Many home craftsmen are thinking about how to make a metal lathe on their own. This desire is explained by the fact that with the help of such a device, which will cost quite inexpensively, you can effectively perform a large list of turning operations, giving metal blanks the required size and shape. It would seem that it is much easier to acquire the simplest desktop machine and use it in your workshop, but given the considerable cost of such equipment, it makes sense to spend time making it yourself.

Homemade lathe - it's quite real

Using a lathe

The lathe, which was one of the first to appear in the line of equipment for processing parts from different materials, including metal, allows you to make products of various shapes and sizes. With the help of such a unit, it is possible to perform turning of external and internal surfaces workpieces, drill holes and bore them to the required size, cut external or internal threads, perform knurling in order to give the surface of the product the desired relief.

A serial metal lathe is a large-sized device that is not so easy to manage, and its cost is very difficult to call affordable. Using such a unit as desktop equipment is not easy, so it makes sense to do it yourself. Using such a mini-machine, you can quickly turn workpieces made not only from metal, but also from plastic and wood.

On such equipment, parts with a circular cross section are processed: axles, tool handles, wheels, structural elements of furniture and products for any other purpose. In such 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 a clear coordination of the movements of all working bodies so that the processing is carried out with the utmost accuracy and best quality execution.

An example of a homemade lathe with drawings

Let us consider in more detail one of the working options of the assembled on your own lathe, pretty high quality which rightfully deserves the most close attention. The author of this homemade product did not even stint 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 machine Main components Caliper, tool holder and chuck
Side view of the tailstock Bottom view of the tailstock
Guide shafts Caliper design Engine driven
Drawing #1 Drawing #2 Drawing #3

Structural knots

Any, including home-made, lathe consists of the following structural elements: carrier frame - bed, two centers - leading and driven, two headstocks - front and rear, spindle, caliper, drive unit - electric motor.

All elements of the device are placed on the frame, it is the main bearing element lathe. The headstock is a fixed structural element on which the rotating spindle of the unit is located. In front 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 receives rotation. The tailstock, unlike the front, can move parallel to the direction of processing, with its help the free end of the workpiece is fixed.

A home-made metal lathe can be equipped with any electric motor, even if it is not too high power, but such an engine can overheat when processing large-sized workpieces, which will lead to its stop and, possibly, failure.

Usually, electric motors are installed on a homemade lathe, the power of which is in the range of 800–1500 watts.

Even if such an electric motor has a small number of revolutions, the problem is solved by choosing the 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 that home workshops are equipped with may not even have such a transmission mechanism in their design: the rotating chuck of the unit is fixed directly on the motor shaft.

There is one important rule: both centers of the machine, leading 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 models of the frontal type: with one leading center. The issue of such fixation is solved with the help of a cam chuck or a faceplate.

In fact, a do-it-yourself lathe can be made with wooden frame, but, as a rule, metal profiles are used for these purposes. The high rigidity of the frame of the lathe is necessary so that the accuracy of the location of the leading and driven center 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 lathe for metal, it is important to ensure that all its elements are securely fixed, always taking into account the loads to which they will be subjected during operation. What dimensions your mini-machine will have, 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 that you will need to use as a drive will also depend on these parameters, as well as on the planned load on the unit.

To equip lathes for metal, it is not recommended to choose commutator motors that differ in one characteristic feature. The number of revolutions of the shaft of such electric motors, as well as the centrifugal force that the workpiece develops, increase sharply with a decrease in load, 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 medium-sized and light parts on your mini-machine. But even in this case, it is necessary to equip 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 blanks 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 watts. Engines of this type are characterized by the stability of the rotational speed in the presence of a load, and when it is reduced, it does not increase uncontrollably.

If you are going to make a mini-machine for turning metal work on your own, then you should definitely take into account the fact that not only transverse, but also longitudinal loads will affect its cartridge. Such loads, if not provided for by a belt drive, can cause destruction of the motor bearings, which are not designed for them.

If it is not possible to use a belt drive, and the leading center of the device is directly connected to the motor shaft, then a number of measures can be taken to protect its bearings from destruction. Such a measure can be a stop that limits the longitudinal movement of the motor shaft, which can be used as a ball installed between the motor housing and the rear end of its shaft.

