these Chinese toggle switches on another engine, which also began to "stutter", it's a shame, I gave 100 rubles for 2 toggle switches. I just threw money in the trash...

Well, with a capacitor - everything is standard, I will not describe 101 times how to connect a three-phase motor to 220v - it's easy to find on Google, or in our article on.

Illumination for sharpening machine step 2

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For backlighting, I used an unnecessary LED table lamp from IKEA, bought for the home, but never came in handy, the lamp is powered by the mains through an adapter, which I unpacked and hid its board in a box on the engine.

Handpiece for lathe step 3

To attach the handbrake, I used a sharpened under right angle furniture corner, then I attached a piece of a 32x32 corner to it, in which I sawed a groove and installed a handpiece from a piece of steel 4 mm on it. Fixing the tool rest with a countersunk screw, thanks to the groove in the corner under the tool rest, the tool rest can be moved closer or further away from the whetstone. The corner is also attached to the casing with a screw, which allows you to adjust the angle of the handpiece relative to the grindstone.

I made a corner for attaching protective glass from a furniture hanger, for this I used a piece of plexiglass 6 mm thick.

Whetstone used 200x20mm gray color- I like these more in terms of rigidity, white ones are very crumbly. I know about stone marking, but I don't professional processing steel, in order to select a stone according to its parameters for a long time.

When installing the stone, I placed two washers made of cardboard, as required, so that when tightening the nuts, the whetstone does not burst.

About the safety of the DIY grinder

We read the theory - we know ...

The casing of my emery is not closed on one side - for safety it’s impossible, the casing should cover the stone as much as possible, but I decided for myself that sometimes it’s convenient for me to grind something on the side of the stone, although this is not recommended. And in general, I usually finish my machines gradually, I think that in the future, when I wish, I will still make a cover on the casing so that it closes the grindstone from all sides.

But, my machine also has safety advantages:

the protective glass on Chinese machines is much thinner than what I used;
the revolutions of the machine are 1380 rpm, although the grindstone is designed for 3000 rpm. in min. So my stone will have a very small chance of breaking.

What did I get

I got an excellent home-made machine for sharpening drills, knives and other tools, the power of the machine is enough even for sharpening axes - checked;
the speed of the machine is low, it grinds emery better at 3000 rpm, but mine works quietly and hard, I would say 🙂

Recommendation for choosing an engine for a homemade grinder

The engine is taken depending on your needs, if you are going to sharpen only awls, small knives, etc. on it, then you fit motor from washing machine from the USSR. Such engines usually have 1380 rpm. per min and 180-250 watts of power. Now there are also engines from modern automatic washing machines, but they are more difficult to connect - you need a special board, but you can adjust the speed on them.

For more confident work, it is better to take a 400W engine and 1380-3000 rpm. Such a sharpener will already be a good help in the workshop.

But if you want to work with large parts, sharpen crowbars, for example :), then you need to use an engine of the order of 750 watts or more and at 3000 rpm.

Photo of emery made by hand:

In any household, a tool such as emery is useful. Sharpen knives, scissors and other cutting objects periodically. And every time you will not go to the master. So many people have a question about how to make emery with their own hands. Of course, you can buy it in the store. But it is quite expensive. And not everyone decides to buy it. Emery made from improvised materials will save money and will work no worse than the factory one.

Principle of operation

Do-it-yourself emery is made from a washing machine and other household appliances. More precisely, from their engines. It is he who will start the device. A shaft is mounted to the engine, to which nozzles are selected. Nozzles can be sharpened to lathe. Installed emery wheel securely fixed. Motor connected to electrical network, rotates the shaft, which transmits rotation to the emery wheel.

Motor selection

Most often, emery is made from the engine of a washing machine as a power element. Do-it-yourself assembled device does not require new devices. Enough old-style cars (for example, Vyatka, Siberia, Volga, and so on). The devices of those times were equipped with durable high quality engines. From the same machine, a switch that has a manual starter is also useful.

It is best to choose an engine for the device, the speed of which is in the range from 1 to 1.5 thousand rpm. It is strictly forbidden to use a motor whose rotation speed exceeds 3 thousand rpm. Otherwise, the emery wheel may not withstand and break. High speeds are suitable for polishing the surface, but not for sharpening it. Therefore, if the engine has an increased speed, it is necessary to use a durable stone.

The motor power should be in the range of 100-200 watts. It will be enough to make homemade emery with your own hands. But this value can be increased by 2 times (and be 400 W).

Such indicators are taken for a reason. The fact is that the characteristics of the engines of a washing machine are similar to those of factory-made emery. But other devices with the same power and speed can be used. The motor can be single phase or three phase.

The used electric motor is connected to the electrical network through a capacitor.

