A simple tool for sharpening drills with your own hands. Making a tool for sharpening drills with your own hands Stand for sharpening drills with your own hands

If you only have to drill wood, then you don't have to think about the sharpness of the drill, since the drill can regularly serve for months and years without sharpening. But when it comes to drilling metal, the sharpness of the drill becomes very important, in other words, you can only drill through the metal. sharp drill... The difference is easy to feel with a brand new drill. Having started to cut into metal quite briskly, with every minute the drill will sink into the metal more and more slowly, and you will have to press on it more and more. The bluntness rate of the drill depends in particular on the revolutions, feed rate, cooling and other factors, however, no matter how hard you try, the operating time of the drill to unsatisfactory performance is measured in minutes. If the volume of work is significant, it will be expensive to constantly buy new drills, so it is better to learn how to sharpen them. Although it is still worth having several drills of the same diameter (3-10, depending on the diameter and, accordingly, the price) in order to return to sharpening only when all the drills are dull.

At the periphery of the drill, the cutting speed is maximum, and therefore the maximum heating cutting edges... At the same time, heat removal from the corner of the cutting edge is very difficult. Therefore, bluntness starts from the corner, then extends to the entire cutting edge. Its rounding is clearly visible. Then the back edge is rubbed off. Strokes appear on it, risks coming from the cutting edge. With wear, the marks merge into a continuous strip along the cutting edge, wider at the periphery and tapering towards the center of the drill. The transverse cutting edge crumples when worn.

At the beginning of bluntness, the drill makes a sharp squeaking sound. If the drill is not sharpened in time, the amount of heat generated will increase and the wear process will go faster.

To make it easier to control the geometry of the drill, the main thing to do is the template described below. With its help, even if sharpening is carried out without tools, you can always check where else you need to remove the metal, and, in the end, get what you should get (it cannot be that it does not work, even if you have to grind off half the length of the drill) ... To maintain symmetry, try to keep the sharpening time of each section and the pressure force constant.

Sharpening of twist drills

The drill is sharpened along its rear edges. It is very important that both feathers (teeth) of the drill are sharpened exactly the same. It is very difficult to do this manually. It is also not easy to manually create the required back face shape and the specified clearance angle (see below for what angle).

There are special machines or devices for sharpening. If possible, it is better to sharpen the drills on specialized equipment. But in a home workshop, such an opportunity, as a rule, does not exist. The drills have to be sharpened by hand on an ordinary sharpener.

Depending on the shape of the back surface, there are different types sharpening: single-plane, two-plane, conical, cylindrical, screw.

With single-plane sharpening, the back surface of the feather is made in the form of a plane. The clearance angle for this sharpening should be 28-30 °. With single-plane sharpening, there is a high risk of chipping of the cutting edges. This method, the easiest to do when manual sharpening, recommended for drills up to 3 mm in diameter.

Universal drills with a diameter greater than 3 mm are usually tapered. In order to understand the features of such sharpening, consider a conical sharpening scheme on a drill machine with a 2φ angle of 118 °. The figure below shows a grinding wheel and a drill pressed against its end by the cutting edge and back surface.

Imagine a cone whose generatrix is \u200b\u200bdirected along the cutting edge and end grinding wheel, and the tip is 1.9 times from the drill diameter. The apex angle is 26 °. The axis of the drill intersects with the axis of the imaginary taper at an angle of 45 °. If you rotate the drill around the axis of an imaginary cone (as if rolling the cone along the end of the grinding wheel), then a conical surface is formed on the back edge of the drill. If the axis of the drill and the axis of the imaginary cone are in the same plane, then the clearance angle will be equals zero... To create a clearance angle, you need to offset the axis of the drill in relation to the axis of the imaginary taper. In practice, this offset will be 1/15 of the drill diameter. Swinging the drill along the axis of an imaginary taper with this mixing will provide a tapered flank and a clearance angle of 12-14 °. The larger the offset, the larger the clearance angle will be. It will be recalled that the clearance angle along the cutting edge changes and increases towards the center of the drill.

It is clear that it is very difficult to fulfill all these conditions of sharpening by hand. The drill intended for sharpening is taken with the left hand by the working part, possibly closer to the intake cone, and by the tail with the right hand.

The cutting edge and the rear surface of the drill are pressed against the end of the grinding wheel and, starting from the cutting edge, with smooth movements right handwithout lifting the drill from the stone, shake it, creating a tapered surface on the back edge of the feather. Then repeat the same procedure for the second pen.

