Drilling metal or wood is a job that you do regularly. A high-quality nozzle does not require sharpening for a long time, but there are some errors in which blunting occurs ahead of time:
- The use of a drill that does not match the material being processed. This does not necessarily mean drilling reinforced concrete with a wood drill, although in this case you will instantly turn the cutting tool into a bar with a rounded end. There are specially made drill bits for drilling various types of metal and hard plastics. In case of discrepancy - the cutting edge quickly becomes unusable;
- Wrong sharpening angle. This value must also correspond to the type of material in which the hole is made;
- Overheat. The most common reason. When working with durable material, we want to quickly finish drilling, and we often forget about such trifles as cooling the work area. If it is not possible to ensure the supply of coolant to the tool, it is necessary to take breaks to cool the cutting edge. You can dip a hot drill into a container of water.
The mechanism of hot blunting is simple: The hot edge is “released”, that is, it loses its hardness. Cutting properties deteriorate, resulting in increased friction. Heating increases more strongly, and the process is aggravated in an arithmetic progression.
As a result, we may lose a good and possibly expensive tool. If there is a grinder for drills at hand, the problem is solved on the spot, if not, you have to invent your own methods of sharpening.
Manual sharpening without tools
Locksmiths with extensive experience sharpen drills with their hands, using only a sharpener with a handy tool. But not all home masters can boast of such skills.
In addition, in this way it is possible to restore sharpness only to products of large diameter. Then it is easier to control the angle. The most popular size (3-5 mm) cannot be sharpened in this way. Even a template won't help here.
Craftsmen who regularly carry out drilling work will be interested in the variety of grinders for drills offered in power tool stores.
However, such devices (despite the obvious ease of use) are quite expensive. So the “home-made” run to the store for another Chinese tip. But home craftsmen with experience still use a tool from the times of the USSR, which corresponds to GOSTs in terms of strength and durability.
The secret is simple - many old-school locksmiths have a homemade sharpening machine in stock.
IMPORTANT! For most household chores, you can get by with simple sharpening tools. Especially if the word "machine" scares you.
The simplest devices for dressing the cutting edge of the drill
To understand the process, let's get acquainted with the components of the tip.
Then, by turning the bed, a plane (more precisely, a cone) of the backing is formed.
Sharpening is checked on the template and evaluated visually. All planes comply with the standard.
A guide is welded to the lower (rear) part of the corner bed to stop the drill shank. The emphasis itself is welded from the coupling and the corner.
Fixation is made with a screw. The stop is set to the limit value of the edge to be ground, and due to this, both cutting elements of the drill are ground symmetrically.
The sharpening of the working edge is made against the rotation of the emery wheel. In this case, the resulting burr is automatically removed by the running surface of the emery. For sharpening, two or three swings of the bed along the radius of the backing cone are sufficient.
This type of drill is sharpened along the outer surface of the emery stone, if necessary, use the lateral (radial) plane - the device can be turned to any angle.
The drill grinder is attached to the workbench with a clamp. You can fix the base permanently - but in this case, the possibility of fine adjustment will be lost.
In principle, it is possible to bring a dull tool into proper condition manually. But how high will the speed and accuracy be with this technology? In addition, if the drill is carbide, this is quite difficult to do. The author proposes to assemble a machine for sharpening drills with his own hands, which will allow them to be used repeatedly.
Industrial-made equipment is quite expensive - from 43,900 rubles.
True, Chinese products (for example, "GQ-D13") can be bought for 6,800 - 7,200.
But it is unlikely that such cheap models will suit a home master, given that the body is made of plastic, and the engine power is in the range of 80 - 120 watts. In addition, only certain types of drills can be sharpened on them, so there is no need to talk about the versatility of use. Therefore, such machines do not count. The feasibility of making a “grindstone” for domestic use with your own hands is more than obvious.
This article does not consider options for manufacturing a grinding machine based on an angle grinder (“grinder” is not in every home, and it is unlikely that anyone will buy it only for these purposes) or an electric / drill (for which you will also have to look for special devices in stores). The simplest and most convenient option is the traditional “grindstone” made from improvised materials, which almost any of us has encountered, and more than once.
There is nothing complicated in the design of such a machine. However, there are a number of features in its do-it-yourself assembly, and this is what the author draws attention to. Having dealt with all the nuances, it will not be possible to make an installation for a “home” application of labor ().
