Drilling metal or wood is a job that you do regularly. A high-quality nozzle does not require sharpening for quite a long time, however, there are some mistakes in which dulling occurs ahead of schedule:
- Using a drill that is not suitable for the material being processed. This does not necessarily mean drilling reinforced concrete with a wood drill, although in this case you will instantly transform cutting tool into a rod with a rounded end. For drilling various types For metal and hard plastics, there are specially made drills. If there is a discrepancy, the cutting edge quickly becomes unusable;
- Not correct angle sharpening. 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 finish drilling quickly, and we often forget about such a little thing as cooling the work area. If it is not possible to supply 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 “releases”, that is, it loses its hardness. Cutting properties deteriorate, which leads to increased friction. Heating increases more strongly, and the process is aggravated in arithmetic progression.
As a result, we may lose a good and possibly expensive instrument. If you have it on hand grinder for drills, the problem is solved on the spot; if not, you have to invent your own sharpening methods.
Manual sharpening without tools
A mechanic with extensive experience sharpens drills by hand, using only a sharpener with a tool. But not all home craftsmen can boast of such skills.
In addition, this method can only restore the sharpness of large-diameter products. Then it is easier to control the angle. The most popular size (3-5 mm) cannot be sharpened this way. Even a template won't help here.
Craftsmen who regularly carry out drilling work will be interested in the variety of sharpening machines for drills offered in power tool stores.
However, such devices (despite the obvious ease of use) are quite expensive. So the “homemade” people run to the store for another Chinese tip. But experienced home craftsmen still use tools from the times of the USSR, which meet GOST standards in terms of strength and durability.
The secret is simple - many old-school locksmiths have in stock homemade machine for sharpening.
IMPORTANT! For most household projects, you can get by with simple sharpening tools. Especially if the word “machine” scares you.
The simplest devices for straightening the cutting edge of a drill
To understand the process, let's take a look at components tip.
Swift clamp. To use this device, it is enough to have an emery wheel (sharpener) equipped with a durable support. The drill is clamped in the device under the right angle edge rotation. By controlling the feed angle of the cutting edge, we shape it on the sharpening stone, then, without changing the angle, we “go” to sharpening the backing.
The device must rest on a tool rest, the angles are controlled by hand. If you have certain skills, you can get good results with obvious savings.
IMPORTANT! Before using the device on high-quality tips, practice on defective ones. This will allow you to “get the hang of it” and “feel the angle,” as the masters say.
Of course, using a template is mandatory.
Then, by turning the stock, a plane (more precisely, a cone) of the back is formed.
The sharpening is checked on a template and assessed visually. All planes comply with the standard.
Or a workshop makes work much easier and allows you to enjoy working with it. The same applies to drills. But even the most expensive of them become dull or break over time. But not everyone, especially beginners, have the skill of correct drill sharpening, and constantly buying new ones is quite expensive. For such cases, you can assemble a special device for sharpening them. This machine is quite simple, but can still greatly facilitate this process.
It is especially convenient for working with small diameters, since they are the most difficult to sharpen.
The machine consists of a sharpening machine and a device for attaching a drill.
Its operating principle is as follows: The drill is rigidly fixed to the helical part in a special vise. Their angle in relation to the whetstone is set using a square; for metal drills it is 60 degrees. Thus, one of the edges is sharpened, then the device is turned over and the other edge is sharpened.
The difference between this project and many of those posted online, according to the author, is the use of these same jewelry vises as a retainer. They are commercially available and cost little.
Here's what they look like:
The principle of their operation is the same as that of ordinary yews: the handle rotates in one direction - the jaws unclench, rotates in the opposite direction - the jaws are clamped, you can fix the workpiece or part.
To use them in the machine you need to modify them a little. The original rivets are removed, these homemade plates are installed and riveted again.
When clamping the drill, the cutting edges should be parallel to the jaws.
Next, four holes are drilled in the newly attached plates, equidistant from their center. They should be located at an angle of 90 degrees with respect to the drill clamped in the vise.
Later, alternately (for each face) an axis will pass through these two holes, which will fix the entire system. The result will be a “swing” effect. Much attention should be paid to marking the holes, since the quality of sharpening the drills depends on their location.
The supports of this “swing” are in this case two hulls from under the gutted ones serve door locks, but they can be made from scratch by cutting racks from metal or wood.
They are rigidly attached to a wooden platform.
Along its four edges, for adjustment required height four screws are screwed in.
It would be best to place the sharpener and rocker on the same panel.
The vices are installed between the posts and hung on the axle.
The device is installed at the desired angle (60 degrees) to the surface of the circle and one of the edges is sharpened.
We turn the vise 180 degrees, the axis is threaded through the opposite holes, and the other edge is sharpened.
The finished result turned out quite well, considering (according to the author) the great wear of the old vise. The photo shows a drill with a diameter of 1.5 mm.