When sharpening, it is advisable to repeat as accurately as possible the shape of the rear surface that was after the factory sharpening, so as not to lose the required rear angles.

Another sharpening method widely used by home craftsmen is as follows. As in the previous case, the drill is taken with the left hand by the working part as close as possible to the intake cone, and with the right by the tail. With the cutting edge, the drill is pressed against the end of the grinding wheel and with a smooth movement of the right hand, without taking the drill off the stone, rotate it around its axis, sharpening the back surface. It is very important to maintain the desired angle of inclination to the end of the grinding wheel when rotating the drill. For this, special bushings are often used when sharpening.

As a result of this sharpening, a tapered surface will be obtained on the back surfaces of both feathers, but the clearance angle will not be formed. During operation, the friction of the rear surface against the walls of the hole and, therefore, the heating will be greater.

Due to friction on the grinding wheel, the tool heats up during sharpening. This causes tempering of the hardened part of the tool. The metal softens and loses its hardness. Inexperienced sharpening renders the tool blade unusable. Therefore, sharpening should be carried out with repeated cooling of the drill in water or in a water-soda solution. This requirement does not apply to solid carbide drills. Do not use oil for cooling when sharpening. If, for whatever reason, the tool is sharpened dry, then:

• a small layer of metal is removed in one pass;
• the speed of rotation of the abrasive wheel should be as low as possible;
• the drill should never be heated to such an extent that the hand cannot tolerate it.

Practice shows that the sharpening of the tool should be carried out against the movement of the grinding wheel. Then the cutting edge is more durable, less often creasing and breaking.

For sharpening, use grinding wheels made of electrocorundum (grades 24A, 25A, 91A, 92A) with a grain size of 25-40, hardness M3-CM2, on ceramic bonds.

In production, sharpening is usually followed by fine-tuning. Lapping makes the surface smoother, removes small dents. A refined drill is more resistant to wear than a sharpened drill. If you have the opportunity to tweak, take advantage of it.

For finishing, grinding wheels made of green silicon carbide grade 63C with a grain size of 5-6, hardness M3-CM1 on a bakelite bond or wheels from Elbor LO, with a grain size of 6-8 on a bakelite bond are used.

One of the main conditions correct sharpening drills - maintaining its axisymmetry. Both cutting edges must be straight and of the same length, the same nose angles (and taper angles) with respect to the drill axis.

The correctness of sharpening is checked with a special template.

a - template; b - checking the angle at the top and the lengths of the cutting edges; в - the angle of sharpening; d - angle between the web and the cutting edge.

It is made independently from a sheet of copper, aluminum or steel with a thickness of approximately 1 mm. The most durable template is of course steel. The template is used to check the angle at the top, the length of the cutting edges, the angle between the bridge and the cutting edge. Instead of the clearance angle, which is very difficult to measure, the taper angle is measured with a template. It is advisable to make a template before using a new drill in order to transfer the desired corners from the last.

The uneven length of the cutting edges and their inclination to the axis of the drill lead to unequal loads. The drill will fail faster due to the intense wear of the overloaded cutting edge.

a - the wedges of the cutting edges are not the same, the middle of the bridge does not coincide with the axis of the drill; b - the cutting edges are sharpened at different angles to the drill axis, the middle of the bridge coincides with the drill axis.

Uneven loading on a part of the drill will cause its runout during cutting and, as a result, an increase in the diameter of the resulting hole.

The easiest way to check for correct sharpening is with trial drilling. If the nibs of the drill are sharpened unevenly, then the less loaded will have less chips from the corresponding groove. Sometimes the chips only protrude through one flute. The hole diameter can be exaggerated compared to the drill diameter.

The device consists of a fixed base and a removable holder with holes for drills of different diameters.

1 - rail; 2 - drill; 3 - emery wheel; 4 - base; 5 - holder.