What you need for assembly
El/motor
On the machine in everyday life, various drills are sharpened, including large diameter ones. In addition, the primary processing of the cutting edges of the tool and their finishing are separate stages of work. Therefore, you will have to change the circle and put the one that is at hand from the pre-purchased ones. Since the machine is equipment for long-term use, it is necessary to mount it for the future. Based on this:
- engine power: about 1.2 - 1.5 kW is enough;
- food: single-phase. Any garage or small workshop (barn) on the site, with rare exceptions, is connected to the 1f 220/50 line. From this it is necessary to proceed.
grinding wheel
Moreover, there should be several of them, with different grain sizes. To securely fix the abrasive on the motor shaft, bushings are prepared that clamp it on both sides.
Sharpening fixture
You can limit yourself to the simplest "shelf", but then you will not be able to withstand the required angle. Such work requires a lot of practical experience.
The device can also be purchased, although it is quite rare for sale.
The best option is to make it yourself. For example, these are:
Circuit elements
- Starter magnetic (with 3 pairs of contacts) for circuit 3 f.
- Start / stop button or 2 different ones - to turn the machine on and off. And necessarily the third - an emergency stop. It is often combined with a pedal, which is much more convenient and safer, since your hands will be busy when sharpening drills.
- Wires. With the specified engine power, it is enough for 1 "square".
The simplest switching circuits for three-phase motors are shown in the figures:
It is easy to find an acceptable one on the Internet, depending on which particular motor is used, how its windings are connected (“star” or “triangle”), to which voltage source it will be connected (1 or 3 phases).
Security elements
- Cover over the circle.
- Screen (optional).
There are certain types of work in which the sharpening of drills is done only on machine tools, and not manually.
- When drilling to a greater depth, when a slight undercutting is required.
- If the drills are universal, allowing you to work even with materials of increased density.
- For making "blind" holes with a special tool.
Sharpening drills with a grinder is not recommended for several reasons. Firstly, angle grinders are unlikely to be securely fixed. Secondly, the accuracy will be unsatisfactory. Thirdly, after the end of such sharpening, it is rather difficult to make the correct fine-tuning of the drill. Fourthly, this technique is suitable only for partial restoration of the operability of a tool of relatively small diameter (no more than 5).
Making a machine is not everything. It must be correctly placed in order to sharpen drills as conveniently as possible. Place, installation height - a personal matter of the master. But there is a general requirement - to exclude the slightest vibration of the equipment and ensure its leveling.
If the workbench in the garage is rather “flimsy”, you will have to mount a special table on metal legs. For this, a large corner, pipe or channel is suitable. The tabletop, taking into account the weight of the machine (primarily the engine), must be durable. Thin sheet metal is not an option. The stand for the machine can also be made of wood, but of sufficient thickness. Its fastening also requires attention. It should be as reliable as possible, at all points provided on the engine frame, and only on bolts.
When deciding on the engine switching scheme, it is necessary to provide for the possibility of changing the number of revolutions. Since you will have to work with different drills, you need to know that the harder the material of the tool, the lower the angular speed of rotation of the abrasive wheel should be.
As practice shows, not all inexperienced craftsmen understand when the drill needs to be sharpened. Signs indicating that the tool is dull:
- rattle (sometimes "buzz") at the initial stage of drilling;
- rapid heating of the metal, often accompanied by a characteristic odor.
Untimely sharpening significantly reduces the life of the drill and is the most common cause of its breakage.
Over time, the drill "bites" into the metal worse. For this reason, it is thrown into the trash and replaced with a new one. However, the problem can be approached in a businesslike way: with the help of special tools, sharpen a dull drill and return it to working condition. Moreover, you can again make the cutting tool sharp at home, without resorting to "high technology".
Types of sharpening
You can sharpen a drill that has become poorly immersed in metal in different ways. This is influenced by the scope of the cutting tool and its diameter. Based on these criteria, sharpening can be single-plane, conical and finishing. Most men who use a metal drill are more accustomed to performing a single-plane procedure, which is considered the most simple. But it, like other types of sharpening, is not suitable for every cutting tool.
