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If you assemble a homemade metal lathe with your own hands, you can get at your disposal functional equipment for processing metal without extra costs. For objectivity, we will consider not only the assembly process, but also the current offers of the market of finished products. The information below will help you make the right comparative analysis taking into account financial capabilities, professional skills and other personal characteristics.
A high-quality homemade product is in no way inferior to its factory counterpart.
What you can do with a homemade metal lathe with your own hands
Using a tabletop metal lathe, you can perform various work operations efficiently and quickly:
- processing of ends and grooves with the required level of accuracy;
- expansion of existing holes conical and cylindrical(countersinking);
- accurate cutting of workpieces according to the length established by the plan;
- creating a relief surface by rolling;
- cutting standard and special threads (external/internal).
To select the required accuracy of movement of the caliper, change the thread pitch lead screw. It is cut with a die on a screw cutting machine. To strengthen the structure, connections are made using welding. The headstock bodies are made from channel bars (No. 12/14).
How to choose the right motor for your lathe
The project presented above is designed to be used power unit power 450−600 W with a maximum operating shaft speed of 2500−3500 rpm.
Such solutions are quite suitable if you choose an existing engine of sufficient power.
In order not to be mistaken, you can study examples of factory machines for metal, good luck with your homemade projects. Based on such a mini-research, it is easy to conclude that following proportions: for processing parts with a diameter of 8-12 cm and a length of 60-80 cm, electric motors with a power of 600-800 W are used. Standard air-cooled asynchronous type models are suitable. Manifold modifications are not recommended. They sharply increase speed when the load on the shaft decreases, which will be unsafe. To prevent such situations, you will have to use a gearbox, which will complicate the design.
One advantage of belt drive should be emphasized. It prevents direct mechanical impact on the shaft from the tool in the transverse direction. This extends the life of the support bearings.
Expert's point of view
Victor Isakin
Tool selection specialist for the 220 Volt retail chain
Ask a Question"Electric motors direct current differ in large dimensions. But they can be connected using a relatively simple circuit, which will ensure smooth adjustment of the speed.”
Assembly order
This algorithm explains the sequence of actions when working with the above drawings. The use of other design documentation implies making appropriate changes to the assembly process.
Start with the front headstock. Install the spindle into it. Next, the entire assembly is connected to the running pipe using bolted fastening. First, threads are cut on the fastening parts. When performing this operation, the alignment of the parts is carefully monitored.
On next stage a power frame is assembled from channels. When the frame is made, the headstock is installed on it. Here you also need to pay special attention to the parallelism of the running tube and the long parts of the frame. They make the markings accurately. The holes are drilled sequentially with an additional reamer boring, checking each fastening unit. One or two mistakes will not excessively affect the strength of the channel, so it is better to make a new one precise hole elsewhere, if necessary.
For your information! Do not forget about installing spring steel washers, which ensure reliability bolted connections in conditions of high vibrations.
When assembling this unit, special attention should be paid to the accuracy of the placement of the central axes of the spindle (1) and quill (2). If a mistake is made, conical surfaces will be obtained instead of cylindrical when processing workpieces. They also check that these elements are parallel to the running pipe. The support bar (3) prevents the tailstock from unfolding. To adjust the height, you can use steel spacers.
The caliper parts are installed sequentially in accordance with the assembly drawing diagram. Here, particularly high precision is not needed, since numerous adjustments are provided. If intensive use is expected, make individual components detachable in order to replace wearing parts without extra costs.
At the final stage, the electric motor is installed and connected to the electrical network according to the selected circuit. Check the functionality of a metal lathe with your own hands in practice. To improve appearance and protect against corrosion, some parts are coated with primer and paint.