In the tailstock of the lathe, its driven center is located, which can be stationary or freely rotate. Most simple design has a fixed center: it is easy to make it on the basis of a conventional bolt, sharpening and grinding under the cone that part of it that will be in contact with the workpiece. By screwing in or unscrewing such a bolt moving through a threaded hole in the tailstock, it will be possible to adjust the distance between the centers of the equipment, thereby ensuring a secure fixation of the workpiece. Such fixation is also provided 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, according to which you can independently manufacture such equipment. Moreover, it is easy to find various videos showing the process of their manufacture. It can be a mini-CNC machine or a very simple device, which, nevertheless, will give you the opportunity to quickly and with minimal labor to produce metal products of various configurations.

Racks of the simplest metal lathe can be made of wood. They will need to be securely fastened to the frame of the unit using bolted connections. The frame itself, if possible, is best made 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 bars.

The video below shows the process of self-manufacturing a caliper for a lathe.

As a node on such a machine, on which the cutting tool will be fixed and moved, a handguard made of two wooden planks connected at an angle of 90 degrees will act. On the surface of the board where the tool will be placed, it is necessary to fix a sheet of metal that will protect the wood from deformation and ensure the exact location of the cutter in relation to the workpiece. In the supporting surface of a horizontal plank moving along the frame of the unit, it is necessary to make a slot, due to which such movement will be sufficiently accurate.

Modern processing of metal parts is almost impossible without a lathe. To save money, you can make this device yourself.

Making an ego is actually not as difficult as it seems, and a drawing of a lathe can be easily found on the Internet. The design of the machine can be the most diverse, as well as its dimensions.

Material for its manufacture at home is easy to find in any garage.

Lathe device

It is impossible to make a lathe with your own hands without knowing its device, so below we present its main parts:

• Drive unit. The basis of the mechanism, generates power. For a low-power machine, a drive from a drill or a washing machine is suitable;
• Bed. Suitable for making steel corner or a frame made of wood, it is a kind of load-bearing frame, so it must be strong to withstand vibrations;
• Rear grandma. It is made by welding a corner to an iron plate. It is needed for fixing during processing of the manufactured device;
• Front grandma. Mounted to the movable frame, similar to the tailstock;
• Caliper. Acts as a support for the working part.

The torque is transmitted by the engine to the working part using the following options:

• Chain;
• With a belt;
• Friction.

Each has its own advantages and disadvantages. Belt - the cheapest and most reliable, easy to manufacture. But the belt wears out quickly and needs to be replaced frequently.

Chain is more expensive, it is more bulky, but it lasts a long time. According to its advantages and disadvantages, friction occupies a middle position. It is worth noting the fact that photos of a lathe with different gears are available on the Internet, and you can easily study them in detail.

Support - extremely important detail machine. It regulates both the amount of effort expended during work and the quality of the part.

It moves in different directions and is therefore highly susceptible to wear. Do not forget to adjust it before starting work.

Assembly sequence of the mechanism

We assemble the frame of the machine with the help of channels and beams. The larger parts you plan to work with, the more durable materials the frame should be made of.

For the production of the headstock, we need a hydraulic cylinder with a wall thickness of 6 mm or more. We press 2 bearings into the cylinder. With bearings large diameter laying the shaft.

It is necessary to fill the lubricating fluid into the hydraulic booster. Then we install a caliper with guides and a pulley.

We install a handbrake to give the cutter stability. We fasten a small strip of metal from below, betraying the wear resistance of the working part.

Which motor to choose?

The motor is the most important part of any machine, because without it it will not function. The total power of the machine depends on its power. A motor with a power of up to a kilovolt (old sewing machines can serve as a donor), suitable for the manufacture of small parts.

Motors with a power of 1.5-2 Kv. used in the processing of large parts. In no case do not forget about the insulation of all electrical parts.

For correct installation motor, it is better to call an electrician than to get injured.

How to make a lathe from a drill?

To save on spare parts and simplify collection, it is allowed to use a drill as a drive. This design has its advantages:

Note!

• the design is assembled and disassembled at any time;
• it is transferred and transported quite simply, because it is quite simple to disassemble it;
• cost savings;

But this method has its drawbacks, because the drill has a low torque, which will make it almost impossible to process large parts.

It is worth modifying a metal lathe with a drill only when a large amount of work is not planned and small parts need to be made.

For the manufacture of this type of metal lathe, ordinary parts are needed (with the exception of the motor and headstock). The function of the headstock is taken over by a drill.

Due to the compactness of the machine, the role of the beds can be performed Smooth surface or workbench. The drill itself can be fixed with a clamp or clamp.

The following safety points must be observed:

Note!

