What to make a knife sharpener. Knife sharpening tool - an essential tool in the household

Interest in making knife sharpeners with your own hands arises for a reason. The consumer qualities of hand cutting tools are enhanced by the use of modern materials and technologies for the manufacture of the blade and precise factory sharpening. At the same time, the price of the product is also growing, but it is becoming easier to spoil a fairly expensive thing with primitive sharpening. Therefore, various household appliances for sharpening knives are needed not only for convenience. To figure out why a knife sharpener is still needed and how to make it right, you have to start with the ideology and evolution of the knife.

Why you need a sharpener

A living relic of our days is a Finnish hunting knife. Not a bandit finca, sometimes of a bizarre shape, but a Finnish-type hunting knife, on the left in fig. Traditional hunting knives (center and left) are similar in shape to it, but the difference between them is very large.

The blade of a Finnish knife is forged from bloomery iron, which can be smelted right in your yard from swamp ore in a domnitsa furnace, without resorting to the blast furnace process, puddling, and other methods of converting cast iron into iron and steel. The viscosity of bloom iron is excellent, it is very difficult to break a blade from it. But the hardness is also low, somewhere around HRS55, the knife gets dull pretty quickly. Finnish hunters did not care: a blade of such hardness can be directed (sharpened) by beating on many natural stones, and there were always enough smoothed moraine boulders in Fennoscandia.

They sharpen the knife with a beating in much the same way as they beat off a scythe, only the touchstone is motionless, and the blade is moved. First, he is pulled along the donkey with the butt away from himself, then he is turned over and pulled with the butt towards him. The position of the cutting edge (RK) on the touchstone is always dragging; the movements are fast: shirk-shirk! On each movement, you need to keep the contact patch of the blade with the touchstone (see below), but the requirements for maintaining the angle of inclination are not so strict. Learning how to sharpen a knife with a bevel is not very difficult, and with some skill, you can also aim a smoothly running profile at the blade, see below. However, the Finnish knife is, in general, a dead end in the evolution of a cutting tool that has survived in special natural conditions.

A good knife has never been cheap, and in an extreme situation, the durability of the blade, combined with the viscosity of the blade, became vital circumstances. Therefore, even in ancient times, knife blades learned to be hardened from the surface and cemented: the core remained viscous, not brittle, and a hard, hardened crust formed on the outside, see next. rice.:

It is still possible to direct a knife with a cemented blade with a beating, but a skill is needed that is not given to everyone. And the abrasive is already needed from a special breed of stone - lithographic grunstein shale. It is scarce in nature; grunstein is still considered a strategic raw material. There is no artificial grunstein and is not expected. To spoil a cemented knife with an inept chop is as easy as shelling pears - a little somewhere, the cementation bark will be torn off to raw metal (this is not visible to the eye), the knife will only be thrown away, the blade will immediately become dull and will crumble.

Note: if you have an old slightly greenish scythe touchstone lying around somewhere, do not throw it away, it is a valuable rarity.

Knife blades don't need the toughness and toughness of hunting and camping knives, and they should cost a lot less. As a result, special steels and powder metallurgy are widely used in the production of home knives. The blade of the "eternal" kitchen knife is structured like a rodent cutter: in longitudinal layers, the hardness of which decreases from the core outwards. In any case, you have to sharpen the knife less often, but the beating is definitely excluded - the blade from it immediately crumbles.

How do you sharpen a knife?

For these reasons, the push-pull sharpening technology (push-pull sharpening or push-pull sharpening technique) has long been invented:

The blade is pushed along the touchstone away from oneself with a twist, holding the butt towards oneself, the position of the RK is running (scraping);
Then, without tearing the blade from the touchstone, pull it with the butt towards you with a twist in the opposite direction, the position of the RK is dragging;
The blade is turned over and repeat paragraphs. 1 and 2;
Pp. 1-3 are repeated, in each cycle reducing the pressure, until the burr formed on the RC comes to naught (does not stick together).

Note: when they say or write “the burr will go away”, etc., this is not true. Metalheads have a slang word for slang; electricians have a “switch”. But in Russian, a burr and a switch are masculine.

Push-pull sharpening saves the blade, but requires high skill from the operator, because. during the sharpening process, a number of conditions must be continuously and precisely observed, see also fig. below:

Maintain the angle of inclination of the blade to the touchstone, smoothly changing it in accordance with the curvature of the RK.
Make sure that the tangent to the generatrix of the blade and the transverse axis of the contact patch of the RC with the touchstone coincide.
Also make sure that the axis of the contact patch is always perpendicular to the longitudinal axis of the touchstone.
Smoothly change the pressure on the blade as the area of the contact patch changes.

It is very difficult to meet all these conditions at the same time, completely symmetrically on the forward and reverse stroke of the blade along the touchstone, and a modern knife, as mentioned above, can be damaged by improper sharpening. Any household knife sharpener is just designed to save the grinder from continuous control of at least part of these conditions.

Note: for successful push-pull sharpening, the length of the whetstone (see below) must be at least 2 lengths of the knife blade from shank to tip.