The base is made of a planed board with a thickness of 30-40 mm, to which at an angle of 30-32 ° (depends on the angle 2φ, see below, 30 ° for 2φ \u003d 120 °, 32 ° for 2φ \u003d 116 °) is sewn (nailed, glued ) wooden lath with beveled at an angle of 25-30 ° (for single-plane sharpening) side edge. This rail orients at the desired angle the holder with the sharpened drill relative to the grinding wheel. The holder is made of a rectangular wooden bar, one of the sidewalls of which is cut off at an angle of 60-65 ° (depending on the angle of the side edge of the rail). With this sidewall, the holder is pressed against the rail on the base board, which provides sharpening of the front corner of the drill within the required limits (25-30 °). On the other sidewall, the holders are marked and drilled perpendicular to the plane of this sidewall through holes for each drill of a given diameter. The length of the holder is chosen such that it is convenient to hold it when sharpening the drills.

You cannot install a device on an ordinary thrust bearing (armrest), so you have to come up with some kind of table or shelf for it, you can transfer the sharpening machine to the table where there will be space for this device. On the base, place the holder with the drill inserted into it to be sharpened close to the rail. Turn the drill in the holder seat so that the sharpened edge is oriented horizontally. Use your left hand to hold the drill at the edge to be sharpened, and hold the drill shank with your right hand. Pressing the tool holder against the beveled bar, slide the drill over the emery wheel and sharpen one edge. Then unfold the drill and cut the second edge the same way.

You can make it easier:

Sharpening angles and other characteristics of the drill

A twist drill is a rod that has two helical grooves to facilitate the exit of chips. Thanks to the grooves on the drill, two helical feathers are formed, or, as they are otherwise called, teeth.

The twist drill consists of a working part, a neck, a shank and a foot.

A - with a tapered shank; B - with a cylindrical shank; a - working cutting part; b - neck; в - feather width; g - foot; d - leash; e - flute screw shaving; g - feather; h - shank; and - jumper; L is the total length; L 0 - the length of the "working cutting part"; D is the diameter; ω is the angle of inclination of the "screw chip groove"; 2φ - apex angle; f is the width of the spiral ribbon; ψ is the angle of inclination of the bulkhead.

The working part is divided into a cutting and a guide. All cutting elements of the drill are located on the cutting part - the intake cone. The guide part serves as a guide during cutting and is a spare part for regrinding the drill. On the feathers of the guide part along a helical line, there are cylindrical chamfers-ribbons. The tape is used to guide the drill in the hole and also to reduce the friction of the drill against the hole wall. It doesn't have to be wide. So, the width of the tape of the drill with a diameter of 1.5 mm is 0.46 mm, with a diameter of 50 mm - 3.35 mm. The drill shank and foot are used to secure the drill in the machine spindle or chuck. The drills can be made with or without a neck.

The drill diameter, measured by the bands, is not the same along the drill length. At the intake cone, it is slightly larger than at the shank. This reduces friction of the ribbons against the hole walls.

In order to understand the structure of the cutting part of the drill, let us consider the basic principles of operation of any cutting tool (including drills). One of the most important requirements for a cutting tool is that the chips to be separated freely move away from the cutting site. The surface of the tool on which the chips run down is called the leading edge. This face is tilted back at an angle from the vertical plane.

1 - wedge; 2 - processed item; γ (gamma) - front angle; α (alpha) - posterior angle; δ (delta) - cutting angle; β (beta) - taper angle.

Thanks to this angle for the tool, it is easier to plunge into the metal and the chips come off more freely along the front edge. The angle between the leading edge of the tool and a plane perpendicular to the cutting surface is called the rake angle and is denoted by the Greek beech γ.

The surface of the tool facing the part is called the back face. It is deflected at a certain angle from the surface of the workpiece to reduce the friction of the tool against the cutting surface. The angle between the flank of the tool and the cutting surface is called the clearance angle and is denoted by the Greek letter α.

The angle between the front and back faces of the tool is called the taper angle and is denoted by the Greek letter β.

The angle between the leading edge of the tool and the cutting surface is called the cutting angle and is denoted by the Greek letter δ. This angle is the sum of the taper angle β and the clearance angle α.

Rake and clearance angles are the angles that must be observed when sharpening.

Now we will find the faces and corners described above on the drill, which does not at all look like the tool shown in the picture above. To do this, we dissect the cutting part of the drill with the AB plane, which is perpendicular to its cutting edge.

The cutting edge is the intersection of the leading and trailing edges of the tool. The rake angle γ at the drill forms a helical groove. The angle of inclination of the groove to the drill axis determines the value of the rake angle. The angles γ and α along the cutting edge are variable, which will be discussed below.

The drill has two cutting edges connected by a bridge located at an angle ψ to the cutting edges.

