Tool for sharpening drills with 2 nuts. Making a homemade grinder for drills

Do you need drills to always be sharpened, and you won't find a special machine in the daytime with fire even in specialized stores? And make a machine for sharpening drills do it yourself. 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 the help 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 grindstone.

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 setting the product on the table.

2. Corner for fixing the drill

The element is intended 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. Fastening for the 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 in order 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 pin 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. Diameter approx. 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

If there is no hole for the installation of the cotter pin in the bolt (hairpin), it is required to make it using a drill and 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 a reliable fixation.

7. Drill stop

It is made from a metal bar and a special vise clamp. The bar is welded to the fixing angle from the bottom. 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 a grinding table and fixed with additional clamps.

Video: how to make a drill sharpener.

Drill sharpening machine

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 Perhaps not immediately from the store counter, but already morally outdated and not used by you.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

It must be secured to the bed, insert a sleeve or a ready-to-install grinding wheel or a universal fine-grained disc into the chuck. Everything. When you turn 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.

Then you do not have to go to a specialist every time, and you yourself will be able to maintain the required sharpness of the drill.

For sharpening, you need a special device that is used in professional work.

However, if it is not there, you can assemble the sharpener by hand and do all the work with your own hands correctly.

From the article you will learn how to make the machine necessary for sharpening metal, as well as how to properly sharpen a drill for metal. The instruction on the video will help you cope with this work faster and do everything right. You will also learn how to sharpen crown, step and other types of drills.

Preparation for work

You don't have to be a professional to know how to sharpen metal drills. This requires a sharp attachment to help keep it in optimal working order.

Since you have to sharpen the device for metal regularly, if you often work with this tool, some people prefer to buy a ready-made sharpening machine, rather than assemble it with their own hands.

The most effective tool for sharpening core drills is the machine on which the grindstone is installed.

It's very easy to use and you don't need to complex instructions to get started.

However, it is advisable to know some of the nuances of how sharpening is carried out before starting the process: the tool is processed from the back along the edges, with the most important role occupies the angle at which the tool is positioned when fed into the machine.

If the angle is wrong, the tool will be damaged and it will be impossible to fix it - you will have to buy a new one.

During sharpening, the greatest attention should be paid to the edge that makes up the cutting part of the device - it should be the sharpest, since it interacts with metal parts: screws, jumpers, etc.

Watch a video on how to properly sharpen the fixtures before starting this process with your own hands.

After that you need to collect necessary tools which you will need to make a grinder. It will not be possible to make it from improvised means - you will have to visit a hardware store.

First of all, you need special circles that are needed for sharpening.

Only one circle will need to be installed on the device itself, but they quickly deteriorate, therefore it is recommended to buy several parts at once so that later you do not spend a lot of time replacing them.

This is especially true if you use the tool constantly - then you will have to sharpen it often. The acquired circle is installed on a rotating shaft.

In addition to these parts, you will need a cooling fluid - it can be water or machine oil. You also need a container for the liquid to be poured into.

If you do everything with your own hands, then you must remember about the liquid, because during the sharpening process the tool becomes very hot.

If you cannot cool it, then its properties will deteriorate, and each time it will fail faster and faster.

A homemade crown tool machine must have the correct angle, and this is the most tricky part in creating a device with your own hands.

To make the angle correct, you need to make difficult calculations, so often consumers decide to purchase a ready-made sharpening tool in order to save time and effort.

The most important angle is at the front, it is determined based on the main clipping plane.

The clearance angle has parameters similar to the front angle, but in accordance with the back plane.

In order to determine how the upper corner is located, you need to look at the device from the side position: in the correct position, it is located between the first and second edges.

Typically, the first angle should have a slope of about 20 degrees, and the back one - 10. The top angle is always the same on all devices: 118 degrees.

Before work, you need to prepare gloves and glasses, as this work can be traumatic.

If you have little experience in creating such machines with your own hands, then pay close attention to how the circle is located, because if its feed angle is incorrect, then the circle will simply break out of your hands.

Watch a video on how to assemble a sharpener - it will help a lot if you have little experience.