Flange preparation

Emery, made by hand, provides for the connection of an electric motor with a stone circle by means of a flange. It must be carved from metal. For this purpose, they usually turn to a specialist (to a turner). You will need to know the parameters of the device, the diameter of the inner hole of the emery wheel, the diameter of the shaft.

The flange is attached to the shaft with a nut, bolt and washer. They also need to be prepared. The thread on the nut and flange must be in accordance with the direction of movement of the shaft coming from the electric motor. If you plan to rotate the stone clockwise, then the thread must be cut to the left. When rotating the shaft counterclockwise, the thread, respectively, must be right-handed. This is necessary to comply with safety regulations. The fact is that with this thread direction, the nut will twist under the action of vibration during operation, preventing the circle from breaking off. If the thread is in the other direction, the nut will unwind. If it unscrews completely, the emery wheel will fly off. And this is dangerous.

It is not always possible to find a turner. Therefore, it is not always possible to machine the flange. In this case, you can resort to an alternative solution. In such a situation, do-it-yourself homemade emery is made using pipes of a suitable diameter. If a gap remains between the sleeve and the shaft, it is eliminated with fabric tape. With a large gap, you can put one sleeve on another.

Emery direction

Before you collect emery for sharpening knives with your own hands, it is important to understand the direction of movement of the rotor. When using the motor from the washing machine, the direction of rotation is reversed. The motor is asynchronous. And this means that there are no obstacles to change the direction of rotation of the rotor. Therefore, it is enough just to swap the ends of the winding in places.

First you need to determine which winding is designed to start the engine, and which for the main work. To do this, you need a tester that will help measure the resistance. In the first case, the value should reach 30 ohms. The resistance in the working winding is much lower and is 12 ohms.

The winding responsible for the working process is connected to the electrical network. The starting winding is connected on one side to the coil. On the second side, it is connected for a short period to the winding output. For this, a relay is used. The engine starts.

In such a simple way, by changing the ends of the winding necessary to start the motor, the direction of the rotor changes. You can even do without a relay. In this case, you must manually twist the emery wheel in the right direction.

Device installation

Emery, made with your own hands, after complete assembly, must be installed on a fixed support (workbench). This is done with bolts. To facilitate the task will help the bracket, which is available in the same washing machine. In a horizontal position, the device is held at the expense of the angle. To eliminate vibration, a rubber edging is put on the corner. It can be cut from a regular rubber hose.

Machine Safety

Emery (made with your own hands or purchased in a store - it doesn’t matter) can harm human health or surrounding material values. Therefore, it is necessary to work on emery in compliance with safety regulations. Wear protective plastic goggles while working.

From a sheet of metal with a thickness of 2-2.5 mm is made protective cover. It will prevent debris from flying when the wheel, chips and other small particles are damaged. Placed under the machine a metal sheet, which will serve as protection against flying sparks.

During operation, the emery wheel is subjected to strong vibration, inertial forces act on it. Therefore, there are times when discs simply break and fly apart. Before starting work, it is necessary to check the circle for the absence of cracks, to make sure that it is correctly installed.

Conclusion

Emery, made from improvised materials with your own hands, will be a good alternative to factory machines. This will allow you to realize yourself as a master and save cash. In a difficult financial situation for many families, even a saving of 2 thousand rubles (namely, the average cost of emery in a store) will be significant. Moreover, apart from appearance, then the factory machine will not differ in any way from the one made independently.

Dear visitors of the site “Visiting Samodelkin”, from the material presented by the author, you will learn how you can independently make a full-fledged emery from the engine from a washing machine and install, for example, in your workshop or garage.

For a craftsman, this machine is simply irreplaceable, because something constantly needs to be sharpened, sharpened). Buy factory sandpaper good quality today it will be a little expensive, but it makes no sense to take a cheap one, because its age is not long. The best option is to make emery yourself, the tradition of using engines from washing machines to make this machine has been going on since the days of the USSR. Surely many still have such emery and work fine for several decades)

And so, let's look at what exactly the master needed to assemble the emery?

materials
1. engine from a washing machine. 220 v 2826 rpm 370 W
2. 2 capacitors with a capacity of 3 microfarads
3. grinding wheel
4. corner
5. professional square pipe
6. rubber stoppers from vials with antibiotics
7. switch (tumbler)
8. wires
9. fork
10. galvanized sheet
11. engine mounting flange
12. bolts, nuts, washers, grover
13. paint
14. solder
15. electrical tape

Tools
1. grinder (UShM)
2. welding machine
3. drill
4. vise
5. metal ruler
6. marker
7. hammer
8. metal scissors
9. screwdriver
10. wrench
11. soldering iron
12. pliers
13. knife
14. brush
15. tap

Step-by-step instructions for assembling emery with your own hands.

As already mentioned above, the best option is to use the engine from a washing machine, for sure many have old washing machines that it’s still a pity to throw away or scrap) so remove the motor and make a grindstone) This is what the heart of the machine looks like.