Sharpening machine for knives with your own hands. Manual machine for sharpening knives and scissors

Most parts for a grinding machine can be made from literally anything, following the general principle of the device. As an example, let's take laminated or polished box plywood 8-12 mm thick, which was widely used in the manufacture of Soviet radio engineering cases.

The base must be heavy - about 3.5-5 kg ​​- otherwise the machine will be unstable and unsuitable for sharpening heavy cutting tools. Therefore, the inclusion of steel elements in the design is welcome, for example, the base of the case can be “forged” with a corner of 20x20 mm.

From plywood, you need to cut out two parts with a jigsaw in the form of a rectangular trapezoid with bases of 170 and 60 mm and a height of 230 mm. When cutting, leave an allowance of 0.5-0.7 mm for the processing of the ends: they must be straight and exactly match the markup.

The third part is an inclined plane made of plywood planks measuring 230x150 mm. It is installed between the inclined sides of the side walls, while the trapezoids of the side walls rest on the rectangular side.

In other words, the base of the machine is a kind of wedge, but the inclined plane must protrude 40 mm in front. On the ends of the side walls, set aside two lines with a thickness gauge, indented by half the thickness of the plywood. Drill three holes in each plank for fastening the parts with screws. Transfer the drilling to the ends of the inclined part, temporarily connect the base parts.

In the rear part, the side walls are connected with a bar 60x60 mm, which is attached to the end with two screws on each side. In the bar, you need to make a 10 mm vertical hole indented 50 mm from the center, that is, 25 mm from the edge. To be sure of verticality, it is better to first drill with a thin drill on both sides, and then expand. From above and below, screw two fittings with M10 internal thread into the hole, and in them - a 10 mm stud 250 mm long. Here it may be necessary to readjust the lower bushing slightly if its threads do not match the stud.

Assistant device.

Remove the flat inclined part from the base - it needs to be finalized by providing a device for fixing and pressing the tool being processed.

First set aside 40 mm from the front edge and along this line with a hacksaw cut a groove about 2 mm deep. With a sectional or shoe knife, chip off the top two layers of veneer from the end of the plank to form a sample into which you can put a 2 mm steel plate flush with the common plane.

The arm rest consists of two steel strips 170x60 mm and 150x40 mm. They need to be folded together along the long end with uniform indents along the edges and three through holes of 6 mm should be made. The strips along these holes must be bolted together, placing the caps on the side of the upper, larger plate. Arc-weld each hat, welding it to the plate, then remove the metal deposits and grind the plate until a perfectly flat plane is obtained.

Attach the narrower striker to the notch at the edge and transfer the holes with a drill, then secure the tool rest with bolts. Before installation, it can also be magnetized with direct current, this will help in sharpening small blades.

Locking mechanism.

The second part of the handbrake is the clamping bar. It is also made of two parts:

• Upper L-shaped bar 150x180 mm with a shelf width of about 45-50 mm.
• The lower strike plate is rectangular in shape 50x100 mm.

The parts need to be folded in the same way as the parts of the armrest were folded, placing the reciprocal bar at the far edge of the upper clamp. In the center we make two holes with an indent of 25 mm from the edges of a small part, through them we tighten the parts with two 8 mm bolts. You need to start them in opposite directions, while the head of the upper (near) bolt is located on the side of the clamping bar. The bolt heads are also welded to the plates and pre-sanded to obtain neat fillets.

On an inclined board with an indent of 40 mm from the edge, draw a line with a thicknesser, and make one 8 mm hole 25 mm from the top and bottom edges. Connect the edges of the holes with a marking and make a cut with an allowance with a jigsaw. Bring the resulting groove with a file to a width of 8.2-8.5 mm.

Fasten the clamping and reciprocal bar through the groove in the plank. Tighten the bolt protruding from above with a nut so that the bar retains minimal mobility, then lock the connection with a second nut. To press or release the bar from below (in the niche of the base), screw the wing nut onto the second bolt.

Sharpening angle adjustment.

On the stud screwed into the base bar, throw a wide washer and tighten the nut so that the rod does not turn in the futors.
The adjusting block must be made from a small bar of hard material with dimensions of approximately 20x40x80 mm. Take carbolite, textolite or hardwood.

