Tools for sharpening knives with your own hands. How to make emery with your own hands: step-by-step instructions Do-it-yourself tabletop sharpening machine
IN everyday life Situations often arise when something needs to be sharpened. Do-it-yourself electric sharpener is the solution for many everyday problems with tool sharpening. These can be household items: knives, scissors or construction tools. Most often in this case there is a need to sharpen drills, axes, and shovels. It is difficult to work with a blunt instrument, the process progresses slowly, and it takes a lot of effort. In this case, you cannot do without a special device, since not every tool can be sharpened by hand with a whetstone.
You can buy an electric sharpener in a store, but you will have to pay a significant amount for it. Or you can assemble it from scrap materials, especially since men who work periodically fall into the hands of all necessary materials. Adapting them for useful purposes is also not difficult. The end result will be sandpaper that is in no way inferior to store-bought sandpaper, but practically free.
Required materials and tools
To make the device you need a little:
- electric motor;
- capacitor;
- bracket;
- flange or pipe cuttings and electrical tape;
- tap for thread cutting;
- metal 2-3 mm thick for the manufacture of a protective casing;
- bolts, nuts;
- rubber for lining.
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Which electric motor is suitable?
The main element without which it is impossible to assemble the device is the engine.
Motors from old ones are usually used household appliances. For example, from Soviet washing machines “Siberia” or “Volga”. Their engines are reversible and have sufficient power and speed. You can install any necessary attachments on the shaft.
The number of revolutions per minute should not exceed 3000 industrial conditions, and for home use 1000-1500 is enough. If you rotate too quickly, the sanding wheel may break. For industrial work use sharpening stones high strength and special flanges. For the home handyman It is unlikely that such materials will be found. High speed is needed not so much for sharpening as for leveling and polishing the product. Again, this is not useful for everyday use.
You shouldn't chase too much power either. When making a machine with your own hands, the top bar is 400 W. On average, motors from washing machines are used, whose power does not exceed 200 W. There is more than enough to sharpen knives, hoes, and drills. In addition, with such power there is no need to fear that the speed will develop too high. Therefore, you won’t have to worry about the safety of the disk (and your own health).
Single-phase and three-phase motors are suitable for electric sharpeners. Both of them can be connected to a single-phase network. For correct connection a capacitor may be required. Typically, asynchronous electric motors are used.
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How to choose a flange
At first glance, everything is simple: take the engine, put emery paper on the shaft, plug the device into the network and start sharpening. However, at the stage of installing the whetstone, a difficulty arises: the diameter of the sharpener, as a rule, does not coincide with the diameter of the shaft. And there are no threads, that is, it is not possible to secure the emery. To eliminate this problem, you will need a flange - a special part that is machined to the size of the shaft and the internal diameter of the abrasive disk.
To turn the flange, you will have to use the services of a turner. On the drawing of the electric sharpener you need to indicate internal diameter grinding wheel and shaft size. You need to indicate in which direction the axis rotates. Perhaps the special flange is the only part that needs to be made to order. But it can also be replaced with improvised materials.
The finished flange is installed on the shaft and secured with a nut, washer and bolt. The nut will have to be threaded. If the shaft moves clockwise, a left-hand thread must be used. When rotating counterclockwise, it is right-handed. Compliance with this rule is strictly mandatory. With this thread cutting, the nut will gradually tighten, and the circle will be fixed more and more securely. If you do the opposite, the nut will gradually unscrew. As a result, the sharpener may fall off the shaft. This is very dangerous, since it is not known in which direction the rapidly rotating stone will fly. It may cause serious damage or injury.
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Analogue of the sharpener flange
However, not everyone has a familiar turner or the right equipment. In this case, you can make an analogue of the flange. The matter will be more complicated, but the result will be reliable.
In this case, you will have to use a bushing system. For work you will need pipe cuttings required length And suitable diameter. The gaps are eliminated using cotton insulating tape. If necessary, the bushings are inserted into each other.
When winding, the electrical tape should lie very evenly. If there are noticeable bumps, the disc will beat when rotating. The bushings are selected in such a way that the internal diameter of the sharpener and the pipe coincide. Ideal option there will be one in which the stone sits on the sleeve without electrical tape very tightly, tightly. Winding will provide a tighter connection; the disk will not rotate on the pipe.
The bushing system fits very firmly and tightly onto the shaft, but fixation with bolts is necessary, since only it can provide the appropriate level of reliability and safety.
You can cut the thread yourself at home. For this you will need a tap.
