The myth about supposedly self-sharpening knives was quickly shattered... About everyday life. This is not surprising, the laws of physics are laws of physics, and even marketers, so to speak, are powerless against them. If there are no sharpened knives in the house, if you remember the famous bard, there is nothing good. Today the editors of the site will help solve the problem of dull blades and tell you how and with what you can properly sharpen a knife at home. We will introduce our readers to different types devices for sharpening knives, we will tell you about their effectiveness, and also teach you how to make a simple sharpening machine at home.
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Types of devices for sharpening knives
A whetstone for sharpening knives is probably the very first device of this type. A simple, and, most importantly, affordable tool has been successfully coping with its task for many millennia.
To this day, the classification of machine tools depends on this once uncontested sharpener. Depending on the type of abrasive material, they can be:
- bars;
- sharpening stones.
By drive type:
- manual;
- electrically driven.
By place of use:
- domestic;
- professional.
However, in modern world A whetstone can only sharpen a simple hunting knife. In other cases, the quality will leave much to be desired. In addition, only soft metals can be sharpened with a stone; if the cutting part of the blade has a hardness above 55 HRC, you cannot sharpen it with improvised means.
Important! Each type of blade has a different edge angle. And during sharpening it must be held along the entire length of the processed surface of the product.
Some types of modern sharpening stones are still used today. An example of this natural stones– Japanese water stone (we showed it in the photo above) or American “Arkansas”. Master sharpeners even conduct special master classes on sharpening knives using natural stone. Interestingly, before the processing process it is soaked in water, sometimes with soap solution and dried after work. The whole process resembles a sacrament for initiates. So it should come as no surprise that these grades are overly expensive and most sharpening devices use artificial abrasive surfaces.
Knife sharpening stones
These are artificially turned bars with an abrasive coating, which are suitable for manual sharpening of both carpentry and plumbing tools, and for kitchen knives.
The bars, depending on the material from which they are made, can have varying degrees of wear resistance and grain size. Let's consider the main types of materials that are used in the manufacture of sharpening stones:
- Natural stones, such as novaculite or Japanese water stone. Working with such a tool is not very easy. They require certain skills and craftsmanship.
- Diamond(with diamond coating) – can be different shapes and graininess. Wear-resistant. Reasonable price.
- Ceramic. Refers to more modern look whetstones for sharpening. They combine the strength of diamond coating with the hardness of natural stone.
- Artificial: electrocorundum or carbide. Quickly grinding abrasive is of low quality and the same price.
Artificial abrasives are created by mixing diamond powders of different fractions, as well as electrocorundum and carbide.
Important! Great value at the same time, it has a material used for gluing the rock, and also percentage all elements. The stronger and better composition(this also applies to the particles themselves), the more durable the sharpening abrasive will be.
Moreover, there are two types of bonding of elements - galvanic bonding and soft bonding. In the first case, the crystals are glued strictly to the surface of their base, made of a nickel alloy. In fact, the crystals are located in a very thin layer on the bar. A soft binder is a chaotic arrangement of binding and abrasive elements. The second type is less wear-resistant.
Sharpening stones for knives
If we talk in more detail about sharpening stones, we need to talk about the main types used in such tools, this will help you understand the process in detail and understand how to sharpen a knife correctly. But before talking about them, it is impossible not to mention the sharpening stages, which in this context will play a decisive role in the description of different materials and machines.
| Stage | Description | Illustration |
| Sharpening | Restoring a blunt edge without adjusting the sharpening angle. |  |
| Finishing | Grinding the edge with fine grain abrasives. |  |
| Edit | Polishing bevels and cutting edges with a ceramic pencil, GOI paste or on a leather belt. |  |
| Resharpening (deep sharpening) | Complete restoration of the desired sharpening angle, blade profile geometry and elimination of chips on the edge. Most often, such work is carried out on special machines. |  |
Let's move on to a description of the main options for sharpening stones.
Japanese water stones Waterstone
They are used equally effectively at all stages of sharpening. There are artificial analogues (ceramic based), but professionals use original, natural materials. Stones require special care, because most important rule masters - a perfectly smooth surface of the grindstone.
A comment
Ask a Question“To check the degree of evenness of the stone, use simple method. Wet the timber and place it on paper sheet on a flat surface. The imprint will allow you to assess the level of evenness of the stone.”
Novaculites, or “Arkansas”, “Turkish”, “Belgian” stones, are natural schists and chalcedony interspersed with tiny particles of garnet and quartz. Today they are used as natural stones, and their artificial substitutes.
Important! Stones only work in combination with a special oil lubricant. The extraordinary and unique structure of the stones allows them to be used at different stages of processing.
Musat for sharpening knives
Musat is a kind of file, most often installed vertically. The peculiarity of this tool is that its surface is magnetized, which means that metal flour will not fall on you.