At 15 mm from the edge, the block is drilled into a 20 mm end on both sides, the hole expands to 9 mm, then we cut the thread inside. With an indent of 50 mm from the axis of the hole made, the second one is drilled, but in the flat part of the part, that is, perpendicular to the previous one. This hole should have a diameter of about 14 mm, and it should also be heavily flared with a round rasp.

The block is screwed onto the stud, so it is possible to relatively accurately adjust the height of the lug without a complex system of screw clamps, as in the original machine, which is a little more difficult to implement in practice. In order for the block to be motionless during operation, it must be locked on both sides with M10 wing nuts.

Carriage and interchangeable bars.

For a grinding carriage, you will need to coaxially weld 30 cm pieces of an M10 stud and a smooth, even bar 10 mm thick. You also need two solid blocks with dimensions of approximately 50x80 mm and a thickness of up to 20 mm. A 10 mm hole should be made in each bar in the center and with an indent of 20 mm from the top edge.

First, a wing nut is screwed onto the bar, then a wide washer and two bars, again a washer and a nut. Rectangular whetstones can be clamped between the whetstones, but it is better to make several replaceable whetstones.
As a basis for them, take a lightweight aluminum profile with a flat part 40-50 mm wide. It can be a profile rectangular pipe or pieces of an old cornice profile.

We skin and degrease the flat part, “Moment” glue on it strips of sandpaper of different grain sizes from 400 to 1200 grit. Choose a cloth-based sandpaper, and glue a strip of suede leather on one of the bars to dress the blades with abrasive paste.

How to sharpen.

For proper sharpening, make several templates from plywood with angles of 14-20? for cutting and 30-37? for cutting edges, the exact angle depends on the steel grade. Fix the blade parallel to the edge of the handle and press it with a bar. According to the template, adjust the angle between the planes of the grinding block and the inclined board of the table.

Start sharpening with a large (P400) stone if the edge does not have the correct angle. Achieve the downhill strip to take the form of a straight strip without meanders and waves. Reduce the grit and pass on both sides of the blade first with a P800 block, and then with a P1000 or P1200 block. When sharpening the blade, pass the stone with a little effort in both directions.

After sharpening, the blade must be corrected with a “leather” bar, on which a small amount of GOI paste is applied. When straightening the blades, the working movement is directed only towards the edge (toward itself), but not against it. And, finally, a little advice: if you sharpen knives with polished blades and engraving, paste over them with masking tape so that the crumbling abrasive does not leave scratches. It also does not hurt to paste over the surface of the handpiece with self-adhesive vinyl.

The service life of any knife directly depends on the methods of its operation and the procedure for sharpening the blade. Devices for sharpening knives are so diverse that they allow a modern person not to resort to the work of specialists, but to do all the work on their own at home. To sharpen knives, you can use both a special industrial-made device, and any device made by yourself. It is important to know that simple elements for sharpening knives (for example, a whetstone) that are at hand can do a bad job and the sharpness of the product will not only not return, but gradually the product will completely become unusable. Moreover, any home-made device for sharpening knives can be based on the use of these very simple sharpening devices. Detailed information on how to make a sharpener with your own hands can be found below.

A home-made manual knife sharpening machine, provided that all the requirements for its creation are met, will simplify the sharpening of knives and its performance will be no worse than a professional one. Correct sharpening includes the following rule: each type of cutting product has a certain edge sharpening angle, which must be constant along the entire length of the blade (see table No. 1). The sharpener, which will be initially based on this principle, will give the master a sharp knife edge for a long time.

Table No. 1. Sharpening angle in parallel with the type of cutting device

Edge processing during sharpening should be even. To fulfill this condition, the following rules must be observed:

• the blade must be fixed in the vise of the fixture reliably and efficiently, without exposing the metal of the blade to damage;
• the movement of the touchstone along the axis of the knife edge must be uniform and strictly at a certain angle;
• the point of contact of the blade must be strictly perpendicular to the longitudinal axis of the sharpener;
• the pressure on the knife blade should change smoothly depending on the change in the contact area between the blade and sharpener.

