Drills must be of high quality and well sharpened by a professional craftsman. In the old days, drill sharpening was done by hand.
Today, special devices for sharpening drills have appeared, and their design is very simple.
Why is sharpening needed?
If the drill becomes dull, it is very difficult, and sometimes impossible, for them to drill through the surface. It is also worth noting that for different types drill surfaces 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 yourself using abrasive discs. During sharpening, the drill must be held by the working surface. You need to hold the tail of the drill with your other hand.
From the side, the drill must be pressed against the abrasive disc. Then it is advisable to turn it with extreme caution, as a result the cutting edge will take the required angle and structure.
Sharpening the drill 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 when sharpening the cutting part. This must be done correctly, as an error in sharpening can lead to the drill being skewed to the side.
Do-it-yourself drill sharpening is not the best good way, since it is capable of carrying with it 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 made of cast iron and steel. This device is made taking into account the types of sharpening, as well as its size. It is easy to change the sharpening angle 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 into the home, but such a machine can only sharpen small drills.
Industrial machines that are made to sharpen drills with large diameters have great power. The industrial machine has a clamp and a sharpening wheel.
With this device, drill sharpening occurs under the supervision of an operator who can easily control 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 safe use The machine must have a housing, outside of which it is necessary to place an axis with an abrasive wheel for operation.
You first need to decide on the installation location of the machine, since it will be connected to an outlet.
Also, our device should be placed on a table, preferably made of metal, where the engine will need to be placed, and marks should be placed for making holes for the bolts.
An abrasive disc is placed on the motor shaft. To secure it to the shaft, you must first put on the washer, then the disk, and then the washer again. After this, install the fastening nut on the pre-prepared thread on the shaft.
An engine from washing machine. The power of its motor will be sufficient for the process of sharpening drills. Wires can also be taken from improvised equipment.
Pay attention!
You need to connect the wires to the starter, which should have three open contacts. The winding must be capable of connecting phase lines using two starters connected in series.
The off button should be connected to NC, and the start button will be connected to NO, and it should also be in parallel connection with two NO contacts of the starter.
When you press the power button, voltage will be applied to the winding and 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 must 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.
To make it, you can use a metal box or make a protective screen out of glass. It is also worth installing a casing that covers the end of the disk by a third. It will protect the worker if the abrasive disc cracks.
Photo of sharpening drills with your own hands
Pay attention!
Pay attention!
Working with a good tool is convenient, effective and correct! Today we have useful homemade product for home and garage - homemade machine for sharpening drills. Correctly sharpening a drill presents some difficulties without experience. Moreover, drills of large diameters (somewhere from 6mm) can still be controlled by sharpening and, at the very least, they can be sharpened after some time. Drills of small diameters, especially in demand by masters of radio and electronic equipment, have to be sharpened literally by touch and under a magnifying glass and without the use of mechanization using corundum blocks. By the way, just recently we published the article “If you haven’t read it, be sure to read it!
Using my deposits of illiquid assets and conducting a review of the Internet, I collected a quick fix A simple device that allows you to sharpen drills from 2.0 to 6.0 mm without much difficulty. Further improvement of the device is possible and is a task for the near future. General view in photos 1 and 2.
As, of course, it is known that metal drills have a sharpening angle at the tip of 120 degrees. (Less for wood and soft metal). The photo shows a yellow square lying between the sharpener and the device, ensuring this angle, i.e. the drill is located at an angle of 60 degrees. to the working end of the abrasive disc. The required angle of the drill head is ensured by the initial inclination of the drill relative to the disk.
The operating principle of the device is not new and has been repeated many times and published online. The difference between this device is the use of so-called jewelry vices, which are commercially available and inexpensive, to secure the drill. I had some very old ones, altered and worn out after 30 years of use. Photo taken from the network.
The principle of operation is simple - by turning the handle we move the jaws apart and by turning them in reverse we clamp something, for example a drill.
These vises have been modified. The rivets were drilled out and plates were installed into these seats and re-riveted with longer rivets. It will become clear later why this was done.
The drill is clamped in a vise so that the cutting edges lie parallel to the jaws.
Along the edges of the riveted plates, coaxial holes are drilled at the same distance from the center and lying on a straight line perpendicular to the axis of the vise (that is, to the drill). An axis will pass through these holes on which this “rocking chair” will swing alternately when sharpening one and the other edge. With ideal marking of the rocker, equality of the cutting edges will be achieved during sharpening.
The rocking chair is mounted on racks (the housings of mortise door latches without internals fit. In turn, the racks are screwed to an oak block. It also contains four support legs to adjust the desired height.
The rocker with the drill is placed between the posts on an axle; the axle is removable. 
Sharpening the first edge (jaws are painted over with a blue marker).
The sharpening of the second rocking edge is turned 180 degrees. (the painted side is not visible). Top view of this node.