• upon completion of the layout of the machine, it is necessary to check the serviceability.
• the electric motor in the machine must be protected by a casing;
• the power of the electric motor must be covered by your electrical network;
• the working tool can only be located parallel to the surface of the workpiece. Otherwise it will bounce;
• when processing the end planes, the latter must be rested against the tailstock;
• you can start work only using eye protection against chips;
• necessary after work workplace leave clean.

A woodworking machine requires the same safety precautions as a metalworking machine.

Machine change

When it is necessary to mount the cone-shaped holes, we fasten two files so that a trapezoid shape is obtained. Next, we mount the device on the springs for supplying the file.

To sharpen various blades, we attach a grinding wheel to the engine.

Summing up, I want to say that the assembly of the machine is quite simple. It is quite possible to make a homemade lathe at home with the help of improvised materials, which is a fairly economical measure.

You can adjust the size and power of the equipment yourself, as well as carry out the necessary modifications.

Note!

DIY lathe photo

1. Chess
2. Making a box

If you have a professional tool at hand, you can explore its capabilities endlessly. So, for example, an ordinary construction lathe is often used as a basis for making souvenirs and various decorative items. beautifully made wooden candlestick looks great on a lathe classic interior at home. A large vase made of wood is able to amaze the imagination. Sometimes in the hands experienced craftsman a seemingly ordinary chock turns into a real artistic masterpiece. How do they do it? What else can you make yourself?

A wood lathe allows you to make not only construction blanks, but also various decorative items, which are designed to please the eye and demonstrate the capabilities of the equipment. Any wood crafts are very practical, they always have a place in the house, so you can safely experiment and try to do something with your own hands. The easiest way is to turn a vase made of wood; you can easily get a jug, a salt shaker and a box for storing any little things. You can offer to make chess.

Vase

How can you make a vase on a lathe? For its manufacture, you may need a certain tool. In addition to the lathe, you need to take cutters, a planer, a hacksaw, a ruler, compasses, an ax and a saw, grinding skins and a chisel.

The process of turning a vase is extremely simple. True, it should be noted that vases are complex in configuration and simple. Consider how you can carve out a simple option.

• First, a block of wood is cut with a saw, 10-20 cm long.
• It must be worked out with a planer, both from the ends and along the length.
• The workpiece is installed in the chuck of the machine.
• The machine is turned on and checked for runout of the part.
• If it is present, it is necessary to carry out alignment.
• The top layer of wood is removed to a depth of 1 cm.
• The chamfer is removed at an angle of 45 ° from the outer end.
• A drill is inserted into the tailstock.
• A hole is drilled with a depth less than the length of the workpiece by 3-5 cm. That is, the bottom of the vase is determined.
• Now, with the help of a cutting, which is called a joint, the cavity of the product is cut out.

Since the vase may have different shape: straight, oval, and so on, then, respectively, the boring of the upper surface is maintained in an exact shape. After that, the product is polished from the outside and from the inside. What is used for sandpaper. The wooden product is removed from the machine, the bottom is finished manually using a planer and sandpaper. After that, the souvenir is varnished.

Chess

Chess is a small figurine, so their manufacture requires a certain experience and hardness of the hand of the turner, as well as his eye. To make a figure, you will need a small log with a section of 50x50 or 60x60 mm. On the one hand, it is formed under a smaller section, for example, 40x40 or 30x30 mm, as shown in the video.

With this smaller end, the workpiece is inserted and clamped into the chuck. Now you need to cut the free end of the blank with a cutter and press it with the center of the tailstock. A layer of wood is removed with a cutter so that the workpiece becomes round. After that, you can proceed to the manufacture of the chess piece itself. You can use traditional forms, you can dream up.

As soon as the figure is completely ready, it must be sanded, and at the end cut off from the pressed part of the workpiece. It remains only to manually varnish it or paint it black or White color. By the way, a wooden candlestick is made on a lathe in the same way. Its length is longer, which means that a longer workpiece will be needed.

Making a box

The box is not the best complex element, which can be turned on a lathe. But if it is a product with a lid, then the drawings will be required here. After all, the lid should enter the box and sit on the groove, that is, the lid should be flush with the edge of the product itself.

To make the box, you will need a cylindrical blank, which is installed in a lathe. The main thing is that the workpiece does not reach the bed.

• First, a layer of wood is removed semicircular cutter to give it a round shape.
• Then, with a joint, you need to earn money on the surface, that is, make it smooth.
• After that, it is necessary to form an internal cavity wooden product. For this, a narrow straight cutter is used. This operation cannot be completed in one pass, so you will have to carry it out in steps.
• Using a triangular cutter, it is possible to expand the internal cavity to the thickness of the walls.
• The bottom of the box is leveled with a straight but wide cutter. They also make a groove for the lid.
• Grinding of internal and external planes is carried out.
• Lacquer is applied on top, wax on the inside.