Simple knife sharpener

The simplest device for sharpening knives is based on the use of an angle frame and a whetstone. The price of such a primitive factory-made device is quite high, as is the price of interchangeable whetstones, while making such a device for sharpening knives at home will not be the slightest difficulty for the master. You will need the following inventory:

1. Wooden blocks of the same size - 4 pcs.
2. Drill (or any other drilling tool).
3. Bolts and nuts (about 4 pcs.).
4. Touchstone.
5. Protractor.

First you need to make a pair of wooden corners, placing the bars to each other strictly at an angle of 90º (Fig. 1). Close the resulting wooden corners with each other in parallel as a whole and drill holes through the diameter of the bolts. Insert bolts into the holes, and tighten the corners a little to each other with nuts.

The point of this invention is to be able to sharpen simply by holding the knife vertically in relation to the sharpening surface located at a given angle.

The most important thing is to correctly fix the donkey between the wooden corners of the fixture. To do this, using a protractor, you need to set the desired angle of inclination of the touchstone and tighten the bolts tightly to clearly fix the position of the touchstone.

With some refinement of the fixture, it is possible to fix the position of the knife relative to the grinding stone. A significant disadvantage of such a machine for manual sharpening is the impossibility of smoothly adjusting the angle of inclination of the grindstone.

Sharpening device from mounting brackets

The diagram and drawings of a homemade knife sharpener from mounting brackets, based on the Lansky fixture, are clearly shown below.

To assemble this device you will need:

1. Metal corners 90*90 mm with a wall thickness of 6 mm.
2. Stud with thread M6 and length 160 mm.
3. Thin rod (electrode, needle, etc.).
4. Touchstone.
5. 2 rectangular pieces of metal (sponges for clamping the donkey).
6. Pliers.
7. Hacksaw for metal.
8. File (or any other tool for processing sharp corners).
9. A set of hardware (nuts and bolts).

In both metal sponges intended for fixing the donkey, you need to drill under the connecting bolt. Fix the donkey. A thin smooth needle, previously bent at an angle of 90 º, must be inserted and fixed in the hole in one of the jaws. In the future, with the help of this lock in the form of a knitting needle, a certain angle of inclination of the touchstone will be set. Such a device for sharpening knives is characterized by an extensive coverage of the sharpening angle, which, no doubt, will be of interest to most craftsmen.

Machines with fixed blades

Machines for sharpening knives with fixed blades will attract the attention of those people who want to sharpen a knife not only qualitatively, but also quickly. The design, which rigidly fixes the knife blade relative to the grinding stone moving at a set angle, allows you to accurately set the angle of inclination.

To create such a homemade machine with your own hands, you will need:

1. The base is a rectangular wooden plate with dimensions of 440 * 92 mm and a thickness of 18 mm.
2. Wooden plate 92 * 45 * 45 mm (for fixing a vertical threaded stud).
3. Wooden block 245 * 92 mm and 18 mm thick (plate to which the knife will be attached).
4. Iron plate 200*65mm and metal thickness 4mm.
5. Piano loop, 92 mm long.
6. Hairpin M8 325 mm long.
7. Nuts and bolts with M8 thread.
8. Drill 6.5 mm.
9. Tap M8.
10. Self-tapping screws 50 mm, 4 pcs.

A die designed to fix a vertical threaded stud must be drilled through with a 6.5 mm drill. The hole should be located at a distance of 15 mm from the edge of the plate, approximately in the center.

Further, in the resulting hole, it is required to cut the thread for the M8 stud. A wooden plate prepared in this way must be screwed to the base at a distance of 265 mm from the edge using ordinary self-tapping screws 50 mm long, screwed into the back of the base.

After securing the wooden part of the restraint, you can proceed to attach the iron plate. In the center of the plate 200 * 65 mm, an oblong groove should be drilled, 90 mm long and about 1 cm wide. The groove should be located at a distance of 60 mm from the edge of the clamping plate. Additionally, it is required to drill a hole at a distance of 20 mm from the opposite edge and cut a thread in it for an M8 bolt. Then you need to attach the clamping plate to the previously prepared wooden base using this bolt. Using another bolt and a suitable washer, it is necessary to fix the clamping plate in the center of the cut groove. The fixation should be clear, but at the same time neat, so as not to damage the surface of the blade.