The finished drill is pictured below. Errors that arose when working “on the knee” and old worn-out vices did not allow sharpening drills from 1 mm. Shown here is a sharpened 1.5mm drill bit. At high magnification, the difference in the lengths of the cutting edges is visible (small, but there)
When working with hard workpieces, work surface drills wear out quickly. A dull drill becomes very hot and loses strength. This occurs due to the “releasing” of the metal. The tool must be sharpened periodically. However, this applies not only to drills.
Drills are inexpensive devices. In any case, those models that are used in household. However, it is wasteful to buy a new tip every time it becomes dull.
There are factory-made sharpening devices, but this violates the concept of economical use of home tools.
Wood drills practically do not become dull, except that the tool can be “driven” at high speeds into a resinous workpiece. Pobedite tips cannot be sharpened with stones. All that remains is to sharpen the drill for metal. Many experienced locksmiths carry out this procedure without any equipment.
However, the accuracy of the work leaves much to be desired, and not everyone has an eye home handyman developed so professionally. In any case, minimal mechanization is necessary.
How to make a homemade device for sharpening drills?
First of all, you need to acquire a means of control. No matter how you sharpen the drill, you need a template to check the accuracy of the work.
Conventional drills for working with ferrous metals they have an edge angle of 115-120 degrees. If you have to work with different materials– check out the table of angles:
| Processed material | sharpening angle |
| Steel, cast iron, carbide bronze | 115-120 |
| Brass alloys, soft bronze | 125-135 |
| Red copper | 125 |
| Aluminum and soft alloys based on it | 135 |
| Ceramics, granite | 135 |
| Wood of any species | 135 |
| Magnesium and alloys based on it | 85 |
| Silumin | 90-100 |
| Plastic, textolite | 90-100 |
Knowing these values, you can prepare several templates and, in accordance with them, sharpen yourself. In this case, you can use the same drill for different workpieces, you just need to change the angle of the top of the working area.
The simplest, but very effective tool for sharpening is bushings. different diameters, fixed to some foundation.
Schematic drawing of the device in the illustration:
IMPORTANT! The tool should not dangle in the sleeve; an error of only one degree will reduce the quality of drilling.
It is best to make a whole clip from copper or aluminum tubes, for standard drill sizes. Or drill into a block of soft material enough holes. The main thing is to install a convenient tool rest on your sharpener, which will allow you to right angle move the sharpening device and serve as a reliable stop.
Our grandfathers used this method. Only an oak block was used as a material for the manufacture of a sharpening machine - an angle.
How to sharpen drills with the correct sharpening angle without much effort and skill? Unfortunately, many of us do not succeed the first time. This device is very simple in design. Therefore, each of you will be able to repeat it. Many people know that the edges of bolts and nuts have the same angle as a standard drill sharpening. We will use this. We will not weld two nuts together to get the correct pattern. The design is a little different.
To start, you need any nut. The larger the diameter, the larger the diameter of the drill that can be sharpened in it.
The nut has 6 faces, 2 of which we need. Take a caliper and mark 4 mm from the edge of the nut. We turn the nut the other way around and make a mark on the edge that is one and a half mm larger than the first one. We make a triangle on 2 sides. Cut with a hacksaw or grinder. The result was a nut with cuts.
We weld another one. The device is almost ready. He misses the puck, which we throw into the middle. You will also need a bolt; it screws into a small nut.
The cuts in the nut have different depths, which differ by 1.5 mm. This difference is hardly noticeable to the eye. We insert the rod, fix it, and apply a ruler. The gap between the ruler and the round timber is smaller on the left than on the right. That is, the device has a certain angle. Where the gap is smaller, the master made a mark.
Operation of the device mechanism
We take a straight, unsharpened drill and place it in the device. Where the mark is, the drill must be placed, as shown in the photo and video. We fix the drill so that it protrudes slightly from the edges. The drill will be sharpened on the working side. In the example shown, it is possible to clamp with a diameter of up to 8 mm.
When we start grinding the edge of the drill using sandpaper, there is a guide in the form of the plane of the edge of the nut, which sets the correct sharpening angle.
This is a great device for those who cannot find the right angle by eye.
The video shows how to position the tool relative to the sanding wheel. From the 6th minute you can see how the drill is processed.
Alexander Polulyakh.
In addition to this video tutorial, another DIY device using bolts and nuts.
Drawing
https://drive.google.com/file/d/0B8iB5ht2WrqOMEJiZlRtZ2VWdVE/view
The fact that during operation a metal drill has the unpleasant property of becoming duller does not require special proof. Moreover, this happens the faster the more often the drill is in use and the greater the amount of work it performs.
A metal drill becomes dull after short use and requires sharpening.