Having received general idea about the geometry of the cutting part of the drill, let's talk in more detail about its elements. The front face of a twist drill is a complex helical surface. Face is a conditional name, since the word "face" implies a plane. A helical groove, the surface of which forms a leading edge, intersects with the intake cone, creates straight cutting edges.

The angle of inclination of the helical groove to the drill axis is denoted by the Greek letter ω. The larger this angle, the larger the rake angle and the easier the chip exit. But the drill becomes weaker as the slope of the helical flute increases. Therefore, for drills with a small diameter, which have lower strength, this angle is made smaller than for drills with a large diameter. The angle of inclination of the helical groove also depends on the material of the drill. HSS drills can work in more stressful conditions than carbon steel drills. Therefore, for them, the angle ω can be larger.

The choice of the angle of inclination is influenced by the properties of the processed material. The softer it is, the greater the angle of inclination can be. But this rule is applicable in production. At home, where one drill is used for processing different materials, the angle of inclination is usually related to the drill diameter and varies from 19 to 28 ° for drills with a diameter of 0.25 to 10 mm.

The shape of the flute should provide sufficient space for the chips and allow them to be easily evacuated from the flute, but not loosen the drill too much. The groove width should be approximately the same as the feather width. The groove depth determines the thickness of the drill core. Strength depends on the thickness of the core. Making the groove deeper will allow the chips to fit better, but the drill will be weakened. Therefore, the thickness of the core is chosen depending on the diameter of the drill. In small diameter drills, the core thickness is a larger fraction of the drill diameter than in large diameter drills. So, for drills with a diameter of 0.8-1 mm, the core width is 0.21-0.22 mm, and for drills with a diameter of 10 mm, the core width is 1.5 mm. In order to increase the strength of the drill, the thickness of the core is increased towards the shank.

The leading edge of the drill is not re-sharpened.

The design of the helical grooves is such that as they approach from the edge of the drill to the center, their angle of inclination decreases, which means that the rake angle also decreases. The working conditions of the cutting edge near the center of the drill will be more difficult.

The clearance angle, as well as the clearance angle, varies in magnitude at different points of the cutting edge. At points closer to the outer surface of the drill, it is smaller, at points closer to the center, it is larger. The clearance angle is formed when sharpening the intake cone and is approximately 8-12 ° at the periphery of the drill, and 20-25 ° in the center.

A bridge (transverse edge) is located in the center of the drill and connects both cutting edges. The angle of inclination of the web to the cutting edges ψ can be from 40 to 60 °. Most drills have ψ \u003d 55 °. The bridge is formed by the intersection of the two back edges. Its length depends on the thickness of the drill core. As the thickness of the core increases towards the shank, the length of the web increases with each sharpening. During the drilling process, the transverse edge only interferes with the penetration of the drill into the metal. It does not cut, but scrapes, or rather crushes the metal. No wonder it was once called the scraping blade. By halving the length of the web, the feed force can be reduced by 25%. However, reducing the web length by reducing the core thickness will weaken the drill.

The 2φ point angle has a great influence on drill performance. If the tip angle is small, the bottom edge of the chips will touch the wall of the hole and there will be no conditions for correct chip formation.

The picture below shows a drill with normal angle intake cone.

In this case, the chip edge fits well into the groove. Changing the nose angle changes the length of the cutting edge and, therefore, the load per unit length. With an increase in the angle at the tip, the load per unit length of the cutting edge increases, while the resistance to penetration of the drill into the metal in the feed direction increases. As the nose angle decreases, the force required to rotate the drill increases, as the conditions for chip formation deteriorate and friction increases. But at the same time, the load per unit length of the cutting edge decreases, the thickness of the cut chips becomes smaller and the heat from the cutting edges is better removed.

Typically the tip angle (2φ) of standard universal drills in carbon steel, chrome steel and HSS is 116-118 ° and is considered suitable for many materials. But in order to provide best conditions work, it is changed as shown in the table.

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Having picked up correct drawing tools for sharpening drills, you can make homemade full-fledged equipment at home. Thanks to such a device, the task of ensuring the desired geometric shape of the tool is greatly simplified.

When using it, there is no need to worry not only about the rotation of potentially dangerous sharpening stones, but also about the sharpening angles, which need to be properly maintained, fishing each degree by hand.

