How to sharpen a drill using a nut - Metals and their processing

Homemade devices for sharpening drills - assembling the machine with your own hands

When drilling holes in parts made of metal, the tool used is subject to active wear, which leads to intense heating of the drills and, as a consequence, to their failure.

To avoid this, it is necessary to regularly restore their geometric parameters, and a special device for sharpening drills helps to do this as accurately and efficiently as possible.

This simple device, which you can make yourself, allows you to quickly and efficiently sharpen dull drills and not spend money on purchasing new ones.

Sharpening a drill on a homemade device

A device designed for sharpening drills is especially relevant in cases where these tools often have to be used on metal, as a result of which they quickly wear out and require regular restoration.

When processing wood, the drill used for these purposes practically does not wear out and, accordingly, requires minimal attention to the parameters of its sharpening.

For drills, the cutting part of which is equipped with carbide inserts, such a device is also not particularly significant, since they are practically not subject to regrinding and are used by craftsmen until they are completely worn out or broken.

Many experienced specialists do not use sharpening devices at all, completely relying on their experience and eye. However, as practice shows, in such cases it is better to use devices that allow you to mechanize this process. This will ensure maximum accuracy and the required quality of the result.

Metalworking machines are required for the manufacture of high-precision fixtures

The modern market offers many devices for sharpening drills that allow you to quickly, efficiently and accurately restore the geometry of the cutting tool, even if you have no experience in performing such procedures. Meanwhile, you can not spend money on purchasing such devices, but make a simple machine for sharpening drills with your own hands.

Manufacturing options

Whatever device or machine is used to sharpen a drill for metal, its quality must be controlled. For this, a special template is used, which can also be serial or made by hand.

This template is necessary primarily to control the accuracy of the angles of the cutting part, which are formed during the process of sharpening the drill. The tools used to work with different materials differ from each other, including the magnitude of such angles.

You can find out the exact values of the latter from the reference table.

Table 1. Drill sharpening angles

Working with different materials and knowing the angles of the cutting part of drills for such materials, you can make several templates at once and use them to control the correct sharpening of the same drill, which in this case acts as a universal tool.

As the simplest device for sharpening drills, you can use a sleeve with an internal diameter corresponding to the transverse size of the drill, rigidly fixed to a reliable base at a certain angle.

When selecting a sleeve for such a device, you must ensure that the diameter of its internal hole strictly corresponds to the transverse size of the drill being sharpened.

The tool being processed should not be allowed to dangle in such a hole, since even a 1–2° deviation of its axis from the required value can seriously reduce the quality and accuracy of the sharpening performed.

Drill sharpening device

It is better to immediately equip a homemade device for sharpening drills with a holder made of copper or aluminum tubes, the internal diameters of which correspond to the standard sizes of the drills you most often use.

You can do it simpler and supplement such a device used for sharpening drills with a wooden block. Holes must be drilled in the block corresponding to the sizes of tools of various diameters.

The most important design element of such a device is the tool rest, which simultaneously solves several important problems:

ensures correct fixation of the drill and its precise movement in relation to the surface of the grinding wheel;
acts as a reliable support for the tool being processed.

Diagram of the simplest device made from a wooden block

A similar device based on an oak block with holes of different diameters was used by our grandfathers, who used it to sharpen drills with high quality and precision. The main task that a homemade machine or device used for sharpening drills must solve is to correctly orient the cutting part of the drill being processed in relation to the working surface of the grinding wheel.

To make a homemade machine for sharpening drills, you can use various designs of such devices. The corresponding drawings are easy to find on the Internet. Moreover, if you understand the operating principle of such a device, then you can make your own sharpening machine according to your own design.

Quite a serious device that provides good sharpening accuracy

Drawings of fixture parts

Promopore Promopore platform Movable platform
Drill fastening and thrust screw Rotary platform Bolts, nuts, pins and washers

There is an important rule that must be observed when working with such a device: during its use, the drill being sharpened should not rotate around its axis. If the tool rotates even at a small angle, sharpening will have to be done again.

After sharpening the drill, it should be allowed to cool. Then you need to check its restored geometric parameters using a template. It must be borne in mind that the cutting edges of the tool may differ from each other in length by no more than tenths of a millimeter. It is especially important to comply with this requirement for drills with a small diameter.

Among the mistakes made when sharpening drills using such a device, two of the most typical ones stand out.