The lid is made from the same material as the box itself. It just requires a thin workpiece, which is fixed in the chuck of a woodworking lathe. First, the processing is carried out with a wide straight cutter, that is, the inner part is formed, it can be flat or concave inward. Grinding required.

Then the outer part is formed, for which the workpiece will have to be turned over. That is, the half-finished part of the lid is cut off and almost finished inside installed in the cartridge. Then the same cutter is used to form outside covers. It can also be flat or convex. At the end, grinding is carried out. Then ready product varnished.

In principle, the order of manufacturing the sides can be changed if there is a handle-holder on the lid. To do this, you will have to take a thicker workpiece to sharpen the handle. It can be round, oval or curly. You can make a handle as a separately turned element, and attach it to the lid of the box with an adhesive.

The diameter of the lid should correspond to the diameter of the inner groove of the box. That is, the cover must freely enter the groove.

These are the products you can do with your own hands on a wood lathe. The most difficult of the above decorative items- it's a box. Here it is necessary to strictly adhere to the dimensions, especially the wall thickness. They made it a little thinner, and there will be a high probability that it will burst over time. In addition, you will have to strictly adhere to the diameters of the lid and the groove on the box itself. If one of the sizes does not match, then either the lid will fall inside the box, or it will end up on the edge of the product.

Therefore, when turning on a lathe homemade crafts wood requires attention and accuracy (the work is not rough). Of course, it is necessary to take measurements with a caliper during the work process.

Elements and cutting conditions

Before talking about processing methods, let's briefly get acquainted with the elements and cutting mode.

Here we will meet new concepts: depth of cut, feed, cutting speed.

All of them are interconnected, and their value depends on various reasons.

The depth of cut is the thickness of the metal layer removed in one pass of the cutter. It is denoted by the letter t and ranges from 0.5 to 3 or more millimeters for roughing to tenths of a millimeter for fine turning.

Feed is the movement of the cutter along the surface to be machined. Numerically, it is expressed in millimeters, denoted by the letter S and indicates the amount of displacement of the cutter per revolution of the part. Depending on the strength of the material being processed, the rigidity of the machine tool and the cutter, the feed rate can vary from 0.1-0.15 mm / rev to 2-3 mm / rev at high-speed cutting conditions. The harder the metal, the lower the feed should be.

The cutting speed depends on the number of revolutions of the spindle and the diameter of the part and is calculated by the formula.

When choosing one or another cutting speed, it is necessary to take into account the hardness of the material being processed and the tool life, which is measured by time. continuous work it to blunt in minutes. It depends on the shape of the cutter, its dimensions, the material from which the cutter is made, on turning with or without a cooling emulsion.

The cutters with hard alloy plates have the greatest resistance, the cutters made of carbon steel have the least.

Here, for example, what cutting speeds can be recommended for turning various materials cutter from high speed steel. Its durability without cooling is 60 minutes.

Approximate data on the cutting speed of metals:

Turning smooth cylindrical surfaces

Smooth cylindrical surfaces of parts are turned with through-cutting cutters in two steps. First, with a rough cutter, a peeling is performed - a rough turning - quickly removing the bulk of the excess metal. The figure shows a straight cutter for roughing:

Rough cutters: a - straight; b - bent; c - Chekalin's designs.

The bent cutter is convenient when turning the surface of the part near the chuck jaws and for trimming the ends. Usually incisors have a working stroke only in one direction, most often from right to left. A double-sided through-cut cutter designed by the innovator turner N. Chekalin makes it possible to eliminate the back-idling of the cutter, reducing the processing time.

After turning with a rough cutter, large risks remain on the surface of the part and the quality of the machined surface is therefore not high. Finishing cutters are used for final processing:

Finishing cutters: a - normal; b - with a wide cutting edge; c - bent, designed by A.V. Kolesov.

The normal type of finishing cutter is used in turning with small depth of cut and low feed. A fine cutter with a wide cutting edge allows high feed rates and a clean and smooth surface.

Trimming ends and ledges

To trim the ends and ledges on a lathe, they usually use scoring cutters. Such a cutter is shown in the following figure:

Cutting in the centers: a - cutting cutter; b - cutting the end with a half-center.

It is best used when turning parts in the centers. In order for the end face to be machined as a whole, a so-called half-center is inserted into the tailstock.