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Direction of work
Before you start making an electric sharpener, you need to see in which direction it will spin. With a device assembled from scrap materials, you can change the direction of rotation without much hassle. The engines that are most often used are taken from Soviet washing machines. And they are asynchronous. This means that when switching some windings, the direction of movement can easily change. Older motors have multiple terminals (3 or 4), which is helpful when changing direction.
The direction will change if you change the terminals of the starting winding. This technique can be useful in case of problems with threads, loosening nuts, etc.
You can do without a trigger coil. Then the work works directly: the working winding is simply turned on in the network, the sharpener needs to be pushed in the right direction, and it will begin to rotate.
To correctly determine where the working winding is and where the starting winding is, you will need a tester. The resistance level of the first is about 12 ohms, the second is all 30 ohms.
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Device protective cover
When all the main parts have been selected, you need to take care of compliance with safety precautions.
It's no secret that sparks fly when sharpening metal products. In order not to get burned yourself, to avoid injury, and also to protect the work surface from scorching, it is necessary to make protective cover. It can be made from scraps of tin or metal. Optimal thickness plates – at least 2 mm. The iron can be screwed directly above the grinding wheel or secured with a clamp. The shield will also reduce the amount of dust.
Additional safety during work will be provided by a folding plexiglass canopy, which is attached to the casing and can be folded down if necessary.
A handyman wouldn't hurt either. When carrying out work, it is much more convenient to rest against it than to keep the part suspended all the time.
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Installation of the device
When the electric sharpener is assembled, you can begin installing it. The sharpener must be secured very firmly and securely, as large vibrations occur during operation.
You can install the motor on a work surface using the same bracket that holds the motor in the washing machine. You will need bolts for this. The opposite side of the engine will rest on the corner. Thanks to this mount, the motor will be in a horizontal position. You can install a rubber pad on the corner: it will reduce vibration.
You can use other installation methods. For example, fix the device on a stand, then it will be more mobile, since it will not be screwed to one place.
That's it, the machine is ready for work. Can be sharpened various parts, tools, drills, etc.
One of important tools among everything auxiliary equipment is a sharpening machine. The design of the sharpening machine is very simple and for its manufacture you will need simple materials. Most families living in their home have a DIY sharpening machine.
Sharpening knives for disc knives.
For several years our company has been successfully selling and producing commissioning sharpening machines for sharpening circular knives used for cutting paper in the pulp and paper industry, packaging industry, and printing.
Our company's product range includes both small and high-performance machines with numerical software, used in the production of circular knives. This equipment allows for high-quality sharpening of all types of circular knives from any materials (including hard alloy) with an outer diameter from 30 to 500 mm. Various machine options make it possible to make the work of the sharpener as easy as possible and achieve high productivity.
It should be noted that this equipment is not cheap. And this is primarily due to the fact that these sharpening machines belong to the class of high-precision equipment with strict tolerances. In the production of these sharpening machines, we use modern materials and components, as well as modern technologies.
Considering the high price of this equipment, competent selection plays an important role. sharpening machine to perform specific tasks. Correct selection of the machine is our first step when working with the customer. Already at this stage, the customer can significantly save their money. The main criteria for selecting a sharpening machine for sharpening circular knives are:
Type disk knife(with one or two sharpening angles, bushing, etc.)
Maximum diameter of sharpened knife
Mounting diameter of the knife being sharpened.
Knife material to be sharpened
Customer requirements for the quality of the sharpened tool or workpiece.
Based on these criteria, we will professionally select the optimal machine for you, both in terms of technical capabilities and price.
Sharpening machines
Grinding machine Monolith TS 1-350
Power: 0.35 kW;
Voltage: 220 V; 
Frequency: 50Hz;
Idle speed: 2950 rpm;
Circle dimensions: 150x16 mm;
Bore hole diameter: 12.7 mm;
Warranty: 12 months.
Machine for Brigadier Standart GM2S
Power: 0.55 kW;
Voltage: 220 V;
Engine speed at idle: 6300 rpm;
Weight: 2.2 kg;
Warranty: 12 months.
315 UAH
Grinding Monolith TMS 1-150
Power: 0.15 kW;
Voltage: 220 V;
Frequency: 50Hz;
Warranty: 12 months.
Chain sharpening machine Sadko SCS-180
Power: 0.180 kW;
Voltage: 220 V;
Engine speed at idle: 6000 rpm;
Diameter grinding wheel: 100 mm;
Weight: 2.2 kg;
Warranty: 12 months.
Replacing the grinding wheel.
Before you begin replacing the grinding wheel, it is strongly recommended to disconnect the power cable of the machine from the outlet.