How to make a lathe from a drill with your own hands
For , plastic, others soft materials The power of a typical household power tool is quite sufficient. This example shows how to do functional machine with your own hands in 15-20 minutes. Using the last photos in the table, the creation of an improved design is described:
| Photo | Assembly sequence with author's recommendations |
|---|---|
 | A serial drill was used as a basis. It is assumed that relatively small workpieces will be processed. For bed in in this case a sheet of plywood is selected and secured to the table. Any other sufficiently strong and level base will do. |
 | It is necessary to securely secure the power tool in a comfortable position so as not to damage it during operation. This problem can be solved using an auxiliary building. It is made of thick plywood (20 mm) taking into account the corresponding overall dimensions. |
 | The individual parts of the structure are fastened with self-tapping screws. An element with a figured cutout is installed in the front part. This socket is created with a shape and dimensions that are suitable for mounting the protruding part of the durable drill body (marked with arrows). |
 | The base is screwed to the tabletop in in the right place. Power tools are installed inside. For rigid fixation, use a clamp. A wooden block is fixed nearby as a support bar. |
 | The cutter can be made from an old file. A standard grinding machine is suitable for processing this workpiece. |
 | A strong steel rod is inserted into the cartridge. A wooden blank is screwed onto it. |
 | Next, check the functionality of the machine. |
 | If you remove a small thickness with a cutter with each pass, you will be able to process workpieces made of fairly hard materials. The finishing surface is created using sandpaper. |
 | To process larger workpieces, you can create a machine with a headstock and a tailstock. The photo shows the main structural elements. The power tool is secured securely, but, if necessary, it can be removed for its intended use. |
 | There is a support with a metal insert (handle) installed here, which helps to move the cutter accurately and accurately. |
Video: lathe in 15 minutes
Features of creating a metal lathe with your own hands
The previous chapter talks about the simplest designs that will help you make a lathe from a drill using inexpensive scrap materials. In some cases, even detailed drawings will not be needed. This approach is sufficient when working with wooden blanks when high precision is not needed.
Related article:
But it will not be suitable if you need to create a metalworking lathe with your own hands. The video demonstrates not only the potential capabilities of high-quality equipment in this category, but also the problems solved by the author of the project:
How can you upgrade a lathe yourself?
The drawings discussed above are a time-tested project. With their help, you can make a functional mini metal lathe with your own hands. But some modern improvements would be in order:
- The belt drive should be covered with a guard to prevent potential hazards.
- For an emergency power outage, a special button is installed in a visible place (at a close proximity).
- Instead of a grille, a protective screen made of transparent polymer is used.
- The incandescent lamp is replaced with an economical, mechanically resistant LED lamp.
- Automatic devices (sensors, fuses) are installed in the electric motor power supply circuit, which prevent overheating and other emergency situations.
- The frame is mounted on damping pads, reducing noise and vibration levels.
- The drive chuck is replaced with a more convenient three-jaw version, which automatically centers the workpiece during the fixation process.
- Fastening in the chuck grinding wheel expands processing capabilities.
For your information! To create quality milling machine With your own hands when working on metal, you need to use other design solutions.
Features of working on homemade lathes
Mastering metal processing is a topic for a separate article. To obtain the required result, the toughness and fragility, as well as other characteristics of the metal and working edges are taken into account. The technology is optimized taking into account the rotation speed of the workpiece and temperature conditions.
Video of metal turning (advice from an experienced master):
Safety precautions when working with a homemade lathe and proper care
After assembly, you must ensure that there are no faults before connecting it to the network. Check the free rotation of the spindle, the absence of delays in the operation of the drive mechanisms and extraneous noise. Alignment is carefully controlled. It is necessary that the power supply parameters meet the needs of the power unit in the mode of highest power consumption when turned on.
Before starting work, make sure that protective screens and casings are available (in good condition). New tool installed with the electric motor stopped using all standard fasteners. Observe processing modes corresponding to the parameters of the cutters and workpiece.
After completion of work operations, waste is removed. Perform lubrication and other work required by the maintenance regulations in a timely manner.
Market offers for metal lathes: types, prices, additional equipment
| Brand/Model | Length* Width* Height, cm/Weight, kg | Power consumption, W | Price, rub. | Notes | |||
|---|---|---|---|---|---|---|---|
 Jet/BD-3 | 50*30*39/ 16 | 260 | 31500− 33400 | Miniature metal lathe for the home workshop. Three-jaw chuck (50 mm). Turning diameter – up to 100 mm. Optional equipment with longitudinal feed. |
44
590 | 55200− 57600 | Lathe for metal semi-professional category. Smooth adjustment spindle rotation speed (100−3000 rpm). Gears for thread cutting as standard. |
 Kraton/ MML-01 | 69,5*31*30,5/ 38 | 500 | 51300− 54600 | Spindle speed - from 50 to 2500 rpm. Workpiece dimensions: up to 180*300 mm. |
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Kraton MML-01 |
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Kraton MML-01
You should carefully evaluate the process of creating a homemade lathe with your own hands. Taking into account real costs, it may turn out to be less economical compared to purchasing finished product. Accurate conclusions can only be drawn taking into account real conditions. In any case, personal implementation of the project implies the potential opportunity to create equipment with unique technical characteristics.