The quality and accuracy of drilling depends on the sharpness of the working tool. Moreover, unlike table knife, the drill must be sharpened correctly. Experienced locksmiths can level cutting edge on a regular sharpening machine, simply holding the drill in your hands (at least according to them). But this method requires skill and many years of experience. Even if you have a steady hand and an excellent eye, without understanding the process, you will simply ruin the instrument.
A few basic rules for sharpening (using the example of twist drills for metal):
For a better perception of the material, let’s remember the structure of the drill.
- Do not press the tip against the sandpaper for more than 2-3 seconds at a time. The metal heats up and the so-called “tempering” occurs, that is, deprivation of hardening. Accordingly, the necessary hardness of the metal is lost. The first sign is the presence of temperature discoloration on the edge.
- For drills with a diameter of up to 4 mm: each time the sandpaper plane touches the drill, the drill is held in one position: rotation around its axis is not allowed. For larger diameters, the sharpening geometry is slightly different.
- On twist drills, only the back surface of the cutting part is sharpened.
- The cutting edge should be directed towards the rotation of the sharpener (for mechanical sharpening).
- The main angle (2φ in the illustration) depends on the type of material being processed.
Which drills should I sharpen and how often?
Feather and other special wood drills cannot be repaired at home, and they do not become dull so quickly. Pobedite tips for concrete cannot be sharpened in principle. The most popular tool remains - twist drills for metal. Of course, they are also used for processing wood (plastic, rubber and even stone), but this is not relevant to the topic.
Twist drill. The cutting edge has small size, therefore, during operation, it quickly heats up due to friction (there is no dissipation area). The main reason for dullness is overheating. At correct use wear does not occur as intensely. Characteristic signs blunt drill:
- A creaking sound is heard during operation.
- Instead of curled shavings, sawdust comes out of the hole.
- Instant heating of the tool without moving deeper.
Important: Do not use a dull drill; wear from overheating will only progress.
So, it's time to sharpen the tool. You don't want to ruin the drill and want to mechanize the process.
Mini sharpening machines are at your service:
All devices are divided into two types: attachments or stops for universal tools, and independent devices narrow specialization. Let's look at the most popular of them, from simple to complex:
This is just the device for those who have a steady hand and a diamond eye. In fact, it only allows you to hold the drill in a given position without fear of injuring your fingers. Angle control is visual, according to the position of the “wings” relative to any landmark. There are few advantages: instant readiness for work, compactness and price. The disadvantages are obvious: manual control of the process does not add accuracy.
In fact, this element is not special device for drills It simply allows you to fix the tool at a certain angle. The accuracy will be higher than in the previous version. Most stops allow you to set the angle of inclination, and even have a marking scale. And yet you have to rely on firmness of hands.
There are also more advanced stands: with replaceable elements and adjustment of not only the angle, but also the height. The devices are mounted not on the emery body, but on the workbench: which makes them more universal.
In fact, such a stop can be adapted to any electric sharpener. An additional bonus is that with the help of such a stand you can sharpen knives, cutters, screwdrivers, chisels, etc.
Semi-professional guides for all types of drills
This is a fairly advanced tool that allows you to control sharpening characteristics with micron precision. All linear parameters are securely fixed, the values are set according to the markings. The drill is mounted in the groove, accidental displacement or rotation around its axis is excluded.
For sharpening, the possibility of both linear movement and movement of the edge along the arc path is provided (for conical sharpening of large diameter drills). Linear movement (along the axis) can be controlled by a master, or a limit stop can be installed.
From the point of view of processing quality, the device has practically no shortcomings. But for correct sharpening the operator must know the drill parameters. That is, there is no automation: therefore the tool belongs to the professional category.
As a development of the line - a guide with its own sharpening unit. There is no need to install a stop on the workbench and change discs. In fact - you have a semi-automatic table machine for sharpening.
Important note: All listed devices are designed to work with standard electric sharpeners. Therefore, before starting to process drills, it is advisable to install a special emery disc.
They are specialized power tools for performing a single task: sharpening twist drills.
Even a person who is far from technology can use the machine (although why would he sharp drills?). The operator only needs to determine the diameter of the drill and immerse it in the appropriate hole. It is convenient to work, errors are practically excluded. However, all drills are sharpened with the same comb. The price to pay for ease of use is the lack of flexibility in settings. For home use – the best choice: especially if there is additional nozzle for sharpening knives and scissors.
There are versions for masters. The drill is installed taking into account the sharpening parameters, the process can be controlled by the operator.
The sharpening angle, the method of edge processing (linear or conical), and the depth of metal removal are selected. The drill is not located in a common holder, but in an individual cartridge.
Industrial sharpening equipment for a metalworking shop
During intensive use of drilling machines, a separate post is required to restore the functionality of the tool. Professional stands for sharpening drills of any diameter save time and effort, but the cost of such equipment is too high for home use.
The information obtained will help you choose a sharpening device without extra financial costs. In addition, there are replaceable nozzles for hand power tool(for example, a drill). But this is a topic for another article.
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. WITH working side The drill will be sharpened. 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