The length of the cutting edges, even with their symmetry and correctly selected angles, is not the same; accordingly, the drilling center is shifted relative to the tool axis. A drill that was sharpened with such an error will create a strong runout during the drilling process, and it will be quite difficult to get it into the center of the future hole on the surface of the workpiece. A tool sharpened in this way is highly likely to break during further use.
When the drill is accurately centered, the angles at which its cutting edges are located are asymmetrical. Since this causes only one cutting edge to work, drilling will occur slowly, while the tip of the tool will actively heat up. This will lead to the tempering of the metal from which the drill is made, and the hole created will be broken (will have a diameter greater than the transverse size of the tool itself).

How to make a machine for sharpening twist drills

As a basis for the manufacture of a sharpening machine for spiral-type drills, you can use any serial sharpening unit that can operate without runout and withstand significant loads. When equipping such a machine with additional devices, the following requirements must be met.

The axis of the tool rest must coincide with the axis of rotation of the grinding wheel, and it can be located with it in the same horizontal plane or be higher than it.
All elements of the structure being created must be securely fixed to ensure the safety of sharpening work.
The design of the device must allow sharpening of drills both manually and semi-automatically.
The device of the tool rest should allow the drill shank to be positioned at any angle.

Assembly for sharpening drills

The manufacture of this device for sharpening drills does not require complex technical devices and scarce materials, which will have to be purchased additionally. All components can be found in almost any home workshop or garage. As equipment and tools with which such components will be modified before assembling the device, you can use a regular grinder and a welding machine.

Since the stop of such a device must be oscillating, which is necessary for sharpening drills in a semi-automatic mode, a loop connection should be used to fix it. When selecting a tube, bracket and bolt for the fastening unit, you should keep in mind that there should be no play in the device. The homemade product of the proposed design has two degrees of freedom.

The platform of such a device, on which the drill being processed is fixed, has the ability to rotate along a vertical axis, making it possible to change the sharpening angle of the tool. In addition, the tool rest, resting on a horizontal axis, can make oscillatory movements, which ensures correct articulation during sharpening.

To manufacture the structural elements of such a device, sheet metal of various thicknesses is used, namely:

support plate – 4 mm;
drill guide plate – 5 mm;
other structural elements - 3 mm.

The tool rest, on the top of which the support plate is installed, must be securely fixed to the body of the sharpening machine. For this, an additional metal “cheek” is used, connected to the device bracket.

The guide plate, on the surface of which it is necessary to make a triangular groove designed to accommodate the tool being processed, is fixed on the support plate using a screw connection.

Plate guide groove

The design and design features of the drill sharpening device in question allow it to rotate at an angle of up to 90°. Thanks to this ability, you can sharpen drills using this device using almost any of the methods used today.

The drill, sharpened using such a device, fits into the guide groove and can move freely in it in the longitudinal direction. In this case, the sharpening angle of the tool does not change.

Installing the drill into the guide groove of the plate

Since the upper surface of the support plate is located slightly above the axis of rotation of the grinding wheel, when using such a device, the optimal sharpening shape of the back surface of the drill is achieved.

The process of sharpening drills using such a device is as follows.

The tool is positioned in the guide groove of the fixture so that its cutting edge is parallel to the edge of the guide plate.
After adjusting the position, the drill is slowly fed to the working surface of the rotating grinding wheel.

The process of working with such a device is well demonstrated in a video that is easy to find on the Internet.

Despite the simplicity of the design, such a device ensures high accuracy of sharpening, for quality control of which you don’t even need to use a template. If you fix the swing plate of this device at a fixed angle, it can also be used for sharpening drills equipped with carbide inserts.

Several recommendations for choosing sanding wheels

In order to successfully sharpen metal drills, most of which are made of high-speed steel, it is necessary to use a sufficiently hard sharpening wheel. For this purpose, you can use an abrasive tool made of silicon carbide.

Such wheels, which can be identified by their green color and marking 64C, should have a grain size in the range of 8H - 16H. When using discs made of this material, you must keep in mind that they become very hot during operation, so you should not allow the drill to be sharpened to be in prolonged contact with the abrasive tool.

To prevent overheating of the drill when sharpening it on such a disk, the tool must be regularly cooled using an aqueous solution of soda.

When sharpening drills using a grinding wheel, it is very important to ensure that the working surface of the abrasive tool runs over the drill being processed, that is, moves from top to bottom, and not vice versa.