If the part is fixed with only one of its ends - when machining in a chuck - then a bent cutter can also be used for turning the end. For the same purpose and for turning the ledges, special scoring thrust cutters are used, which work with transverse and longitudinal feed.

Trimming the ends: a - trimming with a bent cutter, b - scoring thrust cutter and its work.

When cutting ends and ledges, the young master must ensure that the top of the cutter is always set strictly at the level of the centers. A cutter set above or below the centers will leave an uncut ledge in the middle of the solid end.

Grooving

For turning grooves, slotted cutters are used. Their cutting edge accurately reproduces the shape of the groove. Since the width of the grooves is usually small, the cutting edge of the kerf has to be made narrow, so it is rather brittle. To increase the strength of such a cutter, the height of its head is made several times greater than the width.

For the same reason, the head has a small rake angle.

Cut-off cutters are very similar to slotted cutters, but have a longer head. A narrower head is made in order to reduce material consumption when cutting.

The length of the head should be selected according to the dimensions of the part and be slightly more than half of its diameter.

When installing slotted and detachable cutters, you must also be very careful and accurate. Careless installation of the cutter, for example, its slight distortion, will cause the cutter to rub against the walls of the groove, marriage in work, breakage of the tool.

Turning narrow grooves is carried out in one pass of the cutter, which is selected according to the width of the future groove. Wide grooves are machined in several passes.

The order of work is as follows: using a ruler or other measuring instruments, mark the boundary of the right wall of the groove. Having installed the cutter, they machine a narrow groove, without bringing the cutter by 0.5 mm to the desired depth - the remainder for the finishing pass. Then the cutter is shifted to the right by the width of its cutting edge and a new groove is made. Having thus chosen a groove of the intended width, the final, finishing pass of the cutter is made, moving it along the part.

The workpiece installed in the centers should not be cut to the end: the broken part can damage the tool. A short piece clamped in the chuck can be cut clean using a special beveled cut-off tool.

The feed rate and cutting speed for grooving and parting off should be less than for cylinder machining, because the rigidity of traversing and parting cutters is not high.

Cone turning

In the practice of a young turner, turning cones will be less common than other work. The easiest way is turning small cones (no more than 20 mm) with a special wide cutter.

In the manufacture of an outer or inner cone on a part fixed in a chuck, a different technique is used. turning upper part caliper at an angle equal to half the angle of the cone at its apex, the part is machined by moving the cutter with the help of the upper slide of the caliper. This is how relatively short cones are sharpened.

To make long and gentle cones, you need to shift the rear center, move the tailstock a certain distance towards yourself or away from you.

If the part is fixed in the centers in such a way that the wide part of the cone will be at the headstock, then the tailstock should be shifted towards you, and vice versa, when the tailstock moves away from the working one, the wide part of the cone will be on the left - at the tailstock.

This method of taper turning has a serious drawback: due to the displacement of the part, rapid and uneven wear of the centers and center holes occurs.

Interior surface treatment

Hole machining can be done various tools, depending on the required surface shape and processing accuracy. In production, there are blanks with holes made during casting, forging or stamping. For a young metal worker, ready-made holes will be found mainly in castings. The processing of holes in solid workpieces that do not have prepared holes will always have to start with drilling.

Drilling and reaming

Not deep holes on a lathe they drill with feather and spiral (cylindrical) drills.

The spade drill has a flat blade with two cutting edges, turning into a rod. The angle at the top of the drill usually has 116-118 °, however, it can be, depending on the hardness of the material, from 90 to 140 ° - the harder the metal, the greater the angle. The accuracy of the hole when processing with a pen drill is small, so it is used when high accuracy is not required.

Twist drills are the main tool for drilling. The processing accuracy of these drills is quite high. A twist drill consists of a working and part of a conical or cylindrical shank, with which the drill is mounted in the tailstock quill or in the chuck.

Spiral drills: a - with a conical shank; b - with a cylindrical shank

The working part of the drill is a cylinder with two helical grooves forming cutting edges drill. Chips are brought out along the same grooves.

The drill head has a front and back surfaces and two cutting edges connected by a bridge. Chamfers running along the helical grooves guide and center the drill. The value of the angle at the top of the twist drill is the same as the feather drill and can vary within the same limits. Drills are made of alloyed or high-speed steel. Sometimes alloy steel drills are equipped with carbide inserts.

The drill is fixed in two ways, depending on the shape of the shank. Drills with a cylindrical shank are fixed in the tailstock quill using a special chuck, drills with a conical shank are inserted directly into the quill hole.