Sharpening profiles

The profile of a knife blade is linked to the properties of the material and the structure of the blade, as well as to the properties of the materials for which the tool is intended to be processed. Sharpening on a simple blunt wedge (pos. 1 in the figure) gives a stable but rough blade: cutting resistance is high, and the knife tears quite viscous materials. A sharp wedge (pos. 2) quickly becomes dull or chipped; on viscous and / or fibrous materials, the cutting resistance may be greater than with a blunt wedge due to the friction of the cut against the blade.

Ideal in all respects is an animated (smoothly escaping) profile, pos. 3. Experts are still arguing which generator is better - evolvent, hyperbola or exponential. But one thing is indisputable - it is difficult and expensive to make an ogival blade under production conditions, and it is impossible to direct it yourself. Therefore, knives with ogive sharpening are used only in special equipment, for example. microtomes - biological devices for obtaining the thinnest tissue sections.

For disposable blades, e.g. blades of safety razors, faceted sharpening is used, pos. 4, i.e. An ogive generatrix, as mathematicians say, is approximated by line segments. The number of sharpening edges is indicated in the certificate or on the manufacturer's website. For thick coarse bristles, 3-4-faced is better; for delicate hair not on the face - 8-sided. Universal is considered 6-sided.

Angle α

The sharpening angle is always given in half the value of α, because many tools and, for example, bayonet-knives, are sharpened on one side. For knives for various purposes, the angle α is maintained in the following. limits:

10-15 degrees - medical scalpels, straight razors, knives for artistic carving.
15-20 degrees - confectionery (for cakes) and vegetable knives.
20-25 degrees - bread and fillet knives.
25-30 degrees - hunting, camping, survival knives.
30-35 degrees - general purpose household knives.
35-40 degrees - carpentry tools, shoe knives, axes.

One and a half

Sharpening knives, except for special ones, is done almost exclusively with a one-and-a-half profile, on the left in fig. One-and-a-half sharpening is so named because the flat edge of the blade (descent) is formed during the manufacture of the blade and cannot be sharpened. In fact, guiding a knife with one and a half sharpening is no more difficult than sharpening a simple wedge. One and a half sharpening is optimal for a knife that works with a variety of materials, and it is much easier to make a knife sharpener with one and a half sharpening than for faceted sharpening.

In the center and on the right in Fig. the stages of sharpening the blade and the numbers of abrasives used on them are shown. The abrasive number corresponds to the number of its grains per 1 sq. mm surface. The finishing stage has some features:

Hunting and camping knives are not brought. So it is easier to cut hard (eg, bones) with a broach (with filing) with them. In addition, if you accidentally cut yourself, then a slightly lacerated wound stops bleeding faster, heals more easily, and there is less danger of infection entering it.
The blades of dangerous razors, shoe knives and for artistic carving after abrasive are brought to a mirror smoothness on a leather whetstone with GOI paste.
Guiding and finishing the blades of kitchen knives can be reduced to one operation with abrasive No. 800-1100.

Touchstone

A home-made knife sharpener will be much more convenient and accurate if you don’t buy a donkey for it, but make it from a piece of a square professional pipe 200-300 mm long (on the left in the figure below) or a wooden bar.

The edges of the base are pasted over with emery cloth acc. numbers. Glue - clerical glue stick. The advantages of a skin-based touchstone are obvious:

Much cheaper than an emery bar.
It can be made on 4 abrasive numbers, while emery stones are maximum 2-sided.
Wear (development) of the abrasive is possible no more than the thickness of the abrasive layer of the skin; the waviness of the RK due to the rotation of the touchstone on the sharpener rod (see below) is also no more than this value.
As a result, the error in the angle of sharpening from the development and rotation of the touchstone does not exceed fractions of a degree.
The whetstone from the pipe can be put on a threaded rod (in the center in the figure), which speeds up and facilitates the change of abrasive.
A whetstone made of a pipe or a wooden block is held in any clamps for an emery block no worse than the latter, on the right in fig.

Knife sharpeners

The simplest manual knife sharpener is an angular frame in which a whetstone is clamped, pos. 1 next. rice. The same type of “company” is on sale, and this is marketing, marketing: for a plastic board with inclined sockets for donkeys, they want up to $50 or more. Touchstones - non-standard sizes; Ordinary holes won't fit. Worked out - you need to buy the original ones. Price - you know. And all the convenience - when sharpening, keeping the blade strictly vertical is still easier than maintaining its angle of inclination.

The use of the simplest knife sharpener can be further simplified to the complete absence of the need for skills, if it is supplemented with a sliding shoe with a magnetic knife holder, pos. 2. The order of sharpening in this case is the following:

The knife is held by the handle with the right hand, turning in the direction of travel according to the curvature of the blade;
With the fingers of the left hand, except for the big one, they press the shoe to the touchstone;
With the thumb of the left hand, they press on the butt of the blade, pressing the RC to the abrasive.