The most difficult part of assembling this fixture is preparing the adjusting device that will set the angle of sharpening the knife. For this you will need:

• metal square profile 40×40 mm;
• furniture bracket, 40 mm wide;
• a pair of rivets;
• plywood block 42 × 25 and 18 mm thick;
• bolt and nut M5;
• a pair of wing nuts M8;
• touchstone;
• steel bar with a diameter of 0.8 cm and a length of 40 cm.

A pair of holes must be drilled on a plywood bar: a through hole with a diameter of 8 mm along a section of 42 × 18 mm (the distance from the edge along the side of 42 mm is set at 15 mm) and a through hole with a diameter of 5 mm along a side with a section of 42 × 25 mm (distance from edges 10 mm). The square pipe should be cut in half so that a “U”-shaped bracket with a width of 40 * 15 mm and lugs of 20 mm is obtained. In the ears, you need to drill 8 mm holes, into which the M8 pin will be inserted later. Connect the resulting bracket to the furniture hinge using rivets. To the resulting structure, using the second part of the furniture bracket, tighten the plywood bar with an M5 bolt.

Connect the touchstone to the guide rod, which is a steel rod with a cross section of 8 mm. When connecting the touchstone and the guide rod, you should strictly ensure that their center lines coincide. If desired, for the convenience of using a sharpener, a handle-holder can be adapted to the touchstone on the reverse side. It remains to fix the donkey in the guide mechanism, fix it with a lamb and a home-made device for sharpening knives is ready.

Machine tools with fixed sharpening surfaces

Machines with fixed sharpened surfaces are a simple modification of a device for processing household knives. In such a device, there is no possibility of adjusting the sharpening angle, while several different angles can be set in advance for sharpening different types of knives. The work of sharpening blades with the help of such machines is not difficult, it is enough just to drive the blade along the abrasive surfaces in the recess.

The device consists of a pair of planes inclined to each other at a certain angle, one of which is a grindstone.

Electric knife sharpeners

The procedure for creating an electric sharpening machine is simple: it is enough to supply almost any device for sharpening knives and scissors with an electric drive. Such a sharpening machine allows you to quickly and accurately sharpen the product and at the same time provides a better concave shelf at the edge of the blade.

The mechanism of the electric sharpener for sharpening knives contains a guide, which is placed along the axis of rotation of the whetstone, and with the help of which the blade is adjusted at a given angle. The sharpening angle is set and set by the guide, and the clamping force is determined by the master.

Particular attention must be paid to the speed of sharpening, because. the electric drive allows you to sharpen the product at high speed, as a result of which the surface of the knife heats up. Such surface heating leads to the tempering of hardened steel, as a result of which the knife can quickly lose its hardness and its service life will be noticeably reduced. To prevent steel tempering, sharpening on a high-speed electric sharpener should be performed at short intervals and with sufficient breaks to allow the knife to cool.

Making stones for sharpening

It will not be difficult for a modern master to make stones for sharpening with his own hands. For this you will need:

• a wooden plate according to the size of the future grindstone;
• epoxy resin;
• cardboard box according to the size of the bar;
• abrasive;
• protective rubber gloves.

As an abrasive, you can use ready-made powder, or you can prepare an abrasive of your own production, for example, from an old Soviet-made green bar. Such a bar can be powdered and used later as an abrasive.

A wooden plate needs to be processed on one side with sandpaper and a saw to make frequent notches. Epoxy resin mixed with abrasive crumb. Having previously placed the bar in a cardboard box glued to the size of the bar, cover the prepared surface of the wooden bar with a mixture of epoxy and abrasive. After complete curing of the resin, the bar is ready for use.

Another option for making sharpening stones with your own hands is to create a whetstone from small rectangular glass plates about 5 mm thick. Using double-sided adhesive tape, sandpaper is glued to the surface of the glass plate. The whetstone is ready to go.

Tool for sharpening wood blocks

A simple device for sharpening knives is a tool consisting of a pair of wooden slats and a pair of bars with abrasive, with the same geometric dimensions.

