For smooth and accurate work, you need a good tool. And if you need to drill a tree, then you don’t have to worry about the sharpness of the drill, because it can last for several years. Also, sharpening a drill for metal of large diameter (from 6 mm) does not cause much trouble. But when it comes to drills with a small diameter, which are used in radio or electronic technology, then one cannot do without a device for sharpening them.
The dullness of a drill depends on many factors. First of all, it is the speed of revolutions and cooling. The time it takes for a drill to work satisfactorily is often measured in minutes. Of course, you can constantly buy new drills, but believe me - it's very expensive. Therefore, it makes sense to learn how to sharpen drills yourself, and for this you need to make a special tool.
In this article, we will talk in detail about how to make a simple device for sharpening drills with your own hands of small diameter (from 2.0 to 6.0 mm).
The device shown in the photo can be improved and finalized at will.
In the photo, the drill is located at an angle of 60˚ to the working surface, i.e. to the working side of the abrasive disc. This is due to the fact that the drills used for metal have a sharpening angle of 120 ˚.
The principle of operation of this device has already been published more than once on the Internet. But this option involves the use of vices for jewelry work. This is a fairly inexpensive and common tool available on the market. Jewelry vices are shown in the photo.
The principle of operation is the following. With the help of the handle, the jaws are moved apart, and the drill is firmly clamped. The cutting edges must be parallel to the jaws.
The vise shown in the photo has been slightly altered. Plates are additionally installed on them and riveted with new, longer rivets. The plates are needed in order to install an axis with the so-called "rocking chair", with which both sides of the drill will be sharpened alternately.
To install it on the plate on both sides at the same distance from the center, it is necessary to drill two holes through which this axis will pass.
The "rocking chair" is fixed on the racks, which are attached to the oak plate. Height adjustable with four support legs.
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!
Drill sharpening can be done manually, on machines or special abrasive discs.
If you sharpen the drill by hand, then it is necessary:
- firmly hold the shank, and with the other hand guide its spiral part;
- press the cutting edge of the drill against the side surface of the abrasive wheel;
- after sharpening one side, it is necessary to smoothly turn the drill, while the cutting edges must necessarily have the correct inclination to the axis and take the desired configuration.
The drill is sharpened alternately on both sides. When doing this, be sure to control the cutting edges.
Remember! The tip of the drill should be exactly in the center.
Otherwise, it will be rejected during operation. It is worth noting that in no case should you press hard on the drill, otherwise it may get defects (bend).
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 original 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, then you can use coarse sandpaper;
- if the defects are small and the drill is blunted quite a bit, use a lapping wheel. This operation is necessary for thin drills;
- if the concrete drill has defects in the shank cone - process the upper part of the tool, gently 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 that, 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 grinding machines
A home-made device for sharpening drills is designed for through and deaf gimlets made of steels, cast iron and various hard alloys. Depending on the type, the machines can be endowed with different functions. On some of them during operation, you can vary the angle.
Sharpening machines are:
- universal - used for various cutting tools;
- specialized - for one species.
It is to universal machines that devices for sharpening drills are referred, because they can 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 grinder is quite compact and is often used for home use. With it, even small-diameter drills can be processed.
There are seven sharpening methods:
- Single plane.
- Complicated-screw.
- Shaped.
- Elliptical.
- Conical.
- Biplanar.
- Screw.
How to make a drill sharpener
To make a homemade machine you will need:
- toggle switch;
- abrasive wheel;
- plug;
- engine;
- stand;
- wires.
Follow our advice:
- For safety reasons, place a homemade machine in the case, leave only the axis and the abrasive wheel outside. Remember, the device will work from the mains.
- Choose in advance the place where your drill sharpener will stand. It is desirable that it be on a metal table.
- Next, put the electric motor on the tabletop with the help of fasteners (clamps) and mark the locations of the bolt holes, if it has paws.
- After that, remove the electric motor and make 4 holes.
- Later, reinstall the motor 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, on which a granular disk should be put on. For this:
- Install the fixing nut, having previously cut a right-hand thread on the end of the shaft.