The function of maintaining the angle of inclination is removed from the operator, and the rest are distributed to 2 hands. In this case, the skill of sharpening with one's own hands is developed immediately, but a holder is needed that firmly holds the knife and at the same time allows it to slide over its surface. This can be done from the magnets of the carriage drive of the write-read heads from an unusable HDD drive (hard drive). The “screw” carriage drive magnets are niobium, thin, flat, smooth and very strong (shown by red arrows in pos. 3). They are glued with DIFFERENT poles on a steel strip, the force of attraction of the blade will then double. And to ensure sliding, the holder is covered with a fluoroplastic film 0.05-0.07 mm thick. PET from bottles will also work, but it is thicker and the attraction will be weaker. Polyethylene is not suitable, it will be wiped immediately.

Note: remember this holder, we will need it later.

LM

It does not require any special skills and the use of a manual sharpener for knives such as Lansky-Metabo, pos. 1 in fig. The scheme of its device is given in pos. 2, and the order of use - on pos. 3. The disadvantage of the Lansky-Metabo sharpener is the instability of the sharpening angle along the length of the blade: a rod with a whetstone is driven along it. The offset of the touch point is constantly changing, because it describes an arc of a circle, and the blade has a different configuration. Resp. "floats" and the corner. Therefore, the Lansky-Metabo sharpener is mainly used for sharpening hiking and hunting knives with a relatively short blade.

However, this drawback can be turned into a virtue if the blade is clamped in the terminals with the root part A (near the handle) and the tip slightly turned away from you, pos. 4. Then, at the root of the blade, the sharpening angle will be the largest, which is optimal for processing hard materials or using the knife as a cleaver. So after all, they work in such cases, so that the outer arm of the arm-blade lever is shorter.

Towards the middle of the blade B, the sharpening angle will gradually decrease and reach a minimum at the bend of its generatrix B1, which is convenient for fine work. Then, towards the B tip, the angle will increase again, which will make the tip more resistant to drilling, gouging/impact and breakdown (piercing).

Note: Another disadvantage of the Lansky-Metabo sharpener is the difficulty of execution in the desktop version. But this shortcoming, as they say, is fake, see pos. 5.

Detail drawings of the original Lansky-Metabo sharpener are given in fig. The numbers at the windows for the bar (guide) correspond to the FULL sharpening angles.

On the trail. rice. an assembly drawing of the clamp is given, and then - the drawings and dimensions of the Lansky-Metabo terminals, made from a corner 90x90x6 mm. The author of the development hides under the pseudonym Serjant. It is certainly a matter of his modesty. But, by the way, in production, technological innovations that make it possible to use standard profiles for the manufacture of shaped parts are sometimes valued more than serious inventions.

Note: on the trail. rice. given the assembly drawing of the sharpener Serjant. As for the inconvenience of fixing in a vice - see above.

Knife sharpening machine

The most advanced household manual sharpener today is the Apex type knife sharpener. Its appearance, device diagrams and how to use it, see fig. Apex can be made with a continuously variable sharpening angle (pos. 2) or fixed angles like Lansky-Metabo (pos. 3). Normally, they work on Apex as on Lansky-Metabo (pos. 4), but other options are possible for more accurate sharpening, see below.

A homemade version of the Apex sharpener - a sharpener for knives Skomorokh

In 2016, in Runet, it made a noise, perhaps, no less than once the bubafonya stove, the desktop modification of Apex by Ivan Skomorokhov, see fig. on right.

Skomorokh sharpeners are much simpler than the prototype and in no way inferior to it in functionality.

How to make a knife sharpener Skomorokh, see video:

Not only knives...

The original Apex sharpener is not very suitable for sharpening carpentry tools - chisels, planer irons. Apex's sharpening angle floats for the same reasons as Lansky-Metabo. Meanwhile, if the angle of sharpening the chisel along the width of the blade “walks” by more than 1-1.5 degrees, then the tool strives to go sideways, crawl out or go deep into the solid wood along its fibers. It is very difficult to choose a groove for a spike / comb evenly and accurately with such a chisel.

There are special devices for sharpening carpentry tools, about which a special conversation is needed. Homemade products like a roller cart sharpener, see fig. on the right, rather curiosities: not to mention the complexity, they require a stone or steel table, and, most importantly, they do not guarantee against misalignment of the blade on the whetstone, which leads to the same undesirable result.

Meanwhile, 2-3 years ago, in one of the Chinese magazines on technical creativity, Apex’s refinement flashed for sharpening, not inferior to that on a factory electric grinding semi-automatic. The alteration is not difficult, see Fig.: the bar is set horizontally according to the level and the horizon of the bar is held along it, leading to sharpening. Within the angle of rotation of the rod in the horizontal plane of 10-12 degrees to the right and left, the sharpening angle error is less than 1 degree. If the extension of the point of contact is from 250 mm, it is possible to sharpen chisels and pieces of iron planers up to 120 mm wide.

In this mode of operation, zero (theoretically) sharpening angle error can be achieved by keeping the bar stationary and moving the knife held by the magnetic holder, see above. Thus, it is also possible to sharpen the irons of shaped planes if a round cross-section, semicircular, elliptical or segmental whetstone is placed in the clamps. The main thing is that the touch spot should always be a point.