Wooden slats should be carefully sanded with abrasive skins. Then, after applying auxiliary markings, depending on the angle of sharpening the knife, make cuts to a depth of 15 mm. Insert emery bars into the resulting holes so that each groove matches, and then fasten them with bolts. To give the grinding device greater stability, the lower part of the surface can be laid with a piece of rubber.

The types of devices for sharpening cutting tools are different and each master will be able to choose the manual machine that will fully satisfy his needs.

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:

1. 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);
2. 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;
3. The blade is turned over and repeat paragraphs. 1 and 2;
4. 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 comply with 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 sharpening device is 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:

1. 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.
2. 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.
3. 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 block.

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 a 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:

1. The knife is held by the handle with the right hand, turning in the direction of travel according to the curvature of the blade;
2. With the fingers of the left hand, except for the big one, they press the shoe to the touchstone;
3. 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 disadvantage can be turned into dignity 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 planers, 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.

Sharpening a knife is a task that every man has to face from time to time. In almost every home you can now find a sanding block familiar to everyone. However, this simple tool is not the only (and not the most convenient) way to sharpen kitchen knives.

If you don’t want to buy a professional tool, you can make a simple but more efficient grinder yourself if you wish.

1 About the device of sharpening machines for knives

The main nuance that distinguishes a professional tool from an ordinary bar is more accurate work with a sharpening angle. It is the angle at which the cutting edge is sharpened that is the main requirement that affects the sharpness of the blade. If you correctly calculate and achieve this angle, even a homemade grinder will allow you to sharpen knives to razor sharpness.

A handheld desktop tool of this type looks something like this:

Base part. "Sole", which is firmly attached to the table, and on which other elements of the machine are located.

Place for attaching a knife.It is made in the form of a clamp.

Movable rail with fixed sanding bar. The course of the bar must be limited - so that the movement occurs in one plane, sharpening the knife at the desired angle.

The mechanism for adjusting the angle at which the bar can move.

Such devices (with fixing the blades of knives or scissors) are more convenient. They can apply more force, since it is more convenient to move the bar than a knife.

Some machines are arranged the other way around - not a knife is attached to them, but a whetstone, the angle of which can (or cannot) be changed. Such models are simpler, and in fact differ from the usual whetstone lying on the table only in the ability to accurately adjust and maintain the desired angle of inclination.

Such installations are suitable not only for knives - they can also be used to sharpen straight scissors.

1.1 Brief overview of models

Before understanding how to createdo-it-yourself knife sharpening machine -Consider which models you can buy:

1. Lansky. It costs about 6 5-80 $. Has a clip for knives (scissors), a bar - mobile. Angle adjustment - from 17° to 30 ° .
2. SpitJack. It costs about $40.
3. Aligner AKEFC. It costs about $90.
4. Ganzo Touch Pro. It costs about $90-100.
5. Apex 4 Kit Edge. It costs about $200-220. Suitable not only for kitchen knives and scissors, but also for hunting knives.
6. Ruixin ( Korean copies of the above Apex). They cost about $30-40.

In addition to these models - there is a considerable selection of other similar installations. The approximate price range of mid-range grinders is around $30.

Knife sharpener Chief's Choice

You can find more convenient (but also more expensive) electric grinders. These include compact Chief's Choice devices (models 312, 320, CH-310, 1520). They cost from $ 120 to $ 250-300, and allow sharpening at an angle of 20 °. The power consumption of the installations is up to 150 watts. Such an electric sharpening machine for flat knives is mainly used in the restaurant business.For other products (scissors, hunting knives, and so on), such models, of course, are not suitable.

In addition to electric models, Chief's Choice has similar mechanical devices. They are a whetstone installed at a given angle in the body. The user just needs to hold a knife in a special slot - that's all. Such models are cheaper than electric ones (about $ 40-50 ), and are also used mainly in the restaurant business, for kitchen knives.

2 Basic information for creating a homemade machine

Making an electric machine correctly is not a task for an amateur. But to make a desktop manual version is quite realistic.

There are many options for its creation, so we will consider only a few of them.

The most important requirement for the machine being created will be the chosen angle - this directly affects how sharp the cutting edge will be and how long it will last.

