Homemade device for sharpening drills for metal. Sharpening a drill for metal: how to properly sharpen a drill at home. Features of sharpening machines
The modern market is saturated with many types of different equipment designed for sharpening drilling tool. When using it, you do not need to have any special skills or training. For example, such devices include industrial devices riss 8100v, which have a high cost. To save money, you can make a tool for drill sharpening and on metal with your own hands.
Specifics of device operation
IN household electric drills and screwdrivers are often used for drilling various materials made of wood, concrete, metal and ceramics. Many users of such equipment have repeatedly encountered a problem that causes the working part of the drilling tool to become dull during operation.
When working with metal, intense heating of the cutting part of the drill may occur, which exposes it to rapid wear and further unsuitability for use. To avoid this, it is necessary to periodically check the geometric standards of the cutting part and, if possible, sharpen it to the required parameters. Twist drills are usually used for drilling metals. Additional checking of the tool before performing work extends its service life.
When working with wood, the cutting part is practically resistant to wear, and concrete drills are equipped with hard pobedit plates, which do not need sharpening and are used until they are completely worn out.
Drill sharpening tools
Both on an industrial device and on a home-made drill sharpening device, it is recommended to use a specialized template necessary to comply with the requirements for the tool. Using a template makes it possible to set the required angle of the cutting part of the drill, which ensures high accuracy during operation. During drilling work, it is necessary to individually select the sharpening angle of the tool, depending on the materials used.
When working with metals, reference data can be used to provide information about necessary standards when setting the sharpening angle. Sharpening angle parameters for metal drills:
- Steel, cast iron and hard bronze - 116−118;
- Brass, soft bronze - from 120 to 130;
- Copper - 125;
- Aluminum - 140.
A simple drill sharpener can use a sleeve with an internal diameter that matches the cross section drills and fixed on a rigid base at the required angle. The bushing is selected with high precision- so that its internal diameter coincides with the cross-section of the tool being sharpened. It is strictly forbidden to allow weak fixation: this sharply reduces the quality of sharpening.
You can use a wooden block, in which holes of different diameters must be drilled, which will make the device universal.
An important component is the tool rest, which performs the following functions:
- ensures correct fixation of the object being processed and its movement relative to the grinding wheel;
- is an excellent support during sharpening work.
Drawings of a device for sharpening drills can provide significant assistance in assembling it. They can be found in various sources of information. By studying the operating principle of such structures, you can develop your own version, which may differ from the basic one in its individual characteristics.
When working with sharpening devices, you must follow the following rules:
- The tool being processed must be firmly fixed during work, which prevents it from rotating around its axis;
- At the end of the sharpening work, you need to let the drill cool down, then measure its angles using a template. The working surfaces of the cutting parts should not differ from each other.
Even if the angles are correctly chosen and their symmetry coincides, strong runout may occur due to the difference in the length of the cutting edges, which can lead to drill breakage. If the cutting parts are asymmetrical, the drilling process slows down and the cutting part of the tool overheats. This makes the hole broken and increased in diameter.
Screwdriver attachment
To sharpen drills, you can use traditional devices: a sharpener, an electric drill or a screwdriver, with the addition of additional modifications.
Ready-made available for sale industrial fixture for a screwdriver and an electric drill, which is used as a mini-sharpener and allows sharpening at different angles.
To sharpen the cutting part of the tool to homemade device, a number of conditions must be met:
Used for sharpening drills and augers sanding wheels. The most common in living conditions is a white circle made of electrocorundum, designed for sharpening shovels, axes, knives, hoes and other household equipment.
For hard-alloy pobedit drills for concrete, abrasive wheels marked 64C are used. Grain grinding disc It is recommended to use grade 25H. When sharpening rapid blades, use a disc grade from 8H to 16H. When working with silicon carbide emery, the working surface of the drill heats up to high temperatures, therefore it is recommended to cool the metal using water and soda.
If we talk about those drills that are used by craftsmen at home, their cost in stores is low. But even in this case, you should not use them as consumables for single use. After all, updating the drill to the best working condition will not be difficult if the master has the skill or special tools.
There are factory machines that are designed for sharpening, but this is a separate expense item, so most often craftsmen create such devices with their own hands.
Metal drills create the most problems, and wooden blanks the sharpness of the cutting edges is not reduced so quickly.
To make a machine for restoring the sharpness of cutting elements, the necessary control means (template) are used to check the tool.
Typically, tools for ferrous metal, carbide bronze, steel or cast iron - with an edge angle of 115-125 degrees. The length of another material, these parameters are different.
for soft bronze, red copper – 125, for brass alloys – 135;
for aluminum and soft aluminum alloys, granite, ceramics and wood – 135 degrees;
for magnesium and its alloys – 85 degrees;
for plastic, textolite and silumin - from 90 to 100 degrees.