It is also not recommended to work with a cracked grinding wheel (replacement is necessary). Otherwise the circle
during rotation, it can split and fly into pieces, which, in turn, can lead to accidents
cases.
To replace the grinding wheel you must: 
Remove the grinding wheel protective cover.
Unscrew the nut
It is important to know that the right spindle has a right-hand thread, and the left one has a left-hand thread. Such technical features introduced specifically to prevent the locking nuts from unscrewing during spindle rotation.
Remove the outer flange and the old grinding wheel.
Clean flanges.
Install the inner flange.
Install a new grinding wheel.
Place the outer flange on the grinding wheel.
Tighten the spindle nut securely.
Install the grinding wheel protective cover.
To replace a grinding wheel designed for wet use:
Remove the water tank.
Unscrew the nut.
Remove the outer flange and the old grinding wheel.
Clean flanges
Install the inner flange.
Install a new grinding wheel.
Install outer flange
Tighten the spindle nut securely.
Install a water tank
How to sharpen tools correctly?
Sharpening a tool consists of two operations.
The task of the first operation is to achieve an even plane of grinding (it is called a chamfer) without rounding it at the very edge and without burning the steel. During this operation, metal is ground off from one side of the cutting part of the tool (like a chisel) or from both sides (like a knife) to form the required of this instrument blade shapes. Another task of the first operation is to place a chamfer at a certain angle relative to the second plane (face or chamfer) with the blade tip required specifically for a given tool. This angle, called the sharpening angle, can be different: 7-8° for a knife, 15-25° for chisels, 37-42° for planes and 50-53° for a special plane - a grinder.
The sharpening angle of the tool is strictly dependent on the angle of inclination of the cutting edge (plane) of the blade relative to the surface of the wood, which is determined by a complex formula. If in tools such as a knife, chisels, axes, we can adapt to the angle of inclination of the cutting edge during work, which means the sharpening angle of the blade can vary depending on the need (cutting by hand or by hitting with a hammer, mallet), then in For other tools, such as planes, this sharpening angle must be maintained more strictly.
The task of the second operation - editing - is not to spoil the sharpening angle and to achieve a sharp blade tip, which is associated with removing irregularities, small notches, burrs from it, and polishing both surfaces of the blade to a shine.
The first operation is usually performed on a mechanical sharpener - a rotating abrasive wheel. It is finished by hand on a large flat block. It is dangerous to sharpen the blade on a sharpener until sharp, since in this case it is difficult to control the overheating of the steel when high speed circle, when unexpectedly a tarnished color appears on the thin edge of the blade during sharpening - a sign that the strength of the steel is compromised and the sharpening is damaged. Such a place will have to be completely cut off on the same sharpener and sharpened again. 
In order to reduce subsequent handmade on a block, they try to remove the metal as much as possible along the entire chamfer, except for its edge, which is not difficult to do on a sharpener cylindrical: it allows a notch on the chamfer to remove excess metal from its entire middle.
To prevent the steel from overheating, the tool is periodically dipped in water and the sharpener itself is also soaked in water. The disappearance of water droplets on the tip of the blade or their boiling is a sign that it is time to put it in water.
It is advisable for a novice sharpener to sharpen the tool on a sharpener so that the circle does not rotate towards the blade, but vice versa or at a certain angle to it (in different directions). This way, if you move incorrectly, there is less danger of crashing into the blade with a sharpener and ruining the whole work. However, throughout the literature it is recommended to sharpen any tool on a sharpener only when it is rotated towards the blade. But this rule is only suitable for a specialist or craftsman with extensive sharpening experience. There is no doubt that when the surface of the circle moves towards the blade, its sharpening is better: there is less chipping of metal particles on the very edge of the blade - they seem to be pressed during rotation, and do not come off from it when the sharpener moves away from the blade. Also, this does not produce such large burrs as when sharpening “along the blade,” where there are more opportunities for bending the edge, which is what gives the burr. In addition, with strict adherence to the rules for sharpening the tool towards the blade, if it is precisely fixed (using a special stop or trained hands), a clearly defined edge of the blade is obtained.
These are positive aspects sharpening method towards the blade. But it also has negative sides, the weight of which is more significant, especially for a novice sharpener. The main disadvantage is that we cannot sharpen the blade to a sharp point, since the danger of burning it is too great. The tool blade can be brought to the required sharpness only on a water sharpener, the rotation speed of which is very low (as the speed increases, water floods your hands). On all other mechanical sharpeners, sharpening is carried out without water. But even after using a water sharpener, the blade becomes sharp only due to a good sharpening angle and clearly defined edges. In fact, it is cut with notches from grains of abrasive sand and looks like a file with very small teeth. Such a blade will cut wood, but the cut mark will be uneven and not shiny. The blade will require thorough editing - complete removal of the tip and formation of a new one.