Sharpening process and machine advantages

Core drills, step drills and other drills are sharpened in the same way, in several stages. The back of the device will be most involved.

First you need to turn on the device equipped with emery and bring a stepped drill to the circle, for example, which needs to be sharpened. In this case, the cutting part of the stepped drill should be directed towards the sharpener.

When working, the drill must be held very firmly so that it does not slip out.

If you positioned the drill correctly, then it should be parallel to the mechanism.

In this position, it remains only to sharpen it, and then you will receive quality tool which you can use again.

This sharpening method is only suitable for small drills, the diameter of which does not exceed 10 mm.

If the diameter of the drill turns out to be larger, then it is necessary to extend the time spent on sharpening, as well as pay more attention to the front of the tool.

How to sharpen drills with different diameters, see the video.

To sharpen core drills with a diameter of more than 16 mm, you need a full-fledged machine.

In this case, do-it-yourself work will be more expensive and longer, however, using the machine will also make it of better quality, since in this case you can easily set the correct inclined angle.

If you use drills often different sizes, then the machine will quickly pay for itself, because they have to be sharpened constantly.

There are several characteristics of core drills and other drills that can only be sharpened with a machine. Read them before you get started.

Firstly, if a stepped or other device is designed to work with a blind hole, where the axial cutting force is reduced, then such a tool must be sharpened on the machine.

The same is the case with drills designed to work with strong metals, or tools that have a small point and are designed to drill deep holes.

A straightening machine should not only sharpen the drill, but also orient the tool to the work surface relative to the grinding wheel.

That is why the machine is equipped with a sharpening plate that allows you to do this.

The device itself is fixed on the grinding plate, as well as the shaft and motor, thanks to which the machine is started.

The drill of the machine is installed on the turntable, which is also located on the base plate.

It is easy to turn the stove the way you need it and it is convenient - this is another plus in using a full-fledged device.

The machine is started with the help of a motor, so the column can be made from any bearing assembly equipped with a shaft.

It will be necessary to fix the mount on the shaft, where the sharpening drill will be installed. You can fix it with ordinary bolts - they will give the tool the necessary reliability.

After you have installed the drill, you can turn on the machine: after starting, the column will automatically move to the circle and turn it around with its back, which needs sharpening.

Such a system is very convenient, since it allows you to independently correctly set the angle that is needed for high-quality tool processing.

Large machines are used for processing twist, core and other drills, which have a diameter of more than 16 mm, for more small tools compact packing machines can be used.

It is more convenient to work with such devices, tk. they can be moved or installed wherever you want.

The device of such a machine is similar: on one side there is a connection unit responsible for installing the drill on the spindle, and on the other there is a hole in which the drill is installed.

It is much easier to work with this device with your own hands: you need to fix the drill until it stops, and then start the machine.

Easiest but least effective method sharpening the tool - do it with a grinder, or a device on which a movable circle is installed.

This method can only be effective if you can fix the drill in the correct position, which is quite difficult.

This method is traumatic, since the drill can easily slip off the circle during operation.

It makes sense to use a grinder only if you need to process a drill with a minimum diameter, and there are no other devices for this.

In addition, sharpening with a grinder does not imply the creation of debugging, which is a very important part of the process. Finishing is needed in order to make the instrument flat and smooth.

With professional sharpening, fine-tuning is done without fail, since this increases the service life of the device.

If you have a silicon carbide circle, then the finishing process can be done with your own hands at home.

Despite the fact that the process of sharpening a drill is not too complicated, without specialized devices, although it is not recommended to do this with your own hands, because you can not only damage the tool, but also injure yourself if you do not follow the technology of work, or use tools not intended for sharpening , for example, a grinder.

It is impossible to perform high-quality metal processing (including drilling a hole in a metal part) without using a tool whose mechanical characteristics and geometric parameters correspond to the required values. That is why the question of how to sharpen a drill for metal correctly is relevant for home craftsmen who often work with such a tool that wears out (which is natural) during operation.

Sharpening a drill for metal using a special tool greatly simplifies the task

Drills designed for metal work have to be sharpened much more often than those with which woodworking is performed. When processing such soft material like wood, drills are practically not dull and can be successfully operated for a very long time, fully retaining their original characteristics. The situation is completely different with drills, with the help of which holes are made in metal parts. It is necessary to constantly monitor the condition of such drills and immediately take measures if their working part has undergone wear.