...but also scissors

Another refinement of the Apex sharpener for sharpening scissors (also a necessary thing in the household) is shown in fig. on right. Total work - a couple of pieces of a corner or scraps of galvanization and 4 additional holes in the sharpener table. About the process of making do-it-yourself attachments for sharpening scissors to the Skomorokh sharpener, see next. video:

Video: sharpening scissors, attachment to the sharpener Skomorokh

One last thing about scissors

Before grabbing badly cutting scissors and sticking them in the sharpener, check to see if the hinge is loose. Open the scissors and look at them from the side. See how the tip is wrapped with a screw towards each other? That's why scissors cut: the point of contact of the blades during cutting shifts from the roots to the ends. And therefore it is difficult to cut with scissors with the left hand: the inversion of the ends is designed for the kinematics of the right. And if the hinge of the scissors is loose, the blades will move away from each other and will not even cope with paper. In this case, you just need to tighten the riveted hinge with a hammer, and the screw hinge with a screwdriver.

In households, it is often necessary to use cutting, sawing and planing tools. In the process of work, they lose their sharpness, and the blade needs to be restored to its original properties.

Taking the tools to the workshops to be sharpened is a reasonable option, but in order not to waste money again, you can make a device for sharpening knives with your own hands.

General information about knife sharpening

The goal of any kind of knife sharpening is to keep the blade sharp. And the most important factor that affects long-term and efficient operation is the size of the sharpening angle. The practicality of such a parameter is well evaluated in the course of work. If you look objectively, you can see that with a smaller value of the angle, the knife blade as a result is sharper. But with such an action, it turns out that the period of improved cutting qualities is not very long, that is, it becomes dull faster. The sharper a knife blade becomes during the sharpening process, the faster it will become blunt. On the basis of this regularity, it can be concluded that the angle must be chosen correctly and the false value should be observed uniformly along the entire length of the edge.

It should be noted that only those types of blades that have a certain degree of hardening are subject to sharpening. If the hardness of the steel on the cutting parts exceeds 55 HRC, then it cannot be sharpened with any improvised tool.

The golden rule for sharpening knives is to keep the sharpening angle of the cutting edge unchanged throughout its entire length.

To achieve this, professionalism, skills and special equipment are required, which will allow you to hold the tool in your hands, maintaining a given angle of inclination of each cutting edge.

In this case, you can take care of buying a special device, but such products are usually expensive, so you can try to make it yourself. For more information on how to make such a device at home, read below.

Video "Homemade design of a simple knife sharpener"

Features of using the device

Of course, a simple whetstone is fine for sharpening a knife or planer cutting edge. But its quality will not be the best. To ensure uniform removal of the metal layer and the accuracy of processing, it is necessary to use special grinding devices.

The advantage of such a product is not only the convenience of its use, but also factors such as:

The possibility of fixing the blades, which is quite reliable and does not exert excessive load. a properly designed device does not allow damage to the metal during operation.
The ability to install the bar at a certain angle. Due to this, when the cutting edge moves, the angle value will not change.
Variation of installation of different angles of sharpening. With this functionality, it is possible to process various tools, even sharpening knives with a stepped structure.

Materials and tools required for the device

To perform a simple and quite solid fixture, you need to take care of preparing the following blanks and tools:

plywood or a small laminated chipboard sheet;
steel stud with a diameter of 8 mm (the thread on it must be cut along the entire length);
textolite or ebonite bar (as an alternative, you can replace it with hardwoods - beech, oak, etc.);
aluminum plate (with a thickness of at least 5 mm);
fasteners - bolts, nuts (wing nuts);
neodymium magnet (it can be found on an old computer HDD).

Do-it-yourself drawings of a tool for sharpening knives

After preparing and completing the materials, you can begin the process of assembling the fixture. First of all, we take plywood to be used as a bed, which should rest on the mounting legs at a certain angle in the range from 15 to 20 degrees. After that, the hairpin prepared by us is twisted into the lower part, its length should be approximately 35-40 cm. To make the fitting thread stronger, you can use glue or sealant.

In the center of the installed plywood, we fasten the aluminum plate. Before fastening it, it is necessary to make a groove, which in size will correspond to the diameter of the fixing bolts. It is worth noting that we are using an aluminum blade as this will help avoid damage to the steel blade of the knife.

After that, we proceed to the manufacture of a lever that will allow you to fix the emery on the device. To assemble it, use the rest of the stud. Then we take two textolite (or wooden) bars and by cutting out we make holders for the lever. On one side, the stops must be fixed with a wing nut.

Near the handle, it is optimal to provide for the presence of a spring-loaded block, which will allow you to quickly change the emery stone.

As the main elements, you can use blanks from home-made bars - we glue sheets of sandpaper to the aluminum plate, while their grain size should be different. Such a device can be easily fixed in the lever.

The main design feature is the presence of a hinge with a double degree of freedom. Such a device can be easily assembled using the same textolite bars for this. One of them must be screwed onto the threads of the vertical stud, and used as a horizontal pivot and height adjuster for the linkage (this is necessary to set the sharpening angle).