- Secure the disc with washers and nuts.
If the diameter of the shaft and the hole of the disc match, then install the washer on the shaft, and then the abrasive disc. If the diameter of the shaft and hole do not match, then you need to add a bushing.
Pre-make a special side hole in it with a thread for the bolt in order to be able to tightly fasten it to the shaft. After that, you can put on the sleeve.
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 the starter and wires in advance, which will later need to be connected. It is very important that the starter has at least three or 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 the cord, wire, hair.
Advice: Make a metal box to protect the machine from dust, abrasive particles, and you from accidental injury.
How to sharpen a drill on a machine
- When sharpening, it is necessary to ensure that the two shoulders of the drill are the same. If you achieve such a correspondence, then the axis of rotation of the drill will completely coincide with the center of the hole.
- Before sharpening, always make sure that the abrasive disc is firmly fixed.
- Always start the process with a coarser abrasive. After 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 be switched so that the abrasive disc rotates in reverse. It should always move only in the direction of the blade.
Please note that drills do not tolerate excessive heat. Cool the gimlet regularly while sharpening. But in no case do not lower a red-hot drill into the water, as cavities may appear in it.
Accessories
- guide
In order not to keep the drill in the process of sharpening on weight (this can lead to injury), provide a substrate 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 rests on it and is brought to the circle at the right angle.
- Goniometer
Make on the guide described above, risks (marks) at the required sharpening angles. It will become much more convenient to use it.
If this is difficult for you, cut off the top of a regular protractor and glue it onto the guide.
Angles less than 30 0 are not used for sharpening, so we sacrifice them.
- Universal fixture
To facilitate the 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 base substrate described above is made wide. A protractor is glued to it. A hole is drilled into which a bolt is inserted, which serves as the axis for the rotary surface.
A plate is installed on it on a roller slide, on which a pipe with a cartridge is fixed on the axis. The plate itself moves forward/backward using a conventional feed mechanism (threaded axle).
At the bottom of the rotary plate, a displacement limiter is fixed. It serves to rotate the device to the desired angle and for its stopper.
Working with fixture
For fast and high-quality drilling of holes, sharp drills are needed, which tend to become dull over time. Best of all, this tool sharpens the machine for sharpening drills. At home, you can also use special devices.
1
The drill sharpening machine is a highly specialized automated equipment designed only for sharpening drills. According to the scope of use, the following types of these devices are distinguished:
- Industrial - have more power, they 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 production or at home. The device of these machines is characterized by low power, compactness and mobility. On them it is possible to sharpen drills of medium and small sizes, which are used most often in everyday life.
A household drill sharpening machine over all other devices and devices used to restore the sharpness of a tool has a lot of important advantages, among which the following are worth noting in the first place:
- works from the mains with standard voltage;
- high degree of performance;
- ease of operation;
- high level of sharpening accuracy and functionality;
- affordable price, which is within the acceptable limits of the capabilities of any home master;
- has a small weight and compact size;
- convenient ergonomic control system provides regulation of the speed and intensity of sharpening.
2
All household machines are designed for sharpening from high-speed steel of a certain range of diameters, which is structurally embedded in the device. On many machines, you can sharpen tools equipped with carbide inserts - for this, a diamond wheel is supplied or additionally purchased. Usually, their capabilities include sharpening drills with a taper angle at the top in the range of 90–140 ° along the rear surface with backing and sharpening of the cutting transverse edge. But specialized modifications for drills for metal are also produced:
- the left;
- with two-plane backing;
- high performance;
- three-pronged;
- others.
The most convenient for home use are machines with a universal chuck for clamping drills of various diameters within the technically permissible range of sizes, as well as devices equipped with a set of removable chucks 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. Additional accessories can also be supplied: diamond wheels, an additional set of collets, a lamp for the work area and others. The most famous types of such machines: Drill Doctor, GS and their Chinese counterparts.
