Of course, you have heard more than once about the benefits of emery in household, even if you are not a fan of making crafts with your own hands. After all, in every home there are knives, scissors and other piercing and cutting tools, which require sharpening from time to time. But the price of emery in most retail outlets you won't be happy! And so why not think about making this incredible thing yourself? useful tool?
Purpose of emery
Many people use drills to make holes in metal using drilling machine or drill. After a certain time, the drill begins to get very hot and drills worse, due to the fact that it has become dull. And all this happens quite quickly if you drill with a drill at high speeds. There are cases when a drill breaks off in the middle if it was “bitten” when leaving the metal, and the part was not secured.
Accordingly, working with a blunt instrument is pure torture. Nowadays, few people remember how tool sharpeners used to go from house to house with small portable sharpeners and sharpen all kinds of tools, including knives. Nowadays, of course, you can go to the store and buy absolutely new tool with factory sharpening, and you can also sharpen the drill at home.
To sharpen drills, you should use a commercial sharpening machine, or you can also sharpen them using homemade sandpaper. A sharpening machine is a necessary and irreplaceable thing in the household. It can be used to sharpen almost any tool and can also be used for sanding wood.
Every tool store sells electric sanders. Quite a large selection of them. You can buy either a very small sandpaper to correct dull cutting tools, or a fairly powerful one. grinder, with which you can grind off a large layer of metal from any part.
The best purchase would be a double-sided electric sandpaper, with finishing wheels on one side and rough grinding wheels on the other. To prevent injury, these circles must have protective covers in case of destruction or damage to the circle while the engine is running. It is also desirable that the electric sharpener have adjustable working stops for the tools being sharpened and spark-proof shields with protective glass.
Electric sanders with adjustable rotation speed are quite convenient. When removing a large layer, you need to use increased speed, and the “finishing” itself cutting edge It works better at low speeds. This will, of course, prevent the metal from burning. From time to time, when sharpening a tool, it is necessary to cool it in a bath of water.
DIY emery
In the hands of every man there may be an engine from household appliances, and the question immediately begins to linger in my head, how to make emery with my own hands from scrap materials. For this purpose, all kinds of electric motors are used, on the shaft of which they are installed specially machined lathe nozzles that are designed for clamping an emery wheel.
Motor selection
For this purpose, they usually use engines from old-made washing machines, such as “Volga”, “Riga”, “Sibir”, “Vyatka”, etc. The engines on such machines are quite powerful and reversible. Switches with a starter are also used from such washing machines.
Despite the fact that it seems quite simple, from a Soviet engine washing machine homemade emery not at all easy to put together. For example, one of the main questions is how to attach a whetstone to the motor shaft. After all, there is not always a thread, and the diameter of the hole in the stone may not coincide with the diameter of the shaft.
Therefore, a special turned part is needed that would compensate for this disproportion. To make homemade emery with your own hands, you need to know its future parameters. In most cases, asynchronous electric motors are usually used to make emery at home.
For emery, the maximum speed is considered to be about 3000 rpm. A sharpening stone can simply burst at a very high rotation speed. It is best to use an engine at home with 1000 - 1500 rpm. If a 3000 rpm electric motor is to be used, a fairly strong stone must be present and a quality flange made. Most often, high engine speeds are used not for sharpening, but for polishing products.
In order to make emery with your own hands, it is not necessary to use it for such purposes. powerful electric motors. Although experienced craftsmen say that for a homemade sharpening machine the acceptable power is 400 W, and for home use An engine with a power of about 100 - 200 W from a Soviet washing machine is enough. Of course, it is low-revving, but this is very good.
You can use three-phase and single-phase electric motors to make emery with your own hands. Both are included in a single-phase network. The device is connected to a single-phase network via a capacitor.
Flange undercut
To connect the engine and the stone, you need to machine a flange. For such purposes, it is best to contact a turner with a drawing of the emery, the dimensions of the internal diameter of the stone and the diameter of the motor shaft. And the rest is a matter of technology and the availability of available materials.