Musats come in different shapes: round, faceted, flat with beveled edges Each variation has its own merits. For example, round musat weighs little, but oval sharpens better, since its edges provide more complete contact with the surface being processed. Tetrahedral ones are more universal; here you can better refine the required sharpening angle.
Household manual knife sharpening machines
We can talk for hours about the options and varieties of hand-held machines used in everyday life. These include the usual home mini-sharpeners, known to almost everyone, and more specific devices with a polishing wheel.
The easiest way to work is with mini-sharpeners that control the stroke of the tool. In this case, the degree of sharpening depends on the effort the person makes.
Household electric knife sharpening machines
Electric sharpeners are more convenient. Working with them saves time. Most often, such drive machines have different operating modes, which are regulated by switches.
Typically, such machines are compact, safe, simple and reliable, since all grinding wheels hidden inside the case. In this case, the sharpening angle is adjusted by a special spring, which completely eliminates errors in sharpening.
Professional manual sharpeners for sharpening knives
Professional hand tools are a bit like a carpenter's vice. The object to be sharpened, the knife itself, is clamped with special clamps.
The sharpening machine itself is mounted on a stop. It is very important here to properly secure the machine and avoid the device slipping during sharpening.
A comment
Tool selection specialist at VseInstruments.ru
Ask a Question“If you do not have the skills to work with this tool, it is better to use automatic sharpeners. In addition, such a machine cannot be assembled without certain knowledge.”
Professional electric knife sharpening machines
Professional machines are distinguished by their versatility. Usually this is a device with a massive abrasive disk. Such tools allow you to sharpen not only knives, but also locksmith tool, for example, planes and chisels.
The combination of low speed and constant cooling gives high-quality processing products already at the stage of formation of the cutting edge. And at the final stages of work they provide the blade with razor sharpness. The professional tool provides a large number of nozzles and replacement discs. Moreover, the clamp where the blade is secured can move freely along the support in the horizontal direction. Moreover, you can adjust the sharpening angle.
How to sharpen a knife correctly
For high-quality sharpening of the machine, you need experience and certain knowledge. Let's start with the basics.
Optimal sharpening angles and degree of sharpness for kitchen knives
It's no secret that there are a lot of knives for different materials. A good housewife has her own knife for vegetables and meat. Let's consider correct angles sharpening various tools.
| Tool type | Sharpening angle |
| Razor and medical scalpel | 10-50° |
| Professional for chefs | 20-25° |
| Universal | 25-30° |
| For complex work | 25-30° |
| Kitchen cutlery | 55-60° |
| For fillet | 15-20° |
| Home universal | 30-35° |
| Deboning and cutting | 25-30° |
| Professional for fish | 25° |
| Professional for vegetables | 35° |
| Hunting and “Swiss” (spicy) | 30-35° |
| Hunting and “Swiss”, resistant to blunting | 40-45° |
For your information! The sharpest knives are considered to be blades with a sharpening angle of 50°; such versions, with a certain grade of steel, can cut nails. When sharpening knives, you can vary the angle at your discretion within the mentioned range.
In general, the sharpness of a blade depends on the shape of the blade. And it, in turn, must correlate with certain clear correspondences of the relationships between the blade and the blade.
How to sharpen a knife at home with a whetstone
The process is simple, but quite painstaking. Try it without sharpening experience this process pointless. Typically, craftsmen use two sharpening stones with different abrasive densities - with a large grain and a fine one.
A comment
Tool selection specialist at VseInstruments.ru
Ask a Question“The knife blade must be wet. You can use special oils or sharpening lubricants.”
The next step is choosing the sharpening angle. Here we focus on the table above and take the range from and to. Don't forget, the smaller the sharpening angle, the faster the knife will become dull. For a beginner, it will be difficult to maintain the same angle. In order to successfully complete this stage, it is important to hold the knife with both hands.
We start working on a coarse-grained stone, and then, when the edge grinding stage begins, with a fine abrasive
How to sharpen a knife with musat at home
Sharpening takes place by weight. The blade is passed along the entire length of the instrument; usually several such “passes” are enough.
To prevent the blade from slipping, the musat is equipped with a special stopper or guard, which prevents the blade from injuring the hand.
How to properly sharpen a knife on an electric sharpener
The sharpening process is practically no different from sharpening manually. The only difference is that in this case it is not the blade that is wetted, but the sharpening disk itself. Usually this happens automatically, like in the machines we talked about above.
Typical mistakes when sharpening knives with your own hands
Everyone knows that it is better to prevent mistakes than to correct them later. That is why the editors of the site have prepared a list of the most common mistakes beginners make when sharpening knives:
- Incorrect level of sharpening angle.
- Blade sharpening. It occurs when excessive pressure is applied to the sharpener by the blade, which can cause it to become damaged or even crack.
- Sharpening an unprepared tool or a worn sharpening disc.
- Use of musat at all stages of work. As we remember, musat is used to polish the cutting edge.
- Use fine-grained abrasive.