Source: http://met-all.org/oborudovanie/prochee/prisposoblenie-dlya-zatochki-sverl-svoimi-rukami-chertezhi-video.html

Device for sharpening drills at home

The quality and accuracy of drilling depends on the sharpness of the working tool. In addition, unlike a table knife, the drill must be sharpened correctly. Experienced mechanics can straighten the cutting edge on a regular sharpening machine by simply holding the drill in their hands (at least according to them). But this method requires skill and many years of experience. Even if you have a steady hand and an excellent eye, without understanding the process, you will simply ruin the instrument.

A few basic rules for sharpening (using the example of twist drills for metal):

For a better perception of the material, let’s remember the structure of the drill.

Do not press the tip against the sandpaper for more than 2-3 seconds at a time. The metal heats up and the so-called “tempering” occurs, that is, deprivation of hardening. Accordingly, the necessary hardness of the metal is lost. The first sign is the presence of temperature discoloration on the edge.
For drills with a diameter of up to 4 mm: each time the sandpaper plane touches the drill, the drill is held in one position: rotation around its axis is not allowed. For larger diameters, the sharpening geometry is slightly different.
On twist drills, only the back surface of the cutting part is sharpened.
The cutting edge should be directed towards the rotation of the sharpener (for mechanical sharpening).
The main angle (2φ in the illustration) depends on the type of material being processed.

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Which drills should I sharpen and how often?

Feather and other special wood drills cannot be repaired at home, and they do not become dull so quickly. Pobedite tips for concrete cannot be sharpened in principle. The most popular tool remains - twist drills for metal. Of course, they are also used for processing wood (plastic, rubber and even stone), but this is not relevant to the topic.

Twist drill. The cutting edge is small in size, so during operation it quickly heats up due to friction (there is no dissipation area). The main reason for dullness is overheating. When used correctly, wear does not occur as intensely. Characteristic signs of a blunt drill:

A creaking sound is heard during operation.
Instead of curled shavings, sawdust comes out of the hole.
Instant heating of the tool without moving deeper.

Important: Do not use a dull drill; wear from overheating will only progress.

So, it's time to sharpen the tool. You don't want to ruin the drill and want to mechanize the process.

Mini sharpening machines are at your service:

All devices are divided into two types: attachments or stops for universal tools, and independent devices of narrow specialization. Let's look at the most popular of them, from simple to complex:

Hand holder

This is just the device for those who have a steady hand and a diamond eye. In fact, it only allows you to hold the drill in a given position without fear of injuring your fingers. Angle control is visual, according to the position of the “wings” relative to any landmark. There are few advantages: instant readiness for work, compactness and price. The disadvantages are obvious: manual control of the process does not add accuracy.

Stop for electric sharpener

In fact, this element is not a special device for drills. It simply allows you to fix the tool at a certain angle. The accuracy will be higher than in the previous version. Most stops allow you to set the angle of inclination, and even have a marking scale. And yet you have to rely on firmness of hands.

There are also more advanced stands: with replaceable elements and adjustment of not only the angle, but also the height. The devices are mounted not on the emery body, but on the workbench: which makes them more versatile.

In fact, such a stop can be adapted to any electric sharpener. An additional bonus is that with the help of such a stand you can sharpen knives, cutters, screwdrivers, chisels, etc.

Semi-professional guides for all types of drills

This is a fairly advanced tool that allows you to control sharpening characteristics with micron precision. All linear parameters are securely fixed, the values are set according to the markings. The drill is mounted in the groove, accidental displacement or rotation around its axis is excluded.

For sharpening, the possibility of both linear movement and movement of the edge along the arc path is provided (for conical sharpening of large diameter drills). Linear movement (along the axis) can be controlled by a master, or a limit stop can be installed.

From the point of view of processing quality, the device has practically no shortcomings. But for proper sharpening, the operator must know the parameters of the drill. That is, there is no automation: therefore the tool belongs to the professional category.

As a development of the line - a guide with its own sharpening unit. There is no need to install a stop on the workbench and change discs. In fact, you have a semi-automatic tabletop sharpening machine.

Important note: All listed devices are designed to work with standard electric sharpeners. Therefore, before starting to process drills, it is advisable to install a special emery disc.

Electric sharpening machines

They are specialized power tools for performing a single task: sharpening twist drills.