You will have to grind out the flange itself, which is mounted on the shaft and is also fixed with a bolt, and a nut, and a washer with a left-hand thread. You also need to take into account that threads are cut on the nut and flange, depending on the direction of rotation of our electric motor shaft. If the rotation occurs clockwise, then the thread should be left-handed, if suddenly it’s the other way around, the thread should be right-handed. During operation of the table emery machine, the emery nut will spontaneously tighten. If you neglect this factor, the nut will work to unwind, and therefore the stone may fly off. And, of course, this is extremely dangerous.
What should you do if it is not possible to manufacture point bushings of a certain diameter? In this case, pieces of pipes of suitable diameter may be useful, and the gaps between the bushings and the engine shaft can be compensated by winding fabric-type electrical tape between the bushings. In addition, you can put the bushings on top of each other.
In this case, the most important thing when winding electrical tape is to maintain uniformity in order to avoid the formation of large beats during rotation. The sleeve is made from a pipe with a diameter of 32 millimeters, equal to the internal diameter of the emery wheel. An emery wheel is placed directly on it so that it can fit tightly without winding.
This bushing system sits quite tightly on the shaft. But fixation with a bolt and washers is required. At home, you can cut a thread in a shaft using a tap, while holding the electric motor shaft in a vice. In this case, it is necessary to determine the correct hole diameter for the thread.
Direction of work
Before you make emery at home, you need to find out the direction of its work. With homemade emery, you can change the direction of rotation of the rotor. If, for example, the motor is from a washing machine, then it is asynchronous, that is, when switching the corresponding windings, you can change the direction of rotation. Also, in motors from old household appliances there are 3 - 4 outputs. For example, with 4 pins, changing the direction of rotation is not difficult.
For these purposes, we find the starting and operating windings using a tester. The resistance level of the working winding is usually 12 ohms, and the starting winding is close to 30 ohms. The working winding is connected to a 220 W network, and the starting winding is connected securely with one end to one terminal of the coil, and with the other end you need to briefly touch the second terminal of the winding and then immediately discard it (special relays are usually used for this). If you use a capacitor motor, the connection circuit will be different.
This means that your emery will spin in one direction, and if, for example, you swap the leads of the starting winding, then the motor will correspondingly rotate in the opposite direction. You can, in principle, do without a starting coil; in this case, after connecting the working winding to the network, you need abrasive stone twist in a certain direction, and the machine will then start working.
Installation of emery
After you have made your homemade emery, you need to figure out how to properly install it on your workbench. This is done using a bracket, which is also removed from washing machine and is attached to the workbench with bolts. The engine, on the other hand, rests on an angle that supports it in a horizontal position, and also has a cutout that completely follows the shape of the engine housing. To reduce vibration, a edging made from a rubber piece of hose is put on the corner.
To avoid injury from the saw and flying debris from the abrasive wheel when working on a homemade sharpening machine, it is necessary to make a casing. It is best to make it from thicker metal - 2 - 2.5 millimeters. This can be a strip of metal rolled into a half ring.
Under the working body of the emery, you directly need to screw a small piece of galvanized iron sheet, which will protect the workbench from sparks during work. For your own safety, all work must be carried out in special glasses or other protection.
As devices for emery, you can use plexiglass, 5 millimeters thick. This glass is attached to the engine casing using hinges; it can be tilted 180 degrees. Also, for the usefulness of the machine, it is necessary to make a support for the work piece.
Of course, the benefits of an electric sharpener cannot be doubted! After all, you won’t use a new ax or drill every time. And buying sandpaper for this is a bit expensive. But there is a way out, you just have to spend a little time and collect the emery with your own hands. Follow our instructions carefully, provide the necessary protection for the machine and do not neglect safety requirements during operation.
In their practice, radio amateurs are often faced with the need to sharpen different instruments, somehow - a screwdriver, an awl, a small drill, or other tool. “So what,” the skeptic will say, “I have an industrial machine, and I’ll sharpen it on it.” I don’t argue that with good skills, anything is possible. But it is better to choose for the job the one that is most suitable for this. Then the work gets better, and there are fewer defects. And, such a “sharpener” will always be at hand, you can put it away in the closet at any time and take it out when necessary. My wife once bought such a serious device at a sale, the seller claimed that he himself sharpens knives (what else can a woman be interested in).