In order to complete sharpening of a tool on a hard block, it is better to clamp the block in a vice or secure it on a workbench. Then the work can be carried out with a clamp, with two hands. The block must first and then periodically be washed with soap and water using a brush, since it becomes greasy and clogged with fine metal and abrasive dust; it is good to soak it in water. During operation, it is more convenient to wipe the surface of the bar with a wet cloth. It is under such conditions that the surface of the bar grinds off the metal well.
When sharpening a tool, you need to be especially careful that the chamfer is in contact with the surface of the block with its entire plane, so as not to spoil the sharpening angle. You can move the tool along the block in any direction, but as the blade sharpens and a burr appears on it - a thin shiny strip of bent metal on the tip of the blade - you should be more careful with the direction of movements when sharpening. To avoid the risk of cutting into the abrasive with the tool blade, it is better to completely stop its movement towards and along the blade. It is preferable to make movements at an angle of 45° in both one and the other direction in relation to the edge of the blade, in the direction away from it. This is how we reduce the force that bends the tip of the blade into a burr. This sharpening method is confirmed by practice experienced craftsmen. Hairdressers have been known to shave straight razors in a similar manner.
The second sharpening operation - straightening - is performed first on a fine-grained whetstone or a special dressing board, then on a whetstone or on a smooth area of the dressing board worn during sharpening, sometimes on a whetstone or a dressing board covered with leather, using a special paste.
The filling board is covered with fine sandpaper (preferably sandpaper on a cloth). Its edges are glued end-to-end on one of the narrow sides of the board. One side of the filling board should be pre-rounded, with different curvature along the edge. On it we will edit the concave face of semicircular chisels.
When editing on a whetstone, you can first make circular movements with a tool (for example, a chisel), emphasizing the efforts when moving away from the blade, but on the dressing board you must immediately beware of making movements towards the blade: the soft cloth or paper of the skin bends even slightly under pressure and the blade "attacks" the sanding surface under high angle, which will lead to chamfer collapse, i.e. to change the sharpening angle. Also, for the reasons described above, the blade may be damaged by touching uneven surfaces on the sharpening surface. For example, when sharpening a knife on a cutting board towards the blade, it even happens that it cuts off part of the glued skin.
During editing, you must periodically turn the tool from one side to the other until both edges of the blade are polished to a shine and the burr disappears completely. As you finish editing, your hand movements should become more frequent and lighter, and the sharpened edges should also be changed more often.
After straightening, you need to make a test thread, testing the tool in cutting techniques along and across wood, especially hard wood. It is likely that the blade of the tool will “sit” and will not give the desired result. This is not always a sign of bad steel, but is most likely the result of carbon burning out of the edge of the blade during hardening, as discussed above.
True, this also happens with tools that have not been subjected to heat treatment. In any case, it needs to be adjusted again and checked until cutting edge will not stand.
A well-sharpened tool lasts a long time and does not require frequent refilling. It is corrected only after many hours of work. To achieve results faster, if the tool has been in use for a long time, when refilling, you can slightly increase the contact of the edge of the blade being sharpened with the block, taking into account that during initial sharpening its sharpening angle was quite sharp.
In this case, the sharpening angle increases slightly and a secondary chamfer is formed. Naturally, after some time you will have to again straighten the angle of sharpening the blade on a block, or even on a wheel hand drill. Practice has shown that using polishing paste or oil paint"Chromium oxide" is not necessary for final tool dressing. As you work, smoother (worked) and harder places will appear on the dressing board, which will allow you to use the same sandpaper on the board for consistent sharpening: from rough to clean.
The introduction of the Edge Pro sharpening machines was, without exaggeration, a revolution. The prices are really high, but no one is stopping you from copying the principle and creating a similar device yourself. We offer design simple machine for sharpening knives, chisels and any other blades that you can make with your own hands.
Machine base
Most parts for a sharpening machine can be made from literally anything by following general principle devices. As an example, let's take laminated or polished box plywood 8-12 mm thick, which was widely used in the manufacture of Soviet radio equipment housings.
The base must be heavy - about 3.5-5 kg - otherwise the machine will be unstable and unsuitable for sharpening heavy chopping tools. Therefore, the inclusion of steel elements in the design is welcome, for example, the base of the case can be “forged” with a 20x20 mm angle.