The function of the second bar, which has a horizontal hole for the lever, is that it must be screwed to the first.

Thanks to this, it is possible to ensure free type of movement of the entire lever structure vertically.

Knives are clamped with a plate, or fixed on the surface of a neodymium magnet. When removing the first layer with coarse types of abrasive, the blade must be securely fixed.

If it is necessary to perform fine-tuning, then you can install the blade on a magnet and perform the sharpening operation with little effort. The horseshoe of the magnets should be recessed flush with the tabletop and seated with epoxy.

Making a homemade tool for sharpening knives can be considered complete. It is enough to set the desired angle, slowly sharpen the edge with a smooth movement along the entire length of the blade.

Video "Knife sharpener with your own hands"

Device for sharpening knives on an electric emery

An electric sharpener will allow not only to speed up the work, but also makes it possible to obtain high-quality concave edge profiles on the blades, the so-called fuller sharpening. It is impossible to achieve such forms using a linear bar; therefore, these types of devices are not interchangeable, but complementary devices.

It is noteworthy that a person, working on a manual grinding device, controls the speed and intensity of the processes performed, while the emery wheel has a constantly high rotation speed, which can adversely affect the condition of the knife.

When rubbed, the metal surface is subjected to intense heat, which results in "tempering" the hardening of the steel. The material loses many properties, it becomes less hard, which leads to grinding and the appearance of torn edges. Another problem with a "released" knife is the rapid loss of sharpness. In this regard, you need to work carefully on the electric emery, bringing the blade to sharpen the abrasive for short periods of time and taking frequent breaks so that the knife cools down.

Working in such modes, it is quite problematic to maintain constant angles, so the tool needs to be securely fixed during such processing.

To implement the design of such a device is quite simple. In the direction of the rotating axis on the emery there are guides along which the carriages with knives move. The angles are maintained mechanically, and the forces are determined directly by the operator.

This type of fixture is quite simple to do with your own hands - while there is no need to perform precise work to process metal parts. For the manufacture of guides, the foot material is actually used.

On the workbench, near the sharpener, guides are fastened, with the help of which it is possible to change the distance from the knife stops to the abrasive. This distance affects the sharpening angle. On the vertical bar must be present up and down freewheel regulators, which have strong types of fixing the current positions.

The knife blade must be drawn horizontally, pressed against the thrust element. The force in contact with the emery must be adjusted directly in the process. Processing must be performed symmetrically, it is enough just to change the sides of the knife and sharpen them at the same angles.

The use of this method can only be used when processing the classic type of knives. Kitchen, hunting, tourist and other types of cutting planes of various tools need a slightly different approach.

A common type of design for sharpening knives - "joiner"

For such a device, it is necessary to use a specialized emery, with an end type of working surface. The guide under the carriage is placed at the bottom so that it is located away from the rotating axis. This is due to the fact that in this part of the abrasive wheel, its work is considered the most effective. Guides with cutting elements are moved manually, clamps are provided by the own weight of the tool.

A drawing of each structural is presented in the image.

This type of machine was used at the beginning of the last century, and for all the time the technology of its operation has remained unchanged. Due to the simplicity of this device, it is easy to make it for your home workshop. For this, any components made of metal, plastic, wood are suitable.

By replacing the cutting element on the jointer, you can sharpen ice ax knives, the main thing is to maintain the correct angle, which should be more gentle. The same principle applies to sharpening scissors.

To sharpen a chisel and a knife from a planer, you can also use electric emery and locking carriages. But these types of tools are compact, and they can be sharpened with a mechanical device.

There are equivalent ways - along the edges, and across. In terms of quality, the processing is virtually identical; therefore, it is impossible, therefore, to single out a specific type of fixture.

For factory products, transverse edits of the blades are assumed.

By a similar principle, thick plywood is taken from which the card case is made. Any rollers can be used as a guide, preferably in an amount of more than two. By moving the machine along the surface of the emery, the ideal shape is given to the blade of the chisel.

If serious types of sharpening are not required, simpler devices are also suitable for small edits.

Fasten the bars with the required angles of inclination to the chisel. Put emery and a piece of glass near them. Soap solution should be applied to the glass surface.

You will be pleasantly surprised by the effectiveness of such devices.

For transverse sharpening - it is worth making a simpler device, where the guide element is also used as a support. A blade is fixed vertically on the movable part. The only drawback of this is the fixed angle, which is set during the manufacturing process.

But, compared with a knife, the deviations from ideals that have arisen are not so critical.

This type of fixture can be used to sharpen planer knives. But due to the wide size of the blades, the process is somewhat more complicated. In this regard, you can use an electric grinder that has an end working surface.

The stops are made from wooden bars. It is important to provide for the possibility of changing angles. Clamps are provided by the operator, and semi-circular sharpening can be performed, which is very indispensable for carpenters.

Naturally, this device is convenient to use for sharpening the edges of chisels. If you take into account the high performance index, you will be able to restore tools even with a large number of notches.

Now you know how you can create a homemade sharpener to perform all the necessary operations for sharpening knives at home.