Even a person who is far from technology can use the machine (although why does he need sharp drills?). The operator only needs to determine the diameter of the drill and immerse it in the appropriate hole. It is convenient to work, errors are practically excluded. However, all drills are sharpened with the same comb. The price to pay for ease of use is the lack of flexibility in settings. For home use - the best choice: especially if there is an additional attachment for sharpening knives and scissors.

There are versions for masters. The drill is installed taking into account the sharpening parameters, the process can be controlled by the operator.

The sharpening angle, the method of edge processing (linear or conical), and the depth of metal removal are selected. The drill is not located in a common holder, but in an individual cartridge.

Industrial sharpening equipment for a metalworking shop

During intensive use of drilling machines, a separate post is required to restore the functionality of the tool. Professional stands for sharpening drills of any diameter save time and effort, but the cost of such equipment is too high for home use.

The information obtained will help you choose a sharpening device without extra financial costs. In addition, there are replaceable attachments for hand-held power tools (for example, a drill). But this is a topic for another article.

Source: https://instrumentiks.ru/sovety/prisposoblenie-dlya-zatochki-sverl

Homemade drill sharpening tool

One of the main parameters of a twist drill is the tip angle, which for durable metals (steel, cast iron, hard bronze, titanium, etc.) is approximately 120 degrees. Deviation of this angle more or less from the nominal value makes it difficult for the drill to operate effectively.

In the first case, productivity drops and the tool overheats; in the second, the drill may simply break, unable to withstand the excessive load. In order to comply with the sharpening parameters without special devices, you must have high qualifications and experience as a tool sharpener.

Well, it will be almost impossible for a non-specialist, especially in domestic conditions, to do this.

But, having some tools and simple materials, you can make a not very complicated, but reliable device for sharpening the corner at the tip of a twist drill for hard metal.

What you might need to work on the device

To do this you will need the following tools:

calipers;
marker;
metal vice;
Bulgarian;
pliers;
welding machine;
sharpening machine with an emery wheel.

Materials you need to have on hand for work:

regular hex nut;
castle nut;
bolt of the same size and thread as the nuts;
twist drill that requires sharpening.

Manufacturing process

The peculiarity of a hex nut is that any two adjacent faces meet at an angle of 120 degrees. The apex angle of a twist drill for working on hard metals is approximately the same size. This random coincidence can be used to make a tool for sharpening a twist drill.

To do this, using a caliper and a marker on the nut, mark the cutting lines to create a triangular slot, symmetrical with respect to the diagonal connecting two opposite corners of the nut. The drill will be placed longitudinally into it before the sharpening process.

To cut out the intended triangular groove in the nut, it is clamped in a vice and, using a grinder, cuts are made along pre-drawn lines. You can use pliers to remove sawed off pieces of the nut.

Next, take a castle nut and weld it with its base to the first nut on the side of the cut groove. Moreover, it is necessary to maintain their absolute alignment, because when small-diameter drills are sharpened, the bolt, having passed through the castle nut, will begin to screw into the lower nut in order to firmly clamp the drill in its groove.

Now we screw the corresponding bolt into the castle nut, which will securely press the drill placed in the sharpening groove on the sandpaper of the sharpening machine.

All that remains is to sharpen the drill on an emery wheel, using the edges of the lower nut as a template.

To do this, we simply grind the protruding part of the drill flush with the edges of the nut, which even a first-year vocational school student can easily cope with.

After sharpening is completed, the bolt is loosened, the drill is removed from the homemade device and can be used for its intended purpose.

Additions and improvements

During the welding process of nuts, liquid metal may splash onto the threads of castle and regular nuts.
To eliminate this nuisance, it is necessary to screw a bolt into them and thereby protect the thread. Since it will not be possible to cover all the diameters of drills with one device, at least two template clamps will be required: one for small drills, the other for large products. Accordingly, in the first case the nuts will be small in size, and in the second - large.

Watch the video

Source: https://coollifehack.ru/samodelnyj-instrument-dlja-zatochki-sverla/

Sharpening a metal drill with your own hands. fixture and video – Tool Master

Metal drills are always hardened, but the products may become dull over time. Naturally, this is not a reason to throw them away. If you wish, you can sharpen the drill yourself using professional equipment or homemade devices.

Main types of sharpening

Experienced craftsmen know that sharpening a drill for metal varies depending on the diameter and specific application .