We sharpened it a couple of times and came to the conclusion that with our hands on the block, better sharpening it turns out - this can be easily determined by the number of cut fingers half after sharpening. And there it lay, collecting dust in the cabinet, until it dawned on me good idea. It might not have dawned on me if my favorite drill of a deficit diameter had not broken. While I was sharpening it on a large sharpener (and my eyesight, alas, is not what it used to be), I ground off almost everything. So I thought that if there had been a normal sharpener, everything would have turned out differently. But this is a fixable matter. To begin with, I removed this beautiful one from that grinding monster abrasive wheel. Then, after rummaging through the bins, I found a DPM collecting dust.
I quickly sketched out a drawing and went to the turner in the morning, taking with me 0.5 liters of the process accelerator.
Half an hour later the phone rang, asking why you didn’t come and pick it up. He picked it up, exchanged pleasantries, he suggested coming back more often, and we parted ways.
Let's start assembling the sharpening machine
The first step is to make a protective casing for the machine, because as practice shows, if you don’t do it right away, you will never do it again, and this is harmful to health.
You can make it from scraps of tin, I won’t describe the process, everyone defends themselves as best they can. I recommend fixing it with a clamp like this, it’s cheap and reliable:
The next step is to attach the attachment to the motor shaft. To do this, just press the rosin finely, pour it into the hole in the nozzle, turn on the engine and press it into the nozzle. Through friction, the rosin will melt and the shaft will be securely “stuck in the hole.” For extreme sports enthusiasts, I can advise putting a drop of “second” or “moment” glue into the hole, but then, if something happens, it will be much more difficult to remove the electric motor.
To attach the sharpener, you can use the same clamp as shown in the photo above. Moreover, it can be secured either by a clamp in a vice, or by pressing a suitable bracket to the engine with a clamp, which in turn is attached in a suitable way to the table. Well, that’s all, we put an abrasive wheel on the nozzle,
tighten the nut and sharpen whatever your heart desires. A leather gasket is needed to increase friction and reduce the degree of pressure on the disc (thin ones can burst).
With this device I use ground cutting wheels from a grinder, homemade vulcanite circles made from circles of larger diameter, small cutters. The photo shows a full arsenal of sharpening equipment. If desired, the engine can be mounted under the table, thus obtaining a miniature circular saw or grinding machine. But this may require other attachments.
In any household, a tool such as emery is useful. Knives, scissors and other cutting objects need to be sharpened periodically. But you can’t go to the master every time. So many people have a question about how to make sandpaper with their own hands. Of course, you can buy it in the store. But it is quite expensive. And not everyone will decide to buy it. Sandpaper made from scrap materials will save money and will work no worse than the factory one.
Principle of operation
You can make your own emery from a washing machine and other household appliances. More precisely, from their engines. It is he who will launch the device. A shaft is mounted to the engine, to which nozzles are selected. The bits can be sharpened on a lathe. The installed sanding wheel is securely fixed. A motor connected to an electrical network rotates a shaft, which transmits rotation to the emery wheel.
Motor selection
Most often as power element Emery is made from the engine of a washing machine. A self-assembled device does not require new devices. There are enough old-style cars (for example, “Vyatka”, “Sibir”, “Volga” and so on). Devices of those times were equipped with durable engines High Quality. From the same machine, a switch with a manual starter is also useful.
It is best to choose an engine for the device whose speed 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 sanding wheel may not hold up and break. High speed is suitable for polishing the surface, but not sharpening it. Therefore, if the engine has increased speed, it is necessary to use a durable stone.
The motor power should be in the range of 100-200 W. This will be enough to make homemade emery with your own hands. But given value can be increased by 2 times (and amount to 400 W).