Many people do not pay attention to this and continue working until the drill has completely become unusable, after which they throw it away and buy a new one. This happens because the owners simply do not know how to work with metal. Meanwhile, this can be done at home, using the devices and tools available in almost every home workshop.
Signs of a dull drill
If a sharp squeak is heard when the drill comes into contact with the metal, it means the drill is dull.
You can only drill into metal with a very sharp tool. If at the beginning of drilling you hear a sharp creak at the point of contact between the tool and the metal, then this is a sure sign that the drill is dull. If you hear such a nasty sound, it is better to stop working. Otherwise, the tool, as it rotates, will rub against the metal more strongly and, accordingly, generate more heat during the drilling process. The working edge of the drill will wear out faster due to friction and heat.
Home craftsmen mostly use small drills for their needs, Ø no more than 16 mm. To sharpen a dull tool, it is better to use special equipment. But it is quite expensive, so it is rarely purchased for home use. But in any home workshop you can construct a sharpening device from the tools at hand. Sharpening can be done using:
- a grinding machine with an abrasive wheel;
- grinding machine;
- electric drills with replaceable attachments.
You can use any other sharpening device that you can place a sharpening stone on and make it rotate. It is only necessary that such a device can provide a shaft rotation speed of up to 1500 rpm.
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Preparing for work
For your safety, use protective gloves and goggles when sharpening drills.
But before you start working, you need to put on safety glasses and gloves and prepare a container of water. These are mandatory protective devices without which sharpening should be carried out. metal tools very dangerous.
During operation, sparks and microscopic metal dust particles fly off from the sharpener and tool and scatter in different directions. If you do not protect your hands and face, these microscopic particles can cut quite sensitively on exposed skin. But they pose a particular danger to unprotected eyes. Once in them, metal dust particles cause serious vision problems, including complete vision loss.
A container of water is needed to cool the tool being sharpened, because during sharpening it becomes very hot from friction against the rotating plane of the circle. If the drill is not cooled in time, it will inevitably overheat and quickly break down during operation.
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Sharpening technique and sequence
But prepared tools and protective equipment are only half the battle. You can't take on a job without knowing how. After all, this process, although simple, requires strict adherence to the sharpening sequence. It is also very important to initially correctly decide on the type of sharpening. The type is determined by the shape that needs to be given to the cutting edges (“feathers”) of the tool. There are single-plane, double-plane, conical, cylindrical and screw types of sharpening.
To determine whether a drill is sharpened correctly or incorrectly, you need to carefully examine it after sharpening. Factors correct sharpening drills are as follows: it must remain symmetrical about its axis. Its cutting edges must have the same length relative to the axis of the drill and the same sharpening angles.
Sharpening always starts from the back surface of the drill. The surface must be pressed firmly against grinding wheel, maintaining the initially specified angle throughout the entire process. Without the skills, it is very difficult to do everything correctly the first time, so be prepared to have to do several approaches. After each approach, you should carefully inspect the surface being sharpened. Work continues until the back surface looks like a regular cone when viewed from the side, at eye level.
Only after achieving the desired result can you begin to sharpen the cutting part. When performing it, you need to strive to ensure that both “feathers” are sharpened absolutely identically. It is also very important to maintain the correct sharpening angle when working.
With single-plane sharpening, the back surface is processed as one plane, maintaining an angle in the range of 28-30 °. This is one of the most simple ways, which is used for thin instruments with a diameter of up to 3 mm.
When performing work in this way, the drill is pressed at a given angle to the grinding wheel. While sharpening, the tool does not turn over and moves. This often leads to the fact that the cutting edges of the drill may crumble, especially if the metal is of low quality.
It is preferable to sharpen the cutting part of larger diameter drills conically. This is a more complex method, and if for some reason you value the sharpened tool, then it is better to first practice on some broken surface to “get” your hand.
The technique of this method is as follows: with your left hand you take the tool by the working part, and with your right hand - by the tail. You need to keep the working part as close as possible to the intake cone, otherwise high-quality sharpening will not work. In this position, the drill is pressed not only by the cutting edge, but also by the surface of the rear part against the end of the sharpener. Holding by the ponytail right hand The drill is rocked slowly and smoothly to form a conical surface on the back edge of the drill. After finishing sharpening one feather, the instrument is turned to the other sharpener, and everything is repeated all over again. Very important nuance for this method: the drill should never be removed from the sharpener while sharpening the pen.
There is another conical sharpening technique. The drill is also taken by the working part with the left hand, and by the tail with the right hand. But the drill is pressed to the end of the sharpener only by the cutting edge, and then during operation, without lifting it from the sharpener, the tool smoothly rotates around its axis, achieving uniform and high-quality sharpening of the back surface.
With this method of sharpening, a cone will be obtained on both sides on the back surface of the pen, but the drill will remain without a ground corner. Therefore, during operation, such a drill will rub more against the metal and, accordingly, heat up more.