From plywood you need to cut out two parts in the shape of a rectangular trapezoid with a jigsaw with bases of 170 and 60 mm and a height of 230 mm. When cutting, leave an allowance of 0.5-0.7 mm for processing the ends: they must be straight and exactly match the markings.
Third detail - inclined plane made of plywood boards measuring 230x150 mm. It is installed between the inclined sides of the side walls, while the trapezium of the side walls rests on the rectangular side.
In other words, the base of the machine is a kind of wedge, but the inclined plane should protrude 40 mm from the front. At the ends of the side walls, use a surface planer to mark two lines with an indent of half the thickness of the plywood. Drill three holes in each board to fasten the parts with screws. Transfer the drill bit to the ends of the inclined part and temporarily connect the base parts.
In the back side walls They are connected by a 60x60 mm block, which is attached to the end with two screws on each side. The bar needs to be 10 mm vertical hole with a distance of 50 mm from the center, that is, 25 mm from the edge. To be sure of verticality, it is better to first drill with a thin drill on both sides and then expand. Screw two fittings into the hole from the top and bottom with internal thread M10, and in them - a 10 mm pin with a length of 250 mm. Here you may need to slightly adjust the bottom fitting if its threads do not line up with the stud.
Tool support device
Remove the flat inclined part from the base - it needs to be modified by equipping it with a device for fixing and pressing the tool being processed.
First, set aside 40 mm from the front edge and along this line, use a matching hacksaw to file a groove about 2 mm deep. Using a sectioning knife or a shoemaker's knife, chop off the two top layers of veneer from the end of the board to form a recess into which you can insert a 2 mm steel plate flush with the common plane.
The handpiece consists of two steel strips 170x60 mm and 150x40 mm. They need to be folded together along the long end with uniform indentations along the edges and three 6 mm through holes must be made. The strips along these holes need to be tightened with bolts, placing the caps on the side of the upper, larger plate. Arc welding bake each cap, welding it to the plate, then remove the beads of metal and grind the plate until a perfectly flat plane is obtained.
Attach the narrower striker plate to the notch on the edge and transfer the holes with a drill, then secure the rest with bolts. Before installation, it can also be magnetized with direct current, this will help in sharpening small blades.
Locking mechanism
The second part of the tool rest is the clamping bar. It is also made of two parts:
- The upper L-shaped bar is 150x180 mm with a shelf width of about 45-50 mm.
- The lower strike plate is rectangular 50x100 mm.
The parts need to be folded in the same way as the parts of the tool rest were folded, placing the counter plate at the far edge of the upper clamping area. We make two holes in the center with a distance of 25 mm from the edges of the small part, and through them we tighten the parts with two 8 mm bolts. They need to be wound in opposite directions, with the head of the upper (near) bolt located on the side of the clamping bar. The bolt heads are also welded to the plates and pre-ground to obtain neat roundings.
On an inclined board with an indentation of 40 mm from the edge, draw a line with a thickness planer and make one 8 mm hole 25 mm from the top and bottom edges. Connect the edges of the holes with markings and use a jigsaw to make a cut with an allowance. Finish the resulting groove with a file to a width of 8.2-8.5 mm.
Fasten the clamping and strike strips through the groove in the board. Tighten the bolt protruding from above with a nut so that the bar maintains minimal movement, then secure the connection with a second nut. To press or release the strip from below (in the niche of the base), screw a wing nut onto the second bolt.
Adjusting the sharpening angle
Throw a wide washer onto the pin screwed into the base bar and tighten the nut so that the rod does not rotate in the fittings.
The adjusting block must be made from a small block hard material dimensions approximately 20x40x80 mm. Take carbolite, textolite or hardwood.
15 mm from the edge of the block, we drill a 20 mm end on both sides, the hole expands to 9 mm, then we cut a thread inside. A second hole is drilled at a distance of 50 mm from the axis of the hole made, but in the flat part of the part, that is, perpendicular to the previous one. This hole should have a diameter of about 14 mm, in addition, it needs to be flared strongly with a round rasp.
The block is screwed onto a pin, so it is possible to relatively accurately adjust the height of the eye without complex system screw clamps as in the original machine, which in practice is a little more difficult to implement. In order for the block to remain motionless during operation, it must be secured on both sides with M10 wing nuts.
Carriage and replacement bars
For the sharpening carriage, you will need to coaxially weld 30 cm sections of an M10 pin and a smooth, even rod 10 mm thick. You also need two solid blocks measuring approximately 50x80 mm and up to 20 mm thick. A 10 mm hole should be made in each bar in the center and at a distance of 20 mm from the top edge.