Single-plane sharpening is designed for drills with a maximum diameter of 3 mm. During the work process, it is possible that the edges may “paint”, so you need to be very careful. To properly sharpen the product, it should be applied to the circle and moved parallel to the surface.
The conical procedure is intended for larger metal cutting tools. In this case, the tool must be held with both hands, performing sequential sharpening.
Finishing is carried out after finishing sharpening. Thanks to this procedure, it is possible to polish the cutting edge and eliminate even the smallest nicks.

Types of sharpening machines

To sharpen a drill with your own hands correctly, you need to use the appropriate machines. Such devices are divided into 2 groups .

Industrial equipment has significant power. It can be used to sharpen drills with a diameter of 20 mm or more. These machines are installed at large enterprises, and sharpening is carried out in semi-automatic or fully automatic mode.
Household machines are designed for use at home. They are also used in small production. Such equipment is characterized by mobility, average power and compact size.

Recommendations for choosing a household machine

If you are interested in the question of how to sharpen a drill for metal, then be sure to purchase the appropriate machine. An inexpensive model with average power is suitable for home use. It will allow you to sharpen small drills for metal.

Naturally, when purchasing, you need to pay attention to the noise level , as well as the design of the model. The best option would be a simple machine, because choosing the necessary parts for it will not be difficult.

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

Using machines at home

As mentioned earlier, it is advisable to use household machines at home. 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 purchase the appropriate circles.

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

Often included are:

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

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

possibility of working 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.

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Homemade sharpening devices

If you do not have the appropriate machine, you can sharpen it using other devices. We are talking about an electric drill or homemade equipment created according to a drawing . It's best to give preference to the second option, otherwise you may ruin a lot of drills before you master proper sharpening.

You can even create a suitable device with your own hands from wood. So, a beam with holes corresponding to the diameter of the drills is fixed on a horizontal surface. The holes mentioned above are made at a slight angle to obtain the required sharpening angle.

Some craftsmen prefer an electric drill equipped with appropriate attachments. Naturally, the range of such elements is small , which complicates sharpening with your own hands. As a rule, a stone and a leash are included with the nozzles. If you plan to sharpen drill bits using a specific drill, you should immediately shorten the driver.

If you wish, you can make a similar attachment for a drill yourself, following the recommendations given in the corresponding video. Such devices must be equipped with fasteners for fixing the drill.

Features of the sharpening process

If this is your first time deciding to sharpen a part with your own hands, do the work in strict sequence .

The back surface is treated first. So, press the drill tightly and constantly make sure that the sharpening angle remains the same. As a result of processing, the tip of the drill will resemble a regular cone.
Next comes the turn of the cutting part.
The last stage involves finishing the back surface. In this case, you must make sure that the size of the jumper is no more than 0.4 mm. Naturally, for a large metal drill, this parameter should be slightly larger.

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

It is important to remember that the sharpening process produces small particles . Due to heating, they fly away in the form of sparks. It is for this reason that safety precautions must be followed. We are talking about using safety glasses and gloves. Also, when sharpening, you should make sure that the drill is securely fixed. Otherwise, it may accidentally fall out of your hands.

Recommendations for using the machine

If you decide to use an appropriate machine for sharpening, be sure to prepare your work area. In particular, we are talking about good lighting. You should also wear protective gloves and goggles .

First of all, you should decide on the required sharpening angle.
It is important to position yourself so that the grinding wheel is on the right.
Alignment must be performed. To do this, take the working surface with your thumb and forefinger, and the second hand holds the tail edge.
The metal drill must be rotated so that the cutting edge is parallel.
An important point is the elimination of nicks.
All movements should be performed in a certain sequence. So, the left hand is moved down to the left, and the right hand is moved clockwise.

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

Source: https://cs-important.ru/tehnika/zatochka-sverla-po-metallu-svoimi-rukami-prisposoblenie-i-video.html

Do-it-yourself metal drill sharpening (device)

Depending on the diameter of the hole, the material of the workpiece and the required accuracy, drilling can be done in one step or double drilling; usually this technique is used when it is necessary to obtain large hole diameters. Reaming allows you to obtain more accurate parameters for large diameter holes due to the more accurate operation of the second drill. A twist drill is used to drill holes in metal.