Such indicators are taken for a reason. The fact is that the characteristics of washing machine motors are similar to those of factory-made emery. But other devices with the same power and rotation speed can be used. The motor can be single-phase or three-phase.
The electric motor used is connected to the electrical network through a capacitor.
Flange preparation
The emery, made with your own hands, provides for connecting the electric motor to the stone circle via a flange. It must be machined from metal. For this purpose, they usually turn to a specialist (turner). You will need to know the parameters of the device, the diameter of the internal hole of the emery wheel, and the diameter of the shaft.
The flange is attached to the shaft using a nut, bolt and washer. They also need to be prepared. The threads on the nut and flange must take into account 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 in left side. When the shaft rotates counterclockwise, the thread must be right-handed. This is necessary to comply with safety regulations. The fact is that with this direction of the thread, the nut will tighten under the influence of vibration during operation, preventing the circle from breaking off. If the thread is in the other direction, the nut will unscrew. If it unscrews completely, the sanding wheel will fly off. And this is dangerous.
It is not always possible to find a turner. Therefore, it is not always possible to grind the flange. In this case, you can resort to alternative solution. In such a situation, homemade emery is made with your own hands using pipes of a suitable diameter. If there is a gap between the bushing and the shaft, it can be eliminated with fabric insulating tape. At large gap You can put one bushing on another.
Direction of movement of the emery
Before collecting emery for sharpening knives with your own hands, it is important to understand the direction of movement of the rotor. When using a washing machine motor, the direction of rotation changes. The motor is asynchronous. This means that there are no obstacles to changing the direction of rotation of the rotor. Therefore, it is enough to simply swap the ends of the winding.
First you need to determine which winding is intended for starting the engine, and which for the main work. To do this, you will 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 terminal. A relay is used for this. The engine starts.
In this simple way, by changing the ends of the winding necessary to start the motor, the direction of movement of the rotor changes. You can even do without a relay. In this case, you need to manually turn the sanding wheel in the desired direction.
Device installation
After complete assembly, the emery made by yourself must be installed on a fixed support (workbench). This is done using bolts. The bracket found in the same washing machine will help make the task easier. In a horizontal position, the device is held at the angle. To eliminate vibration, a rubber edging is placed on the corner. It can be cut from a regular rubber hose.
Safety precautions when working on the machine
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 with emery in compliance with safety precautions. While working, you must wear protective plastic glasses.
A protective casing is made from a sheet of metal with a thickness of 2-2.5 mm. It will prevent debris from flying away 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 subject to strong vibration and is subject to inertial forces. Therefore, there are times when discs simply break and fly apart. Before starting work, you need to check the circle for cracks and make sure it is installed correctly.
Conclusion
Emery, made with your own hands from scrap materials, 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 savings of 2 thousand rubles (which is how much sandpaper costs on average in a store) will be significant. Moreover, apart from appearance, then the factory machine will be no different from the one made independently.
Knives and scissors should always be in working order in the house, and at the dacha the need for sharp tools is even greater: shovels, hoes, scythes, etc. Sharpening everything by hand is tedious and unproductive. You must have a sharpening machine at your disposal. But this is far from cheap tool and therefore it’s worth trying to make a sharpening machine with your own hands.
The design of household sharpeners is subject to the following rules.
- Main details sharpening machine are the frame and the electric motor mounted on it.
- Limbs are attached to the end of the motor shaft, and sharpening and grinding wheels are mounted on it. On the sides, in front of the grinding and grinding wheels There are columns with guides for adjusting the horizontal feed of the tool being processed. The longitudinal feed of the sharpened part is performed manually: the part moves in the desired direction.
- Grinding and grinding wheels must be equipped with protective covers.
- A two-button switch is installed on the body.
- The weight of the frame must be such as to ensure the stability of the sharpener.
- To reduce noise and vibration, the frame is equipped with rubber feet.
To make a sharpening machine, you can use a regular electric drill .
Sharpening machine functions
For household use need a sharpening machine universal type. Unlike a special one, this type of sharpener can be used to process most household tools. An electric sharpener is used to solve the following problems.