It may happen that the taper shank is small in size and does not fit the hole. Then you have to use the adapter sleeve, which, together with the drill, is inserted into the quill.

Adapter sleeve for drills with tapered shanks: 1 - drill shank; 2 - bushing.

To push the drill out of the quill, you need to rotate the handwheel to tighten it into the tailstock housing. The screw will rest against the drill shank and push it out. With the help of a special holder, you can also fix the drill in the tool holder.

When drilling, care must be taken to ensure that the drill does not lead to the side, otherwise the hole will be incorrect and the tool may break. The drill is fed by slow and uniform rotation of the tailstock handwheel or by moving the caliper if the drill with the holder is fixed in the tool holder.

When drilling deep holes, it is necessary from time to time to remove the drill from the hole and remove chips from the groove.

The depth of the hole should not exceed the length of the working part of the drill, otherwise the chips will not be removed from the hole and the drill will break. When drilling blind holes to a given depth, you can check the drilling depth by divisions on the quills. If they are not, then a mark is made with chalk on the drill itself. When a characteristic screech is heard during drilling, this means that either the drill is skewed or it is dull. Drilling must be stopped immediately by removing the drill from the hole. After that, you can stop the machine, find out and eliminate the cause of the squeal.

Reaming is the same drilling, but with a larger diameter drill through an existing hole. Therefore, all drilling rules apply to reaming.

Other methods of processing internal surfaces

In the practice of a young turner, there may also be such a case when the diameter of the desired hole is much larger diameter most large drill in its set, when you need to make a groove in the hole or make it conical. Each of these cases has its own processing method.

Boring holes is carried out with special boring cutters - roughing and finishing, depending on the desired cleanliness and accuracy of processing. Roughing cutters for turning blind holes are different from roughing cutters for turning through holes. Finishing of through and blind holes is carried out with the same finishing cutter.

Boring cutters: a - rough for through holes; b - draft for blind holes; c - finishing

Boring has its own difficulties compared to external turning. Boring cutters have low rigidity, they have to be significantly extended from the tool holder. Therefore, the cutter can spring and bend, which, of course, negatively affects the quality of processing. In addition, it is difficult to monitor the work of the cutter. The cutting speed and feed rate of the cutter must therefore be 10-20% less than with external processing.

Particularly difficult is the processing of thin-walled parts. Clamping such a part in the chuck, it is easy to deform it, and the cutter will select thicker chips on the depressed parts. The hole will not be strictly cylindrical.

For correct processing when boring, the cutter is set at the level of the centers. Then you need to bore the hole 2-3 mm in length and measure the diameter.

If the size is correct, you can bore the hole to its full length. When boring blind holes or holes with ledges, as well as when drilling, a mark is made on the cutter with chalk indicating the depth of boring.

The cutting of the inner ends is carried out with scoring cutters, and the turning of the internal grooves is carried out with special slotted grooving cutters, in which the width of the cutting edge exactly matches the width of the groove. The cutter is set to the appropriate depth according to the chalk mark on the body of the cutter.

Internal groove measurement: ruler, caliper and template

In addition to boring cutters, countersinks are used to bore cylindrical holes. They are similar to twist drills but have three or four cutting edges and are not suitable for making holes in solid material.

Spiral tail countersinks: a - from high-speed steel; b - with hard alloy plates

Very clean and precise cylindrical holes are made with reamers. Both of these tools are not used to expand the hole, but to fit the exact size and shape.

Reamers: a - tail; b - back

Making taper holes

Turning the inner cones is perhaps the most difficult task. Processing is carried out in several ways. Often, conical holes are made by boring with a cutter while turning the upper part of the caliper.

In solid material, a hole must first be drilled. To facilitate boring, you can drill a stepped hole. It should be remembered that the diameter of the drill must be selected in such a way that there is an allowance of 1.5-2 mm per side, which is then removed with a cutter. After turning, you can use a conical countersink and a reamer. If the slope of the cone is small, a set of conical reamers is used immediately after drilling.

The last of the main operations performed on a lathe is threading.

Mechanical threading is possible only on special screw-cutting machines. On the simple machines this operation is done manually. tricks hand made external and internal threads are outlined above.

Measuring tool

In turning, the same tool is used as in metalworking: a steel ruler, calipers, calipers and others. They have already been mentioned before. New here may be various patterns that the young master will make himself. They are especially convenient when making several identical parts.

Remember that all measurements can be made only after the machine has completely stopped. Be careful! Do not measure a rotating part!