Drill device

The working part consists of cutting edges, two spiral backs, two ribbons, which are connected by a jumper. The outer surface of the tool is formed by two narrow guide strips. The outer surfaces of which form two spiral grooves. Through the screw channels formed by the backs, coolant can be supplied to the cutting edge, and the resulting chips can also be removed.

The working part of the drill is formed from cutting edges; in most drills used, there are two of them. Depending on the material, the angle between the cutting edges may vary.

Table of recommended sharpening angle depending on the workpiece material

Drill sharpening angle
Drilling material	Vertex angle, degrees
Steel, cast iron, hard bronze	110-120
Brass, soft bronze	120-130
Copper	125
Aluminum	140
Magnesium alloys	90
Plastic, silumin	90-100
Plastics	90-100
Stone and other fragile materials	140

To secure the working tool in the machine, the shank can be cylindrical or conical, which is made according to the 1:20 standard and is called a Morse taper. The Morse taper is divided into 7 standard sizes, No. 0, - No. 6. This design ensures reliable centering and holding of the tool in the machine. In order to ensure universal fastening, adapter bushings are used for different cone sizes.

Designation, Morse Cone No.	Taper	Cone angle	Cone angle
	1:19,212=0,0521	2 °58′	1 ° 29 ‘
1

Source: http://themechanic.ru/zatochka-sverla-po-metallu-svoimi-rukami-prisposoblenie/

Homemade tools for sharpening drills

A drill is perhaps one of the most common devices for mechanical processing of materials, both in everyday life and in production, which allows you to quickly and accurately make a hole in a surface with a wide variety of structures.

Whether it's a hand hammer, an electric drill, or a large radial drill press, they all use a drill bit as the 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 rotated, remove material.

Drill angle: individual approach to each material

Depending on the type of surface, requirements for processing quality and a number of other conditions, the shape of the drill can have a very different appearance. 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 sharpening angle of the drill. Its value depends on the hardness of the material being processed and can have its own values for each material:

carbon steels, alloys of cast iron and hard bronze - from 116º to 118º;
products made of brass, 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 pobedit tips for working on concrete or stone (when the tool fails literally in a minute), then the cutting edges become dull most actively when drilling hard metals.

The service life of the drill in this case depends on the hardness of the surface being machined, as well as the rotation speed, feed force and the presence of cooling of the cutting tool. It is extremely easy to determine when the cutting qualities of a drill are deteriorating by the characteristic sharp whistle and the need for more pressure on the drill.

As a result, the drill heats up very quickly, drilling time increases significantly with a simultaneous decrease in the quality of the resulting hole, and the drill must be replaced to continue normal operation.

Since drills are considered consumables and have a relatively low cost in small sizes, many simply throw them away and replace them with new ones.

However, this approach can only be justified if the volume of work is small, the price of the part is low, and the proximity of a hardware store is close. It is much more economical and faster to sharpen a metal drill with your own hands.

There are a lot of devices for carrying out 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 sharpening form is the key to effective work.

As a result of processing, the cutting edge of the drill is given a certain geometry, a priority for a particular diameter of the drill and the structure of the surface being processed. To obtain the required shape, accordingly, different methods of sharpening the cutting edge are used. 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, ensuring a thirty-degree slope of the rear corner.

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 of larger diameter, sharpening in the form of a cone is usually used, forming an angle at their tip in the range of 118-120º.

Ways to achieve the desired sharpening quality

In principle, if you have certain skills, sharpening can be done without an auxiliary tool. The main thing is to maintain the required processing angle, as well as the equal length of the working surface of the cutting edges and their symmetrical inclination relative to the drill axis.

However, achieving this in practice is not so easy; a very small error in 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 agree that it is not advisable to purchase an expensive machine to put a pair of metal drills in order.

In addition, a homemade device for sharpening drills will help you cope with this task, albeit with less comfort, but also not bad.

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

A nut, a screw, a direction - that’s all the device

Perhaps one of the fastest and most affordable options is to make a device for sharpening drills from a nut. Its six faces form an angle of 120º on adjacent planes and can serve as an excellent template for setting the desired sharpening angle of the cutting edge of the drill.

The procedure for making such a device is quite simple and does not take much time. The nut, flat side up, is clamped in a vice and, using an angle grinder (grinder), longitudinal cuts are made along the line connecting the opposing corners of the hexagon.