It is important to take into account all these subtleties already at the stage of organizing work. To learn how to properly sharpen a knife with a whetstone, watch this video.
Making your own knife sharpening machine
Purchasing a ready-made knife sharpening machine is not always necessary. For household needs you can do it yourself. It doesn't matter if it's mechanical or electric machine you will create, be guided, as mentioned earlier, by already existing diagrams and drawings.
What tools are needed to make a knife with your own hands?
To make a simple machine we will need:
- A piece of chipboard 10-12 mm thick. Can be used from old cabinet furniture.
- Wooden block.
- Metal rod M8 or M6.
- Sheet steel 1 mm thick.
- Fastening screws or nuts with washer corresponding to the diameter of the stud used.
- Abrasive material.
- Metal hacksaw or jigsaw
- Screwdriver.
Step-by-step instructions for making a do-it-yourself sharpening machine
Let's consider assembling a simple knife with your own hands from scrap materials.
| Illustration | Description of action |
 | As we can see, the base here is quite simple - several chipboard boards. Size - 37x12 cm. Pressure board - 30x8 cm. When lifted - something about 7 cm. |
| Nut with a diameter of 6 mm for fixing clamping mechanism The blade is attached to the lamb. The clamp itself is made of a piece of plexiglass; you can use a metal plate. | |
 | A magnet is used, attached to 2 self-tapping screws in a special recess. |
 | A groove is drilled into the plexiglass with a drill for free movement. |
| You can use ready-made special stones as a bar or make it yourself. | |
 | The sharpening process does not cause problems, the main thing is to follow the recommendations outlined above |
We tried to introduce you to the main points related to the right technology sharpening knives with your own hands, as well as with the features of this whole process; in addition, you now know how to make the simplest manual knife sharpeners with your own hands. And if you have questions for the author of the article, ask them in the comments and tell us about your own experience, which will certainly be useful to our readers.
Materials
1. Plywood or plastic plate 10 mm thick.
2. Screws, wing screws, washers and rod (0.5 m) with M6 or M8 thread.
3. Magnets from a used computer hard drive
4. Bearing from an old coffee grinder.
5. Emery (abrasive skins) sheets and bars of different grain sizes: 120, 320, 600, 1500.
Manufacturing
1. The stationary part of the machine is made of plywood (plastic). Strips 30 cm long and 5 cm long and (10...12) cm wide are fastened with the letter G from the bottom with an aluminum corner. We install 1 or 2 magnets in the upper part (fill them with epoxy resin). We drill a hole in the lower opposite part and install a threaded rod (height 12...15 cm) with a bearing vertically.
On the surface (to support the knife being sharpened) we install a prepared aluminum (or stainless steel) plate with a slot in the middle (up to 2 mm thick) with a wing clamp.
2. The moving part has two options:
Option A. For sharpening with whetstones.
Option B. For sharpening with abrasive cloths.
The aluminum profile has 4 sides with a width of 25 mm.
A strip of abrasive sandpaper of different grain sizes is glued to each side: 120, 320, 600, 1500. For stickers, I use a stationery glue stick. Afterwards, the used strip of skin is easily removed with a knife and a new strip is glued on.
Sharpening process
1. Install the knife to be sharpened as in the photo.
The knife is clearly fixed by a magnet and there is no need to secure it mechanically.
Using a movable stop, we set the knife up to the required position and secure the stop with a wing screw.
We place the moving part of the machine on the knife.
Now we set the sharpening angle by lowering or lifting the bearing using screws.
For the first sharpening, turn the side with the minimum grit number 120 (the coarsest) towards the knife blade.
sharpen until you get a continuous strip on the edge of the blade (0.5...1 mm wide)
We turn the knife over and repeat everything.
We continue the process with sandpaper 320, 600, 1500.
Now you can shave with a knife.
The same procedure for sharpening with sharpening stones. But in this case there are several disadvantages:
1. middle part The bar develops over time and then the sharpening angle “floats”, which is not the case in the first option.
2. Bars with different grain sizes need to be changed, but in the first option, to change the grain size you only need to rotate the edge. The bar is removed by pressing the spring with two fingers.
All knives are now fully sharpened. If some of the knives become dull during use. I only sharpen these 600 or 1500 grit knives with two or three strokes on each side of the knife.
Thank you for your attention!
"Useful homemade products"from Gamir Khamitov.
Almost everyone home handyman in stock cutting tools. 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: have the tool sharpened and pay a lot of money, or assemble a knife sharpening device yourself and sharpen the products yourself.
Causes of blade dulling
The dulling of the blade can be explained as follows. During cutting, the blade is exposed to tiny abrasive particles, be it fruits or vegetables. Cutting edge The blade gradually wears off and the knife becomes dull. Another reason is to hold the blade when cutting at a certain angle.
Some areas of the blade are subject to increased stress and increased wear.