Video "Device for sharpening various types of knives"

Almost every home craftsman has cutting tools available. Over time, the cutting edges lose their former sharpness, and working with such a product becomes unbearable. There are two options for solving this problem: give the tool for sharpening and pay a lot of money, or assemble a device for sharpening knives yourself and sharpen the products with your own hands.

Reasons for a dull blade

Blade blunting can be explained as follows. During cutting, the smallest abrasive particles, whether fruits or vegetables, act on the blade. The cutting edge of the blade is gradually erased, and the knife becomes dull. Another reason is the retention of the blade when cutting at a certain angle.

On some parts of the blade, the load increases, and increased wear occurs.

There are types of knives that cannot be sharpened on their own because of the embossed blades. Also, knives made of ceramics cannot be sharpened. But, as a rule, the quality of steel for such products is high, and they rarely become dull. There is a variety of knives of low quality, and they have to be sharpened very often. As practice shows, if the steel is of poor quality, then sharpening will solve the problem for a while, and then the blade will become dull again.

To sharpen knives, you will need abrasive wheels. If it is not possible to purchase ready-made circles, then you can make them yourself using wooden blocks and sandpaper of different grain sizes.

The standard sharpening angle is 20 - 30 degrees. It is quite difficult to maintain the angle during sharpening, and therefore it is necessary to make a simple knife sharpener, in which it is not necessary to maintain the optimal angle. The basic rule in this process is the observance of a precisely set constant angle. Strength is not required here. The main thing is that the bar and the blade meet at a certain angle. This is the basic rule of sharpening technique.

Basic Mistakes

As it may seem at first glance, sharpening is simple, but if you delve into the process itself, you can notice a fairly large number of different nuances. Most people make commonplace mistakes when sharpening knives, which leads to uneven sharpening or damage to the knife. Common Mistakes when sharpening:

The cutting edge has not been sharpened. As a result, small burrs form on the sides, which temporarily sharpen the blade, and after a short work with the knife, the blade becomes dull again. To prevent this problem, carefully sharpen both edges, and then, as you sharpen, use sandpaper or a circle of different grain sizes.
The presence of paint, oil, dirt on the tip. The bottom line is that when turning, grease, dirt, oil and other components are mixed with grinding abrasives and lead to scratches and micro-splitting of the blade. After such sharpening, the blade becomes dull quickly.
Pressure plays an important role. It is necessary to remember one simple rule: sharpness does not depend on the applied force, but on the duration of sharpening. Excessively strong pressure leads to chipping of microparticles from the blade and to poor-quality sharpening.
Wrong choice of angle. The angle may vary - depending on the grade of steel and on the purpose of the tool. For home kitchen knives, it is 20 - 25 degrees. For other types of blades that have to withstand heavy loads and work with hard materials, the angle will be 40 degrees.

Guided by simple, but at the same time relevant rules for sharpening, you can not only save time, but also not spoil the product.

Sharpener "House"

Nice tool for sharpening knives. Despite the simple design, the sharpener does its job well. This design consists of a rectangular bar, the upper face of which is made in the form of a gable roof. The angle of inclination of one face is 20 - 25 degrees, which is optimal. The product must be installed with a blade close to one of the ridges of the roof, then take an abrasive wheel or a bar with emery and move along a horizontal line. This ensures a constant angle of inclination, which leads to uniform sharpening of the blade.

There are also complex designs of a homemade grinder. For the manufacture will need the following materials:

A piece of board measuring 500x150x20 mm.
Threaded metal stud that will serve as a guide for the bar.
M8 bolts and nuts and wood screws.
Clamping nuts or nuts - "lamb".
Ordinary textolite or plexiglass, which will serve as a substrate for a knife and a kind of movable bed.
To attach the knife, you should take a neodymium magnet. The usual one will not work, since its downforce is quite small.

The board must be cleaned, processed, and then made into a rectangle. Another board should be made in a rectangular shape, which will serve as a stand or support. Its height should be such that the slope of the main board is 20 degrees. You can fasten them together with wood screws. Then attach the resulting structure to the workbench or cut out the tabletop in advance, to which one of the studs will be attached. After securely fastening the stud to the tabletop, you need to take a 200x100 bar and make two holes in it: one for the main stud, on which the movable carriage with a sharpener will be attached, and the other for the stud, which is attached to the tabletop.

Now you can start assembling the carriage with the sharpener holder. On the pin that will hold the carriage, you need to make two clips made of wood, plexiglass or metal. Drill holes in the clamps, put them on the stud and fix them on both sides with nuts. The carriage will rotate freely on its axis.

The next step will be the installation of a neodymium magnet on a previously prepared plate. It is necessary to make a longitudinal groove in it - so that the tripod can be moved up and down. Drill a hole in the middle of the bed and insert a bolt with a nut, which, in turn, will press the plate. At the end of the plate, you can simply glue a neodymium magnet to hold the knife.

Homemade device is ready to use. With it, you can sharpen chisels and planers.