The fact that a drill for metal needs to be sharpened is evidenced by whole line signs:

• a creak and hum made by a worn-out instrument;
• intensive heating of the drill during its use;
• poor quality of the holes created.

Working with a worn drill bit is not only ineffective but also unsafe. At any time, such a drill, on the working part of which significant loads fall on, may break, and its individual fragments, flying into different sides at high speed can cause serious injury.

Drill sharpening parameters

Both in production and at home, metal drills can be sharpened on emery machines equipped with a grinding wheel of the appropriate hardness. It is best to use off-the-shelf equipment in such cases. If it is not available, then you can sharpen drills on hand-made devices. It should be borne in mind that the characteristics of this equipment, as well as the tools for sharpening drills used with it in the kit, largely determine the quality of such a procedure.

Most important parameters that should be considered in order to properly sharpen a drill for metal with your own hands are:

1. the angle at which the back of the tool is to the drilling plane;
2. angle of sharpening of the front surface of the cutting part;
3. the length of the transverse bridge on the cutting part;
4. apex angle cutting tool;
5. length of cutting edges.

To sharpen the drill to be of high quality, it is necessary to ensure that it is fed into the processing zone at the required angle. To solve this problem, various devices are used, which are equipped with grinding machines.

It should be borne in mind: if the sharpening of the drill for metal is performed incorrectly, this can lead not only to a poor-quality result, but also to the breakdown of the tool.

What is needed for the procedure

To sharpen a drill for metal yourself, you must first determine what tasks it will be used for. In production conditions, for sharpening drills, as a rule, special devices are used to ensure maximum accuracy and productivity of such a process. When sharpening drills at home, you always have to look for ways to make the result of this process of high quality.

V minimal set for sharpening drills for metal should include:

• emery machine;
• grinding wheels of various hardness, selected depending on the material of manufacture of the drill to be sharpened;
• container for coolant and the liquid itself, which can be used plain water(or machine oil);
• devices to withstand correct angles sharpening.

When sharpening drills with your own hands, you need to pay attention to the following parameters:

• the angle between the plane of the front of the drill and its base cutting edge(this angle, measured in the main cutting plane, is called the front angle);
• the clearance angle, which is measured in the same way as the front angle, but along the back plane of the drill;
• tool nose angle, measured between two cutting edges.

To sharpen metal drills in accordance with all the rules, you must adhere to the following values ​​of the above parameters:

• cutting edge rake angle - 20 °;
• back angle - 10 °;
• apex angle - 118 °.

If you need to sharpen a drill bit for metal at work or at home, you must strictly follow safety precautions. This process is accompanied by the formation of a large number of sparks, from the effects of which it is necessary to protect the organs of vision. In addition, since this procedure is performed with sharpened metal tools, it should be carried out using gloves to protect the hands.

An emery machine equipped with a grinding wheel is universal device, which allows you to sharpen a drill for metal with high quality even at home. Using such a device, the technological operation should begin with machining the flank of the tool. The drill to be sharpened is held in relation to the grinding wheel in such a way that its cutting part is parallel to the surface of the wheel. This sharpening technique is ideal for metal drills with a diameter of less than 10 mm.

To sharpen drills with a high quality, the diameter of which is more than 16 mm (including those equipped carbide inserts), it is best to use an emery machine with a special attachment. The use of the latter makes it possible not only to control the sharpening angle of drills of significant diameter, but also to carry out such a process with maximum safety.

Grinding machines equipped with additional accessories are recommended to be used in cases where it is necessary to sharpen drills of the following categories:

• used for drilling blind holes, which is characterized by a decrease in the axial cutting force;
• universal, characterized by increased strength;
• used for drilling deep holes and characterized by a small amount of undercut.

The main task solved by devices that allow high-quality sharpening of a drill for metal on a grinding machine is the correct orientation of the cutting part of the tool in relation to the surface. That is why there is a special base plate in the design of such a device. The machine itself, the motor that drives the grinding wheel in rotation, as well as the turntable, on which the tool to be processed is fixed, is installed on it. The use of such a column allows you to sharpen drills in almost any spatial position, positioning their cutting part in relation to the surface of the grinding wheel at the required angles.