Masters, if necessary, make templates according to the above data. By the way, theoretically, a single drill can be suitable for all these metals and other materials, if you sharpen different working surfaces each time.
An elementary handicraft device that is often used, bushings attached to the base. There are many drawings on the Internet for self-made. It is necessary to take into account that the tool must be well clamped, the accuracy depends on 1 degree.
If desired, you can make a large holder using aluminum or copper tubes corresponding to the standard characteristics of drills, or drill many holes in a soft metal workpiece. It is necessary that the sharpener has a comfortable hand rest to move the device and hold the stop.
This primitive sharpening machine is easy to install on a workbench or table.
A practical example of working with a drawing
The essence of the problem: there are drills, they need to be sharpened.
We will use one of the sharpening methods, close to the factory ones. Too lazy to catch with your hands. Better than the monkey method - set it and you're done. It took approximately 1 hour to manufacture the device according to the finished drawing.
A little welding work according to the template. A corner was made. We put the washer on, it’s just pressed on.
Let's try the first sharpenings, if everything is assembled correctly, we will refine and refine it, make a quick adaptation.
After sharpening the drill, we carry out a test. Two casting chips are visible, which means that sharpening was carried out correctly.
The only drawback is that one chip is longer than the other, which means they missed the length of the edges. It is necessary to make a stop that will regulate the length and ensure symmetry of the edges. To do this, we will make a thrust washer that will be aligned and machined. Or we’ll cut it to make it possible to process shorter drills. 
Dull drill bits may break during operation and injure you. It is much better and easier to work with sharp ones. In this manual you will find drawings and a device for sharpening drills.
Step 1: Comparison of sharp and dull drill bits
The left side is blunt. This can be seen by the light reflection on the cutting edge between the two grooves. The photo on the right shows a sharp cutting edge.
Step 2: Sharpening Tool
Experienced people know how to sharpen drills with their own hands. In theory, the shank should be kept in right hand at an angle of 59° relative to the drill sharpening device. When the drill touches the sharpener, you need to move the shank further down to the left, while at the same time turning the drill around its axis clockwise. I've never succeeded in doing this.
I bought the sharpening tool you see in the photo almost thirty years ago. Such simple devices for sharpening drill bits are still sold at almost the same price.
Step 3: Set the degree
The guide on the stand can be installed in seven positions. My drills have an angle profile cutting edge 59°, you need to set this degree on the guide. Tighten the wing nut.
Step 4: Align the Edge
The sharpening tool has a small pointed tip, and the edge of the groove needs to be set against it. The tip can be lowered or raised to bring it to the edge of the groove.
Step 5: Offset Amount
First you need to set the offset (the distance between the yellow lines), it must be equal to the radius (the distance between the green lines).
Step 6: Width and Angle of Cutting Edge
Pay attention to the angle of the red line. If you took the drill too far in the previous step, the cutting edge will move closer to the tip. The edge was too wide and the profile too flat. Because of this, it will slide along the surface of the metal and it will be difficult for you to drill. You can reduce the offset a little, but only a little, otherwise you may accidentally damage the sharpening tool tip on the stand's sharpening wheel.
Step 7: Ideal Cutting Edge Angle
Ideally, the edge should be as small as possible. It will be the lower point between the beveled edges of the drill grooves, indicated in the photo by a yellow line, this drill will cut metal very well.
Step 8: Clamp
Once you have the stem aligned, tighten the mounting screw.
Step 9: Set the length
Set the sharpening guide to the length of the drill. The end should be in the moving tray and not hanging in the air. Loosen the metal painted nut. Adjust the black nut. Tighten the painted metal nut.
Step 10: Setting the Height
The shank should be at right angles to the grinding wheel. For sharpening I use a radial cutting machine. The tip must be aligned with the center of the axis grinding wheel.
Step 11: Attach the machine to the table
The bit should only lightly touch the grinding wheel. If you press too hard, it will be very difficult to sharpen. It will overheat and you will remove too much metal.
The base of the sharpening guide should be at right angles to the grinding wheel (green line). A top part turn the guide so that the tip points slightly left of center(angle between green and yellow lines). Move the machine forward until the drill bit touches the surface of the grinding wheel. Fix the machine on the table.
Step 12: Get Ready to Sharpen
Turn the tip to the right. Turn on the grinding wheel.
Step 13: Sharpening
Slide the tail of the guide to the right (red arrow) until the drill touches whetstone. Yellow wavy lines represent sparks. When the drill is in this position, it will actually be sharpened.
