Homemade tools for sharpening drills. A device for the correct sharpening angle of a drill. Homemade devices for sharpening drills with your own hands.

To quickly and efficiently drill holes you need sharp drills, which tend to become dull over time. This tool is best sharpened by a drill sharpening machine. You can also use special devices at home.

1

A drill sharpening machine is a highly specialized automated equipment designed only for sharpening drills. Depending on the area of use, the following types of devices are distinguished:

Industrial – have greater power; they can be used to sharpen various drills with a diameter of 20 mm or more. The main purpose of such equipment is intensive work at large enterprises with a high degree of profile specialization. IN industrial equipment the drill is sharpened in a fully or partially automatic mode at the desired angle using a fastening unit (special clamp).
Household - used exclusively in small industries or at home. The design of these machines is characterized by low power, compactness and mobility. They can be used to sharpen medium and small size which are used most often in everyday life.

A household machine for sharpening drills, compared to all other devices and devices used to restore the sharpness of a tool, has a lot of important advantages, among which, first of all, it is worth noting the following:

operates from an electrical network with standard voltage;
high degree of productivity;
ease of operation;
high level of sharpening accuracy and functionality;
affordable price, within the acceptable limits of the capabilities of any home craftsman;
has a light weight and compact size;
a convenient ergonomic control system provides regulation of the speed and intensity of sharpening.

2

All household machines are designed for sharpening high-speed steel of a certain diameter range of equipment that is structurally incorporated into the device. On many machines, you can sharpen tools equipped with carbide inserts - for this, a diamond wheel is supplied or additionally purchased. Typically, their capabilities include sharpening drills with a cone angle at the apex in the range of 90–140° along the back surface with backing and sharpening of the cutting transverse edge. But specialized modifications for metal drills are also produced:

left;
with a two-plane backing;
high-performance;
three-pronged;
others.

Most convenient in home use machines with a universal chuck for clamping drills various diameters within the technically acceptable range of sizes, as well as devices equipped with a set of removable cartridges that are mounted on the body of the machine itself and are always at hand.

Such equipment is usually equipped with a window through which you can observe the centering of the drill in the working area of the machine. The machine comes with standard accessories: CBN wheels, a set of collets, keys, spare parts. Can also be supplied additional accessories: diamond wheels, additional set of collets, lamp for working area and others. The most famous types of such machines: Drill Doctor, G.S. and their Chinese counterparts.

According to the range of sizes of drills processed, these machines produce two main types (with different extreme diameter values): from 2 mm to 13 mm and from 13 mm to 34 mm. Their disadvantages: poor sharpening of thin drills (the precision of the machines is not designed for this) and the inability to sharpen very thin ones. For tools of small diameters, you will need a special machine for sharpening drills - for example, VZ-389SP, designed for sharpening tools measuring 0.4–4 mm and equipped with a 30x optical device to control the sharpening process.

3

Before selecting a machine for sharpening drills, it is necessary to determine the future scope of work for it, because when purchasing you need to be guided by certain operational parameters . If the device is intended to be used at home (for example, in a country house or in a garage), then you can purchase a low-power, inexpensive model - given that the machine will not be used constantly, high-power equipment will be completely useless. In addition, industrial devices are designed for sharpening drills of large diameters and consume much more electricity than household models.

When purchasing a machine, please pay attention Special attention for the presence of a special regulator designed to adjust the spindle rotation. This option will make work as efficient and safe as possible.

Another important parameter is the size of the drills, which should be determined by the range of intended work. Selectable household machine must have a sufficiently low noise level, especially when the equipment is planned to be used for other purposes separate room, but directly in the residential area.

It is also necessary to pay attention to the design of the model you like - it is best if it is as simple as possible. In this case, any breakdown will not cause much trouble - it will not be difficult to find and purchase the necessary new part and install it in place of the failed one. It should be noted that most foreign models in terms of their Maintenance quite expensive, but find the required part replacement is sometimes difficult. And the last recommendation: you should choose a machine for sharpening drills only in specialized retail outlets and stores where a warranty card and technical passport will be issued.

4

At enterprises, in some cases, the driller sharpens the drills himself by hand on conventional sharpening machines, which are equipped with a special device for this purpose. To do this, he must first study the rules for sharpening drills and undergo special training courses. The drill sharpening device used is steel structure, equipped with a movable clamp for a drill with an adjustable angle of inclination relative to the rotating grinding wheel and having a mount for fixing on the body of the sharpening machine.