Benefits of using special tools

The great advantage of using grinding machines equipped with special devices, is that the movement of the processed tool on them is provided by a drive connected to an electric motor. The structural diagram of such a drive includes a bearing assembly and a shaft. At the end of the latter, a drill is fixed, which must be sharpened.

Before starting the procedure, the tool is fixed on the device at the required sharpening angles. After the drill for metal is fixed on the movable column of the fixture, it itself is brought to the rotating grinding wheel. Thus, all the corners that need to be formed on the flank of the cutting part are automatically maintained during the sharpening process. Among the main disadvantages of such a drill sharpening machine, its large size is usually noted.

If you are looking for an answer to the question of how to properly sharpen a drill for metal without performing complex manipulations with the tool being processed, you can recommend more compact devices. One of these devices is a packing machine. It is installed on the spindle of a conventional electric drill, from which its main working element, the grinding wheel, is driven into rotation. One end of such a device is equipped with a special coupling that connects the device to the rotating spindle of an electric drill, and the other with a cover with holes different diameters, into which the working parts of the sharpened metal drills are inserted.

It is very easy to teach someone to use this tool, which allows you to quickly sharpen a drill at home. At the same time, you can not even show such a process on video or live, everything is clear and without a demonstration. To sharpen a drill for metal using such a device, it is enough to insert the tool into the hole of the corresponding diameter until it stops and turn on the electric drill, which will rotate the grinding wheel. A tool sharpened with such a simple device has all the required geometric parameters.

It would seem that you can sharpen a drill using any device capable of rotating a grinding wheel. Meanwhile, without the use of devices for fixing the tool in the sharpening process, such a procedure cannot be performed efficiently. It can also lead to serious injury. You can turn to this simplest sharpening method only if you need to sharpen small diameter drills that are easy to hold in your hands during processing.

At manual sharpening a corner fixed on the support will help to maintain the required parameters

Work good tool it is convenient, effective and correct! Today we have useful homemade product for home and garage - homemade machine For sharpening drills, sharpening a drill correctly presents some difficulties without experience. Moreover, drills of large diameters (somewhere from 6mm) are still amenable to sharpening control and, at least, they can be sharpened after some time. Drills of small diameters, especially demanded by masters of radio and electronic equipment, have to be sharpened literally by touch and under a magnifying glass and without the use of mechanization using corundum blocks. By the way, recently we published an article "" who has not read, be sure to read it!

Using my deposits of illiquid assets and conducting a survey of the Internet, I collected on hastily a simple device that made it possible to sharpen drills from 2.0 to 6.0 mm without much difficulty. Further improvement of the adaptation is possible and is a task for the near future. General form in photo 1 and 2.

As, of course, drills for metal are known to have a sharpening angle at the top of 120 degrees. (Less for wood and soft metal.) The photo shows a yellow square lying between the sharpener and the fixture, which provides this angle, i.e. the drill is located at an angle of 60 degrees. to the working end of the abrasive disc. The desired nape angle of the drill is provided by the initial tilt of the drill relative to the disc.

The principle of operation of the device is not new and has been repeatedly repeated and published on the network. The difference between this device is the use of so-called jewelry vise for fixing the drill, which are available on the market and are inexpensive. I had these very old, reworked and worn out over 30 years of use. Photo taken from the network.

The principle of operation is simple - by turning the handle, we move the jaws apart and by reverse rotation we clamp something, for example a drill.

These dots have been revised. The rivets were drilled and plates were installed on these seats and re-riveted with longer rivets. Further it will be clear why this is done.

The drill is clamped in a vice so that the cutting edges are parallel to the jaws.

Along the edges of the riveted plates, coaxial holes are drilled at the same distance from the center and lying on a straight line perpendicular to the axis of the vise (that is, to the drill). An axis will pass through these holes on which this "rocker" will swing alternately when sharpening one and the other face. With ideal marking of the rocker, equality of cutting edges will be achieved when sharpening.