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Many home craftsmen are thinking about how to make their own metal lathe. This desire is explained by the fact that with the help of such a device, which will be very inexpensive, you can effectively perform a large range of turning operations, giving metal workpieces the required dimensions and shape. It would seem much easier to acquire the simplest table machine and use it in your workshop, but given the considerable cost of such equipment, it makes sense to spend time making it yourself.
A homemade lathe is quite possible
Using a lathe
A lathe, which was one of the first to appear in the line of equipment for processing parts made of different materials, including from metal, allows you to manufacture products various forms and sizes. Using such a unit, you can turn the outer and inner surfaces of the workpiece, drill holes and bore them to the required size, cut the outer or internal thread, perform knurling in order to give the surface of the product the desired relief.
A serial metal lathe is a large device, which is not so easy to operate, and its cost is very difficult to call affordable. It is not easy to use such a unit as desktop equipment, so it makes sense to do it yourself. Using such a mini-machine, you can quickly turn workpieces made not only of metal, but also of plastic and wood.
Such equipment processes parts with a round cross-section: axles, tool handles, wheels, structural elements of furniture and products for any other purpose. IN similar devices the workpiece is located in a horizontal plane, while it is given rotation, and the excess material is removed by a cutter securely fixed in the machine support.
Despite the simplicity of its design, such a unit requires clear coordination of the movements of all working parts so that processing is carried out with extreme precision and best quality execution.
An example of a homemade lathe with drawings
Let's take a closer look at one of the working options for the assembled on our own lathe, quite high quality which rightfully deserves the closest attention. The author of this homemade product did not even skimp on the drawings, according to which this device was successfully manufactured.
Of course, not everyone needs such a thorough approach to business; often simpler structures are built for home needs, but as a donor for good ideas This machine fits perfectly.
Appearance of the machine Main components Caliper, tool holder and chuck
Side view of the tailstock Bottom view of the tailstock
Guide shafts Caliper design Engine drive
Drawing No. 1 Drawing No. 2 Drawing No. 3
Structural units
Any lathe, including a homemade one, consists of the following structural elements: a supporting frame - a bed, two centers - a drive and a driven, two headstocks - front and rear, a spindle, a support, a drive unit - an electric motor.
All elements of the device are placed on the bed; it is the main load-bearing element of the lathe. The headstock is a stationary structural element on which the rotating spindle of the unit is located. In the front part of the frame there is a transmission mechanism of the machine, with the help of which its rotating elements are connected to the electric motor.
It is thanks to this transmission mechanism that the workpiece being processed receives rotation. The tailstock, unlike the front one, can move parallel to the direction of processing; it is used to fix the free end of the workpiece being processed.
A homemade metal lathe can be equipped with any electric motor, even not very high power, but such a motor can overheat when processing large workpieces, which will lead to its shutdown and, possibly, failure.
Typically, electric motors are installed on a homemade lathe, the power of which is in the range of 800–1500 W.
Even if such an electric motor has a small number of revolutions, the problem is solved by choosing an appropriate transmission mechanism. To transmit torque from such electric motors, belt drives are usually used; friction or chain mechanisms are very rarely used.
Mini-lathes, which are equipped in home workshops, may not even have such a transmission mechanism in their design: the rotating chuck of the unit is fixed directly on the electric motor shaft.
There is one important rule: both centers of the machine, driving and driven, must be located strictly on the same axis, which will avoid vibration of the workpiece during its processing. In addition, it is necessary to ensure reliable fixation of the part, which is especially important for frontal-type models: with one leading center. The issue of such fixation is resolved using a jaw chuck or faceplate.
In fact, you can make a lathe with your own hands using wooden frame, but, as a rule, metal profiles are used for these purposes. High rigidity The frame of the lathe is required so that the accuracy of the location of the driving and driven centers is not affected by mechanical loads, and its tailstock and support with the tool move freely along the axis of the unit.
