Device for making metal patterns. A do-it-yourself cold forging machine will not only save you money, but also give you the opportunity to earn money. We make a torsion machine

A person who is not indifferent to forged products can only be envied. It has everything you need to implement the most daring design projects. Devices for the manufacture of cold forging elements can be purchased ready-made or made by hand, but in one case or another, you can be sure that it will be convenient and easy to work with them. At the same time, great physical strength is not required, all that is needed is to press the necessary buttons and turn the special levers in a timely manner.

The only thing to remember is that making cold forged products requires strict rules and consistency. In other words, cold forging is a step-by-step technological process in which metal blanks are deformed, depending on the desired project. To have a better idea about this work, you need to figure out what types of forging are, what popular forged elements are called, and what it looks like to make forged products with your own hands.

In the manufacture of metal products, 7 types of cold forging can be distinguished. These are some kind of stages of creating elements that need to be performed when working with blanks.

All work must be carried out in accordance with the requirements and rules, otherwise you should not hope for a beautiful forged product.

The most important stage is the forging of metal blanks. This is the largest, most responsible, complex and serious process, so it must be treated very carefully. Cold forging can be of several types:

Draft - it is carried out under high pressure. This is necessary in order to increase the workpiece on the sides, by reducing its height.
Broaching - this stage is performed by heating a metal part, followed by processing it with a hammer. This is necessary in order to reduce the cross-sectional area by increasing the length of the metal rod.
Firmware - this stage involves making holes inside the workpiece. When performing such work, you can get holes of different diameters and lengths. It is open and closed.

The draft and broach makes the structure of the metal workpiece more fragile, so further work must be carried out very carefully in order to prevent breakage of one or another part of the structure.

Cold Forging Tools

The manufacture of forged products in a cold way involves the use of several fixtures or machines. As mentioned above, they can be purchased or made by hand, but first, let's figure out what parts can be obtained using various machines.

For hand-made products, you will have to make special templates that allow you to create elements of various shapes and sizes.

How to work with the snail mechanism, you can see on the proposed video:

Universal mechanism - it allows you to perform several functions, cutting, riveting and forming metal products. By the way, such a device can be easily assembled with your own hands, which will greatly save your budget.
Gnutik - such a mechanism allows you to create an arc deformation of a metal part. But here it is necessary to carry out accurate calculations and measurements in order not to be mistaken with the bending radius.
Twister - the mechanism of this plan allows you to bend the workpiece along the longitudinal axis of the finished product. The principle of operation of such a mechanism is to bend the product by clamping it on one side and the other. In this case, the rotating handle will allow you to twist the part.
Wave - a mechanism of such a plan allows you to get wave-like parts from metal blanks. On such a machine, it is customary to make the “Boyarsky” or “Wave” gratings.
Stamp press - the name speaks for itself. Such a mechanism allows stamps with various carved elements to be applied to metal parts. Each master should have several such stamps in his arsenal, then the finished products will be more diverse. The principle of its operation is very simple, under the influence of pressure, clear prints from the templates remain on the metal elements.
Mechanical knot - this mechanism allows you to bend metal rods into a circle. In this case, the diameter of such products may be different. Therefore, in the arsenal of masters, such a device is indispensable.

Do-it-yourself cold forging, step-by-step instructions and expert advice

Oddly enough, but forged products can be made even at home. Of course, they will not be as pretentious as hot-worked elements, but as a decorative design they have no equal. All you need is a few of the tools described above, materials, and most importantly, desire. The rest is technology compliance.

The manufacturing process consists of several stages:

Starting work, check your calculations again, even a small error can spoil the appearance of the finished product, not to mention the fact that it may not fit the intended composition in size. Correcting and adjusting finished parts is always more difficult, it is much easier to check everything several times.

After making all the details, you can begin to assemble the intended composition. For fastening, it is better to use welding, but you should not overdo it with it, so as not to damage smaller elements.

The final stage will be the processing of the finished product, which involves grinding and painting the finished composition.

If you took up the production of forged elements in a cold way, then you probably studied the price market and assessed your financial capabilities. If not, then first pay attention to the cost of materials, the necessary equipment and how the finished product is processed. But in any case, a product made by oneself is worth all the costs. And you can reduce them on the equipment, if you make it yourself.