Features of using homemade sharpening devices

While drilling holes in metal products, drills wear out quite a lot, which leads to their heating and loss of their properties. To avoid such a phenomenon, measures are required to ensure the regular restoration of their geometric parameters. This can be done using special equipment for sharpening drilling tools. The creation of such a simple device can be done independently, which will allow high-quality sharpening without any significant financial costs.

Many experienced specialists practically do not use sharpening devicesbecause they are absolutely confident in their experience and the eye that allows them to sharpen their drills correctly. But in practice, the use of such devices is extremely necessary, since it allows mechanization this process ... As a result of such work, the maximum accuracy and quality of the sharpening will be ensured.

The modern market offers different kinds equipment that allows you to carry out the restoration of geometry in a quality manner cutting tools, even in the absence of experience in this matter. At the same time, there is no urgent need to purchase such products, since they can be made by hand according to the existing drawings of tools for sharpening drills.

Drawings of the simplest devices

The simplest devices for sharpening can be sleeves, the inner diameter of which corresponds to the transverse dimensions of the drills. The sleeve is rigidly fixed to a secure base, taking into account a certain angle. When selecting a bushing for such devices, you should pay attention to the correspondence of its inner diameter with transverse dimension sharpened tools. It is forbidden for the machined tools to dangle in the bushing, since, even with a deviation of 1-2 degrees along the axis from the required values, the quality and accuracy of sharpening may significantly decrease.

Such homemade gadgets for sharpening drills must be equipped with clips. For their manufacture, copper or aluminum tubes are suitable, the inner diameter of which is typical size used drilling tool.

In some cases, the task can be simplified by setting on this structure wooden blockin which holes are to be drilled, with a diameter corresponding to the tool used. One of essential elements such a product is considered the presence of a handyman, which is necessary for:

• ensuring correct fixation of the drilling tool and the possibility of accurate movement in relation to the surface of the abrasive stone;
• creating a stop point for the drill to be ground.

Such products made of oak bars, in which holes of different sizes are provided, are the most reliable. Thanks to them, high-quality and accurate sharpening of tools is carried out. The main task that must be solved by a home-made machine or similar device is the correct orientation of the cutting part of the machined tools to obtain the accuracy of the required sharpening angle.

For the manufacture of homemade machine for sharpening drills, a number of different design variations of such equipment can be used. With the appropriate drawings and understanding of the principle of operation of this equipment, you can make grinding equipment yourself at home.

The structure consists of the following elements:

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Mount for drill and stop screw

Bolts, nuts, pins, screws

Exist important rules, which must be observed during the operation of such a device, namely, the sharpened tool should not rotate around its axis. In the event of even a slight turn, sharpening must be done again.

The sharpened tool must be cooled in a natural way... After that, check its restored geometric parameters. You can use a template for this. It should be borne in mind that each cutting edge of the drill may differ from each other by no more than a tenth of a mm. Wherein, special attention worth paying this parameterif the drills have a small diameter.

Video "Attachment for sharpening drills according to the drawing"

Drawing of a complete fixture

Quite an easy way to make homemade sharpening equipment, which is practically no different from the factory product. It takes about 1.5-2 hours to assemble it according to the finished drawings.

To make do-it-yourself tools for sharpening drills, it is necessary to provide for the following supplies, equipment and tools:

• welding machine;
• electric drill;
• grinders;
• standard locksmith tool kit;
• a corner, the size of the shelves of which is 30x30, and its length is 100-150 mm;
• metal plates having different thickness (3-5 mm);
• pins or pieces of steel rods, the diameter of which is 10-12 mm;
• washers, screws, bolts and nuts of various sizes.

First of all, the bed is made, which will be the base in the grinding device. To do this, a steel plate is used, onto which a steel bar (12 mm in diameter) is welded at an angle of 75 degrees. It will be the axis.

After that, a washer should be placed on the welded rod, which will be a thrust bearing. The angle of rotation of the bed when sharpening the drill will be negligible, so there is no reason to use a standard ball bearing.

The stock where the sharpened tool will be placed is made from a prepared corner. One side on corner profilethat faces the side whetstone, it is necessary to grind off at an angle of 60 degrees. On the stock, according to the drawing, a bracket is welded, by means of which the fixation of the pivot assembly of the device will be performed. As a result of this, a structure will be made, the corners of which, in the case of a parallel position of the bed and the bed, should be located to the surface of the abrasive stone in accordance with the angle of the drill to be sharpened.

