Homemade device for sharpening drills for metal. Sharpening a drill for metal: how to sharpen a drill at home

Dull bits can break during use and injure you. Much better and easier to work sharp. In this manual you will find drawings and a device for sharpening drills.

Step 1: Comparing a sharp and dull drill

Left is dull. This can be seen from the light reflection on the cutting edge between the two grooves. The photo on the right shows a sharp cutting edge.

Step 2: Sharpening Tool

Experienced people know how to sharpen drills with their own hands. In theory, the shank should be held in the right hand at an angle of 59° relative to the drill grinder. When the drill touches the sharpener, you need to move the shank further down to the left, at the same time turning the drill around its axis clockwise. It never worked out for me.

The sharpening tool that you see in the photo, I bought almost thirty years ago. Such simple drill sharpeners are still sold for almost the same price.

Step 3: Set the Degree

The rail on the rack can be set to seven positions. My drills have a 59° cutting edge angle profile, you need to set this degree on the guide. Tighten the wing nut.

Step 4: Straighten the Edge

The sharpening tool has a small pointed tip, and the edge of the groove must be set to butt against it. The tip can be lowered or raised to fit the edge of the groove.

Step 5: Steer Amount

First you need to set the offset (the distance between the yellow lines), it must be equal to the radius (the distance between the green lines).

Step 6: Width and Angle of the Cutting Edge

Note the angle of the red line. If you moved the drill too far in the previous step, the cutting edge will move closer to the top. The edge is too wide, and the profile is flat. Because of this, it will slide on the surface of the metal and it will be difficult for you to drill. You can reduce the stem a little, but not much, otherwise you could accidentally ruin the tip of the sharpening tool on the sharpening wheel of the stand.

Step 7: Ideal cutting edge angle

Ideally, the edge should be as small as possible. It will be the bottom point between the bevelled edges of the drill grooves, indicated by the yellow line in the photo, this drill will cut metal very well.

Step 8: Clamp

After you set the stem, tighten the fastening screw.

Step 9: Setting the Length

Set the sharpening guide to the length of the drill. The end should be in the mobile tray, not hanging in the air. Loosen the painted metal nut. Adjust the black nut. Tighten the painted metal nut.

Step 10: Setting the Height

The shank should be at right angles to the grinding wheel. For sharpening, I use a radial cut-off machine. The tip must be aligned with the center of the axis of the grinding wheel.

Step 11: Fixing the Machine to the Table

The bit should only lightly touch the grinding wheel. If you press too hard, it will be very difficult to sharpen it. It will overheat and you will remove too much metal.

The base of the sharpening guide should be at right angles to the grinding wheel (green line). And turn the upper part of the guide so that the tip looks slightly to the left of the center (the angle between the green and yellow lines). Move the machine forward so that the drill touches the surface of the grinding wheel. Fix the machine on the table.

Step 12: Get ready to sharpen

Turn the tip to the right. Turn on the grinding wheel.

Step 13: Sharpening

Move the tail of the guide to the right (red arrow) so that the drill touches the whetstone. Yellow wavy lines represent sparks. When the drill is in this position, in fact, it will be sharpened.

Step 14: Rotate the bit

Keep moving the tail of the guide to the right until the drill is over the edge of the stone. To sharpen on the other side, you need to turn it around its axis by half a turn.

Turn off the machine first. Then loosen the fastener and turn it half a turn. The edge of the groove should be close to the sharpening tip. Repeat the previous two steps.

Turn off the machine. Pull out of the mount. Check the width of the transverse cutting edge. If you are unhappy with the quality of your sharpening, change the stem and repeat the process.

Step 15: Sharpened Drill

The photo shows a good sharpening. The cutting edges are not worn or rounded, they are sharp and clear. The length and angle of the transverse cutting edge is also quite good.

Step 16: Thin Drills

Such a sharpening tool is good for 3 mm and more. If it is thinner, it will no longer be possible to sharpen it with this device.