It should be noted that sharpening is carried out without water, so the abrasive paper or wheel will wear out a lot, but this option is quite suitable for sharpening knives and tools at home.

home knife sharpener

If the farm has a grinding machine, it will facilitate the process, but there is one circumstance. When sharpening on the machine, it is almost impossible to evenly press on the knife. Therefore, it is possible to make a knife sharpener that will serve as a guide for the blade and provide uniform pressure. Get a simple but effective electric sharpener. For its manufacture you will need the following components:

Bar.
Four bolts or four studs with M8 thread.
Four lambs.
Wood screws.

Opposite the electric grinder, a guide is attached along which the slider will move. The guide itself can be attached to a workbench or pre-made frame. She must be mobile. To do this, you can cut a longitudinal groove in the frame and fix the tripod with two pins. Then take two bars, drill holes on the sides, insert the studs and tighten them with lambs on both sides. The next step will be the mount on which the cutting product will lie. This can be done using small pieces of timber, which should be attached to the sides of the moving carriage.

After that, you can start sharpening. Set the movable carriage to the desired height and clamp it with the lambs. Move the tripod itself to the desired distance, securely fasten and sharpen the product by moving the knife along the side guides.

Sharpener LM

If in the future it is planned to engage in professional tool sharpening in large quantities, then you can make a sharpener, which is called: Lansky-Metabo. Fixture drawings for sharpening knives with your own hands are as follows:

If the product is clamped in the clamps by the root part, then the sharpening angle will be the largest. A knife with this angle can be used as a "cleaver" and processing hardwood. You can also easily sharpen knives from a jointer. Clips for a knife can be made from a corner or from a tree. The disadvantage of this design is the complexity of the assembly and the large number of parts.

If it is not possible to assemble a complex tool for sharpening knives, then you can get by with improvised means and make manual knife sharpeners. A simple sharpener can be made from a corner frame in which a whetstone is mounted.

If the sharpener is supplemented with a sliding carriage, then you do not have to hold the knife at a certain angle, which, in turn, will have a good effect on sharpening the blade. To make a movable carriage, you will need a triangular bar and a magnet. It is best to use a neodymium magnet, which allows you to attract the knife and fix it securely. If there is no such magnet, then you can take components from the HDD (hard disk).

Before you give a knife or other product for sharpening, you should familiarize yourself with the material that will help not only in making a sharpener with your own hands, but also save a certain amount. The main aspect is to gain additional experience that will come in handy in the future.

Greetings, DIYers!
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 tool for sharpening knives evenly.

Initially, the master wanted to buy a ready-made knife sharpener in China (namely, in the Aliexpress online store), but he thought why not try to make such a sharpener himself with his own hands. Moreover, the prices for this product from Chinese friends are rather big.

For self-production, you will need the following materials and tools:
1. Ordinary board;
2. Sandpaper;
3. Screwdriver;
4. Hammer;
5. Thick electrode 1 pc;
6. Electric jigsaw;
7. A piece of laminate;
8. Bolts and nuts;
9. Wooden handle;
10. Hex key;
11. Fluoroplastic or textolite (glass fiber).

Let's get down to actually making the sharpener.
To begin with, take an ordinary board and cut a piece out of it. Then it is necessary to process the resulting wooden blank, namely, to grind it with sandpaper.

It will serve as the basis of our homemade grinding tool.
In terms of size, it turns out that we have 26 cm in length, the width of the blank turned out to be 6.5 cm, and the height of the wooden base is 2 cm.

Also in this board you need to make holes. In total, this part of the future product will have 6 through holes. We drill 2 holes for the rack itself (more on that later). Next, we drill another hole of a smaller diameter, and also drill 3 more holes on the other side of the board, which will serve to fasten the pressure plate.

We insert nuts into the holes made.

In the future, these nuts can be put on glue so that they do not fall out, but so far everything seems to be quite tight anyway.
Then we will be engaged in the manufacture of the guide rack itself. Her master made from an ordinary thick electrode. It needs to be folded in half. Further, with the help of a hammer, the author beat off the entire upper part from the welding electrode and polished it. By the way, you can grind with an ordinary screwdriver. To do this, simply insert the electrode into the chuck of the screwdriver and, holding the sandpaper in your hand, grind the product.

At this stage, the workpiece obtained from the electrode (guide post) is inserted into these two holes.
We insert not at a right angle, but at a slight slope. The guide angle is anywhere from 65 to 70 degrees.

Everything sits down quite tightly, but also for greater reliability of our design, in the future it will be possible to put the guide post on epoxy glue, or on some other glue, or on something else.

But perhaps the master is mistaken and this is not fluoroplast. Fluoroplast is most often white and some kind of slippery. Most likely it is textolite or fiberglass. But in fact, it's not that important. The main thing is that this material is quite hard and does not wear off.
From this piece (fluoroplast or not fluoroplast), the author sawed out a kind of pressure plate. He made holes in it, as well as small holes, so that the hats went a little deeper into the plate.

Then we put this plate on the previously made wooden base. Fasten with screws.

The author took the screws with a hex key. The craftsman 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 secret, since the sharpening part of the tool will not touch this screw.

Further, the author made such a plate from the same fluoroplast.

In this plate, I made 2 holes for the same hex screw.
Further, the whole thing is put here and pressed with the help of a lamb.