There are types of knives that are impossible to sharpen yourself due to the textured blades. Also, knives made from ceramics cannot be sharpened. But, as a rule, the quality of the steel in such products is high, and they rarely become dull. There are 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, 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 maintaining a precisely specified constant angle. No force required here. The main thing is that the block and blade meet at a certain angle. This is the basic rule of the sharpening technique.
Basic mistakes
As it may seem at first glance, sharpening is simple, but if you delve into the process itself, you will notice a fairly large number of different nuances. Most people make simple mistakes when sharpening knives, which leads to uneven sharpening or damage to the knife. Common Mistakes when sharpening:
- The cutting edge was not sharpened. As a result, small burrs form on the sides, which temporarily give sharpness to the blade, and after working with the knife for a short time, the blade again becomes dull. To prevent this problem, you should carefully sharpen both edges, and then, as you sharpen, use sandpaper or a wheel of different grits.
- Presence of paint, oil, dirt on the tip. The bottom line is that during turning, fat, dirt, oil and other components mix with grinding abrasives and lead to scratches and microchips of the blade. After such sharpening, the blade quickly becomes dull.
- Pressure plays an important role. You need to remember one simple rule: sharpness does not depend on the force used, but on the duration of sharpening. Excessively strong pressure leads to chipping of microparticles from the blade and poor sharpening.
- Incorrect angle selection. The angle may vary depending on the grade of steel and the purpose of the tool. For home kitchen knives it is 20 - 25 degrees. For other types of blades that will have to withstand heavy loads and work with hard materials, the angle will be 40 degrees.
By following simple but at the same time appropriate rules for sharpening, you can not only save time, but also not damage the product.
Sharpener "Domik"
A good tool for sharpening knives. Despite simple design, the sharpener does its job well. This design consists of a rectangular block, the upper edge of which is made in the form 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 roof ridges, then take an abrasive wheel or a block 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 for a homemade sharpening machine. For manufacturing you will need the following materials:
- A piece of board measuring 500x150x20 mm.
- A metal pin with a thread that will serve as a guide for the bar.
- M8 bolts and nuts and wood screws.
- Clamp nuts or wing nuts.
- Ordinary PCB or plexiglass, which will serve as a substrate for the knife and a kind of movable frame.
- To attach the knife you should take Neodymium magnet. The usual one will not work, since its downforce is quite low.
The board must be cleaned, processed, and then made into a rectangle. Another board should be made rectangular in 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 a tabletop in advance, to which one of the studs will be attached. After securely attaching the pin to the tabletop, you need to take a 200x100 block and make two holes in it: one for the main pin, on which the movable carriage with the sharpener will be attached, and the other for the pin, which is attached to the tabletop.
Now you can begin assembling the carriage with the sharpener holder. For the pin that will hold the carriage, you need to make two clamps from wood, plexiglass or metal. Drill holes in the clamps, put them on the stud and secure them on both sides with nuts. The carriage will rotate freely along its axis.
The next step is to install 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 frame and insert a bolt with a nut, which, in turn, will press the plate. You can simply glue a neodymium magnet to the end of the plate to hold the knife.
The homemade device is ready for use. It can be used to sharpen chisels and planes.
It should be noted that sharpening is carried out without water, so the abrasive paper or wheel will wear out greatly, but this option is quite suitable for sharpening knives and tools at home.
Homemade knife
If the farm has a sharpening machine, it will make the process easier, but there is one circumstance. When sharpening on a machine, it is almost impossible to apply even pressure on the knife. Therefore, it is possible to make a device for sharpening knives, which will serve as a guide for the blade and ensure uniform pressure. The result is a simple but effective electric sharpener. To make it you will need the following components:
- Beam.
- Four bolts or four studs with M8 thread.
- Four lambs.
- Self-tapping screws for wood.
Opposite the electric sharpener, a guide is attached along which the slider will move. The guide itself can be attached to the workbench or a pre-made frame can be made. It must be mobile. To do this, you can cut a longitudinal groove in the frame and secure the tripod with two studs. Then take two bars, drill holes on the sides, insert studs and tighten them with screws on both sides. The next step will be the mount on which the cutting product will rest. This can be done using small pieces of timber, which should be attached to the sides of the moving carriage.
After this you can start sharpening. Set the movable carriage to the desired height and clamp it with the thumbscrews. Move the tripod itself to the required distance, securely fasten it and sharpen the product by moving the knife along the side guides.
Sharpener LM
If in the future you plan to do professional sharpening of tools in large quantities, then you can make a sharpener called: Lansky-Metabo. Fixture drawings for sharpening knives with your own hands look like this:
If the product is clamped in the clamps with the root part, the sharpening angle will be greatest. A knife with this angle can be used as a “cleaver” and for processing hard wood. You can also easily sharpen knives from jointer. Knife clamps can be made from angle iron or wood. The disadvantage of this design is the complexity of assembly and the large number of parts.