To sharpen thin ones, make a special block of a wooden block about 10 cm long. Please note that the angle between the red lines is 77 °.

Step 17: The Angle Between the Faces of the Wooden Block

Side view of the block. The angle between the red lines is 59°.

Step 18: Guide Line

A triangular notch is visible on the upper plane of the bar. This cut goes along the entire upper face of the block and serves as a bed. The angle between the red lines is also 59°. The edges of the triangular cut serve to align the cutting edges. Edges can be checked by eye.

Step 19: Attaching to the Bar

Place the drill into the cut in the block. Set the block in a vise so that the shank is above the grip, and the grip extends slightly beyond the beveled side of the block. Rotate so that one of the cutting edges aligns with the leading edge of the triangular notch. Fasten with a clamp. Put some oil on the whetstone. Swipe along the beveled side of the device, thereby sharpening the drill.

When the whetstone stops cutting metal, turn the bit half a turn and sharpen the other edge. You can check homemade sharpening with a magnifying glass, if necessary.

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

For sharpening, you need a special tool 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 a machine necessary for sharpening metal, as well as how to properly sharpen a drill for metal. The instruction in the video will help you to 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 pro to know how to sharpen drill bits for metal. This requires a sharp fixture that will help keep it in optimal condition for operation.

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

The most effective device for sharpening core drills is a machine on which a whetstone is installed.

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

However, it is desirable to know some of the nuances of how sharpening is carried out before starting the process: the tool is processed from behind along the edges, while the most important role is occupied by the angle at which the tool is located when it is fed to the machine.

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

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

Watch a video on how to properly sharpen tools before you start this process yourself.

After that, you need to collect the necessary tools that 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 will need special circles that are needed for sharpening.

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

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 liquid for cooling - it can be water or machine oil. You also need a container in which the liquid will be filled.

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

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

A homemade hole saw must have the right angle, and this is the most difficult part in making 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 to save time and effort.

The most important angle is in front, it is determined based on the main cutting plane.

The rear corner has parameters similar to the front, but in accordance with the rear plane.

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

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

Before work, you need to prepare gloves and goggles, since 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.

The sharpening process and the advantages of the machine

Crown, stepped 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 bit to be sharpened to the circle. In this case, the cutting part of the stepped drill should be directed to the sharpener.

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

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

In this position, it remains only to sharpen it, and then you will get a quality tool that can be used 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 is larger, then you need to extend the time spent on sharpening, and also pay more attention to the front side 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 will need a full-fledged machine.

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

If you often use drills of different sizes, then the machine will quickly pay for itself, because. you have to sharpen them 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.

This is also the case with drills designed to work with strong metals, or tools that have a small undercut and are designed for drilling deep holes.

The correct machine must 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 grinding plate that allows you to do this.

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

The drill of the machine is installed to the rotary column, which is also located on the base plate.

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

The machine is started with the help of an engine, 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 deploy it with the back, which needs sharpening.

Such a system is very convenient, because 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 that have a diameter of more than 16 mm, for smaller tools, compact attachment machines can be used.

It is more convenient to work with such devices, because. they can be moved or installed in the place where you need.

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

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

The easiest, but least effective way to sharpen a tool is to do it with a grinder, or with a device on which a movable circle is installed.

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

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

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 fine-tuning, which is a very important part of the process. Finishing is needed in order to make the tool even and smooth.

With professional sharpening, fine-tuning is mandatory, as this increases the service life of the device.

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

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

Drills must be of high quality and well sharpened by a professional craftsman. In the old days, drill sharpening was done by hand.

To date, special devices for sharpening drills have appeared, and their design is very simple.

What is sharpening for?

If the drill is blunt, then it is very difficult, and sometimes impossible, for them to drill through the surface. It is also worth noting that for different types of surfaces, drills must have a certain sharpening angle, for example, for a plastic surface, the angle will be 30 degrees, for hardened steel, this angle will be 130 degrees.