One-plane sharpening should be resorted to if the diameter of a dull drill is no more than 3 mm. True, when making a cutting tool sharp in this way, one must be extremely careful, otherwise it is threatened with surface destruction. In order for single-plane sharpening to be successful, you need to attach the drill to the abrasive wheel and move it in the same direction as its surface.
It is necessary to use the conical procedure when it is necessary to sharpen a large product intended for cutting metal sheets and parts. Such sharpening assumes that the drill is fixed with two hands and processed sequentially. Then, with the cutting tool, the so-called finishing is carried out. It must be performed after both single-plane and conical sharpening. Finishing is a procedure that grinds the cutting edge of the drill so that even small notches remain..
Angles at which the procedure is performed
A drill that has become dull after intensive and long-term operation is usually sharpened at an angle of 120 0. This is a universal sharpening parameter for any material, but it is only suitable for products with a diameter of less than 1.2 cm. And if this size is from 12 to 80 mm, then the cutting tool is processed at a different angle. The main thing is to choose it based on the material.
Sharpening a drill at an angle chosen at random will make it sharp, but will certainly ruin it. It will not drill holes well and heat up quickly, or worse, it will break during use.
How to sharpen a dull drill with simple tools
You can return the cutting tool to its properties using an abrasive bar. They will have to grind the drill manually, carefully removing excess metal. But this business will take so much time that next time you will definitely want to make the product sharp with any device, but not with an abrasive bar.
But it won’t hurt anyone to understand what sharpening with an abrasive bar is. To learn the nuances of processing a cutting tool with such a device, you can watch the following video:
Electric grinder
A device that runs on electricity and can sharpen a drill is not for everyone. But he has a huge plus: at home, it is easiest to adapt to handle a blunt product with an electric grinder. Sharpening with this tool is supposed to start with an edge located in the same direction as the axis of the abrasive wheel. How long to remove excess metal from the drill, it is necessary to determine "by eye". The work should be completed at the moment when the shadow from the edge on the groove disappears.
In sharpening the drill with an electric sharpener, a certain sequence must be observed. The first step is to process the back surface of the edge, and only after that proceed to remove the unnecessary layer from the second edge of the blunt cutting tool. When turning a drill for metal with a sharpener, you should follow the rules:
- pay attention to the angle of sharpening the product;
- make sure that the drill is fixed on the axis of rotation;
- observe the process so that the edges are the same length;
- excess metal should be removed gradually, slowly expanding the gap between the sharpener washer and the workpiece;
- completing sharpening, it is necessary to give the edges of the drill a cone shape.
Sharpening a drill with an electric tool is simple, but this will require straining your eyesight without losing sight of any trifle. In order to learn how to properly focus on the processing process, you need to practice, possibly rendering several metal drilling products unusable.
Video about working with an electric grinder
Bulgarian processing
Sharpening the drill with an angle grinder provides for the following: the cutting tool is fixed in a vice, the angle of attachment is selected, then a disc is mounted on the grinder, which rotates and is brought to the edges of the blunt product. This method of giving the drill sharpness lost over the years of operation has a large number of disadvantages:
- the grinder needs to be placed on a flat surface with the disc down and kept in its place, for which it is necessary to enlist someone's help or use a vice that performs the work of a carpenter;
- the grinder can ruin the drill if it is not securely fixed;
- when sharpening a cutting tool with a grinder, there is a high risk of injury, as the drill may accidentally jump off a rotating disk;
- it is advisable to sharpen with a grinder only a product that has a small diameter;
- it is impossible to grind with a grinder, giving the cutting tool evenness and smoothness.
The role of the stand for the cutting tool during its sharpening with a grinder should be performed by the edge of the shield covering the abrasive disc. The shutter rotation can be changed. When starting to process the drill, it must be positioned so that it is convenient to put a finger on it for support.
Video on the use of a grinder for sharpening metal drills
Using the drill bit
The drill is attached in the same way as the grinder, therefore it is characterized by similar disadvantages. In addition, one more thing can be added to them: a drill for metal can only be sharpened with an electric tool that has a cam chuck, into which instead of a drill you need to insert a disc holder from a grinder.
The drill, which is planned to be used for sharpening the drill for metal, is recommended to be equipped with a grinding disc with a piece of sandpaper glued to it. It is desirable that the base on which the rough material is glued is very hard.