The rocking chair is fixed on the racks (the housing of the mortise door latches without guts. The posts, in turn, are screwed to the oak block. It also contains four support legs to adjust the desired height.

A rocking chair with a drill is placed between the posts on the axis, the axle is removable.

Sharpening the first face (the jaws are painted over with a blue marker).

The sharpening of the second side-rocking chair is turned 180 degrees. (the painted side is not visible). Top view of this node.

The finished drill is in the photo below. Errors that occurred when working "on the knee" and old worn vise did not allow sharpening drills from 1 mm. Shown here is a 1.5 mm sharpened drill. At high magnification, the difference in the lengths of the cutting edges is visible (small, but there)

A drill is, perhaps, one of the most common both in everyday life and in the production of devices for mechanical processing of materials, which allows you to quickly and accurately make a hole in a surface with a very different structure. Be it a hand brace electric drill or a large radial drilling machine, they all use a drill as a cutting tool. It is a hardened carbide metal rod of various diameters, with a shank and a working part in the form of two or more cutting edges, which, when rotating, extract material.

Drill angle: individual approach to each material

Depending on the type of surface, the requirements for the quality of processing and a number of other conditions, it may have the most different kind... The most common option is when its working part consists of two cutting edges twisted together in a spiral, forming a cone at the end of the drill, the height of which determines the angle of sharpening of the drill. Its value depends on the hardness of the material being processed and for each material it can have its own values:

• carbon steels, cast iron and hard bronze alloys - from 116º to 118º;
• soft bronze and copper - from 120º to 130º;
• aluminum and wooden surfaces- 140º;
• polymers and plastics - from 90º to 100º.

Conditions for a long and active drill life

If we exclude the thoughtless (or hopeless) option of using a drill without victorious soldering for working on concrete or stone (when the tool fails in just a minute), then the most actively blunt cutting edges when drilling hard metals. The service life of the drill in this case depends on the hardness of the work surface, as well as the speed of rotation, the feed force and the presence of cooling of the cutting tool. It is extremely easy to determine the moment of deterioration of the cutting qualities of the drill by the characteristic sharp whistle and the need for more pressure on the drill. As a result, the drill heats up very quickly, the drilling time significantly increases with a simultaneous decrease in the quality of the hole obtained, and to continue normal work the drill needs to be replaced.

Better to lose an hour, and then drill in five minutes

Since drills are considered consumable and on small sizes have a relatively low cost, many are simply thrown away, replacing them with new ones. However, this approach can be justified only with a small amount of work, a low cost of a part and the proximity of a hardware store. It is much more economical and faster to sharpen a drill for metal with your own hands. There are a lot of devices for this operation, and, as a rule, the price of such equipment directly depends on the speed, versatility and quality of processing of the cutting tool.

The correct form of sharpening is the key to effective work

As a result of processing, the cutting edge of the drill is given a certain geometry, which is of priority for a particular drill diameter and the structure of the machined surface. To obtain the required shape, use, respectively, and different ways sharpening the cutting edge. There are single-plane, conical, two-plane, screw and cylindrical types of sharpening. At home, the first two methods are most often used as the simplest, and drills with a diameter of up to three millimeters are sharpened in one plane, providing a thirty-degree slope of the clearance angle. The disadvantage in this case is the high probability of destruction of the working part of the edge due to its thinning, therefore, for drills with a larger diameter, sharpening in the form of a cone is usually used, forming an angle on their tip within the range of 118-120º.

Ways to Achieve the Desired Sharpening Quality

In principle, having certain skills, sharpening can be carried out without an auxiliary tool. The main thing in this case is to observe the required processing angle, as well as equal length work surface cutting edges and their symmetrical inclination relative to the drill axis. However, it is not so easy to achieve this in practice, a very small error for any of the listed indicators is enough, and your drill will not work properly. The use of special devices simplifies the process, but you must admit that it is inexpedient to purchase an expensive machine to put in order a pair of metal drills. Besides homemade device for sharpening drills will help to cope with this task, albeit with less comfort, but also not bad.

With all the variety of versions, the principle of operation of all devices of this type is based on the formation of a rigid template or guide along which the sharpened tool is fed to the emery wheel in a certain plane.