If a land plot is purchased, whether it be a house or a summer cottage, the question of registration of the plot always arises. Forged products are one of the most beautiful and showing self-sufficiency and good taste of the owner of jewelry. It can be either just a forged brazier, or whole compositions of forged products.

From forged metal, you can make gazebos that amaze with their beauty, a bench, a staircase will perfectly fit into any interior. Forged make fences (fences), even balconies. You can make a railing on the porch.

All this beauty today can be done by yourself, it is not difficult, as it may seem at first glance. The fact is that these things can be created without resorting to the services of a forge. Do-it-yourself cold forging machines can be used right at home. And the forging photos clearly illustrate the results.

Types of forging machines

For work on cold forging, special machines are used. Moreover, for each curl or bend you need your own machine for cold manual forging. They are:

With manual drive;
With electric drive.

The former are used when it comes to small amounts of work. They are easier to create. Their downside is their low productivity. Do-it-yourself drawings of a forging machine will show the entire assembly process in an accessible way.

The latter will be necessary when it comes to the streaming production of forged products. Their productivity is much higher, and there is no need to exert physical effort - the drive is carried out by an electric motor.

For those who are just taking their first steps in the manufacture of forged things, it makes sense to start with such a machine called the "Snail". A do-it-yourself forging snail will be an excellent helper when making gates and benches.

If the first steps have been taken and there is an interest in developing the chosen direction, you need to move on to mastering the torsion bar. With it, you can achieve the use of non-template approaches to the execution of forged products. Your things will acquire individuality - you can diversify the manufactured products.

Stages of cold forging

Although the process of making forged things is very exciting, you need to remember that this process must be performed in a certain sequence.

To understand the sequence of technological actions, you need to know the stages of forging or forging elements with your own hands:

Draft.
Broach.
Firmware.

The draft is necessary to increase the existing metal workpiece from the side by reducing the height. It is performed under fairly high pressure.

Broach gives a reduction in cross-section, increases the length. The workpiece must be heated, then "pass" with a hammer.

Firmware is the creation of holes inside the workpiece. Holes in the workpiece itself can be made of various sizes and diameters.

Distinguish firmware:

open;
Closed.

After the stages of upsetting and broach, the structure of the thing becomes more fragile. It is important to take this into account in the future and be extremely careful when working with the product, since the thing can simply be broken.

Forging step by step instructions

All forged items can be made by hand right at home. It will not be possible to perform special patterns, however, all the basic elements can be done by yourself. It is important to follow all the steps and technology.

There are several technological stages:

Checking all accounts. Even minor inaccuracies can spoil the entire end result. Correcting mistakes will be very difficult, and often impossible.
Assembling a decorative composition.
The fastening of the elements to each other is done by welding. However, it is important to remember that it can damage small decorative elements.
Processing of the resulting product - by grinding and painting the entire resulting product.

Disadvantage of cold forging

The only drawback of cold forging is the impossibility of correcting an error in the process. If the workpiece is damaged, then it will have to be thrown away at best as scrap metal, or left as a keepsake and used for training in the future.

The whole point of cold forging is that the metal is not heated, but is bent by processing in a "cold" form. This is how the desired shape is given to the metal.

The advantage of cold forging is the absence of the need for special equipment, as well as the absence of the need to use fire hazardous equipment, manufacturing conditions are acceptable for any person with any health. No high temperatures required.

DIY forging photo

Stamping, forging and bending
Machine tools and equipment for cold forging
Twisters
snails
How to build a curl?
torsion bars
Wave and zigzag

Looking at the fences, gates and wickets, as in the picture, at houses that are clearly not of an elite class, a person who has some idea of the equipment of the forge and the nature of the work there may think: where do they get so much money from? A more knowledgeable blacksmith will not have such a question: these beauties, as well as the metal decor of furniture, light garden buildings, swings, benches, etc., are created by cold forging.

Cold art forging prices are affordable because production costs and initial equipment costs are low, and labor productivity is not bad for artisanal conditions. Therefore, an individual blacksmith specializing in artistic cold forging can count on a fairly quick start and good profitability. Perhaps one of the owners of the samples in Fig. made your own: cold forging with your own hands is doable in a garage or barn without experience, and forged parts for small pieces of furniture, balusters, barbecues and all sorts of other metal utensils (see, for example, the figure on the right) can even be done at home conditions.