If you plan to sharpen a cutting tool with a hand drill, then you need to mentally prepare for the difficulties. Still, she has nothing that can be made a stand for a drill. Therefore, it is necessary to use some kind of improvised object as it.
In general, when starting to grind a product with a drill, you need to find two even surfaces. One of them will become a platform for fixing the device itself, and the other - a stand for the drill. Both surfaces, for example, a table and a box, must be placed so that they are on the same line. Between them it is supposed to install a disk inserted into the chuck of a hand drill in a vertical position.
Video about processing a cutting tool with a drill
Features of sharpening various types of drills
A drill for metal can be victorious, spiral and stepped. There are certain requirements for sharpening each. But before you figure out how to return the properties lost over time to the drill, you should inspect it and test it in operation. This will allow you to understand whether the product really needs to be polished. Signs of a dull cutting tool are its strong heating, loud sounds heard during its use, and poor-quality drilling. True, resorting to sharpening is not always wise. A drill with a cutting surface length of more than 1 cm should be discarded.
How to grind a victorious drill?
In order for the victorious product to create holes in the metal to bite into the material again, it is necessary to arm yourself not only with a sharpening tool, but also with coolant. It will not work with a simple emery stone to sharpen a drill of this type; you will have to arm yourself with an electric sharpener.
In order for the cutting tool to drill into metal as efficiently as before, on the device used to sharpen it, the number of revolutions per second should be reduced. The fact is that the higher the strength of the material, the lower should be the speed of its processing.
The Pobedite drill is supposed to be ground with short touches to the sharpener. The process of sharpening this product requires increased attention, because the edges of the drill bit sharpen rather quickly. Each cutting side of the tool must be sharpened to match the other side in size. If this rule is violated, then the center of the axis of rotation will shift, and the drill will make holes in the metal that are too large and curved along the edges.
When grinding a cutting tool, it is important to keep the ratio of the back and front angles of the cutting edge under control. Care must also be taken to ensure that the drill does not become hot, as this can lead to cracks and chips. If suddenly the product processed by a grinder or other device heats up, then it must be lowered into a special liquid or plain water. But, seeing that the tip is reddened and glowing, you should not immediately cool it in order to prevent damage. Before immersion in water, the drill must cool down under the influence of air.
How to sharpen a spiral product?
To restore the sharpness of the drill in the form of a spiral, you need to grind its back edges. During this process, care should be taken to ensure that one drill bit is sharpened in the same way as the other. It is very difficult to do this without a special unit, especially for those who do not have experience in sharpening metal drills.
When sharpening a twist drill with one's own hand, it is unlikely that it will be possible to give an ideally correct shape to the back edges and a given back angle. Therefore, it is more reasonable to grind such a product on a special machine or fixture. If only the household had an ordinary chisel, and the man who needs to process a dull twist drill had experience in sharpening cutting tools.
How to properly process a step drill?
The cutting tool for metal, which has the form of steps, is several times more difficult to sharpen than a twist drill. A product with a straight flute for chip removal should return the lost sharpness according to a certain pattern. Along the cutting edges of the steps from the side of the gutter, it is supposed to be carried out with a disk, making light touches.
When processing a step drill, the angle formed between the surface behind the step and the groove must not be displaced. There are even more sharpening nuances in a product whose chute is spiral. The technology of its processing is no different, but it requires extreme accuracy and great experience in grinding drills.
Gallery of drills of various types
A cutting element of this shape can also become dull The product is already mounted on the tool and is ready to work Drills can break, so it is advisable to have a whole set 
Such a drill bites into the material quickly 
In case of twist drill breakage, have spare cutting parts 
The tips of the step drill can have different diameters. The cutting element is shaped like a cone. The drill of this type is smoothly immersed in the metal.
Evaluation of the quality of grinding
Having sharpened the drill for metal, it is imperative to check whether everything is done correctly. Quality control of cutting tool processing is easy to check. It is only necessary to inspect the jumper located in the center of the end of the tip of the product, evaluate the length of the cutting edges and understatement.
If the sharpening was done without errors and did not spoil the drill, then the jumper will be located in the center of the end of the tip. With proper rehabilitation of a blunt tool, its edge will be between the deepest points of the troughs through which metal chips are removed. This means that the edges of the sharpened drill should be short.
