No matter how high-quality and expensive the drill, its service life is not infinite. However, every time to buy new components does not make sense. It is enough to figure out how to sharpen the drill in order to save yourself from unnecessary expenses. To do this, you can use elektrotochilo or - in his absence - an abrasive bar. You also need to know that the spiral and pobedit drills sharpen in a slightly different sequence.
Elements of spiral drill.
General information about self-sharpening drills
There are usually no problems with sharpening wood drills - they serve perfectly, retaining their original characteristics for months and even years. With drills for metal or concrete, the situation is quite different - they must be sharp, using dull accessories to create holes in hard materials is impossible.
Understand that the time has come to sharpen the drill, you can on the appearance of the characteristic sharp squeak in the drilling process. It is not recommended to use blunt products for work, for the reason that in such conditions much more heat will be emitted, and this will contribute to even faster wear of the drill.
Studying information on how to sharpen the drill, you need to learn to understand not only the features of such work, but also to know what equipment is used for this. The best option is a special machine.
Diagram of the device for sharpening the drill.
In the absence of an industrial unit, you can use a home-made powerhouse with an abrasive stone.
When choosing a sharpening technology, you must take into account the shape that you need to give the back wall of the product. You can make one-and two-plane shape, as well as screw, cylindrical and conical.
Drill sharpened on the rear faces. It is important that both pen products are sharpened equally. To do this manually is extremely difficult. In addition, to create the desired shape and the required rear angle by hand is also very difficult.
For work you will need:
- Electric sharpened or special machine, complete with diamond stone.
- Wooden plank.
- Water for cooling.
A diamond stone machine is expensive equipment, and not everyone has access to such units. For use in the home, you can collect homemade elektrotochilo. An ordinary square board will be suitable as a base. It is installed on the engine with a capacity of 100-300 W and a rotational speed of 1500 revolutions. An abrasive wheel is attached to the motor shaft. Such an easy to assemble device will allow you to sharpen the drill without any problems.Back to table of contents
The process of self-sharpening spiral drill bits
Scheme angle sharpening drill.
Earlier it was noted that sharpening can be one-plane and two-plane. At drills with monoplane sharpening, the back wall looks like a single plane. The slope may be 28-30 °. To sharpen such a drill, you simply need to attach it to an abrasive wheel so that the cutting part runs parallel to it, and then start the sharpening procedure. This simplest method is suitable for products with a diameter of not more than 3 mm.
For drills whose diameter exceeds 3 mm, it is better to use the method of conical sharpening. It is rather difficult to do this manually without appropriate skills, but if you wish, you can do it. You need to take the drill with your left hand at the minimum possible distance to the intake cone. The product is taken by the right hand at the tail. With the back wall and the cutting edge, the product to be sharpened is pressed against the abrasive stone. By gently swinging with the left hand on the back, a conical surface is created. In the process of sharpening the drill does not need to be torn off from the stone, the movements should be smooth and relatively slow. The second pen is sharpened in the same manner.
In the process of sharpening, try as much as possible to repeat the original shape of the back of the product to maintain the necessary rear corners. This method is suitable for drills with a diameter of up to 1 cm. In case the diameter of the product exceeds 1 cm, a sub-point is necessarily performed. The meaning of this procedure is that it is necessary to increase the slope of the cutting edge and reduce the rake angle. This increases the resistance of the product to chipping, which allows to increase its service life. The width of the transverse part is reduced, making drilling much easier.
Scheme sharpening drill.
When working with drills with a small back angle, an additional undermining of the rear surface is performed. Due to this, it will less rubbing a hole in the material during the drilling process.
On the production after sharpening, the finishing is usually performed, which allows removing small notches and smoothing the surface. Thanks to fine-tuning increases the wear resistance of the drill. With such an opportunity, this treatment is recommended to be done. It is performed using round grinding stones made of silicon carbide on a bakelite bond.
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Step by step instructions for sharpening pobeditovogo drill
Resource pobedit drills also not forever. After some time, such products require sharpening. A dull drill will warm up too much in the process, produce an unpleasant squealing sound and generally reduce the quality of drilling. For self-sharpening fit the same machine as in the previous instructions. Plain water is great for cooling. It is important to take into account the fact that sharpening of the winning product can only be done with a diamond stone, simple emery stones are not suitable for this.
Before starting work, make sure that it can be done, for this measure the height of the cutting part of the product: if the height of the soldering is about 1 cm, you can proceed to sharpening.
The harder the metal, the slower the processing should be. The drill bit is sharpened with a short touch of a diamond stone. As a rule, it takes a little time to sharpen, because in essence, this procedure boils down to a small trimming of the edges. Control each stage of work, it is important not to remove the excess from the working part of the product.
Diagram of the device pobedit drill.
The process of sharpening drills with taps practically corresponds to the operation for drills of small diameter, i.e. Sharpening the back is flat. The drill is grinded to the very soldering.
The front surface is also recommended to sharpen. If the product was soldered directly to the surface of the drill, it is impossible to do without a point. Without it, the service life of the product itself and the quality of work will be significantly reduced. The front surface is eroded in view of the soldering center becoming thinner.
When performing each stage of work, it is necessary to ensure that the cutting sides of the product are the same size. If this does not work out this way, the displaced center will lead to a decrease in quality and a violation of the geometry of future holes.
Regardless of the unit used for sharpening, it is necessary to monitor the ratio of the rear and front corners of the cut edge in relation to the rotation. Another rule, especially relevant for sharpening drills for concrete: the higher the hardness of the material, the higher the sharpening angle should be made. In the case of the winner, it should be equal to 170 °.
The drill bit must not overheat. This can lead to cracking and detachment of carbide inserts. To prevent this, the drill should be cooled with liquid from time to time. Plain water is suitable for cooling.Back to table of contents
Useful recommendations for sharpening drills
Thus, there is nothing complicated in the process of sharpening. It is only necessary to take the process as carefully and responsibly as possible, constantly ensuring that the edges have the correct length and ratios that most closely correspond to the factory ones.
It is important to control the heating temperature of the drill. Overheating, as already noted, leads to cracking of the material.
If you do not follow and the tip is heated too much, do not immediately immerse it in water, because sudden cooling can also cause cracks. Allow the material to cool naturally. on air.
Do not be surprised if after sharpening the drill will not work as effectively as after purchase. This is especially true for pobedit drills. Products of different brands are also sharpened in different ways, and it is simply impossible to reproduce all the conditions at home. If you have failed to achieve a decent result when sharpening in the ways considered, it is better to buy a new drill and treat it more carefully.
To extend the life of components, follow all the recommendations of the manufacturer, for example, use metal drills only for working with metal, they should not be drilled with concrete. Ensure that the drill does not overheat during operation. Periodically turn off the drill and moisten it with water. Create holes gradually, no need to try to do them from the first approach, thereby exposing the drill to extreme load.
Follow these guidelines and your drills will last as long as possible. And if necessary, you can now sharpen them with your own hands, using the considered instructions. Have a good job!