If it is not possible to assemble a complex tool for sharpening knives, then you can make do with improvised means and make manual knife sharpeners. A simple sharpener can be made from a corner frame into which a touchstone is mounted.
If you add a sliding carriage to the sharpener, you won’t 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 block and a magnet. It is best to use a neodymium magnet, which allows you to attract the knife and fix it securely. If such a magnet is not available, then you can take components from the HDD (hard drive).
Before you give a knife or other product for sharpening, you should familiarize yourself with the material, which 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, which will be useful in the future.
Currently, there are several types: a machine for sharpening knives, a machine for a hairdressing machine, and others. This article talks about how to make a machine for sharpening knives at home: detailed drawings with dimensions, photos and videos (2-3 videos) are presented.
Often, when sharpening knives at home, household members use abrasive whetstones. However, in order to use them in practice, you need the necessary skills and experience working with them. After all, if the knife is sharpened at the wrong angle, the blade remains dull.
Layout of the block to the blade.
Before actually manufacturing the machine, you need to listen to the advice of sharpeners.
When sharpening a knife, the master performs the following actions:
Defines the angle between work area blades and whetstone. Moreover, for each model the angles are different;
The knife is located at an angle of 90 degrees to the direction of the block. The grooves that are formed when the razor blade of the knife rubs against the block should be at 90 degrees to the knife line. The angle in such a situation is equal to half the sharpening;
Typically the angle is 25 degrees;
The mechanic begins processing from the beginning of the foot blade;
When adjusting the sharpening angle, the master paints over part of the foot blade with any marker. As a result, the mechanic directly controls the work area.
As a rule, after sharpening the working blade has non-uniform deformations. Therefore, when processing independently, the “point of reference” should not be the sharp part of the knife.
Choosing whetstones for sharpening a knife
The main indicator of a block is its grain size.
The whetstone is the main component that makes the blade thin and sharp. As a result, before choosing a design, you need to select the necessary blocks.
When sharpening knives on their own, household members use these types of whetstones
which have a high grain size. Using such bars, the shape of the leg blade is corrected.
having medium grain size. With the help of such bars, the mechanic removes grooves that form during primary processing knife
whetstone, which is covered with GOM paste. In such a situation, the mechanic polishes the blade.
When processing knives for the kitchen, you can use two types - with medium and high grain. And also in this case it is necessary to use a touchstone.
Base
When making a sharpening machine at home, you can use various parts. In particular, you can use laminated box plywood 12 mm thick, which was previously used to create radio equipment housings.
When constructing a machine at home, a household member performs the following actions:
Selects a base for such an installation, which must weigh at least 5 kg. Otherwise, it will be impossible to sharpen chopping devices and tools on the machine. Therefore, when making similar equipment the tenant uses various steel corners measuring 20x20 mm;
Next, 2 parts are cut out of plywood with a jigsaw, which have a trapezoidal shape, the base is 170 by 60 mm, and the height is 230 mm. When cutting, the mechanic makes an allowance of 0.7 mm for sharpening the ends: they end up straight and fit according to the markings;
Installs 3 parts between the inclined walls on the sides - an inclined surface made of plywood with dimensions of 230 x 150 mm.
In such a situation, the trapezoidal sides are located laterally on a rectangular surface.
The result is a base - a wedge. In such a situation, a protrusion of an inclined surface measuring 40 mm is formed in the front part;
Then, along the side wall ends, the mechanic marks 2 lines with a thicknesser. At the same time, it retreats by half the thickness of the plywood;
Drills the ends of the inclined surface and connects the base parts for a while;
At the back of the structure, the mechanic connects the side walls using a 60x60 mm block, which is attached to the end with two screws on both sides; - makes a 10 mm gap in the block.
In such a situation, it retreats 50 mm from the center - 25 mm from the edge. To maintain a vertical position, first drill with a thin drill from 2 edges, and then expand;
Then, at the top and bottom, two threaded fittings are screwed into the slot, and in the fittings - a 10 mm pin, the length of which is 250 mm.
If the threads do not match the studs, the lower fitting is adjusted.
Tool support device
When making a handhold device, the following steps are performed:
Removes the flat inclined part from the base, modifies it and installs a fixation device on it, as well as the clamp of the device used;
Measures 40 mm from the edge in front and at this mark, using a garden hacksaw, cuts out a groove, the depth of which is 2 mm;
Using a shoemaker's knife, chip off the top 2 veneer layers from the end of the board. The result is a sample into which the mechanic inserts a 2 mm steel plate at the same level as the general surface;
The tool rest consists of 2 steel strips measuring 170x60 mm and 150x40 mm. The machine operator connects them along the large end, which has equal edge indentations, and makes 3 through slots of 6 mm.
Using bolts, tighten the planks along the cracks made. In such a situation, the machine operator leaves the bolt heads on the side of the large top plate;
Then he removes metal defects of the weld in the form of beads and grinds the plate to give it a smooth surface;
Applies a small striker plate to the edge recess, moves the slots with a drill and secures the support with bolts.