On one side of the hardware you can make six recesses (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 sample, are selected based on the diameter of the drill being sharpened. After this, the entire outer surface of this simple device is carefully processed with sandpaper or a file to remove burrs.

That's all, the simplest device for sharpening drills with your own hands is ready. Now the drill that requires sharpening is placed inside the guide (between two opposing corners) so that the edge being processed slightly protrudes 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 off the protruding cutting edge, using the side surfaces of the hardware as a guide, forming a sharpening angle of 120º.

If necessary, the drill in the groove can be secured with a clamp, and instead of an angle grinder, a sharpening machine with an emery wheel is used.

There is never too much hardware: modernization of a nut device

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

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

Wooden guides for sharpening drills

Now let's look at how to make a device for sharpening drills from blocks or thick plywood. The structure consists of a wooden guide rigidly attached to the base.

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The base part of the device is made of a flat rectangular board (thick plywood) on one side of which a rectangular cutout is made to provide access to the side surface of the emery wheel.

Then an overlay is prepared from plywood in the form of a right triangle or trapezoid with a side slope 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 drill being sharpened along it, both in length and height.

The finished overlay is attached to the far edge of the base board using self-tapping screws at an acute angle towards the emery wheel. Sharpening drills for metal with a device of this type requires its clear fixation along the outer (wide) surface of the abrasive.

Each cutting edge is formed separately by smoothly rolling the drill towards the rotation of the circle, then the same procedure is repeated for the second side, achieving perfect balance. With frequent use, wear may occur on the wheel, and you will have to either move the device along the sandpaper or replace the abrasive.

This method is good because it makes it easy to obtain the required inclination of the cutting edge by quickly replacing the upper guide with the required size.

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

Professional solutions: excellent results for little money

All homemade devices provide an acceptable, but, alas, imperfect result. Even without taking into account the high probability of error when making sharpening devices yourself, there are still a number of parameters, non-compliance with which leads to rapid failure of drills. That is why large manufacturers are developing complex devices and even machines to bring cutting tools into working condition.

One of these mechanisms is a device for sharpening drills, drill grinde, which makes it possible to restore the sharpness of 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). Ideal sharpening quality is guaranteed by precise positioning of the drill thanks to the clamping screws.

The heel (rear corner of the cutting surface) is formed due to a small axial inclination, which sets the arc movement of the drill during processing.

Source: https://FB.ru/article/61710/prisposoblenie-dlya-zatochki-sverl-kak-zatochit-sverlo

Device for sharpening drills and accessories for it +

about step drills

Drill sharpening can be done manually, on machines or with special abrasive discs.

If you sharpen the drill by hand, then you need to:

hold the shank firmly and guide its spiral part with the other hand;
press the cutting edge of the drill against the side surface of the abrasive wheel;
after sharpening one side, it is necessary to smoothly rotate the drill, while the cutting edges must have the correct inclination to the axis and take the desired configuration.

The drill is sharpened on both sides alternately. At the same time, be sure to control the cutting edges.

Remember! The tip of the drill should be exactly in the center.

Otherwise, it will deviate during operation. It is worth noting that under no circumstances should you put too much pressure on the drill, otherwise it may get defects (bending).

For example, if after sharpening you notice that the cutting edges are not the same and are inclined at different angles to the axis, then this means that the middle of the transverse edge is not in the center of the drill, and it will not work correctly.

Therefore, all experts recommend using a special sharpening machine for drills.

When sharpening, be sure to pay attention to the initial angle of the tool. It is he who will become your guide in the future. Then inspect the gimlet for damage:

if you find serious defects, you can use coarse sandpaper;
if the defects are small and the drill is only slightly dull, use a finishing wheel. This operation is necessary for thin drills;
if the concrete drill has defects in the shank taper, process the upper part of the tool, carefully pressing it against the grinding wheel;
After processing, carefully inspect the back surface of the drill again;
If you notice, or determine with a template, that you have a perfect cone, you have sharpened the tool correctly.

After this, process the cutting edge of the drill. The size of the jumper for rational turning of the tool should be 1-1.7 mm.

What are the features of sharpening machines?

A homemade device for sharpening drills is designed for through and blind drills made of steel, cast iron and various hard alloys. Depending on the type, machines can be equipped with different functions. On some of them, you can vary the angle during operation.

There are sharpening machines:

universal – used for various cutting tools;
specialized - for one type.

Devices for sharpening drills are classified as universal machines, because they can be used to process:

taps;
cutters;
dugouts;
countersinks.