Next, you need to check the length of the cutting edges - the gap between the jumper and the edge of the drill along the line of the edge that cuts the metal. This parameter can be measured with a regular ruler or compass. Naturally, no edge should be different from the other. Otherwise, you will have to take the sharpening device again and process the surface that turned out to be short.
You can understand if the edges of the drill have an underestimation, if you put it vertically so that the tip points to the floor, and rest the jumper against some flat surface. Then you need to glance at the back surface, while being on the side of the sharpened product. If the visible edge does not rise gradually upwards, then it is necessary to work again on the cutting zone of the drill.
Sharpening drills, without a doubt, requires skill. You can get your hands on this one. It is only necessary to study all the subtleties of the process and see firsthand how the grinding of blunt cutting tools is performed.
Do you need the drills to always be sharpened, and you can’t find a special machine during the day with fire even in specialized stores? And make a machine for sharpening drills with your own hands. You can easily assemble a simple structure if you have at least a little experience in working with basic tools.
Homemade machine
The device for sharpening a drill can be of great value in the household, as with the help of this device you can independently sharpen drills of any diameter and type. In addition to the manufacture of a special unit, you will need an electric motor with a grindstone.
Main materials:
- Metal plate with holes - 1 pc.;
- Bolt or stud 70x15 mm long;
- Set of washers;
- Corner - 30x30 or 40x40;
- Plates - 3-4 mm thick;
- Cotter pin - 30x1.5 mm;
- Clamps.
In addition to materials, you will need tools for their machining and connection, in particular electric welding and a grinder.
Instruments:
- Electric welding.
- Drill.
- Bulgarian.
- Hammer with percussion tips.
- Special clips 2 pcs.
- Spanners.
- Pliers.
Manufacturing process:
1. Making the mounting plate
The mounting plate is made of a metal lining with holes about 3-4 mm thick. On the one hand, the part is cut off by 3 centimeters, while during cutting it is required to save the finished hole. The cut off part will be needed for the manufacture of the next part of the grinding device, and a large element for lining during the installation of the product on the table.
2. Corner for fixing the drill
The element is designed to fix the drill during sharpening. It is made by cutting off a part of a regular corner 30x30 or 40x40. The total length varies between 60-90 mm, while the extreme part is cut at an angle of 60 degrees to give the plane to be sharpened the desired level.
3. Fixing bracket
The cut off part with a hole from the plate is connected to another metal plate, while the elements are superimposed on each other and welded to the corner by electric welding. For welding, a mounting cutout should be cut on the plates in order to butt-fit the parts and scald them.
In the connected parts, a hole is drilled along the diameter of the bolt or stud, and the parts themselves are carefully scalded on all sides to stiffen.
4. Bolt welding
A bolt or stud is designed to fix the corner. The element is welded at an angle of 75 degrees to the main plate. During scalding, the lower plane should be taken into account, if necessary, remove the slag in order to prevent the product from being skewed.
5. Fastening the washer to the bolt
The washer on the bolt is installed at a level of 25 mm from the upper extreme part. The approximate diameter is 30 mm. The element is welded using electric welding in the desired design position, observing all levels along the plane.
6. Hole in the stud
In the absence of a hole for installing a cotter pin in a bolt (stud), it is required to make it using a drill and a drill of the required diameter. Due to this technical element, the fixing angle will be fastened. The diameter may be different, but the main condition is reliable fixation.
7. Drill stop
It is made of a metal bar and a special vise clamp. The rod is welded to the fixing angle from below. The clamping mechanism is mounted on a bar, while on the device a special bowl-stop for the drill should be equipped from the corner.
The system is mounted on a grinding table and fixed with additional clamps.
Video: how to make a tool for sharpening drills.
Drill grinder
This method is available to anyone. For this you will need a drill. Perhaps not immediately from the store counter, but already obsolete and not used by you. She will act as an engine.
It must be fixed on the frame, insert a sleeve or a grinding wheel ready for installation or a universal fine-grained disk into the chuck. Everything. Turning on the drill, you get a rotating abrasive, which is a pleasure to sharpen the drill.
A very simple sharpening solution. However, do not forget about the devices for sharpening the drill, which fixes the element to be sharpened relative to the sharpener.