When assembling a metal lathe, it is important to ensure reliable fixation of all its elements, be sure to take into account the loads to which they will be subjected during operation. The dimensions of your mini-machine and what structural elements it will consist of will be influenced by the purpose of the equipment, as well as the size and shape of the workpieces that are planned to be processed on it. The power of the electric motor, which you will need to use as a drive, will depend on these parameters, as well as on the size of the planned load on the unit.
To equip metal lathes, it is not recommended to choose commutator electric motors that differ in one characteristic feature. The number of shaft revolutions of such electric motors, as well as the centrifugal force that the workpiece develops, increases sharply as the load decreases, which can lead to the part simply flying out of the chuck and can seriously injure the operator.
Such electric motors can be used if you plan to process small and light parts on your mini-machine. But even in this case, it is necessary to equip it with a gearbox that will prevent an uncontrolled increase in centrifugal force.
It has already been proven by practice and design calculations that for turning units on which metal workpieces up to 70 cm long and up to 10 cm in diameter will be processed, it is best to use asynchronous electric motors power from 800 W. Engines of this type are characterized by stable rotation speed when there is a load, and when it decreases, it does not increase uncontrollably.
If you are going to make your own mini-machine for metal turning, then you should definitely take into account the fact that its chuck will be affected not only by transverse but also longitudinal loads. Such loads, if a belt drive is not provided, can cause destruction of the electric motor bearings, which are not designed for them.
If it is not possible to use a belt drive, and the driving center of the device is directly connected to the electric motor shaft, then a number of measures can be taken to protect its bearings from destruction. A similar measure can be a stop that limits the longitudinal movement of the motor shaft, which can be used as a ball installed between the electric motor housing and the rear end of its shaft.
The tailstock of the lathe houses its driven center, which can be stationary or freely rotating. Most simple design has a fixed center: it is easy to make it on the basis of a regular bolt, sharpening and grinding the part that will come into contact with the workpiece to a cone. By screwing or unscrewing such a bolt, moving along a threaded hole in the tailstock, it will be possible to adjust the distance between the centers of the equipment, thereby ensuring reliable fixation of the workpiece. This fixation is also ensured by moving the tailstock itself.
In order for the workpiece to rotate freely in such a fixed center, the pointed part of the bolt that comes into contact with it will need to be lubricated with machine oil before starting work.
Today it is not difficult to find drawings and photos of lathes from which you can independently make such equipment. Moreover, it is easy to find various videos demonstrating the process of their manufacture. This could be a mini CNC machine or a very simple device, which, nevertheless, will give you the opportunity to quickly and with minimal labor input produce metal products of various configurations.
The stands of a simple metal lathe can be made of wood. They will need to be securely fastened to the unit frame using bolted connections. If possible, it is better to make the frame itself from metal corners or a channel, which will provide it with high reliability, but if they are not at hand, you can also pick up thick wooden blocks.
The video below shows the process self-made lathe support.
We turn at home without a machine: a short guide on turning for beginners (from personal experience).
Quite often in model making a situation arises when you need to turn some parts or elements of a model on a lathe. For beginners, this becomes an intractable task - the machine is very often inaccessible, and it is not always possible to order from a turner. And often you just want to do everything yourself... What to do in such a situation?
This short article presents my personal experience, I do not pretend to be correct in everything, but still the methods given allow solving most problems.
Where to begin?
I started doing turning work using a regular hand drill with a manual drive (with a handle on the side;-), this was about 20 years ago). The drill shank was clamped in a vice, a workpiece was inserted into the chuck (a polystyrene or wooden rod, sometimes aluminum, as well as brass and steel - but this is very rare) and ground to the required shape. Later I switched to an electric drill, and then to a laboratory mechanical stirrer. All this equipment has disadvantages. Hand drill- you carry out all the work with only one, right (left-handed-left), hand, and the left (right) is well pumped up (;-)). The revolutions of the workpiece are also determined by your capabilities, as is the duration of the “approaches” of work.