There are also frequent cases when an enterprise does not use any devices at all when sharpening by hand on a conventional sharpening machine. In this case, the drill right hand hold by the shank, and with the left hand - as close as possible to the cutting part. The cutting edge of the tool is pressed against the side surface of the abrasive wheel and at the same time the drill is gently rocked with the right hand, trying to ensure that its back surface accepts the required form and acquired the correct slope. You need to remove the metal in small layers, lightly pressing the tool against the circle. It is necessary to ensure that the cutting edges of the drill are the same length and have the same sharpening angles.

Mistakes made during manual sharpening can lead to the following drill defects:

cutting edges of unequal length;
the angles formed by the cutting edges with the tool axis are different;
The cross blade has a one-sided groove.

As a result of these defects, the drill will:

beat;
incorrectly, one-sidedly loaded on the cutting edges - may break;
drill holes larger in diameter than the drill itself.

After sharpening the tool, you should check the width of the transverse edge and the correct position relative to the cutting edges, the length of the latter, the angle: in plan φ, the inclination of the transverse edge, the clearance angle α, double sharpening φ1, at the apex 2φ. To check all these parameters, enterprises use special templates. The correct location of the jumper is determined using an optical device. In some cases, enterprises check the runout of the drill - they use a special device for this.

Metal drills made from high-speed steels are sharpened on grinding wheels made of white and normal electrocorundum on a ceramic bond with a grain size of 16–40, hardness SM, as well as on wheels made of CBN. When sharpening tools equipped with carbide inserts, synthetic diamonds are used, as well as green silicon carbide with a grain size of 16–40.

5

Without a special machine, you can use the following equipment to sharpen drills at home:

ordinary sharpening machine;
electric drill;
homemade sharpening devices.

To use a simple sharpening machine, it is better to purchase a special device, because before you yourself learn how to properly sharpen a tool without it, you can ruin more than a dozen drills. This device for sharpening drills has approximately the same structure as the industrial one described above. There are options not with mounting on the machine body, but with separate installation on a horizontal surface near the rotating grinding wheel. Such a device can be homemade. It can be made of wood: a beam with several holes for the diameter of the required drills, drilled at an angle, is attached to its base, ensuring desired angle sharpening. It is possible to provide for a change in the inclination - the sharpening angle.

In the case of an electric drill, a special attachment is used for sharpening drills. Unfortunately, they are available on sale only for sharpening at an angle of 118° and only for tool sizes of 3.5–10 mm (domestic) and 2.5–10 mm (imported). Moreover, both of them are only for drills with a spindle neck with a diameter of 43 mm. The body of these attachments has 15 holes for drills different diameters. The attachments are equipped with a stone, the sharpening surface of which is located at a certain angle, and a leader for it, inserted into the drill chuck.

By changing the length of the leash once (shortening it), the attachment is configured to work with one specific drill. They work with it as follows: a leash with a stone at the end is inserted into the drill chuck; the nozzle is put on the spindle and secured with a screw; start the drill and insert drills into the hole of the nozzle body of the appropriate diameter. You can also make such a device yourself. IN homemade nozzle it will be possible to provide the required sharpening angles and tool diameters.

Homemade devices can be made in the form of conventional sharpening machines. It is better to immediately provide a method for attaching and sharpening drills, so as not to invent additional accessories for this.

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;
cutting edge press 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.

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.

Exactly to universal machines include devices for sharpening drills, 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.
Domestic grinder for drills - 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.

Advice: 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 an old motor washing machine. It is ideal for homemade device sharpening.

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.

Advice: Make 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

Guide

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.

Goniometer

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 30 0 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 90 0 and repeat the operation, bringing the drill to the noticed point.

Making a device for sharpening drills with your own hands is quite simple; the conditions for success will be knowledge of the rules for sharpening cutting tool as well as the ability to work hand tools and technical savvy.

The basic rules for ensuring high-quality sharpening are:

in one pass it is necessary to remove a small layer of metal;
during the work process, the drill is repeatedly cooled in an aqueous or water-soda solution;
the rotation speed of the sanding wheel should be as low as possible;
the drill should not overheat during sharpening;
During the work process, the drill is directed against the movement of the abrasive wheel.

The volume and nature of the work performed depend on the type of wear on the cutting tool. Depreciation can be classified by:

back surface;
jumpers;
corners;
chamfer;
front surface.