Fixation device
The second important part of the tool rest is the clamping bar. It can be made from 2 parts.
L-shaped plank measuring 150x180 mm, the width of the shelves is 50 mm (top);
A rectangle-shaped strike plate measuring 50x100 mm (bottom).
When making a clamping bar, the machine operator performs the following actions:
Places the bottom bar on the far edge of the top bar;
Makes 2 holes in the center and retreats 25 mm from the edges of the part, connects the parts through the holes with two 8 mm bolts;
Screws in 8 mm bolts on 2 sides. In such a situation, the head of the nearest bolt is located near the top bar;
Welds the bolt heads to the plates and grinds them in advance until roundness is formed;
Yes, the inclined board retreats 40 mm from the edge and draws a line with a thicknesser;
Makes one 8 mm 25 mm gap at the bottom and top edges;
Using markings, he connects the edges of the slots and uses a jigsaw to make a cut with an allowance. Use a file to expand the groove to a width of 8.5 mm;
It fastens the planks using a groove that is in the board; the top bolt is tightened with a nut and thus firmly fastens the plank.
Then tightens connection 2 with nut;
When pressing the bottom bar (in the niche of the base), screw a wing nut onto the second bolt.
Sharpening angle control
When adjusting the sharpening angle, the mechanic performs the following actions:
Throw a large washer onto the pin, which is located in the block of the machine base, and tighten the nut.
The rod does not rotate in the foot; the block for adjusting the sharpening angle is made from a small carbolite block, the dimensions of which are 20x40x80 mm.
15 mm from the block edge, drill a 20 mm end on both sides, widen the gap to 9 mm, then make a thread inside;
He steps back 50 mm from the axis of the new slot and drills another one in the flat part of the workpiece - 90 degrees to the previous one. Such a slot has a diameter of 14 mm. In such a situation, the mechanic greatly flares the hole using a round rasp;
Screws the block onto the pin - sets the desired height of the eye without using fixing screws;
Secures the block on both sides with M10 hex nuts.
Using replaceable blocks and making a carriage
When making a sharpening carriage, the machine operator performs the following actions:
Welds 30 cm M10 threaded rods with a smooth rod whose thickness is 10 mm;
Uses 2 solid bars 50x80 mm and the thickness is 20 mm. In all blocks, in the center and on top, 20 mm is retreated from the edge, and then a gap is made 10 mm wide;
Screws a wing nut onto the rod, then a large washer and 2 bars, then a nut and washer;
Clamps rectangular sharpening stones between the stones or makes several replaceable sharpening stones.
As a timber base, the machine operator uses a rectangular tube from a profile or a piece of cornice, the width of which is 50 mm;
Sands the flat machine part and cleans it of grease using glue “ Super Moment» glues strips of sandpaper with a grain size of up to 1200 grit.
The sandpaper should have a fabric base, and on 1 of the blocks you need to glue a strip of suede to apply polish to the blades.
Simple homemade machine
The most common version of the machine design is 2 pairs of wooden slats, which are fastened together with screws. The machine operator installs a block between such parts.
The main reason for the popularity of usemanual homemade machine for sharpening various knives is its stability. During operation, the machine structure does not move in any way on the workbench.
When fixing a block, the mechanic uses support bars that are located between wooden elements.
However, such homemade machine has the following disadvantages:
The master positions the blade to the stone manually. When working for a long time, it is difficult to keep track of the sharpening angle;
When making such an installation, it is necessary to use a fixing unit. The machine structure must be stable, so it must be firmly mounted on the workbench;
During the work, the ties loosen and the location of the block changes.
Another advantage of such a scheme is ease of manufacture. This machine design is most often used when sharpening knives for jointers and for the kitchen.
Wood slats can be of different thicknesses. When making a simple sharpening machine yourself, you can use various available components.
When first studying all the nuances of manufacturing, you need to watch thematic videos that describe in detail how to make a machine at home.
A DIY knife sharpener will be very useful in the household.
With the help of fairly simple ones, you can carefully and safely sharpen cutting tools, which is simply necessary in the kitchen, fishermen and hunters, and in the workshop.
Of course, a wide range of sharpeners are offered in stores, but homemade devices will save you from unnecessary costs.
A dull knife is a torment for the housewife when she slices bread, cooks food, or cuts meat. Cutting with them is not only difficult, but also dangerous, because... exactly blunt instruments are more likely to cause injuries. There is no point in proving the need for a sharp blade for a fisherman, hunter, shoemaker, etc. It is absolutely clear to everyone that a knife requires periodic sharpening. Another thing is how to provide it.
Many people use tools such as abrasive stones, emery wheels and sandpaper, files. Most often, abrasive or grinding stones are purchased for these purposes, and the procedure itself is carried out “by eye”. After such sharpening, the knife becomes sharp, but also dulls quite quickly.