Electric drill - the length of the workpiece is limited, up to a maximum of 10 cm, and then with difficulties (I will explain why below), mechanical stirrer - the maximum clamping diameter is 7.5 mm, but the shaft is hollow, you can easily process workpieces of 20-25 cm, and sometimes more, if the rear end of the workpiece is secured against beating. Replacing the chuck will not help, since 7.5mm is the internal diameter of the hollow shaft. Now I have finished installing myself from a hollow shaft internal diameter 15mm, mounted on 3 bearings, and a chuck with a maximum clamping diameter of 13mm, driven through a belt drive by a 220V selsyn motor with a speed control module. The latter is very useful, as is the use of a synchronizer - it is easy to control the speed (from 10 to 2500 on my engine), and change the direction of rotation using one toggle switch. The big “+” of the synchronizer is that it does not lose power when the speed decreases. Unfortunately, I can’t provide a photo yet; everything at the factory is being modified to fit a steel plate-frame. According to experience, for processing wood and polystyrene, 1000-1200 rpm is optimal (if more, the wood burns and the polystyrene melts); duralumin, brass, steel - 1800-2200. The main requirement for such drives (let's call them that) is the maximum possible absence of backlash, both axial and, especially, transverse.
By the way, regarding machines, they don’t always provide purchased ones best result, especially if they are made in the Middle Kingdom. Plastic structural elements (especially the bed and frame, see the Unimat advertisement in M-Hobby) allow you to safely refuse to buy one; the rigidity is insufficient. And not all aluminum alloys provide the necessary structural rigidity (especially if they save on production in order to reduce the cost). I have seen quite good machines made in Germany (the same Proxxon PD230 and PD400) and the Czech Republic, as well as quite normal products from the Middle Kingdom (there are a lot of them there, but they are brought to us extremely rarely) at prices ranging from $1,500 and above, which Not accessible to all modelers, not even beginners. Buying at foreign auctions and online stores is also not always good and convenient - delivery can cost 50 (this is still very cheap!) or more dollars. And then it is necessary to deliver not by mail, but by carriers such as UPS, DHL, FedEx, and this is even more expensive.
Material
Materials for home turning work can, in principle, be anything - polystyrene, wood, aluminum and its alloys, copper, brass, bronze, steel (and you can also process hardened ones, which a turner usually has difficulty doing, and not every cutter will pull, but Diamond burs and a needle file are quite normal). From my own experience, I can say that harder materials (brass, duralumin, steel) are better, since it is more difficult to make a mistake - grinding off more than necessary. And the dismounting of the tool leaves only an easily removable scratch. But they also take much longer to process. For testing, I recommend taking polystyrene - a sprue from models. It’s the easiest one to get your hands on.
The necessary tools are files, needle files (regular and diamond), dental burs (if you have a drill), diamond-coated burs (when processing metal workpieces), drills (you will find Soviet ones from P9, P12 and P18 - you are incredibly lucky!), various sandpaper grain, felt, coarse fabric (fiberglass), for wood and polystyrene - knives, chisels (knives must be worked with carefully - only with the root part, and only if it is impossible to work with another tool, and for chisels it is necessary to additionally make a support, as on lathes on wood). Sometimes for processing aluminum, duralumin and brass I use a reamer from high speed steel and jigsaw files with fine teeth - it’s convenient to remove a fairly thick layer of material by placing them at an angle of 45 degrees and pressing cutting edge to the workpiece.
If it is necessary to manufacture long products (blanks for tank guns, etc.), it is worth, IMHO, breaking them into several parts (parts). For example, a tank gun barrel in a heat-insulating casing with an injector - part from the muzzle to the injector, injector, part from the injector to the turret. In this case, it is worth considering the connection of the parts. This approach will reduce material costs and simplify processing. The muzzle brake is similar - the barrel should be made separately from it, otherwise you will have to remove a lot of material - after all, the diameter of the muzzle brake is 2 or more times larger than the diameter of the barrel. And you will have to grind all this down.
So, I described everything necessary to start work (it seems that there is nothing extremely inaccessible, except for a mechanical stirrer costing about 1000 euros, there is nothing here).
Then let's begin
Although, before starting to describe the process, let me remind you of the need to comply with safety regulations and the need for personal protective equipment, especially when working with metals. At the very least, polycarbonate safety glasses are a good idea to wear. It is also worth putting something to collect the shavings, for example, a cat litter tray (if your tummy doesn't mind ;-)). The optimal working position, strange as it may sound, is sitting. And, preferably, on a comfortable chair. The drive must be securely mounted on the table, leaving workspace for your hands. Carefully place the tool nearby so that it is always at hand.
Well, now, actually, let's begin.