Nut, screw, direction - that's all adaptation

Perhaps one of the fastest and available options will make a device for sharpening drills from a nut. Its six edges form an angle of 120º on adjacent planes and can serve as an excellent template for setting the desired angle of sharpening of the cutting edge of the drill. The manufacturing procedure for such a device is quite simple and does not take much time. The nut is clamped with the flat side up in a vice and using an angled grinder(grinders) make rip cuts along the line connecting the opposing corners of the hex. On one side of the hardware, you can make six grooves (according to the number of vertices), thus forming three guides.

The size of the nut, as well as the width and depth of the guide recess, are selected based on the diameter of the sharpened drill. After that, the entire outer surface of this simple device is carefully processed sandpaper or a file for deburring.

That, in fact, is all, the simplest tool for sharpening drills with your own hands is ready. Now the drill requiring sharpening is placed inside the guide (between two opposing corners) so that the edge to be machined protrudes slightly beyond the top of the hexagon. The device is clamped in a vice, tightly fixing the drill in the groove of the nut with the tip up, and using the same grinder, carefully grind the protruding cutting edge using lateral surfaces hardware as a guide, forming a sharpening angle of 120º.

If necessary, the drill in the groove can be fixed with a clamp, and instead of angle grinders, they are used with an emery wheel.

There are never too many hardware: modernization of a nut tool

This design can be slightly improved by making deeper (depending on the diameter of the sharpened drill) V-cuts in the opposing vertices and welding a smaller nut on the same side of the fixture. In this case, the drill can be fixed with a clamping screw screwed into a nut welded from above.

As a result, there is no need to use a vice and a clamp (the main thing is not to pinch the screw, so as not to bend the drill). Such a device allows you to successfully cope with the sharpening of drills even with a small diameter (up to three millimeters), when it is almost impossible to maintain and control the sharpening angle without special tools.

Wood guides for sharpening drills

Now let's look at how to make a tool for sharpening drills from bars or thick plywood. The structure is a wooden rail rigidly attached to the base. Basic part devices are made of a flat rectangular board (thick plywood) with a rectangular cutout on one side of which, providing access to the side surface of the emery wheel. Then a lining is prepared from plywood in the form right triangle or a trapezoid with a side inclination at the base of 60º (from the top - 30º), which guarantees a sharpening angle of 120º. The dimensions of the guide should ensure free placement of the sharpened drill along it, both in length and in height.

The finished overlay is attached with self-tapping screws to the far edge of the base board acute angle towards the emery wheel. Sharpening of drills for metal with a device of this type requires its precise fixation along the outer (wide) surface of the abrasive. Each cutting edge is formed separately, by smoothly rolling the drill against the rotation of the circle, then the same procedure is repeated for the other side, achieving perfect balance. With frequent use, wear may occur on the wheel, and you will either have to move the tool along the emery or replace the abrasive. This method is good in that it allows you to easily obtain the required slope of the cutting edge by quickly changing the upper guide to the required size.

Using guide bushings for sharpening

Another option for processing drills, actively practiced at home, is a wooden upright rack with hollow metal bushings of various diameters, which are placed in the bar at the angle required for sharpening. As a result of machining, a taper is formed at the back of the cutting edges, but without the correct clearance angle.

Professional solutions: great results for little money

Everything homemade devices provide an acceptable, but, alas, imperfect result. Even without taking into account the high probability of error at self-production there are a number of parameters for sharpening, non-observance of which leads to a quick failure of the drills. This is why large manufacturers are developing sophisticated devices and even machines to bring cutting tools into working order.

One of these mechanisms is the drill grinde, which makes it possible to return the sharpness to spiral drills for metal with a diameter of three to nineteen millimeters. The device easily copes with the task of forming a cutting edge of any inclination, while having a scale with standard sharpening angles (98, 118, 136 and 176 degrees, as well as for countersinks). The perfect sharpening quality is guaranteed by the precise positioning of the drill thanks to the clamping screws. The heel (clearance angle of the cutting surface) is formed due to the small axial tilt, which sets the arc motion of the drill during machining.