First, a wing nut is screwed onto the rod, then a wide washer and two bars, again a washer and a nut. You can clamp rectangular sharpening stones between the whetstones, but it is better to make several replacement sharpening stones.
As a basis for them, take a light aluminum profile with a flat part 40-50 mm wide. This could be a profile rectangular pipe or pieces of old cornice profile.
We sand and degrease the flat part, and “Moment” glue strips of sandpaper of different grain sizes from 400 to 1200 grit onto it. Choose a cloth-based sandpaper, and glue a strip of suede leather onto one of the bars for straightening the blades with abrasive paste.
How to sharpen correctly
For proper sharpening, make several templates from plywood with angles of 14-20º for cutting edges and 30-37º for chopping edges; the exact angle depends on the grade of steel. Fix the blade parallel to the edge of the tool rest and press it with a bar. Using the template, adjust the angle between the planes of the sharpening block and the inclined board of the table.
Start sharpening with a large (P400) whetstone if the edge does not have the correct angle. Make sure that the descent strip takes the form of a straight strip without bends or waves. Reduce the grit and go along both sides of the blade first with a P800 stone, and then with a P1000 or P1200 stone. When sharpening the blade, apply the whetstone with slight force in both directions.
After sharpening, the blade needs to be straightened with a “leather” whetstone, onto which a small amount of GOI paste has been applied. When editing blades, the working movement is directed only towards the edge (towards you), but not against it. And finally, little advice: if you sharpen knives with polished blades and engraving, glue them masking tape so that the crumbling abrasive does not leave scratches. It also wouldn’t hurt to cover the surface of the tool rest with vinyl self-adhesive.
Every housewife dreams of sharp knives. It is difficult to do without such cutting tools in the kitchen. Not everyone succeeds in sharpening correctly: it seems like you tried your best, but the knife still doesn’t cut well or quickly becomes dull. Often the cause of this is improper sharpening. You can get out of this situation if you use a knife sharpening machine.
Modification of sharpeners
The stores sell a large number of all kinds of devices and machines, ranging from the simplest to automatic machines. However, many of them either do not bring sharpening to the final goal, or are too expensive. All machines can be divided into three categories:
- superhard;
- hard;
- soft.
To sharpen the tool, you need to manually move it over the abrasive, achieving the desired effect. Many people use this method, but not everyone succeeds. The reason is that for proper sharpening, the sharpening angle must be strictly observed. It depends on the hardness and volume of the material being cut.
For the tools below The following angles in degrees must be maintained:
- razors - 8-12;
- blades for cutting fillets - 10-15;
- kitchen knives - 15-20;
- hunting tools - 20-25;
- heavy knives (for example, machetes) - 30-50.
The next thing you need to pay attention to when sharpening knives is the grain size of the abrasive material. To sharpen very dull knives, abrasives with coarser grains are used. This will help remove excess metal faster. When leveling the surface, use medium emery stones, and for grinding you need very fine grains. Usually On sanding wheels and bars the abrasive size is indicated in numbers:
- 300-350 - very large, used for pruning;
- 400-500 - average, allows for basic sharpening;
- 600-700 - shallow, you can level the blade on it;
- 1000-1200 - very fine, with its help it is possible to polish the tool.
To sharpen a knife by hand, place a block or an emery wheel on a table or workbench and secure it. Cutting tool hold the abrasive with the blade facing away from you, position it at the desired angle. At first they use a protractor. Subsequently, when certain experience appears, it will be possible to do without it.
They begin to sharpen the blade, strictly ensuring that the angle is maintained. This kind of work requires attention and experience, so it may not work out right away. It will be much more convenient to do it if you make your own device for sharpening knives. A self-assembled product will cost much less.
Use of machines
The most simple device which can be done at home is wooden corner. A block will be placed in it. The base is made in the form of a box, the size of which is selected according to the abrasive. The second side of the corner has the same shape and is mounted in a vertical position. To make the device more stable, the base is connected to a wide board.
A block is inserted vertically into the device. In this position the angle is 0°. To create the desired slope, the lower edge of the abrasive begins to be moved away from the vertical, the angle is measured with a protractor. To prevent the block from “moving”, a stop is placed at the bottom (you can simply screw in a screw). To sharpen the blade, move it along the sandpaper strictly in vertical plane. For fine processing and grinding, the bars are changed. Since the stone is ground unevenly, they constantly need to be leveled using harder stones. Using sandpaper eliminates such hassle.