Why is this happening? The knife blade is made of various steels, has different thickness and sharpening parameters. The process of high-quality sharpening should completely restore the shape of the blade, and only in this case will its sharpness meet the planned standards.
Ensuring uniform sharpening without fixing the position and guide elements is very difficult even for professionals. The task is much easier when you use special devices, which allow you to stabilize the processing mode (loads, directions, speed).
To mechanize rather labor-intensive work, it is better to use appropriate sharpening machines. Both devices and machines can be made with your own hands.
Basic principles of sharpening
When properly sharpening a knife, the basic condition must be met: forming a sharp edge of the blade while maintaining its shape, which is ensured by removing metal at a certain angle.
Turning is carried out with an abrasive material that has different grain sizes. Its choice is determined by the strength characteristics of the steel. Proper sharpening implies a certain order of work.
Sharpening angle
The effectiveness and quality of the event under consideration is limited by a fundamental parameter - the sharpening angle. Depending on their purpose, knives have the following meanings:
- Straight razors have the smallest angle – (7-11)°;
- fillet knives – (11-14)°;
- kitchen knives for most products, incl. bread, vegetables, meat, etc. – (16-21)°;
- hunting tools and knives for general technical purposes – (21-26)°;
- universal Hunter knives– (21-40)°;
- a special tool that is used for cutting and chopping (for example, a machete) – (29-50)°.
The sharpening angle largely determines the thickness of the blade. At the smallest angles it should resemble a razor, and at large angles it becomes possible to manufacture especially strong, massive knives.
Important. Holding the abrasive element and the knife itself in your hands, it is very difficult to ensure a given angle along the entire length of the blade, which leads to uneven manual sharpening.
The main task of the device is rigid fixation one of the elements and a clear direction of movement of the second element.
Types and choice of abrasive
To sharpen knives you need abrasive stone which will ensure the necessary cutting of metal. The abrasive ability is provided by a certain surface grain size, i.e. the number of abrasive grains per unit area. According to this parameter, the following stones are distinguished:
- very coarse abrasives (international classification - extra coarse) - have a grain size of less than 260;
- coarse abrasives – 310-360;
- medium abrasives – 390-510;
- fine abrasives – 590-720. This is the main category of sharpening stones used for cutting knives;
- very fine (ultra, extra fine) or grinding abrasives. They are used for sharpening razors and fine surface finishing of knife blades.
According to the nature of their origin, abrasive stones are divided into natural or natural(corundum, slates) and artificial (ceramics, artificial diamond). In addition, rubber elements are sometimes used for fine processing. When using abrasives, their surface moistened with water or soap-water solution(water instrument) and oil(oil stones).
The shape of abrasives can be round (discs) or rectangular (bars). The bars are most often used, and they are selected so that length significantly exceeded the length of the knife blade.
To fully sharpen the tool, it is recommended to have 2 bars of medium and fine grain. It is better to complement the set with a very small stone. The best option is to use double-sided bars, in which one side has a medium grain and the opposite has a fine grain.
Manual sharpening procedure
Any devices are designed to facilitate work and improve its quality, and general order manual sharpening remains the same:
- The process begins with a coarse or medium-grained bar, which is laid on a plane. It is advisable to ensure its fixation.
- The knife blade is brought to the abrasive surface at an angle equal to half the sharpening angle. The main task is to ensure a constant angle throughout the event.
- With a smooth movement with light pressure, the blade moves from the beginning to the end of the block in the direction “away from you.” The edge of the bar must always be perpendicular to the direction of movement of the blade. Do not allow the blade to break off at the end of the stone.
- After reaching the edge of the bar, movement is carried out in the opposite direction, while the sharp edge must always be on the surface of the abrasive. Changing direction is achieved by turning the handle.
- The process is repeated until a burr along the entire length appears on the back of the blade tip. She should move to the opposite side when changing direction of movement.
- Next, take a medium-grained block, but with smaller grains. Sharpening continues, but the movements are carried out initially only “from oneself” until the metal shines on one side, and then the second side is also processed.
- A fine-grained block is taken and the blade is processed until a mirror surface appears.
- If a small burr remains, sharpening is completed by using a very fine grit sanding block. Some experienced people prefer to use instead of such a block leather belt. It polishes the knife blade perfectly.
Homemade devices
Home craftsmen make sharpening devices various designs, but they all include 2 main elements - abrasive stone and knife fastening mechanism. A ready-made abrasive block is best suited for the device, but you can also make it yourself.
To do this, stick to glass with a thickness of at least 4 mm. sandpaper different grain sizes. The connection can be ensured with double-sided tape.
Fixed device
One of the simplest devices to make from 2 wooden blocks of triangular shape. They are fastened together with thumbscrews. An abrasive block is clamped between the wooden elements at the desired angle. This angle is set strictly according to the protractor.