1. Choose required material according to your capabilities and part requirements. When using an electric drill, we cut the workpiece to the required length (usually I take the length of the workpiece inside the chuck + up to 5 maximum workpiece diameters, more is possible, but not advisable - the higher the workpiece extends from the chuck, the greater the runout at the initial stage of processing). If there is a hollow shaft, the length of the workpiece can be any. It is desirable that the length of the workpiece be 5-10 mm longer than the length final product. Optimal diameter workpiece - equal to or maximum 1.5-2mm larger than the maximum diameter of the product (optimally 0.5-1mm larger - processing tolerance), otherwise you will have to sharpen a lot and for a long time. I wrote earlier about how you can center a hole at the end of a workpiece. Try to clamp the workpiece so that it protrudes beyond the front end of the chuck by a maximum of 1 (one) of its diameter (up to 5 is possible, try, but it’s harder), otherwise it is difficult to center and start processing, the workpiece deflects - runout occurs. If you still need to sharpen from a long workpiece (protrudes more than 10 diameters), then make a rigid support - put pieces of rubber tubes on a couple of bearings and firmly fasten them under the workpiece, and the distance between the axes of the bearings is less than or equal to them (the bearings) radius, and they are installed in a checkerboard pattern.This will replace the tailstock of the lathe - it will provide additional support.
You can use more of these supports, and mix the workpiece a little to treat the area in the area of the support. But then the supports will also need to be adjusted in height during the work. But this is not right away, not for the first tests. By the way, the tailstock on a lathe does not help much in processing very long parts - when processing approximately halfway through the length, the part still bends, and the harder the cutter presses, the greater the bend. Process the end of the workpiece with a flat file, then with a needle file. If necessary, center and drill the hole - with a rotating workpiece and a sharp, correctly sharpened drill clamped in a chuck or pliers (this is the main thing, otherwise it leads the drill, breaks and leads the hole) drilling a hole with a depth of 12-15 drill diameters is not a problem, and in steel and brass it is easier than in polystyrene (!). Do not press hard on the drill and do not try to drill the hole right away. It is better to start with a thinner drill bit, and then gradually increase the diameter to the required size. And first drill 1-1.5 times the diameter of the drill, check the alignment. If everything is fine, continue, and if not, process the end and center again.
A small displacement (around 0.05-0.1mm) is not scary, it is practically unnoticeable. A slightly larger displacement can be evened out - grind off the side of the workpiece (if its diameter is at least 1-1.5 mm larger than the product) opposite to the displacement of the hole (processing should be carried out approximately 1/3 of the circumference, bringing the cut to “NO”). During processing, this cut will be ground off, the hole will be in the center of the round product. And if possible, do not try to drill deep (more than 5 diameters) holes in the end of cylindrical or hexagonal workpieces with a rotating drill while the workpiece is stationary - this is very difficult to do and usually the drill moves away a lot. The hole in the workpiece goes in an arc. 
2. At this stage, you can also make a profile hole - conical, stepped, with a spherical expansion - using appropriate burs, needle files and cutters, with some experience this is not difficult to do. For a conical one, simply drill several concentric holes, the smallest has the greatest depth, and then the larger the diameter, the shallower the depth of the hole. And then use a file or conical bur to process the surface, and then sand it with sandpaper.
3. Start processing the workpiece from the protruding edge. Mentally or on a drawing (this is better), divide it into sections 0.8-1.2 long in diameter, sometimes up to 2 initial diameters of the workpiece are possible. Processing is carried out with coarse files, needle files, burs (cutters) clamped in a drill (turned on). Do not keep the file and needle file in one place, constantly make reciprocating movements with them - this way they cut the material better, the surface of the workpiece is cleaner and smoother, and the tool itself becomes less clogged. Select the position of the needle file and the file during processing, its angle relative to the axis of the workpiece experimentally, and see how the processing process proceeds at different positions. First, try roughly, using a file or cutter, to give the workpiece the maximum diameter in this area, and then a shape close to the required one. Then, using needle files of the appropriate cross-section, you process the workpiece precisely.
Here I can give one recommendation: if a part has surfaces of double curvature, for example, the muzzle and breech of guns of the 18th-19th centuries, do not try to make it exactly according to the drawing, trust more in photographs. Do it according to the principle of “similar - dissimilar”, “like - dislike” instead of the usual “corresponds - does not correspond”. The closer you get to the desired profile of the product, the weaker the pressure on the tool (needle and file). It is better not to use a drill and cutters at this stage - there is a high probability of removing too much material, and the cutter coming off can seriously damage the product. This is often impossible to fix.