Precautionary measures

When working on a lathe, you must be guided by the following rules:

1) it is possible to start working on the machine only after a detailed acquaintance with the machine and processing methods;

2) not to work on a faulty machine or an unusable (blunt) tool;

3) firmly fix the part and monitor the serviceability of the enclosing devices;

4) do not work in loose clothing: tie sleeves at the wrist, long hair hide under a headdress;

5) remove chips in a timely manner and keep order at the workplace;

6) do not stop the rotating cartridge with your hands;

7) In the event of a malfunction, switch off the machine immediately.

Machine Care

The more carefully the machine is maintained, the better and longer it will work. This simple rule should be firmly remembered and carefully followed. Lathe care is as follows.

The main thing is the lubrication of all rubbing parts. Before starting work, it is necessary to inspect the machine and check whether there is enough lubrication. Bearing lubrication should be monitored most closely by filling grease fittings and lubrication holes with engine oil. The machine at this time, in order to avoid an accident, must be stopped.

After work, you need to clean the machine, remove chips, wipe the bed guides and calipers, and lubricate them thin layer oils.

The taper holes of the spindle and tailstock quills must be absolutely clean. The accuracy of the machine will depend on their good condition.

Before starting work, you should also check the condition of the drive belt. It must be protected from oil splashes and drops, as an oily belt slips and quickly works. The belt tension should not be too strong, but not too weak either: a loosely tensioned belt slips, and with a strong tension, the bearings heat up and wear out quickly. The drive belt guard should also be in order.

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• Basic work performed on a lathe

Lathes are designed for processing bodies of revolution. When working on a lathe, cylindrical, conical and shaped surfaces are turned, both internal and external, as well as threading and knurling. In addition, they can be drilled, but this is only possible if the hole is in the axis of the part or with some offset from it.

Varieties and characteristics of woodworking machines

Variety of types, sizes and shapes wooden parts involves a variety of equipment on which processing takes place.

The list of types of woodworking machines includes:

Sawing

This group is used for sawing blanks and whole woods, as well as for shaping flat elements. Sawing, in turn, should be divided into the following subgroups:

• Sawmills, with the help of which the longitudinal and transverse sawing of the material is carried out using linear saws that reciprocate relative to the workpieces. This equipment does not belong to economical equipment, moreover, it is quite bulky, so it is quite rare.
• Circular saws, which are automatic and manual, performing sawing wood in inclined and vertical planes using circular saws. Such equipment has found application in molding. It is classified according to the number of saws, their diameter, power and performance.
• Tape, functioning automatically and with manual control. Cutting the tree occurs with the linear movement of the tape. It is used both during harvesting and during further processing. The advantage of this equipment can be called ease of maintenance and cost-effectiveness, but lower accuracy when compared with circular saws.

Planing

Designed to remove the top layer of material when moving cutting tool. The main varieties of machines of this type include:

• Thickness gauges, one and two-sided. Single-sided are only capable of processing the upper plane, so they are used only when processing large workpieces. They are widely used due to the simplicity of their design, which means ease of management and maintenance. Double-sided can process the bottom and top plane at the same time. Their advantage is high productivity, but at the same time they are more difficult to maintain.
• Jointers, which not only process planes, but are also able to chamfer at a certain angle.

Turning

Lathes are divided into a large number of varieties, based on accuracy, dimensions of the machines themselves and workpieces, etc. Woodworking varieties of lathes are used for turning decorative elements, body parts and fasteners. The main classification parameter is the degree of automation and versatility. According to the degree of automation, there are the following varieties:

• Manually controlled machines involve the regulation of the spindle speed, the supply of parts and other parameters for the workers.
• Automated equipment is equipped with replica devices, which reduce the processing time of the part, but all processes are still under human control.
• Automatic processes involve the implementation of all transitions in automatic mode. All parameters are controlled by the machine computer. have become very popular in recent years.

If we talk about versatility, then it is worth highlighting:

• Versatile equipment that allows you to perform parts various shapes, size and complexity.
• Specialized, which provides processing of parts in a certain range of sizes.
• Special, designed for the manufacture of only one specific part.

Drilling

They are necessary for drilling holes that are in the axis or not in the axis of the parts, as well as for processing holes. They are classified according to many parameters, but the main one can be called the configuration by which they are divided into:

• Vertical drilling, which perform work only in a vertical plane;
• Horizontal drilling, processing only in a horizontal plane;
• Radial drilling, allowing you to change the angle of the tool.