Then the master made just such a guide for grinding stones.

The length of the guide is 57 cm. Its author made it from an ordinary steel bar. Also cleaned it up. And on one of the ends I put just such a handle (it seems to be from an old Soviet file).

You can also strengthen this connection by putting a wooden handle from a file on the glue, but here it itself is quite tight, nothing falls out.

Regarding the attachment of the sharpening stones themselves. The author took a small piece of the clamp, cut it off and made holes. As a result, we got these corners, two of the same.

And here I put a nut with threaded threads and a clamping screw.

The master also put a spring on the guide so that you can change the grinding stones without unscrewing the nut with the clamping screw.

The sharpening stones themselves, or rather the base for these stones, were made by the author from an ordinary piece of laminate. Just cut it into strips.

The width of the strips is 2.5 cm, and the length is about 20 cm.

There are already ready-made grooves on the pieces of laminate, in fact, where the corners of the guide part of the device will become.
Then the author pasted the sandpaper on the pieces of laminate with double-sided tape and signed which one where. And, in fact, this is how it all happened:

The whole thing is set up quite easily. With the groove of the laminate, we get into one corner of the guide, and with the second corner, with the help of a spring, we press the grindstone.

Everything. Nothing falls out. Everything is flat and pretty tight.
Let's continue to collect further our device. We insert the guide with the grinding stone fixed on it into the hole prepared in advance for it, and you can safely begin the process of sharpening the knife.

The move is quite large due to the fact that here the author removed a small chamfer on both sides.

With repeated use of knives, every housewife is faced with a problem when they begin to become dull and it becomes simply impossible to work with them. In addition, it is unsafe, as the knife may slip off while cutting and injure you. To prevent this from happening, the knives should be sharpened in a timely manner using a special sharpening device.

You can purchase a knife sharpener from your local hardware store or market, where you can find different types of devices. You will have to choose on your own. But, in order not to be mistaken, you need to know how to properly evaluate them in terms of convenience and quality of operation.

The options offered do not always suit consumers, so many make sharpeners with their own hands, using special stones, tools and drawing sketches with dimensions. The photo shows options for homemade knife sharpeners.

Features of knife sharpening

When sharpening knives, the main thing is to make the correct angle of contact of the edges of the blades so that they serve you for a long time and efficiently. Therefore, when sharpening knives yourself, it is necessary to maintain the existing angle of inclination of the blades.

Each knife blade has its own optimal angles of inclination:

from 10 to 15 degrees - for a medical scalpel or straight razor;
from 15 to 20 degrees - for household knives used for cutting bread, vegetables or fruits;
from 20 to 25 degrees - for multifunctional knives for cutting a variety of products;
from 25 to 30 degrees - for reliable companions of hunters and tourists on long trips;
from 30 to 40 degrees - for cutting materials that are particularly hard.

To sharpen the correct angle of the blade, you will need special tools, since it is difficult to do this manually.

The design of such devices is not complicated, so it is easy and quick to make it yourself, and detailed instructions for making sharpeners can be borrowed from the Internet.

Types of knife sharpeners

From a rather large assortment of various types of knife sharpeners, choosing the right option for yourself is quite simple.

The main elements of the grinding device are the stop for fixing the knife and the abrasive bar, which is used as ready-made abrasive materials (stones) or homemade. But before you get to work, you need to learn how to make a knife sharpener with your own hands.

Types of stones for sharpening

There are several types of grindstones:

water. Sharpening stones used in water wear out less during operation.
oil. In structure and configuration, they are similar to water ones, but with a more oily surface.
natural. For their manufacture, only natural raw materials are used with preliminary processing in the production process.
artificial. In this case, the name speaks for itself, that is, the abrasive material is created artificially.
rubber. They are not as common as the previous ones, besides, they are inconvenient in the process of application.

What can you make a sharpener for sharpening

To make a whetstone with your own hands, you can use the simplest way. Take a small rectangular glass plate about 5 mm thick. Using double-sided tape, fix strips of coarse and medium grit sandpaper on both sides of it.

The bar is ready for use, if necessary, worn sandpaper can be easily replaced with a new one. This method is the most budgetary in terms of cost.

The disadvantages of this device include:

rapid wear of the abrasive and fragility of the product (when fixing the beam, you need to be careful that the glass does not crack).
possible overheating of the material during rapid movements during the sharpening process.

You can find the best knife sharpener ideas on the relevant websites.

Wooden bars

This method of making a tool for sharpening knives is also simple and accessible to everyone. You will need four identical bars: two abrasive and two wooden.

At the beginning of work, sand the wood blocks with sandpaper so that their surface becomes smooth without burrs. Make a marking of the bar in accordance with the required angle of inclination. Attach a whetstone and mark its width on a block of wood.

Note!

Make 1.5 cm deep cuts on the basting and insert the abrasives into the grooves. Secure the stones with bolts. A piece of rubber fixed at the bottom will give stability to the structure.

In addition, you can make an adjustable sharpener with your own hands, but the next article will tell you how to do this.

DIY knife sharpener photo

Note!