In cases where a perfectly drilled hole is not required, the sharpening angle can be 90 degrees.

How to properly sharpen a drill

You can sharpen the drill with your own hands using abrasive discs. During sharpening, the drill must be held by the work surface. Hold the tail of the drill with the other hand.

From the side, the drill must be pressed against the abrasive disc. Then it is desirable to turn it with utmost care, as a result, the cutting edge will take the required angle and structure.

Drill sharpening must be done on each side separately. It is also necessary to ensure that the tip of the drill is located exactly in the center at the time of sharpening the cutting part. This must be done correctly, as an error in sharpening can cause the drill to mow sideways.

Sharpening a drill with your own hands is not the best way, as it can carry a number of inaccuracies, for example, the cutting edges may not be correct in relation to the tool axis.

Sharpening device

The device is designed for sharpening blind or through drills, which are made of cast iron and steel. Such a device is made taking into account the types of sharpening, as well as its size. It is easy to change the angle of sharpening on the machine.

There are two types of devices that will help sharpen a drill: a household and an industrial machine. In the first case, the sharpening device takes up little space and fits perfectly for working in the home, but such a machine can only sharpen small drills.

Industrial machines have great power, which are made in order to sharpen drills with a large diameter. The industrial machine has a clamp and a circle for sharpening.

With this device, the sharpening of the drill takes place under the supervision of the operator, who easily controls the process. Such devices are designed for long-term operation.

How to make a machine for sharpening drills with your own hands

We will need the following materials: an abrasive disc, a switch, a motor with good power, a stand, wires, an axle and a plug. Also, for the safe use of the machine, it must have a housing, outside of which it is necessary to put an axis with an abrasive wheel for work.

First you need to decide on the installation location of the machine, as it will be connected to a power outlet.

Also, our device should be placed on a table, preferably made of metal, where you will need to put the engine, and place marks for making holes for the bolts.

An abrasive disk is put on the motor shaft. To fix it on the shaft, you must first put on the washer, then the disk and again the washer. After that, install the mounting nut on the pre-prepared thread on the shaft.

As a motor for our device, the engine from the washing machine is perfect. The power of its motor will be sufficient for the process of sharpening drills. Wires can also be taken from improvised equipment.

Note!

You need to connect the wires to the starter, which should be with three open contacts. The winding must be able to connect phase lines using two starters connected in series.

The off button must be connected to NC, and the start button will be connected to NO, and it must also be in parallel with two NO contacts of the starter.

When the power button is pressed, voltage will be applied to the winding, as a result, the circuits should close. When the button is released, the voltage supplied to the starter should not be removed. When disconnected, the engine should stop.

The engine itself is a safe device, but to protect its mechanisms from dust, it is necessary to make a frame that will protect it from environmental influences.

For its manufacture, you can use a metal box or make a protective screen of glass. It is also worth installing a casing that covers the end of the disk by a third. It will protect the worker in case the abrasive disc cracks.

DIY drill sharpening photo

Note!

Note!

If you are constantly dealing with sharpening hard workpieces, then the surface of the drill will become unusable very quickly. It will become dull, get very hot and eventually lose its former strength. All this is a consequence of the "letting go" of the metal. That is why such a tool needs periodic sharpening using special devices.

How to make homemade devices for sharpening drills, what templates exist for this and what you need to prepare for work, you will learn from our article.

Features of sharpening drills

Drills are inexpensive devices, especially if we talk about those that are widely used for domestic needs. However, if possible, then after blunting it is better to sharpen the tools than to buy new ones.

There are factory-made sharpening devices, but you will spend a lot on buying them, and this will not make up for the savings if you refuse to purchase new tools. That is why many masters collect machine tools for sharpening by hand.

It is worth noting that blunting applies to metal drills, since wood tools are practically not affected, except when used at high speeds with a resinous workpiece. Also not subject to sharpening Pobedite tips for stone or concrete.