To do this, you need to take sandpaper with coarse, medium and fine grain, as well as a leather belt. A block of wood is cut to the size of the abrasive and processed with sandpaper. One blank is made from a leather belt. Each face of the bar is numbered, and numbers are placed near the top and bottom edges. A tape with a large grain is glued to the plane numbered 1, 2 - with a medium grain, 3 - with a fine grain, 4 - leather from a belt.
The tapes are attached indented from the edge. Thanks to this, the numbers will be visible, and the block will fit into the grooves of the box. They begin to sharpen the blade from 1 or 2 and then move on to the next edges. As the sandpaper wears out, it is cut off with a knife and a new one is glued. Compared to bars, paper is much cheaper.
This device can be modified. Vertical rack attached to the base through a hinge so that it can tilt back, increasing the sharpening angle. On the side where the stand tilts, a stop is placed, for example, two plates fastened together through longitudinal slots with a wing bolt or nut. In this case, the lower edge of the bar will be motionless.
Convenient designs
Although the designs described above have a number of advantages, they have one significant drawback- you need to constantly monitor the vertical of the blade, and this is tiring. It is much easier to work with an electric machine for processing kitchen tools.
Emery, as the device for sharpening knives is called, makes the task much easier. The blade is brought to the circle so that it is directed against its rotation. But even in this case, it is necessary to monitor the sharpening angle.
To make it easier to work, you can make wooden stand. It consists of two parts: the base and the corner itself. The support helps raise the knife to the desired height; another workpiece with an inclined platform is placed on it; it is this that will give the necessary tilt to the blade. You can make several such corners, they will be designed for different ways sharpening. To fix the guide, you can use nails without heads. They are driven into the base, leaving 10-15 mm, covered with paint, and a corner is placed on top. The painted areas are drilled with a drill of the same diameter as the nails.
The device works well when there is no casing covering the emery stone, but it is not entirely safe. In the case of using protection, you can use another sharpening stand. On the side of the electric sharpener, a wooden block with a vertical slot for the knife is installed. The height is selected so that the angle of the blade being sharpened corresponds to the required condition. The knife is inserted into the cutout and slides along it.
This electric sharpener has a significant drawback - it is difficult to set the sharpening angle. To get rid of it, the design should be complicated. To do this, a three-arm holder with the ability to adjust the angle is installed. It is attached directly to the sandpaper, but can also be used as independent device. To make such a device you need skills and special machines, and this is not suitable for everyone.
Another disadvantage is that when using an electric knife sharpening machine, the stone is ground down. It will have to be constantly adjusted during operation to make the blade sharp. In addition, with this method, the sandpaper is used irrationally; it has to be changed, throwing away a significant part of the abrasive.
Homemade devices
Some owners use a manual knife sharpening machine with an adjustable sharpening angle. The essence of such a device comes down to the fact that one of the elements (knife or abrasive) is in a stationary state, while the other is made to reciprocate. Two groups of such machines can be distinguished:
- with fixed abrasive;
- with fixed blade.
The first group includes a trolley machine. The abrasive is installed on a flat surface. Treated stone or thick glass can be used as such a surface. To make the holder, a board 2-3 cm thick is cut out, its length should be approximately 1.5 times greater than the abrasive material, the width does not play a decisive role. For a better look and a smooth surface, it is treated with a plane and sandpaper. Along the long edges, stops are nailed and glued to provide strength.
Then you should make the wedges. To do this, take the treated board again and cut out a rectangle. Its thickness should be equal to the height of the abrasive material, the length should approximately correspond to the width of the holder. To calculate the width of the device, you need to subtract the length of the abrasive and the width of the two stops from the length of the holder.
When assembled, you get the following picture: an abrasive and a wedge should fit on the holder between two stops. After this, the rectangle is cut diagonally, but not from corner to corner, but with a slight indentation, so that triangles with cut off vertices are obtained.
When the wedge and abrasive are placed in the holder, they begin to lightly hit the bases of the triangles with a hammer. These parts must slide over each other, their overall width increases, and the abrasive is clamped. To prevent the holder from moving on the glass, its bottom is covered with thin rubber.
The dolly will allow the knife to move while maintaining a constant angle. The wheels can be anything, you can use bearings, the main thing is that they are smooth. A guide with a blade holder is attached to the trolley. Here too There are two ways to adjust the sharpening angle:
- changing the height of the abrasive;
- turning the guide with the blade (in this case the cart must have 4 wheels).
In the second option, you can use a rotating mechanism.