The thinner it is (i.e., the smaller the sharpening angle) - the sharper the knife will be, but the less it will last. In addition, with a knife that is too sharp (at an angle of less than 15-20º, it is not recommended to cut hard foods: it will become dull faster.

Specific figures include:

sharpening angle of knives (kitchen, hunting) - 15-30º (or better - 20-30º);

sharpening angle of scissors (hard) - about 50º.

2.1 First way

To begin with, let's analyze the simplest option.

To create a machine, we need:

2 wooden corners (optimal side length - 20-30 cm).

6-8 screws with clamp nuts.

Sharpening bar.

Trance porter to set the corner correctly.

The structure is done like this:

3-4 holes are drilled in both corners -so as to hold them together.

The bar is installed between the corners at the desired angle.

The corners are tightened with screws, fixing the bar in the desired position.

For sharpening knives (kitchen, hunting - it doesn't matter) or scissorsyou just need to hold the blade down on the bar. The blade must go strictly vertically..

If necessary, corners can be marked with corners. To change the angle (or to replace the bar) - you just need to loosen the screws tightening the corners, and move the bar. Then the screws are tightened again.

Such a device is good because it allows you to change the angle. Among its shortcomings, one can note the fact that, in fact, it is not much more convenient than working with a conventional whetstone.

2.2 Option two

Now let's complicate the task: we will make a grinder more convenient to use.

This will require:

A piece of laminate (chipboard, plywood).

Wooden lath (length - approx. 1 meter thickness and height - approx. 2 -4 cm), or two slats - one 50-70 cm long, the second - up to 40.

Sandpaper.

2 bolts with tightening nuts.

Wood saw.

Protractor.

Marker (pencil, pen, felt-tip pen - any marking tool).

The process itself looks like this:

Now - need to make a stand, which will allow you to drive the bar at the same angle. For this:

Now left make a sandpaper holder(which will be used in place of the whetstone). For this you need:

Take the second rail, and put it on the U-shaped rack and knife holder.

Cut off the desired part (the one that goes from the holder to the rack, + 5-10 cm of stock).

On one edge - glue emery.

The optimal abrasive is from P600 to P2000.

And Among the shortcomings of this design can be noted:

the impossibility of adjusting the angle: the product allows you to work only at one angle, chosen initially (not a disadvantage if the machine needs to be made for the kitchen);

to use emery of a different abrasive, you will have to make a separate rail for each.

As an option, in order not to make several rails, you can stick 4 pieces of emery with different abrasives on one rail.

When working (sharpening), such a machine is placed on the edge of the table. The bolts protruding from below will rest against it, so that the machine will stand in one place when the rail with emery moves.

2.3 How to make a homemade knife sharpening machine? (video)

2.4 How to sharpen?

H not to spoilknife - grinder must be used correctly:

The movements of the knife along the bar should be smooth, without jerks, and not very fast.

The pressure on the blade should be even. The pressing force is selected individually.

The blade must be sharpened evenly along its entire length.

If necessary, you need to cool the knife by lowering it into the water.

After sharpening is completed, it is advisable to sand the blade with sandpaper, with a grit of up to 800.

To check the quality of sharpening, you can put a sheet of paper on a suitable surface (for example, a cutting board) and draw a knife over it. A well-sharpened blade will cut paper. With poor sharpening, the sheet will wrinkle or tear.

Every housewife sooner or later begins to dull the knives with which she cuts bread, vegetables or butchers meat. Using a dull knife is not only inconvenient, but also unsafe. At any time, it can break off the cut product and cause injury. Therefore, periodically the tool should be sharpened, using a special device for sharpening knives.

Such sharpeners in a wide range are available in stores. But for one reason or another, they do not always suit the consumer. In this case, you can make a device for sharpening knives with your own hands, having previously studied the types of stones for sharpening, the features of the tool and the proposed drawings.

Sharpening knives - prerequisites

For effective and long-term operation of the knife, the most important factor when sharpening it is blade angle. In the process of sharpening, it is necessary to restore the previously set angle, which will fully comply with technological standards and quickly, freely and efficiently cut the material.