But many drills for metal are sharpened using all the additional devices with their own hands, but the accuracy of such work is far from always ideal, so it is advisable to use at least a minimum of mechanics.

How to make a do-it-yourself drill sharpener: a tutorial video

To make such a device yourself, you will need a control tool (template). No matter how the drill is sharpened, the accuracy is checked by a special template.

Simple drills for ferrous metal have an edge angle of 115 to 120 degrees. If the metal is different, then the sharpening angles will also be different:

You can prepare right away multiple templates depending on the listed values ​​​​and, in accordance with them, do sharpening with your own hands. The same drill can be used for different types of workpieces, you just need to change the angles of the top of the workplace.

A simple but very convenient dragging device is bushings of various sizes that are attached to the base. You can make them yourself, based on special drawings. Remember that the tool in the sleeve should not dangle, and the quality of drilling may deteriorate even if the error is only one degree.

You can make a large clip based on aluminum or copper tubes, depending on the typical parameters of the drills, or you can take a bar of soft material and make many holes in it. In the grinder, it is very important to put a convenient handrest, thanks to which it will be possible to move the sharpening device at the right angle and hold the stop.

The listed sharpening devices have been manufactured for many decades in a row and are still in demand. For sharpening machine assembly with your own hands, you can take an oak bar instead of a corner.

The simplest sharpening machine can be assembled by simply placing a workbench or table opposite the side of the emery. Even such a simple device provides high quality and accuracy of work.

Features of sharpening on a simple device

On the Internet you can find finished drawings devices for sharpening drills, or sketch them yourself, but for this you should understand the principle of working with a drill.

During work Absolutely forbidden allow the drill to move around its axis. If it turns at least a millimeter, it will be damaged, and you will have to grind a small distance for re-processing.

After finishing work, the drill should cool down, also measure with templates. The edges must be perfectly symmetrical down to tenths of a millimeter. This is especially important if the drill has a minimum diameter.

Sharpening may be accompanied by such errors:

As from improvised means with your own hands assemble a grinder for twist drills for metal?

For the basis of the device, you can take any grinding machine that is able to work properly, there is no axis beating in it, and it keeps the speed under load.

The task looks like this:

• the handist must strictly stand horizontally on the same axis with the rotation of the emery;
• the design must be safe, reliable and durable;
• it should be possible to sharpen both manually and semiautomatically;
• the shape of the handpiece should facilitate the free lowering of the drill shank to the desired angle.

Specific details for the manufacture of this device are not required, almost every home master has everything you need. Workpieces are processed grinder, welding or grindstone.

For the semi-automatic mode, a rocking stop is assumed, so you need to make a loop connection. Pick the right one for lack of backlash bolt, bracket and tube holes.

The platform must move vertical axis so that you can change the angle of sharpening the drill. This axis can be fixed, and the hand rest should swing, while leaning on the horizontal axis, which provides the desired articulation when sharpening.

Base plate made of metal 4 mm thick, and the main parts of the structure must have a thickness of 3 mm, respectively. This ensures its high strength. The handpiece with the body of the emery is rigidly connected. It is impossible to fasten it to the protective casing, therefore, use the metal "cheek" to screw the bracket.

Then we fasten the guide plate for drills with a thickness of 5 mm to the base plate. In it, to fix the drill during processing, it is sawn triangular groove.

The design has an angle of rotation of 90 degrees, which allows you to provide z sharpening by different methods. Starting from the Leontiev method and ending with pressing at a certain angle and creating an acute edge angle due to the curvature of the emery.

The drill during processing will not only stand firmly in the groove, it can also be fed along the groove to the abrasive, and the sharpening angle will not deviate. Due to the partial excess of the plane of the base plate above the axis of movement of the disk, it is possible to achieve the desired shape of sharpening the back of the edge.

Before performing work, the drill should press on the plate and set the cutting edge parallel to it. The adjustment is over and you can bring the tool to the emery. Sharpening must be done slowly and carefully, carefully monitor the angle.