When sharpening a knife on such a device, the blade must be constantly held strictly vertical. Naturally, ensuring such a direction is much easier than constantly guiding the knife at an angle.
Movable structure
To improve the quality of sharpening, it is necessary to fix not only the abrasive, but also the knife. You can also make such a device yourself. It is assembled on a flat, horizontal, massive surface. The device consists of 2 parts - rigidly fixed abrasive stone at the desired angle(similar to a fixed structure) and trolleys on wheels(on rollers) with a knife fixed horizontally.
The trolley moves manually along a guide rail. Provided by hand light pressure on the blade to the abrasive surface. This ensures the desired sharpening angle and eliminates the need to provide the desired direction manually.
Direction changes can be made different ways. The simplest one is to make a cart with wheels at the top and bottom. When the bar ends, the cart simply turns over.
Dot machine
Sharpening machines have more complex design, which allows you to change the sharpening angle. Several options for a constructive solution can be given:
- A knife is fixed on the platform with the possibility of adjustment. It is adjusted to the required angle and fixed permanently. The abrasive bar is installed on a movable rod mounted on a vertical support. It moves strictly horizontally. Sharpening is achieved by moving the abrasive relative to the knife blade.
- It is fixed on a fixed frame, but the block can be moved along the guide to set the desired sharpening angle. The knife is installed in a movable table and secured magnetic holder, which makes it possible to turn it over.
DIY example
As an example, we can cite the technology of self-production of a sharpening accessory - an analogue Lansky sharpeners. It has a standard design.
The knife is fixed on a horizontal base, and its fastening is ensured by magnet. The sanding element is located on a rod along which it can move perpendicular to the knife. The guide rod is installed in the holes of the vertical post.
These holes are drilled at an angle to the surface of the post and thus set a certain angle for the rod. Several holes are drilled vertically in the rack and by rearranging the guide you can also change the sharpening angle.
Manufacturing adaptations are carried out in the following order:
- On the base plate (, board, a metal sheet) on the edge slats are installed, limiting the displacement of the knife in the transverse direction. One of them is mounted in slots with thumbscrews for fixing knives with different blade widths. In the center of the knife location area is fixed magnet.
- The emery block is secured on two pieces of corner, which are fastened with pins. Holes are drilled on both sides of this part for installation on the rod.
- Steel rod with a diameter of 10-15 mm is passed through the indicated holes, and is installed at the end limiter to prevent the block from falling. The other end is cut thread.
- On an aluminum U-shaped profile 30-50 mm wide, 5-6 holes are drilled with a diameter 1-2 mm larger than the diameter of the rod. The holes are drilled at an angle corresponding to the sharpening angles, taking into account the height of the location on the rack.
- The rod is installed in the correct hole and fixed bolts.
This device works in the following way:
- the knife is fixed on the base and attracted by a magnet;
- a block of the required grain size is installed on the sharpening element;
- the rod is fixed in the desired hole on the stand;
- by hand, the block moves along the rod, processing the blade, and the movement is carried out “from oneself” and “towards oneself”;
- with the other hand, the knife gradually moves in the longitudinal direction.
See detailed drawings, descriptions and illustrations of a knife sharpener with and without a magnetic holder in the video below:
Scissor sharpener
With the help of knife tools you can also sharpen scissors, but such an undertaking has its own specifics. The sharpening angle is within (60-74)°. Tailor's scissors usually have an angle of (72-74)°. The cutting part at the point of contact of both parts is flat, and the bevel is made on one side. Main sharpening carried out from the outer, beveled side. The inner surface is only sanded with a fine stone.
The process is carried out in this order:
- Disassembling scissors. To do this, you need to unscrew the screw holding the halves together and carefully separate them. A negative screwdriver is used.
- Using coarse abrasive, it is carried out sharpening at the right angle. Movements are made only in one direction - “towards yourself”. Half of the scissors is held by the ring, and turning begins from the tip of the blade.
- Using small block, is carried out fine-tuning.
Some scissors cannot be disassembled. They can also be sharpened, for which they open up as much as possible. The halves are sharpened one by one.
How to check the sharpness?
There are several popular methods for checking the quality of knife sharpening:
- Paper. Take a sheet of paper (for example, for a printer) and cut off a strip at the edge. If the knife is well soaked, the strip is easily cut and has smooth edges. A dull knife crushes the edge and cuts unevenly, with tatters.
- Tomato. Sharp knife cuts a tomato in half evenly, and a blunt one crushes it.
- Hairs on the arm. A sharp blade works like a razor and cuts hairs, while a dull tool only crushes them.
- Sharpness can be checked finger, remaining cautious. The presence of burrs indicates poor quality processing. Absolutely straight edges indicate high-quality work.
Knives tend to become dull, making them difficult to use. Sharpening devices and machines will help solve the problem, providing correct sharpening blades, restoring the specified angle. There are many designs of simple knife blades, and the owner must decide which one to choose.