Depending on the type of drill sharpening, it technical characteristics, as well as their purpose, the following types of processing are recommended, such as:

Type of sharpening	Diameter	Purpose and characteristics of sharpening angle
Single normal – “N”	up to 12.0 mm	For universal use. Angle – in accordance with the material being processed.
Single with jumper point – “NP”	up to 12.0 mm	For processing steel castings. Angle – 115-120°.
Single with a point of the jumper and ribbon - “NPL”	over 12.0 mm	For steel and steel castings as well as cast iron. Angle – 115-120°.
Double with a pointed jumper - “DP”	over 12.0 mm	For steel and cast iron with unskimmed crust. Sharpening is performed at two angles: 116-118° and 70-75°.
Double with a point of the jumper and ribbon - “DPL”	over 12.0 mm	For universal use. Angle – in accordance with the material being processed.
According to Zhirov's method	over 12.0 mm	Used in processing fragile materials. The main sharpening angle is 118*, additional sharpening angles are 70° and 55°.

Sharpening angles for twist drills used in machining various materials must be clarified before using them, because they vary from 85 to 135*, which is due to their viscosity.

How to make a machine with your own hands

To sharpen twist drills, any sharpening machine (unit) can be used, powered by an electrical network of 380/220 Volts, equipped with an emery wheel and equipped with a special device that ensures the fixation of the drill being sharpened at a certain angle to the axis of rotation of the abrasive element of the device.

Basic requirements for special devices, ensuring high-quality performance of work:

The axis of the device must coincide with the axis of rotation of the abrasive wheel. It can be in the same horizontal plane with it or be slightly higher than it.
The equipment and fixtures used must be securely fastened.
The design of the device should make it possible to sharpen the drill at different angles, depending on the user’s needs.

To make one of the options for such devices you will need:

Manual locksmith tool, angle grinder (“grinder”), welding machine.
Sheet steel 3.0 - 4.0 mm thick, as well as small diameter steel tube available.

Work on the manufacture of the machine is carried out in the following sequence:

The sharpening machine used (No. 5 in the diagram) is firmly fixed to the selected surface.
A platform is made from strip steel (No. 1 in the diagram), on which the drill will be fixed (No. 3 in the diagram).
The shape of the site can be arbitrary, the only condition is that a groove is made at the location of the drill using a grinder.
Holes are drilled on the platform (No. 6 in the diagram), which serve to secure the mounting plate (No. 2 in the diagram), as well as holes that provide connection of the device to the grinding machine (not indicated in the diagram).
The shape and size of the mounting plate can be arbitrary.
The attachment point to the base of the grinding unit is made from a metal tube and strip steel. The presence of a tube allows the device to move in vertical plane– it becomes possible to change the sharpening angle of the drill.
The attachment point for the sharpening device to the body of the sharpening machine depends on the type and design of the sanding wheel protection unit (No. 4 in the diagram), as well as the presence of a stop (platform) of the specific sanding unit.
If desired, the attachment point can be equipped additional elements, providing oscillatory movement of the device in the horizontal plane, which will ensure the required articulation during the work process.
After all the elements of the device are assembled, it is attached to the stop (casing) of the sharpening machine and the functionality of the manufactured device is checked.

To sharpen screw drills, you can use various emery wheels, but in light of the fact that this consumables(the tool) is made of durable steel, then the abrasive elements must correspond to this.

A device for sharpening drills is useful in any household. After all, working with a dull drill is a pain. You can make the mechanism yourself using unnecessary and outdated parts.

Rules for sharpening drills

Drills can be sharpened on special sharpening discs, manually or on machines. Before starting work, carefully examine the drills: if there are serious defects on the surface, you need to start sharpening with a coarser abrasive. If the tool is a little dull, use a finishing disc.

When sharpening manually with your own hands, you need to follow the rules:

hold the shank with one hand and adjust the working end with the other;
process the cutting edge with the side of the sharpening disc;
First, one side is sharpened, after which the drill is carefully turned over and the second is processed.

During processing, it is important to maintain the original shape of the drill and the direction of the cutting edges. It is necessary to ensure that the point of the tip does not move from the center, otherwise the tool will deviate to the side during operation. If after sharpening the angle of the cutting edges is not the same, the work of the drill will be poor. This is determined using a template made by yourself or by eye: the shape of the tip should be a cone. To avoid errors, it is better to edit on specialized devices.