- When drilling thick metal, the drill often overheats and breaks. It is impossible to continue working with such a device, but it is still too early to dispose of it. At correct sharpening The drill will last a long time.
- To sharpen scissors, knives and other tools, you need a tabletop sharpening machine. This design is optimal for domestic use.
- For grinding metal surfaces using a felt circle.
- A cam chuck can be installed on the other side of the shaft to fix drills, and in this case the sharpening machine will also be used as a drilling machine.
Criteria for selecting sharpening machine parameters
When choosing components for designing a sharpening machine, it is necessary to take into account the following technical indicators of the device:
- power: it should allow processing massive parts and tools (for example, an ax) without significantly reducing the rotation speed of the electric motor shaft;
- diameter of the mounting hole: it is taken into account for the manufacture of equipment;
- the diameter of the grinding and grinding wheel is selected depending on the size of the parts being processed;
- rotation speed: it should not exceed 3000 rpm (it is better to limit it to 1500 rpm);
- the ability to adjust the rotation speed - a convenient function necessary for processing various parts;
- weight – matters when it is necessary to move the sharpener.
How to make a sharpening machine
In order to assemble a homemade sharpening machine, you need to purchase an electric motor with a power of about 1 kW (this will be enough), as well as a shaft, bearings and two pulleys.
Helpful tip: you can use a unit from an old washing machine as a motor for the sharpener.
Choosing an electric motor
You need to remove the engine from an old washing machine of the “Vyatka”, “Riga”, “Sibir” brands. A starter and switch will also come in handy. There may be a problem with attaching the grindstone: the motor shaft does not have a thread and does not have the same diameter as the hole in the grindstone. The problem can be solved using a custom adapter part. The motor from the “washing machine” is low-power: within 100 – 200 W, but this will be enough.
Rotation speed 2700 rpm. and the indicated power are the optimal parameters for a grinding wheel with a diameter of 150 mm. Increasing the rotation speed will lead to the destruction of the stone.
Grinding the flange
The solution to this problem is carried out in stages.
Important: the direction of thread cutting depends on the direction of rotation of the motor shaft. If the shaft rotates clockwise, a left-hand thread is required, if in the other direction, a right-hand thread is required. Otherwise, the nut will unwind and the stone will not stay on the shaft.
Determining the direction of rotation
The direction of rotation of the electric motor rotor is not always satisfactory. To change it, in asynchronous motor windings need to be switched. To do this, do the following.
Assembling the sharpening machine
The final assembly of the sharpening machine consists of the following steps.
- From steel angles using welding machine the frame is being manufactured.
- An electric motor with pulleys is screwed to the frame with screws and nuts. To prevent the nuts from loosening under the influence of vibration, engravers or additional nuts are used.
- A bar is made from the angle and installed to regulate the inclination of the part to be sharpened.
- From sheet metal a protective casing is manufactured and attached. Its thickness should be 2-2.5 mm.
- A curtain is cut out of plexiglass, which is attached to the top of the cutout in protective casing in a mounted way.
- The starter button is attached to the frame. Network cable must be kept away from moving parts of the machine.
- After assembly it is executed trial run and checking the work of the sharpener. In this case, there should be no strong beating of the sharpening stone or vibration of the bed.
Important: it is necessary to maintain a safe distance between the grinding wheel and the workbench plate (minimum 10 mm).
In conclusion, we suggest you watch the video in which the designer will introduce you to another design of a sharpening machine.
Greetings, Samodelkins!
Today I want to show you how you can use the materials that are (or at least should be) in almost every workshop to make an excellent device for sharpening knives evenly.
Initially, the master wanted to buy a ready-made device for sharpening knives in China (namely in the Aliexpress online store), but he thought why not try to make such a sharpener with his own hands. Moreover, the prices for this product from Chinese friends are rather high.