Based on my own observations, I can say that no two files are absolutely identical. They are all slightly different and behave differently. The profile of the needle file for processing a specific area must be selected based on your own experience; it is difficult to give specific recommendations. For example, it is good to cut thin grooves with triangular ones and process the end of a stepped product. A rectangular file does not allow you to process the edge of the “step” so accurately. 
4. After completing the processing of this area, turn off the drive and push the workpiece to the length of the area being processed, and repeat the processing again. On the drawing (if you use it), it is useful to indicate the diameters at the beginning and end of the area being processed, as well as the width and height (depth) of the protrusions (belts) and grooves, their position from the end of the part. This will speed up the processing process. It is good to mark the position of the belts and grooves on the workpiece (after processing to the maximum diameter in this area) first with a thin marker, and then sharpen it with the edge of a triangular file - this way you will see them during the work process and will be able to navigate by them.
5. Continue with step 3 until the end of your product. Then, using a thin file and sandpaper, remove traces of transitions during processing, if any. At this stage, you control the final appearance of the product. You grind the workpiece, polish it if necessary (felt, fiberglass (for steel, aluminum, brass - that’s it!), just a rough cloth, then felt or felt with GOI paste or analogues).
The TOKARKA channel previously demonstrated the manufacturing process. The master will show how he made a special attachment for it, with which you can perform the same work as with a regular drill. How to do without a lathe and turn an adapter for a chuck on the motor spindle.
The device can be used as a simple primitive drill, if the engine is powered from a power supply. If secured in a vice or on wooden block, like a home micro-electric sharpener.
The first thing we will process is an aluminum corner, which is available in any construction super-market or construction market. It needs a slightly larger width than the engine. This is where the engine is mounted. If you don't have a milling machine, regular will do file or hacksaw and with it.
The metal is removed to give the product a beautiful appearance. If you like the corner as is, don’t cut it down. If you want to make a drill, you don’t need a corner. You can also take steel. I took aluminum, it conducts heat well and is easy to process.
If you want to do sharpening machine, just take any metal plate and fasten it in cleats or screw it with self-tapping screws to a wooden block.
Using a caliper, I scratched a line on which there will be three holes, two of which are for mounting screws. It was set in such a way that the engine was unlocked from the sole by a couple of millimeters.
After I established the distances between the axes of the holes for the screws, I divided them in half. I also placed the center on the corner, and set this distance in each direction from it.
Automatic core. It is convenient to work - one hand remains free. Punching is done before drilling. If this is not done, the drill may move to the side and the workpiece will be damaged. A machine and a drill or screwdriver are suitable. The master’s machine is homemade and low-powered. For larger diameters, the holes must be brought to the required caliber using a round file.
The holes for the mounting screws are sharpened a little so that the screws fit in freely. When doing work, super-high precision is not needed, but you need to try to do it more accurately.
40 volt motor from a broken printer, powerful. I found an engine without a casing and gears on the axle. If you want to remove the gear, use a file and turn on the engine. If not collet chuck or three-jaw, the tool can be secured to the motor pulley using an electric terminal block. They are sold in electrical stores, but they are not the best option- beating. If you had to use a terminal block, shorten the tool leg as much as possible.
This is an old Proxon FBS 240 E drill. The motor in it burned out, it was expensive. To get out of the situation, I took a 40-volt power supply from the printer and installed the engine inside the drill. If you can buy a small cartridge, like on a drill, it will be ideal for the engine, it has a small mass. The original one was much larger and I had to make two special plastic stands myself so that the engine would stand exactly in the center. I wrapped paper around the neck from which the engine axis comes out and soaked everything in epoxy resin; the diameter began to match. There was a special gear on the axis of the original motor that had to be removed. It went into a counter-toothed hole on the spindle. Such blocks and engines are not very expensive. If you manage to buy a broken drill on the market, you can fix it. Excellent convenient device.
This is a working drill. You see her all the time various videos. It has a lever-shaped switch which turned out to be convenient. A powerful engine and a chuck in which to securely clamp the tool would be perfect for an engine from cordless screwdriver at 12 volts. It has a low rotation speed, but the torque is large. But for it to work, you need a fairly large current, which can be provided from a battery or power supply unit of the computer, while it works great and has forced cooling.