Have grinding machine, which is shown in the drawing, fixed angles of inclination are provided, but for greater possibilities it is desirable to provide the ability to adjust the angles. In such cases, there will be a greater chance of using the fixture when it is necessary to restore the instruments, with different angles sharpening, for example, if it is necessary to sharpen drills for metal, concrete, etc.

To create a more functional unit, you can use drawings of other structures that have the ability to adjust the angles:

Video "Device made from the drawing"

Drills for metal are always hardened, but products can become dull over time. Naturally, this is not a reason to throw them away. If you wish, you can sharpen the drill with your own hands using professional equipment or home-made devices.

The main types of sharpening

Experienced craftsmen know that metal drill sharpening can be different. depending on diameter and application characteristics.

• Single-plane sharpening is designed for drills with a maximum diameter of 3 mm. In the process of performing the work, it is possible to "chip out" the edge, so you need to be very careful. To sharpen the product correctly, it should be applied to the circle and moved parallel to the surface.
• The tapered procedure is intended for larger metal tools. In this case, the tool must be held with both hands, making consistent sharpening.
• Finishing is carried out after the end of sharpening. Thanks to this procedure, it is possible to grind the cutting edge and eliminate even the smallest notches.

To sharpen the drill with your own hands correctly, you must use the appropriate machines. Similar devices are divided into 2 groups.

If you are interested in the question of how to sharpen a drill for metal, then be sure to purchase the appropriate machine. For home conditions fit inexpensive model with medium power. It will allow you to sharpen small drills for metal.

Naturally, when buying, you need pay attention to noise levelas well as the design of the model. The best option the machine will become a simple machine, because it will not be difficult to choose the necessary parts for it.

It is necessary to buy such devices only in specialized places, since here a technical passport is provided in the kit. Moreover, you will be given a warranty card.

Using machines at home

As mentioned earlier, at home it is advisable to use household machines... With their help, it is possible to sharpen various types of drills. It is important to remember that for some varieties you will have to buy the corresponding circles.

To sharpen the drill yourself, you should give preference to a machine equipped universal chuck... It allows you to clamp elements of different diameters.

The kit often includes:

• keys;
• collet;
• spare parts;
• lamp for the working area.

The most popular equipment is from Drill Doctor and GS. Such products are intended for sharpening drills with a diameter of 2-13 mm and 14-34 mm. Unfortunately, this equipment does not allow sharpening too thin drills. For this purpose, you will have to purchase a special machine.

All equipment intended for sharpening drills at home, has a number of advantages:

• the ability to work from the mains;
• high performance;
• ease of use;
• functionality;
• sharpening accuracy;
• affordable price;
• compact dimensions;
• light weight;
• convenient control system, thanks to which you can adjust the intensity of sharpening and its speed.

Homemade sharpening devices

If you do not have an appropriate machine, then you can sharpen using other tools. We are talking about an electric drill either homemade equipment, created from the drawing... It is best to opt for the second option, otherwise you can ruin many drills before you master the correct sharpening.

You can even create a suitable device with your own hands from wood. So, on a horizontal surface, a bar with holes corresponding to drill diameter... The aforementioned holes are made at a slight inclination in order to obtain the required sharpening angle.

Some craftsmen prefer an electric drill equipped with appropriate attachments. Naturally, the range of similar elements is small, which complicates the do-it-yourself sharpening. As a rule, a stone and a leash are included with the attachments. If you plan to sharpen the drills using a specific drill, the leader should be shortened immediately.

If you wish, you can independently make a similar drill attachment, guided by the recommendations given in the corresponding video. Such devices must be equipped with fasteners to fix the drill.

Features of the sharpening process

If you first decided to sharpen a part with your own hands, do the work in strict sequence.

1. The back surface is treated first. So, the drill is pressed tightly and constantly monitored so that the sharpening angle remains the same. As a result of processing, the tip of the drill will resemble a regular taper.
2. Next comes the turn of the cutting part.
3. The last stage involves finishing the back surface. In this case, it is necessary to make sure that the size of the jumper is no more than 0.4 mm. Naturally, for a large drill for metal, this parameter should be slightly higher.

If something didn't work out right the first time, don't despair. It is best to start practicing with tools that are unlikely to be needed. The main thing is to learn how to press correctly and maintain an angle. In this case, it is necessary to take into account the fact that the lateral parts of the drill, and not the tip, are responsible for drilling. Accordingly, the edges must be sharpened.