For each blade, its optimal angle is selected:

• for a razor and a scalpel, the sharpening angle should be 10-15 degrees;
• knives for cutting bread, fruits and vegetables are sharpened at an angle of 15–20 degrees;
• multifunctional knives for various products are processed at an angle of 20–25 degrees;
• hunting and hiking knives - at an angle of 25-30 degrees;
• knives for cutting hard materials - at 30-40 degrees.

Without a special device, it is difficult to sharpen the blade at the right angle. Holding the knife with your hands, it is quite difficult to provide required angle of inclination cutting tool. To facilitate this process, there are special devices that you can make with your own hands. Their designs are quite simple, and the production itself will take not so much time.

There are many types of sharpeners for knives, among which you can choose the one that best suits your needs.

All devices consist of two parts:

• a bar of abrasive material;
• stop for attaching a knife.

As a bar, you can use ready-made special stones or make it yourself.

Sharpening stones - types and manufacture

On sale you can find several types of stones:

Aquatic instruments. When working with them, water is used, which saves the surface of the stone.

Oil the stone resembles water in structure and shape, but its surface is the most oily.

Natural tools are made from natural stones that undergo industrial processing.

artificial stones are made from non-natural components.

Rubber tools can also be found on sale, but working on them is not very convenient.

For self-production of an abrasive bar, you can use small rectangular glass plates and a thickness of 4-5 millimeters. On the surface of the plates with the help of double-sided tape, you need to stick sandpaper of different grain sizes. The cost of such bars will turn out to be quite small, and sandpaper can be replaced at any time.

However, when using a glass bar, you should be very carefully tighten the nuts otherwise the glass may crack. In addition, no water is used in its application, so the abrasive wears out quickly. For the same reason, when sharpening knives, fast movements should be avoided, which can lead to overheating of the material, and, therefore, to loss of blade properties.

Tool for sharpening wood blocks

It is enough just to make a sharpening tool from two wooden and two abrasive bars, which should be the same size.

For greater stability of the sharpener to its lower surface, it is recommended attach a piece of rubber.

Do-it-yourself sharpener from mounting brackets

The Lansky sharpener is taken as the basis for such a device, the drawings of which can be easily found on the Internet.

• metal plates measuring 4x11 centimeters;
• standard aluminum corners;
• metal rods about 15 centimeters long;
• a set of nuts and bolts;
• grinder with a vise or file;
• file.

Instead of a grinder, you can use a file, since this tool is only needed for grinding sharp corners from the corners and cleaning the places where the metal is cut.

Steps for making a sharpener:

1. According to the drawing, markings are made for future holes in the plates.
2. Holes are drilled and threaded into them.
3. With the help of a file, all sharp corners and edges are rounded. This will allow you to comfortably use the made knife.
4. Holes are made in the corner in accordance with the drawing.
5. The hole for the spoke support is expanded with a needle file.
6. The holes for the studs are threaded.
7. The rods are inserted into the extreme holes and fixed with nuts of the appropriate diameter (M6).
8. An M8 bolt is screwed into a wider hole, the length of which should be about 14 centimeters. A wing nut must first be screwed onto it, on top of which two ordinary nuts are screwed. The bolt in the structure will be used as a support post.
9. Bolts are attached to the remaining holes, with which the knife will be clamped.
10. Nuts are screwed onto the ends of the rods, a corner is strung, which is fixed with nuts. By lowering or raising the rods, it will be possible to adjust the sharpening angle.
11. From a thin metal rod in the form of the letter G, a rod with an M6 thread, two holders and a lamb nut, a device is assembled that will hold the stone for sharpening. The end holder should be with a through hole for the knitting needle.

Such a device for sharpening knives has a fairly wide range of degrees of pressure angle and is most convenient to use.

Massive sharpener with stand

With your own hands, you can simulate a knife sharpener from Apex, the drawings of which are easy to find on the Internet. Such a knife sharpener is presented in the form of a stand, on which a platform is installed at an angle, and a support for the end of the nozzle in the form of a rod is placed on the side. This is a very convenient device with which you can sharpen any cutting tools with high quality.

Required materials and tools:

Stages of work:

The angle of sharpening on such a device adjustable with bar and lamb, which fixes the part at the desired height.

Each of the described devices has its own advantages and disadvantages. When choosing a suitable option, you need to proceed from your needs and skills in such work that you will need to do with your own hands.