Now we will demonstrate how to make an adapter from pieces of brass round timber to secure the cartridge to the motor shaft. If you don’t have brass on hand, mild steel will do, that is, not hardened steel or a piece of plastic. The diameter of the round timber is about 10 mm.
To accurately mark the center, I took a sharp awl and laid a 5 mm thick duralumin plate. I drew 4 lines in the shape of a plus. I scratched such markings on both ends to make accurate core punching. At the center of the intersection of the lines, a square was formed - the exact center of the workpiece. We apply several blows to the same point so that the indentation becomes as deep as possible.
The workpiece was securely secured in the drill chuck. The drill itself was turned on at medium speed, and the drill was clamped in hand vice. Due to the fact that the motor shaft has a diameter of 3.2 mm, I took a 3 mm drill. During drilling, the hole will definitely break a little. The goal is to drill the workpiece a little more than halfway deep. Then we'll rearrange it reverse side and drilling again. If you don’t have a hand vice on your farm, a chuck will do, but the drill needs to be firmly tightened in it. Do not apply excessive pressure to avoid breaking the drill.
Please note that the hole at the beginning of the channel is slightly broken; it fits freely on the motor shaft at least 3 mm. If the drill is 3.2 mm, then the channel is too wide.
If the adapter is made of plastic, be sure to use a gasket, for example, plastic stopper. This is to prevent it from simply being broken with a hammer. Dents are formed on brass from direct blows with a hammer; it can be ground off, but the speed of insertion increases.
The hole in the chuck for mounting on the tool spindle has a conical shape. The master grinds it into a cone shape with a large file. The good thing about processing is that it does not require a lathe, and the adapter when correct execution It will turn out smooth and will work without beating. It turned out that the tip of the adapter fits freely into the hole and the cartridge itself rests against the remaining part of it. This is exactly what we will be polishing now. During processing, do not press too hard on the file. Brass is not a hard metal and is easy to process. After trying on the cartridge, it turned out that it fits quite deep. For further processing, I took a round file with a large tooth and used it to cut out a recess in the middle so that seat the cartridge had two points of support on the adapter. Then you get a taper, you can adjust it very precisely. Please note that when planting, it pushes into the back of the adapter and the tip dangles freely inside. This means that the back part needs to be sharpened, but this should be done not with the largest file, but with a medium one. The operation is called fine fitting. It is much slower than rough peeling, but thanks to it high accuracy is achieved.
The end of the adapter still dangles inside, but much less. Next we will use a file with the finest notch.
The turning is complete, the fit is perfect, the cartridge fits tightly and does not wobble. Now it's time to clean the files from shavings. We use a brush with brass bristles. Steel bristle brush fits better. There was no vibration when turned on. This indicates that the cartridge rotates without runout, which means the work was done correctly. Any three-jaw in a lathe and drill can be tightened tightly without applying brutal force if you tighten each jaw individually.
Let's check the vibration when the tool is inserted. It exists due to the fact that the circle and the leg are not very precisely made; the centrifugal force leads to vibration. If you want to make a small sharpening machine, but don’t want to bother with the corner, then you can buy a couple of pipe clamps at a plumbing supply store, screw them into a block and secure the engine in them. For further work the cartridge must be removed. A piece of square is needed so that the engine on the corner can be properly secured in the electric handle. You will understand how it will stay there. The plate fits into the grooves on the handle and the holes are needed for screws to pass through them and be screwed into the square.
The duralumin square is fixed to the plate with two screws, and a corner on which the engine is fixed will be screwed on top of it. I glued the square onto the plate using super glue, now the hole is 2.5 mm in diameter. Square to corner with super glue. Use an M3 tap to tap the thread. Using a reamer, I chamfered the holes deep enough so that the countersunk heads would not stick out too much. The nozzle with the motor is held quite securely and does not move in one direction or the other.
The last thing left to do is to grind off the corners on the corner so that the look is neat and you don’t get hurt on them. The nozzle is completely ready. I wrapped electrical tape around the engine so it wouldn't be scratched. I soldered the two wires, inserted them into the terminal blocks, and now everything works. Unfortunately this maximum voltage, which we managed to squeeze out of the converter, that is, 22 volts in total. This means that the engine operates at only half the power, although without load the converter provided up to 40 volts. This is probably due to the cartridge being too heavy, which takes up most of the power.