Step 14: Rotate the Bat
Continue moving the tail of the guide to the right until the drill bit clears the edge of the stone. To sharpen the other side, you need to turn it around its axis half a turn.
First turn off the machine. Then loosen the fastener and turn it half a turn. The edge of the groove should be flush with the sharpening tip. Repeat the previous two steps.
Turn off the machine. Pull it out of the mount. Check the width of the cross cutting edge. If you are unhappy with the quality of the sharpening, change the stem and repeat the process.
Step 15: Sharpened Drill
The photo shows a good sharpening. The cutting edges are not worn or rounded, they are sharp and crisp. The length and angle of the transverse cutting edge are also quite good.
Step 16: Fine Drill Bits
This sharpening tool is good for 3 mm and larger. If it is thinner, it will no longer be possible to sharpen it using this device.
To sharpen thin ones, make a special block from wooden block approximately 10 cm long. Please note that the angle between the red lines is 77°.
Step 17: Angle between the edges of the wood block
Side view of the block. The angle between the red lines is 59°.
Step 18: Guide Line
A triangular cutout is visible on the upper plane of the bar. This cut goes along the entire upper edge of the block and serves as a bed. The angle between the red lines is also 59°. The edges of the triangular cut are used to align the cutting edges. You can check the edges by eye.
Step 19: Attach it to a block
Place the drill bit into the cut on the block. Place the block in the vise so that the shank is above the grip and the grip extends slightly beyond the beveled side of the block. Turn so that one of the cutting edges aligns with the guide edge of the triangular cutout. Secure with a clamp. Drop a little oil onto the sharpening stone. Slide along the beveled side of the device, thereby sharpening the drill.
When the sharpening stone stops removing metal, turn the drill half a turn and sharpen the other edge. Check homemade sharpening You can use a magnifying glass if necessary.
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 cause the drill to skewer 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. U industrial machine There is 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 following materials: abrasive disc, switch, motor with good power, stand, wires, axle and 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, also it should be connected to 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 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!
When should you sharpen a drill?
Drills for wood can be used for a very long time without requiring sharpening, which cannot be said about drills for metal or concrete; they become unusable quite quickly. Experienced craftsmen are able to identify dull drills by sight or by contact with the metal of the drill. However, if you are new to construction, it will be quite difficult to determine the sharpness of a drill by instinct, so use these factors to determine that the drill needs to be sharpened:
- a creaking or whistling noise is heard during drilling;
- the tool you are working with heats up very quickly;
- the quality of the resulting hole is very low - there are nicks;
- The chips come out of only one spiral flute.
Please note that if you use a drill with a dull tip, it may break. If it breaks, the flying parts of the drill can cause serious injury. In addition to injuries, the drill can “bite” the material and if you use a powerful tool, it can be torn out of your hands, which often causes serious injuries. Therefore, under no circumstances should you delay sharpening the drill or replacing it.
About that. how to choose a screwdriver based on expected construction work, you can read in our article
2. Basic parameters of the drill
In order for you to properly sharpen a drill tip, you need to understand the basic elements:
- a cutting part formed by the convergence of the groove surface and the flank surface;
- the front surface, which is located under the cutting edge;
- back surface, located behind the edge;
- a bridge between two rear surfaces.
During the drilling process, it is often the cutting edge, the bridge and the rear surfaces of the drill that suffer the most. Therefore, the drill must be restored by sharpening the rear surfaces. But not everything is so simple: in order for the edge to be sharp again and a clear bridge to form, the sharpening angles must correspond to the values indicated in the table:
Provide maximum efficiency work is possible if these values are observed - the cutting edge will always be the first to come into contact with the surface of the workpiece. The length of the cutting edge depends on the apex angle. With a properly sharpened cutting edge angle, the chips will fit well into the groove and come out. If you make the angle sharper, the width of the cut strip will increase, but the chips will clog the groove. If you make the cut angle too obtuse, the drilling efficiency will decrease.
3. Sharpening the drill on a grinding machine.
With a regular sharpening machine you can easily sharpen a drill bit for metal, wood or concrete. Important point— the machine must be equipped with a platform, which is located in front work surface grinding disc. The distance between the platform and the end of the circle should be no more than one millimeter. Stores sell sharpening machines that may not have this platform. If your sharpening machine is not equipped with a platform, but the desire to sharpen a drill still remains - scroll below, where we will tell you how to sharpen a drill with your own hands using a grinder or sandpaper.
Be sure to keep in mind that an angle grinder is a very dangerous tool and you must follow safety precautions when sharpening drills using a grinder.