Machines are divided into two categories:

Industrial - have high power and are designed for sharpening large-diameter tools. Power depends directly on the engine.
A household drill sharpening machine is quite compact and is often used for home use. It can be used to process even small-diameter drills.

There are seven sharpening methods:

Single-plane.
Complex screw.
Shaped.
Elliptical.
Conical.
Two-plane.
Screw.

How to make a device for sharpening drills

To make a homemade machine you will need:

toggle switch;
abrasive wheel;
stub;
engine;
stand;
wires.

Follow our tips:

For safety reasons, place the homemade machine in the case, leaving only the axle and abrasive wheel outside. Remember, the device will work from the network.
Select in advance the location where your drill sharpening device will be placed. It is advisable that it be on a metal table.
Next, place the electric motor on the tabletop using fasteners (clamps) and mark the locations of the holes for the bolts, if it has legs.
After this, remove the electric motor and make 4 holes.
Later, reinstall the engine and secure it carefully with the bolts.

Tip: If the engine does not have legs, you can strengthen it with metal strips (clamps).

The electric motor for our future machine must be equipped with a special elongated shaft, onto which a granular disk should be placed. For this:

Install the fastening nut by first cutting a right-hand thread at the end of the shaft.
Secure the disc with a washer and nuts.

If the diameter of the shaft and the disc holes match, then install a washer on the shaft, and then an abrasive disc. If the diameter of the shaft and the hole do not match, then you will need to add a bushing.

First make a special side hole in it with a thread for a bolt in order to be able to secure it tightly to the shaft. After this you can put the sleeve on.

If you can’t decide on an electric motor, then just take the motor of an old washing machine. It is ideal for a homemade sharpening device.

It is worth noting that you must prepare in advance the starter and wires that will subsequently need to be connected. It is very important that the starter has at least three to four open contacts. Its winding must be connected using two buttons to the phase line.

Attention! The electric motor will be unsafe, regardless of the type - during operation, the rotating shaft can accidentally wind up a cord, wire, or hair.

Tip: Make a metal box to protect the machine from dust, abrasive particles, and you from accidental injuries.

How to properly sharpen a drill on a machine

When sharpening, you must ensure that the two shoulders of the drill are identical. If you achieve such a correspondence, then the axis of rotation of the drill will completely coincide with the center of the hole.
Before you start sharpening, be sure to ensure that the abrasive disc is tightly secured.
Always start the process with a coarser abrasive.
Once a burr appears on your drill, you can change the abrasive to a finer one.
Watch the sharpening angle.
Do not allow the windings to switch so that the abrasive disc rotates in reverse. It should always move only in the direction of the blade.

Please note that drills cannot tolerate excessive overheating. Cool the gimlet regularly while sharpening.

But under no circumstances put a red-hot drill into water, as cavities may appear in it.

Additional accessories

about the Forstner drill

To avoid holding the drill suspended during sharpening (this can lead to injury), provide a support or guide in the form of a small attachment. It is made from a strip of metal, bent as shown in the figure and screwed to the frame (base). The drill is rested on it and brought to the circle at the desired angle.

Make marks (marks) on the guide described above for the required sharpening angles. It will become much more convenient to use.

If this is difficult for you, cut off the top part of a regular protractor and glue it to the guide.

Angles less than 300 are not used for sharpening, so we sacrifice them.

Universal device

To facilitate sharpening of tools, in particular drills, a mechanism has been developed consisting of a drill chuck, a shaft, roller guides (sled) and a protractor.

The main substrate described above is made wide. A protractor is glued onto it. A hole is drilled into which a bolt is inserted, which serves as an axis for the rotating surface.

A plate is installed on it on a roller slide, on which a pipe with a cartridge on the axis is fixed. The plate itself moves forward/backward using a conventional feed mechanism (threaded axis).

At the bottom of the rotating plate there is a displacement limiter indicator. It serves to rotate the device to the desired angle and to lock it.

Working with the device

A drill is inserted into the chuck.
The plate is turned to the desired angle and locked with a pointer.
Twist the handle to achieve the required sharpening of half the drill.
Notice the division.
Turn the drill 900 and repeat the operation, bringing the drill to the noticed point.

Source: https://refite.ru/prisposoblenie-dlya-zatochki-sverl.html

Drill sharpening device – Builder