Types of sharpening equipment

A homemade device is designed for sharpening drills made of various metals, cutters, taps, milling cutters, countersinks, cutters.

Equipment can be:

specialized - processes a single type of tool;
universal - used for all types of cutters and drills.

Homemade mechanisms often belong to the universal household type. Industrial machines are powerful and work with large tools. There is no need for such at home; they are noisy, take up a lot of space and are energy-consuming.

Household homemade machines are suitable for sharpening drills of small and medium diameter; they are compact and economical.

Making a sharpening machine

To assemble the machine with your own hands, you need to prepare:

electric motor;
grinding disc;
toggle switch;
stand;
electrical cable;
stub.

All components of the machine are placed inside the body with your own hands. This will make work safe and convenient. Only the motor pulley on which the grinding disc is mounted should be accessible. The machine is permanently attached to the workbench, so the location must be selected in advance.

place the electric motor in Right place, mark the attachment points on the table;
drill holes for the mounting bolts;
return the electric motor to its place and screw it to the workbench; clamps made of thin metal strips are suitable for fastening;
install the protective housing;
put on the engine pulley grinding wheel.

It is advisable to select an engine with an extended pulley, otherwise it will have to be delivered. First, put on the washer, then the circle. If the diameters of the pulley and disk do not match, an adapter sleeve is used. A threaded hole is made on the side of the bushing, and an additional fastening bolt is screwed into it.

By power for homemade machine suitable engine from washing machine. Do not select a high-speed engine, as sharpening of drills occurs at low speed.

Now you can connect the electrical component: toggle switch, motor and connect them to the outlet.

Additional devices

Additional accessories made by yourself will make the work of sharpening drills more convenient and accurate.

Template for verification. The template is cut out of a sheet of thin (1 mm) soft metal (aluminum, copper). The template reveals the angles at the tip, the length of the working edges, the angle between the working edge and the bridge. Since it is almost impossible to check the rear sharpening angle of a drill using a template, the sharpening angle is checked. The template is cut out before using the drill for the first time.

Guide. This is a small attachment that is made of a metal strip and is fixed to the body with a bolt. During operation, the drill is placed on a guide and brought to the grindstone.

Goniometer. On the stand, which is described above, divisions of sharpening angles are applied. You can cut off a piece of metal protractor with corner marks and attach it to a stand. You need to cut off a part with angles of more than 30 degrees, since smaller ones are not used when sharpening.

A device that makes drill sharpening easier. It consists of a fixed frame and holder, in which holes are provided for inserting cutters different sizes. The holder can be removed. The bed is made of a 50 mm board, a rail is attached to it at an angle of 32 degrees. The rack positions the holder with the tool at the required angle. The holder is cut out with your own hands from a block, the surface of which is removed at an angle of 65 degrees. The beveled part is laid against the rail. The bevel angles of the holder and the rack depend on the type of sharpening.

Multifunctional mechanism

Sharpening drills will become easier when using this mechanism. The device consists of:

roller slides;
guide;
shaft;
protractor;
drill chuck.

The guide should be made wide enough, and a protractor is attached to it. The rotation axis is a bolt inserted into the provided hole. Guides and a movable plate are placed on the rotating part. An axis and tube are fixed on its surface; on one side the axis ends with a drill chuck, on the other - with a handle. The movement of the thrust plate is ensured by a threaded axis.

At the bottom of the thrust plate there is a limiter (also known as a pointer), which simultaneously indicates the required displacement angle and fixes it in the desired position.

The mechanism works as follows:

the drill is fixed in the chuck;
the thrust plate is locked at the required angle;
the tool is rotated along the longitudinal axis using a handle;
mark the angle;
turn the cutter 90 degrees and process the second half, reaching the marked angle.

Rules for sharpening on a homemade machine

When machining drills, both hangers must be identical. This means that the drill will fit smoothly into the hole and perform drilling efficiently.
Before starting the machine with your own hands, securely attach the grinding wheel to the pulley.
Carry out initial processing with a disc with a coarse abrasive. When you notice a burr on the drill, the disc should be replaced with a thinner one.
While sharpening, maintain the required angle at all times.
The circle should only rotate in one direction, along the blade.
Do not allow the cutter to overheat; it should be cooled periodically during processing. Do not immerse overheated tools in cold water, this promotes cracking of the metal.

Several options for sharpening drills in the videos.