Thanks to this homemade tool, high sharpening precision and almost no template is needed. True, it will take time to install the machine and adjust the angle, but then you sharpen drill bits quickly in the right amount.

But if you need to sharpen a drill equipped with a carbide nozzle, then you can attach a swinging plate to a fixed angle. To do this, put several washers under the axle nut.

Using an emery wheel in a homemade sharpening tool

For universal grinding work, white circles based on electrocorundum are mainly used. They are used for sharpening shovels, axes, knives and metal blanks.

In order to process carbide drills or high-speed metals, it is necessary to take abrasive green wheels based on silicon carbide marked 64C. But for domestic needs, the grain size of the circle is enough for 25N.

Sharpening drills requires a finer fraction in the area from 8N ​​to 16N. Remember that silicon carbide emery gets very hot during operation, so the drill cannot be kept in contact with such an abrasive for a long time. Let the metal cool down after 2-3 passes and chill it in soda water.

Edge quality depends on direction abrasive rotation. Its working surface must run into the cut (go from top to bottom).

Peripheral emery surface during processing must be even. It can be edited with a nozzle based on CBN. If the disc has a small diameter, it is allowed to use pliers, in which the elbor cutter will be held.

So, we looked at how at home you can assemble and use devices of varying complexity in order to sharpen drills and more. You can choose the appropriate option depending on your household needs.

The technological process of mechanical processing of materials includes a wide variety of operations, which require high-quality and sharp tools. So, in a mechanical workshop at any machine-building enterprise, a set of turning, milling, drilling and more complex machines can be used. They use their own type of tool, for each of which there is a specific method of sharpening.

Features of the drills

Machining of metal is associated with huge loads on the tool. In general, it consists of three main parts: connecting, body and cutting. So the cutting part is a small wedge-shaped element designed to penetrate the metal and remove part of it from the workpiece.

If, for example, everything is clear in a turning tool or a disk cutter with the shape and design of the cutting part, then when processing holes on a drilling machine, everything is much more interesting and complicated, so you need to know how to sharpen the drill correctly. This is a tool designed for axial metal processing. That is, the feed movement is directed strictly along the axis. This should be considered before sharpening the drill for metal, because the wrong cutting angle will lead to vibration and breakage.

The main elements of the cutting part of the drill

Before sharpening a drill for metal, you should familiarize yourself with the design of its cutting part, which includes the following elements:

1. Main cutting edge.

2. Auxiliary helical cutting edge (ribbon).

3. Jumper.

4. Front surface.

5. Back surface.

What is needed for sharpening?

At the enterprise, everything necessary for the restoration of the instrument is always at hand. But the home master has to look for an alternative to high-quality factory fixtures in simpler solutions that can be used in an ordinary garage. And yet, before sharpening a drill for metal, stock up on a minimum set:

1. Grinding wheel. It must be mounted on a rotating shaft. The device is popularly known as "emery". Very common in the garage.

2. Capacity for coolant.

3. Coolant (water or engine oil).

In order to withstand the angle of sharpening the drill, such a set may not be enough. After all, you will have to control the process "by eye", which is unlikely to work out without some experience. In this case, the basic kit also needs to include a tool for sharpening the drill, which you can buy or make yourself.

Controlled parameters

When everything is ready, it is necessary to familiarize yourself with some theory in order to have an idea about the main parameters of an axial cutting tool. Before you sharpen the drill correctly, you need to know its angles:

1. Front. Defined in the main cutting plane (running perpendicular to the main cutting edge) as the angle between the rake face and the main plane (perpendicular to the cutting speed vector). It is directed tangentially to the circle of the drill.

2. Rear. Also defined in the principal shear plane as the angle between the flank and the cutting plane (passes through the velocity vector and the cutting edge).

3. Corner at the top located between the two main cutting edges when viewed from the side of the drill.

The optimal value of the front angle is 18-20 degrees, the rear one is 10-12. The corner at the top in drills for metal has a standard value of 118 degrees.