It is important to remember that during the sharpening process fine particles are formed... Due to heating, they fly apart in the form of sparks. It is for this reason that it is necessary to adhere to safety precautions. It is about the use of safety glasses and gloves. Also, when sharpening, make sure that the drill is securely fixed. Otherwise, it may accidentally escape from the hands.

If you decide to use an appropriate machine for sharpening, be sure to prepare workplace... In particular, it comes good lighting. You also need wear protective gloves and goggles.

To properly sharpen the drill with your own hands, you need use a suitable device... It can be a household or industrial machine, as well as an electric drill with a special attachment. If you have not tried sharpening a drill before, check out the corresponding video first.

In principle, you can also manually bring a blunt tool into proper condition. But how fast and accurate will this technology be? In addition, if the drill is carbide, this is difficult to do. The author proposes to assemble a drill sharpening machine with his own hands, which will allow you to use them repeatedly.

Industrial equipment is quite expensive - from 43,900 rubles.

However, Chinese products (for example, "GQ-D13") can be bought for 6,800 - 7,200.

But such cheap models are unlikely to suit home master, if we consider that the body is made of plastic, and the engine power is within the range of 80 - 120 W. In addition, only some types of drills can be sharpened on them, so there is no need to talk about the universality of use. Therefore, such machines do not count. The feasibility of making a do-it-yourself "sharpener" for domestic use is more than obvious.

This article does not consider the options for making a grinding machine based on angle grinders (there is not a "grinder" in every house, and hardly anyone will buy it for these purposes only) or an electric drill (for which you still have to look in stores special devices). The simplest and convenient option - a traditional "winepress" made of scrap materials, which almost any of us came across, and more than once.

There is nothing complicated in the design of such a machine. However, there are a number of features in assembling it with your own hands, and this is what the author draws attention to. Having dealt with all the nuances, it will not be difficult to make an installation for "home" use of labor ().

What you need to build

El / engine

On the machine in everyday life, various drills are sharpened, including those of large diameter. In addition, the initial processing of the cutting edges of the tool and their finishing are separate stages of work. Therefore, you will have to change the circle and put the one that is at hand from the previously purchased ones. Since the machine is a long-term equipment, it is necessary to mount it for the future. Based on this:

• engine power: about 1.2 - 1.5 kW is enough;
• power supply: single-phase. Any garage or small workshop (shed) on the site, with rare exceptions, is connected to the 1f 220/50 line. This should be the starting point.

Grinding wheel

Moreover, there should be several of them, with different grain sizes. To securely fix the abrasive on the engine shaft, bushings are prepared that clamp it on both sides.

Sharpening device

You can limit yourself to the simplest "shelf", but then you will not be able to maintain the required angle. Such work requires a lot of practical experience.

The device can be purchased, although it is quite rare on sale.

The best option is to make it yourself. For example, these are:

Scheme elements

• Magnetic starter (with 3 pairs of contacts) for circuit 3 ph.
• Button "start / stop" or 2 different - to turn on and off the machine. And necessarily the third - an emergency stop. It is often combined with a pedal, which is much more convenient and safer, since when sharpening drills hands will be busy.
• Wires. At the specified engine power, it is enough for 1 "square".

The simplest connection schemes for three-phase motors are shown in the figures:

An acceptable one is easy to find on the Internet, depending on which motor is used, how its windings are connected ("star" or "triangle"), to which voltage source it will be connected (1 or 3 phases).

Protection elements

• Shroud over the circle.
• Screen (preferred).

There are certain types of work in which drills are sharpened only on machine equipment, and not manually.

• When drilling to deeper depths where light re-sharpening is required.
• If the drills are universal, they can work even with materials of high density.
• For making blind holes with a special tool.

It is not recommended to sharpen drills using a grinder for several reasons. First, angle grinders are unlikely to be securely fixed. Secondly, the accuracy will be unsatisfactory. Thirdly, after the end of such sharpening, it is rather difficult to make the correct fine-tuning of the drill. Fourthly, this technique is suitable only for partial restoration of the working capacity of a tool of a relatively small diameter (no more than 5).

Making a machine is not all. It needs to be positioned correctly in order to sharpen the drills as conveniently as possible. The place, the height of the installation is a personal matter of the master. But there is general requirement - eliminate the slightest vibration of the equipment and ensure its leveling.