The basis of the "cold forge" is a cold forging machine. For a complete production cycle that can satisfy any conceivable fantasies of yours or the customer, 5-7 types of machines will be required, 3-5 main ones of which can be made by hand. However, in the beginning, before spending money on a machine or materials for it, it is highly desirable to master the beginnings of blacksmithing. Therefore, some methods for making artistic forging parts without a machine tool and equipment for them, which can be quickly made from improvised materials, will also be considered below.

Stamping, forging and bending

So what is cold forging? It differs from stamping in that the metal under the influence of the working body almost does not flow or flows weakly. Take a look at a beer can or, say, an aluminum or tin kettle. They are extruded with one blow of the punch of the punch press; kettle etc. . products of complex shape - a composite sliding punch. It is impossible to obtain the working force necessary to create such a high pressure at home, except for one case, see below.

Cold forging differs from hot forging, of course, in that the workpiece is not preheated. Actually cold forging, which is forging, is the riveting (hardening) of a part with a long series of regular blows of a certain force. In this case, the structure of the metal changes significantly: the hardness of the surface layer increases, and the core provides overall toughness and fracture strength. Handicraftsmen - toolmakers and gunsmiths - literally hunt for buffers and wheel tires of railway cars, pieces of rails.

Drawings of a snail machine for artistic forging with a specification of parts are given in fig. We will talk about the dimensions of the links (segments) of the folding share further, but for now, pay attention to the steel grades: there are heavy loads on the share. If you make it from ordinary structural steel, the template will lead to the middle of the gate or section of the fence.

Note: more detailed drawings of a snail machine of a similar design with a description and detailing can be found at: http://dwg.ucoz.net/publ/osnastka/instrument_dlja_kholodnoj_kovki/5. In the same place you will find drawings of a homemade bender and devices for bending rings.

The material for the folding swivel share, as well as the complexity of its manufacture, are not the only weak points of the snail machine with a collar. An even more serious problem is the articulation of the share links (shown by red arrows in the figure on the right). The joints of the share segments must:

It is difficult to fulfill all these conditions together even in a well-established and equipped industrial production, therefore the resources of folding templates for cold forging are generally much less than their material by itself would allow. Poor use of material properties is a serious disadvantage. In addition, for the same reasons, another weak point of the snail machine with a collar is the eccentric clamping of the part. Therefore, home-made snail machines for artistic forging, made according to a lever scheme, work more successfully for beginner homemade blacksmiths.

Snail with lever

The lever snail for cold forging is designed similarly to the well-known pipe bender. A home-made lever-type snail machine with a fixed template is significantly inferior in performance to a snail with a collar. The workload in it is more fully transferred to the base, therefore, a strong frame made of special steel or a thick plate of ordinary steel, securely fixed to the supporting surface, is required. As a result, an open-air workshop or production area is required. Work on the lever snail is moving slowly: turning the lever until it is jammed, you need to move the pressure roller. It is possible to curl on a lever snail up to 3-4 turns. However, the advantages of a lever snail for home craftsmen are significant, especially when working for yourself:

All parts, except for the pressure roller, can be made of ordinary steel.
It is possible to use a standard roller bearing as a pressure roller.
The use of the material properties of the parts is almost complete: the template and the bed made of ordinary steel can withstand more than 1000 work cycles.
You can bend both according to the template (pos. 1 in the figure below), and along the spacers, pos. 2 there.

In addition, the lever snail machine allows you to use a technological technique that is considered the prerogative of industrial twister machines: the template is shifted to the side, and a spacer is placed in the center, pos. 3 in fig. Thus, a small reverse bend is obtained in the core of the curl. The detail looks spectacular and, when working for sale, the product is valued more.

The lever snail has another rather fat little plus: on such a machine, you can bend flat curls with a small core from a strip laid flat. A snail with a collar and a swivel share here completely fails: the workpiece will go in a vertical wave. Wide curls and flat strip rings can be bent on a broaching machine with grooved rolls, see fig. on right. But the broach speed, so that the workpiece does not lead, this requires a significant one, so that a narrow core of the curl will not work.

On a lever snail machine, this problem is solved by installing a pressure roller as high as the thickness of the strip and with a flange (rim), like a railway wheel, only wider. Bending with this method takes a lot of time: the lever must be applied a little bit, otherwise the inner edge of the workpiece will wrinkle; from this rebord does not save. But it is impossible to get a curl from a flat strip with a narrow core in a handicraft production in another way.