Sharpening process

Now let's talk about how to sharpen a metal drill on ordinary sandpaper. The main sharpening of this axial tool is carried out on the rear surface. To do this, turn on the emery, firmly take the drill in your hand so that the main cutting edge is directed towards the rotation of the grindstone. Now we bring the edge to the grindstone, after which we turn the drill by the shank so that the cutting edge is parallel to the surface of the circle. We do the same operation with the second cutting edge. The result is the so-called simple sharpening of the drill, which is optimal for most metal processing modes.

Simple sharpening is used for drills with a diameter of up to 10 mm. By increasing this parameter, you can additionally perform a subpoint of the front surface. As a result, the rake angle decreases, which means that the thickness of the blade (the so-called cutting edge angle) and, accordingly, the drill life increases.

Sharpening with a fixture or machine

The method described above can be called artisanal, since it is simply impossible to achieve precise control of the drill parameters directly during sharpening. In the best case, you will check the angles after sharpening is completed, and in the worst case, you will simply check how much better the drill has become. And how to sharpen a drill?

Of course, for this it is better to use more advanced options that will allow you to tune in to certain angles in advance. In this case, you will need a device or machine for sharpening drills.

If the scale of work in your workshop is large enough, and regrinding of the tool is required constantly, then purchasing a machine will be optimal. It will greatly simplify the process, especially if you need to regrind carbide drills for metal. The main advantage of its use is the exact observance of predetermined parameters. With a large amount of work, it is unacceptable to use an incorrectly sharpened tool, as this will lead to a decrease in productivity. Modern grinding machines allow you to obtain various types of drill sharpening:

1. X-type. Mainly used for drilling in blind holes. Designed to reduce axial cutting force.

2. XR type. Used for universal drills. Cutting into the material is somewhat worse than in the first type, however, such drills have increased strength and durability.

3. S-type. The sharpening described above is used here, which also allows you to increase the life of the drill in the processing of various materials (from cast iron to stainless steel).

4. N-type. A subpoint is also used, but of a smaller size. Drills with this sharpening are used for deep drilling.

Fixture design

As it has already become clear, manual sharpening of a drill is the business of a professional who not only knows the correct angles, but also feels the cutting process. Unfortunately, such a flair comes only after many years of practice with a drilling machine or drill. You should not experiment, as you can make your own or purchase a sharpening device. In both cases, it will include the same structural elements and work on the same principle.

So, the main task of the fixture is the correct orientation of the drill relative to the plane of the grinding wheel. To do this, its design includes a base plate, on which it is desirable to place both the device itself and the electric motor, on the shaft of which the grindstone is located. There is also a rotary column on the plate, on which the drill is fixed. It must be able not only to rotate, but also to move towards the grinding wheel.

As a column, you can use any bearing assembly with a shaft, for example, from an old drill. A drill bed is fitted on the shaft rings (you can use an adapter sleeve), to which it is pressed with screws. After fixing the drill, the grinder drive is turned on, the column is brought to the grinding surface and rotated to give the back surface of the drill the correct shape. It is important that during the initial setting of the fixture, the angle at the top of the drill is 118 degrees.

Sharpening nozzles

Another simple and convenient way involves the use of a device such as a nozzle for sharpening drills. Its main advantage lies in its versatility and ease of use. The device has a cylindrical shape. On the one hand, there is a connecting node, through which the nozzle is installed on the drill spindle. On the other side there are holes for installing drills of a certain diameter. For sharpening, the drill is inserted into the hole, after which the sharpening mechanism is driven by the drill motor.

Security measures

The sharpening of the drill is associated with the formation of small particles that break away from the sharpener during wear. They heat up and scatter in different directions in the form of fiery sparks, so for safety, you should use goggles and gloves.

When sharpening a drill without a tool, make sure to securely fix its position. Otherwise, upon contact with the sharpener, it can simply be pulled out of your hands.