For self-made will be needed following materials and tools:
1. Ordinary board;
2. Sandpaper;
3. Screwdriver;
4. Hammer;
5. Thick electrode 1 pc;
6. Jigsaw;
7. A piece of laminate;
8. Bolts and nuts;
9. Wooden handle;
10. Hex key;
11. Fluoroplastic or textolite (fiberglass).
Let's get down to actually making the sharpener.
First, let's take an ordinary board and cut a piece out of it. Then you need to process the resulting wooden blank, namely, sand it with sandpaper.
It will serve as the base for our homemade sharpening device.
In terms of size, we get it to be 26 cm in length, the width of the workpiece is 6.5 cm, and the height of the wooden base is 2 cm.
You also need to make holes in this board. In total, this part of the future product will have 6 through holes. We drill 2 holes for the stand itself (more on that a little later). Nearby we drill another hole of a smaller diameter, and also on the other side of the board we drill 3 more holes that will serve to attach the pressure plate.
Insert nuts into the holes made.
In the future, these nuts can be placed on glue so that they do not fall out, but for now everything seems to be quite tight.
Then we will start making the guide post itself. The master made it from an ordinary thick electrode. It needs to be bent in half. Next, using a hammer, the author knocked off the entire upper part of the welding electrode and ground it. By the way, you can also grind using an ordinary screwdriver. To do this, simply insert the electrode into the screwdriver chuck and hold it in your hand sandpaper polish the product.
At this stage, we insert the resulting workpiece (guide post) from the electrode into these two holes.
We insert it not at a right angle, but at a slight angle. The guide angle is somewhere between 65 and 70 degrees.
Everything fits quite tightly, but also for greater reliability of our design, in the future it will be possible to attach the guide post with epoxy glue, or with some other glue, or with something else.
But perhaps the master is mistaken and this is not fluoroplastic. Fluoroplastic is most often white and somewhat slippery. Most likely it is textolite or fiberglass. But in essence it’s not that important. The main thing is that this material is quite hard and does not wear off.
From this piece (fluoroplastic or non-fluoroplastic), the author cut out a kind of pressure plate. He made holes in it, as well as small recesses, so that the caps would extend slightly into the depths of the plate.
Then we place this plate on the previously made wooden base. Secure with screws.
The author took the screws with a hex key. The master also made a small hole in the base of the future knife sharpener so that this key would always be in this sharpener.
The whole thing is clamped and they (the screws) are actually not visible on the plate.
But here, the master did not do the countersunk work, since the sharpening part of the tool will not touch this screw.
Next, the author made such a plate from the same fluoroplastic.
In this plate I made 2 holes for the same hexagonal screw.
Next, the whole thing is placed here and pressed with the help of a lamb.
Then the master made just such a guide for the sharpening stones.
The length of the guide is 57 cm. The author made it from an ordinary steel rod. Also cleaned it up. And on one of the ends I put this handle (it looks like it came from an old Soviet file).
You can also strengthen this connection by placing the wooden handle of the file on the glue, but it fits in quite tightly here and nothing falls out.
Regarding the attachment of the sharpening stones themselves. The author took a small piece of the clamp, cut it and made holes. As a result, we got corners like this, two identical ones.
And here I put a nut with a thread and a clamping screw.
The master also installed a spring on the guide so that sharpening stones could be changed without unscrewing the nut with the clamping screw.
The author made the sharpening stones themselves, or rather the base for these stones, from an ordinary piece of laminate. Just cutting it into strips.
The width of the strips is 2.5 cm, and the length is about 20 cm.
The pieces of laminate already have ready-made grooves, which is where the corners of the guide part of the device will go.
The author then glued the sandpaper onto the laminate pieces using double sided tape and signed which one is where. And, in fact, this is how it all turned out:
This whole thing is quite easy to set up. Using the groove of the laminate we get into one corner of the guide, and with the help of a spring we press the sharpening stone with the second corner.
All. Nothing falls out anywhere. Everything lies flat and quite tightly.
Let's continue assembling our device. We insert the guide with the sharpening stone attached to it into the hole prepared in advance for it, and you can safely begin the process of sharpening the knife.
The stroke is quite large due to the fact that here the author removed a small chamfer on both sides.