Milling

Such machines are used for processing flat and shaped surfaces. Like drilling, they are divided according to the planes in which the cutter works. By configuration, they should be divided:

• Horizontal milling, in which the spindle is located horizontally relative to the table surface;
• Vertical milling, the tool of which is located perpendicular to the table and the part fixed on it;
• Universal, allowing you to change the location of the workpiece without reinstalling it.

Grinding

These machines are designed for finishing and involve the removal of the upper layer of a small thickness with a tool with an abrasive coating. Distinguish:

• Surface grinding, on which flat surfaces are processed;
• Cylindrical grinding, designed for bodies of revolution;
• Special grinding machines, which are designed for processing complex surfaces;
• Edge grinding. Used for final processing of curly elements.

Gnutary

Represent hydraulic presses with special clamps. Used to give an element a special shape.

Assembly

Most often this automatic devices for assembly individual elements into a semi-finished or finished product.

Work technology

Lathes are designed for processing bodies of revolution. This equipment performs the following tasks:

• Trimming ends;
• Turning of external surfaces;
• Thread cutting of any type;
• Cutting parts;
• Application of corrugations;
• Drilling and boring internal holes.

However, this is not the only thing that can be done on this machine. In addition, it can be used for polishing and lapping holes. Polishing can be done using a special felt wheel and GOI paste. With their help, the product acquires mirror surface, however, surface accuracy is not guaranteed. Finishing the surface of the hole is carried out using a lap. This operation allows you to get an accurate hole with a low roughness index.

Machining on a lathe is achieved by rotating the part relative to a fixed tool.

The tool can be clamped in the spindle or in centers. Center is special devices, which are fixed in the spindle and in the tailstock. To ensure it, it is necessary to first center (drill a hole in the axis with a special drill) the workpiece on both sides. The setup for processing in centers allows you to complete all transitions in one setup.

Types of machines for turning metal work

According to the degree of accuracy, the equipment should be divided into: normal accuracy; accurate; especially accurate; increased accuracy; super precision.

By type are divided into:

• face-turning;
• carousel;
• screw-cutting;
• turning and revolving.

The first two varieties are designed for processing large parts, from half a meter to several meters. Screw-cutting lathes are the most common, since they are universal and are designed to process parts up to five hundred millimeters. Turret turning machines are semi-automatic machines. Processing on such equipment is carried out on stops.

Turning methods

On a lathe, parts are turned and holes are drilled. Complex work is also carried out, which is the execution of turning and grinding only on a lathe. To perform the grinding operation in this case, high-precision cutters and laps can be used if this is a hole. Such a measure allows to reduce the production time, and hence, to reduce the cost of parts.

Grooves of the inner diameter are made using a drill, countersink and reamer, as well as cutters. In addition, taps can be used that cut threads inside the hole (a die is used for external surfaces).

Alignment of the dimensions of parts occurs with the help of a dial (measuring scale on the caliper), as well as with the help of measuring instruments(calipers, micrometers, etc.).

Types of cutters used

Cutters for machining on a turning wall are:

• through passage, designed for processing flat surfaces of the ends of the part;
• undercut, used for turning cylindrical surfaces;
• cutting, which cut off the finished part from the workpiece;
• shaped and fillet, which are used for turning shaped surfaces and fillets;
• threaded, which are divided into external and internal;
• boring cutters, which are used to process internal surfaces;
• grooving, similar to cutting, used for turning grooves.

In addition, the incisors are divided into:

• solid, most often made of high-speed steel;
• composite with soldered hard alloy plates, the holder in this case is made of carbon steel;
• fixed with a removable plate that can be replaced in case of wear or chipping.

Safety

During work on the lathe, it is necessary to use a protective cover that closes the rotation zone of the part. Thus, the worker is protected from flying chips.

The employee must stand on a special wooden deck, this provides protection against electric shock.

Clothing should cover the body, leaving only the hands, head and neck open. Shoes must be closed. All this is necessary to protect against chips. Clothing should not be tight or too loose. In the first case, it will hamper movement, and in the second case, it can cause injury when tightening clothes into the spindle.

Before starting work, the worker must be given special glasses that protect the organs of vision from chips or dust. If loose material is turned (for example, graphite or wood), then in addition to glasses, respirators must be issued to protect the organs of vision. Also, when working with bulk materials, an extract is necessary, which will protect not only what is sharpening directly, but also other workers in the workshop.

Before removing the part, not only turn off the rotation of the spindle, but also dull the sharp edges.

Most importantly, a person is allowed to work on a lathe only after passing the briefing.