If the workbench in the garage is rather "flimsy", you will have to mount a special table on metal legs. A large corner, pipe or channel is suitable for this. The tabletop, taking into account the weight of the machine (primarily the engine), must be strong. Thin sheet metal is not an option. The machine stand can also be made of wood, but of sufficient thickness. Its attachment also requires attention. It should be as reliable as possible, at all points provided on the engine bed, and only on bolts.

When deciding on the circuit for turning on the engine, it is necessary to provide for the possibility of changing the speed. Since you will have to work with different drills, you need to know - the harder the material of the tool, the lower the angular speed of rotation of the abrasive wheel should be.

As practice shows, not all inexperienced craftsmen understand when a drill needs sharpening. Signs that the instrument is dull:

• grinding (sometimes "hum") at the initial stage of drilling;
• rapid heating of the metal, often accompanied by a characteristic odor.

Failure to sharpen in time will significantly reduce drill life and is the most common reason its breakage.

Do you need the drills to be always sharpened, and you won't find a special machine in the daytime with fire even in specialized stores? And make a do-it-yourself drill sharpener. You can easily cope with the assembly of a simple structure if you have at least a little experience in working with basic tools.

Homemade machine

The drill sharpener can be of great value in household as with this device you can independently sharpen drills of any diameter and type. In addition to making a special unit, you will need an electric motor with a sharpening stone.

Main materials:

1. Metal plate with holes - 1 pc .;
2. Bolt or hairpin 70x15 mm long;
3. Washer set;
4. Corner - 30x30 or 40x40;
5. Plates - 3-4 mm thick;
6. Cotter pin - 30x1.5 mm;
7. Clamps.

In addition to materials, you will need tools for their mechanical processing and connections, in particular electric welding and grinder.

Instruments:

1. Electric welding.
2. Drill.
3. Bulgarian.
4. Hammer with percussion tips.
5. Special clips 2 pcs.
6. Spanners.
7. Pliers.

Manufacturing process:

1. Making the mounting plate

The mounting plate is made of a metal backing with holes about 3-4 mm thick. On one side, the part is cut by 3 centimeters, while during cutting it is required to save the finished hole. The cut-off part will be needed to make the next part of the sharpening device, and a large element for the lining when placing the product on the table.

2. Corner for fixing the drill

The element is designed for fixing the drill during sharpening. It is made by cutting off a part of a regular corner 30x30 or 40x40. total length varies in the range of 60-90 mm, while the extreme part is cut off at an angle of 60 degrees to give the sharpened plane the desired level.

3. Attachment for fixing angle

The cut part with a hole from the plate is connected to another metal plate, while the elements are superimposed on each other and electrically welded to the corner. For welding, an assembly cutout should be cut out on the plates to fit the parts back to back and weld.

In the connected parts, a hole is drilled along the diameter of the bolt or stud, and the parts themselves are carefully scalded on all sides to give rigidity.

4. Welding the bolt

A bolt or stud is used to fix the angle. The element is welded at a 75 degree angle to the base plate. During scalding, the bottom plane should be taken into account, if necessary, remove the slag in order to prevent the product from skewing.

5. Fastening the washer to the bolt

The washer is installed on the bolt at a level of 25 mm from the upper extreme part. The approximate diameter is 30 mm. The element is welded using electric welding in the desired design position, observing all levels along the plane.

6. Hole in the hairpin

In the absence of a hole for installing the cotter pin in the bolt (hairpin), it is required to make it using a drill and a drill of the required diameter. Due to this technical element, the fixing angle will be fastened. The diameter can be different, but the main condition is reliable fixation.

7. Drill stop

It is made of a metal bar and a special vise clamp. The bar is welded to the fixing angle from below. The clamping mechanism is mounted on a bar, while a special bowl-stop for the drill should be equipped on the device from the corner.

The system is mounted on the grinding table and fixed with additional clamps.

Video: how to make a drill sharpener.

Drill sharpening machine

This method is available to anyone. For this you need a drill. Perhaps not immediately from the store counter, but already obsolete and not used by you. She will act as a motor.

It must be fixed on the bed, insert a sleeve or a ready-to-install grinding wheel or a universal fine-grained disc into the chuck. All. Turning on the drill, you get a rotating abrasive, which is a pleasure to sharpen the drill.

A very simple sharpening solution. However, do not forget about the tools for sharpening the drill, which fixes the sharpened element relative to the sharpener.