According to the range of sizes of processed drills, these machines produce two main types (with different extreme diameters): from 2 mm to 13 mm and from 13 mm to 34 mm. Their disadvantages: poor sharpening of thin drills (the accuracy of the machines is not designed for this) and the impossibility of sharpening 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 with a size of 0.4–4 mm and equipped with a 30x optical device to control the sharpening process.
3
Before choosing a machine for sharpening drills, it is necessary to determine the future scope of work for it, because when buying it is required to be guided by certain operational parameters . If the device is supposed 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 in constant use, high-power equipment will be completely useless. In addition, industrial devices are designed to sharpen drills of large diameters and consume much more electricity than household models.
When buying a machine, you should pay special attention to the presence of a special regulator designed to adjust the rotation of the spindle. This option will make the 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. The selected household machine must have a sufficiently low noise level, especially when the equipment is planned to be used not in some separate room, but directly in a 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 put it in place of the failed one. It should be noted that most foreign models are quite expensive in terms of their maintenance, and sometimes it is not easy to find the right replacement part. And the last recommendation: you should choose a machine for sharpening drills only in specialized outlets and stores where a warranty card and technical passport will be issued.
4
At enterprises, in some cases, the driller grinds the drills himself by hand on conventional grinding machines, which are equipped with a special device for this purpose. To do this, he must first study the rules for sharpening drills and take special preparatory courses. The used tool for sharpening drills is a steel structure, equipped with a movable drill clamp with an adjustable angle relative to the rotating grinding wheel and having a mount for fixing on the body of the sharpening machine.
It is also not uncommon for an enterprise to use no tools at all when sharpening by hand on a conventional grinding machine. In this case, the drill is held by the shank with the right hand, and with the left - 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 takes the desired shape and acquires the correct slope. You need to remove the metal in small layers, gently pressing the tool to the circle. It is necessary to ensure that the cutting edges of the drill are of the same length and have the same sharpening angles.
Mistakes made during manual sharpening can lead to the following drill deficiencies:
- cutting edges of unequal length;
- the angles formed by the cutting edges with the tool axis are different;
- the transverse blade has a one-sided undercut.
As a result of these defects, the drill will:
- beat;
- incorrectly, unilaterally loaded on the cutting edges - it may break;
- drill holes of a larger diameter than the drill itself.
After sharpening, the tool should be checked for the transverse edge for its width and correct position relative to the cutting edges, the length of the latter, the angle: in terms of φ, the inclination of the transverse edge, the clearance angle α, double sharpening φ1, at the top 2φ. To check all these parameters, enterprises use special templates. The correct location of the jumper is found out using an optical device. At enterprises, in some cases, the runout of the drill is checked - they use a special device for this.
Drills for metal 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 CM, as well as on CBN wheels. When sharpening tools that are equipped with carbide inserts, they are used from synthetic diamonds, as well as from green silicon carbide with a grain size of 16–40.
5
Without a special machine, at home you can use the following equipment to sharpen drills:
- conventional grinding machine;
- electric drill;
- homemade sharpeners.
To use a simple grinding machine, it is better to purchase a special tool, because before you learn how to sharpen a tool without it, you can ruin more than a dozen drills. This device for sharpening drills has approximately the same device as the industrial one described above. There are options not with mounting on the machine body, but with a 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, providing the desired sharpening angle, is attached to its base. It is possible to provide for a change in the slope - the angle of sharpening.
In the case of an electric drill, a special nozzle is used for sharpening drills. Unfortunately, they are 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 those and others are only for drills with a spindle neck with a diameter of 43 mm. In the body of these nozzles there are 15 holes for drills of different diameters. The nozzles are equipped with a stone, the sharpening surface of which is located at a certain angle, and a leash for it, inserted into the drill chuck.
By changing the length of the leash once (shortening it), the nozzle is adjusted 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 fixed with a screw; start the drill and insert the drills into the hole of the nozzle body of the appropriate diameter. Such a device can also be made independently. In a homemade nozzle, it will be possible to provide the necessary sharpening angles and tool diameters.
Home-made devices can be made in the form of conventional grinding machines. It is better to immediately provide for a method of fastening and sharpening drills on them, so as not to invent additional devices for this.