Other models
Machine tools in which the tool being processed is stationary have become very popular. A kitchen or other knife is mounted on an inclined platform. Secure fastening obtained by using a magnet; all kinds of clamps (spring or threaded) are also widely used.
To the site with opposite side a rod is attached to the knife. It is allowed to use a steel rod with a diameter of 8 mm. The inclination of the platform is selected so that it approximately corresponds to the desired angle of the tool being sharpened. A clamp is attached to the rod, which can be moved if necessary, thereby more accurately setting the angle. A guide moves freely in it - the same metal rod as the rod. For better sliding, a plastic or nylon bushing is inserted into the clamp.
At the other end of the guide (near the tool being sharpened) there are two brackets that are tightened with a nut or wing. A block is inserted into them and secured with a wing or nut.
The machine operates as follows: a blade is placed in the clamps on the inclined platform, the block is tightened with brackets on the guide, and the desired angle is set using the clamp. The angle is measured with a protractor mounted on the blade. The bar begins to make forward movements, processing the entire surface. During grinding, the abrasive is moved in only one direction - from the heel to the blade.
Another machine uses a trapezoid. The long sides are made of steel bars connected to each other wooden blocks. One rod is attached through a bearing to rotating mechanism, the other is a guide along which the block moves freely. The knife stand is installed under the carriage on a flat surface. If the first rod of the trapezoid gets in the way when sharpening the tool, the stand can be raised higher.
Thin paper, such as newspaper, will help determine the quality of sharpening. You need to try to cut strips out of it with quick and smooth movements. If this succeeds, then the blade is sharpened correctly.
Dear visitors to the site “Visiting Samodelkin”, from the material presented by the author you will learn how you can independently make full-fledged emery from an engine from washing machine and install it, 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 emery good quality Today it will be a little expensive, but it doesn’t make sense to take a cheap one, because it won’t last long. The best option is to make emery yourself; the tradition of using motors from washing machines to make this machine dates back to the times of the USSR. Surely many people still have such sandpapers and they work great for several decades)
So, let's look at what exactly the master needed to assemble the emery?
Materials
1. motor from a washing machine. 220 V 2826 rpm 370 W
2. 2 capacitors with a capacity of 3 µF
3. grinding wheel
4. corner
5. professional square pipe
6. rubber stoppers for antibiotic bottles
7. switch (toggle switch)
8. wires
9. plug
10. galvanized sheet
11. flange for mounting the engine
12. bolts, nuts, washers, screws
13. paint
14. solder
15. electrical tape
Tools
1. grinder (angle grinder)
2. welding machine
3. drill
4. vice
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 mentioned above, the best option is to use a motor from a washing machine; many people probably have old washing machines that they would hate to throw away or scrap) so remove the motor and make a sharpener) This is what the heart of the machine looks like.
The performance characteristics must be indicated on the case, or on a plate screwed to it.
A sharpening wheel can be purchased at a store, but many thrifty owners have plenty of such goodness in their garage.
Making a counter bolt.
The mark is sawed through for a screwdriver.
It twists.
Transfers the outline of the pattern to a metal corner.
He cuts it out using a grinder.
Trial fitting and fitting.
The supporting frame of the grinding machine will be made of professional pipes of rectangular and square sections.
The workpiece is attached to the workbench using a clamp; the author makes the cut using a grinder.
Trying it on in relation to another pipe.
This is roughly what it will look like in the future.
A piece of metal is cut off at the edges to fit the supports.
Trying again.
For uninterrupted starting of the engine, 2 capacitors were taken and connected to each other like this.
Tries to insert elements into their rightful place.
Everything fits perfectly, the structure is being reassembled for evaluation.
Surface metal parts carefully sanded with a grinder and a wire brush.
After which the master begins welding the machine frame itself.
Welds on the engine mount.
Installs capacitors.
Then he sharpens it using a flat file.
The same operation is carried out on the other side.
This is the final detail. These holes are used to move the table along the guides,
and herself work surface the table will be smooth.
Additionally, the stand and the tabletop itself are cut out.
Welded into a single structure.
Cleaned up.
Trial installation.
This is what it should look like.
With mounted grinding wheel.
As you understand, the table can be moved and moved away by first loosening the fastening.
After that, the threads necessary for installing rubber plugs are cut into the legs.
To avoid staining the workbench with paint, place a newspaper under the object to be painted)
Here they are, rubber stoppers for bubbles.
Screwed directly to the legs.
This is what we get in the end.
To turn the emery machine on and off, the master connects a switch.
Connects the wires.
Attaches to the machine body.
Marks the center.
Drills it out and tries it on.