In general, at the start of blacksmithing and art activities or making a forged fence, gate, gate, bench, swing, gazebo, etc., arranging a garden for yourself, it is still better to use a lever snail machine for cold forging. Moreover, it can be made from improvised materials without accurate and detailed drawings, see for example. next video.

Video: do-it-yourself artistic forging machine is simple

How to build a curl?

There are enough sketches of curls for artistic forging on the Internet, but when trying to adjust their sizes to those required for oneself, it often turns out that the product loses spectacularly due to a seemingly insignificant violation of proportions. Therefore, it is also desirable to be able to build forging patterns of curls, which obviously have aesthetic merit.

Patterns for cold forging of artistic curls - volutes - are built on the basis of mathematical spirals. The logarithmic spiral is most commonly used; it is one of the widespread natural forms, expressing the fundamental laws of nature. The logarithmic spiral is found in the shell of a mollusk, and in our hearing aid, and in the form of a treble clef in musical notation; in the fretboard of the violin itself, too.

The principle of constructing a logarithmic spiral by points is that when the radius forming it rotates, starting from a certain initial R0, by a fixed angle?, its length is multiplied by the spiral divergence index p. For volutes p, as a rule, they take no more than 1.2, because the logarithmic spiral diverges (unwinds) very quickly; on pos. In fig. for example, a logarithmic spiral with p = 1.25 is shown. To make it easier to build a spiral point by point with sufficient accuracy for blacksmithing, accept? = 45 degrees.

In the case when a denser arithmetic spiral is required, when the radius forming it is rotated by the same 45 degrees, 1/8 of the spiral pitch S is added to the previous radius, pos. B. In both cases, R0 is taken equal to or greater than the diameter d of a workpiece of uniform cross section, pos A. If the initial end of the workpiece is pointed, R0 may be less than d, up to the ductility limit of the metal.

It remains to decide how to lay a visually harmonious spiral with a given opening size a. To solve this problem analytically, i.e. using formulas with any predetermined accuracy, one will have to solve equations of cubic and higher degrees. Computer programs for the numerical technical calculation of volutes are not found on the Internet, so we will use an approximate method that allows us to get by with one worker and, possibly, one verification graphical construction. It is based on the assumption that for small p the sums R2+R6 and R4+R8 do not differ much. The step-by-step algorithm for constructing a volume for a forging template follows from this:

based on the available material, we determine R0;
we take the number of turns of the volute w according to the principle: as God puts on the soul of the left hind paw of his beloved cat;
using the data of the table in Fig., we calculate the diameter of the volute b such that it is slightly less than the width of the opening under it a, see pos. G;
we calculate the working initial radius R according to the formula in pos. G;
we build a volute profile on a scale by points;
if necessary, we fine-tune R according to the same formula and build the profile of the working template finally.

Note: if you will calculate intermediate values from the table, do not forget - you need to take them in geometric proportion!

torsion bars

It is possible to twist rods for artistic forging with a screw without a machine at all, see fig. on right. To prevent the workpiece from bending at the root (clamped in a vice) end, a wooden block or something like it with a V-shaped cutout at the top must be substituted under the end of the guide tube farthest from them; it is better to grab the pipe to this support with a clamp, and fix the stand on the workbench. The pipe should be shorter than the workpiece and inside about 1.5 times wider than its largest diameter, because. the workpiece, when twisted, is pulled together and distributed in breadth.

Torsion machine for cold forging allows you to increase productivity and improve the quality of the parts obtained. The working force in it is transferred to the support to a large extent, so the frame is needed strong, in the form of a spinal frame from an I-beam from 100 mm or a pair of welded channels of the same size; the pipe will visibly deform. On the supporting surface, the frame must be securely fixed with the help of paws welded to its ends from the same profile, pos. 1 in fig.

The workpiece - a square bar - is held by mandrels-chucks with sockets also of a square section; they are visible there in pos. 1. Because the bar is shortened in length during twisting, the cartridges in the spindle and tailstock must be securely fixed with screw clamps. For the same reason, the tailstock is sliding. To make it possible to twist individual sections of the workpiece, a sliding stop with an insert with a square hole is also used.

If you only need to make a fence for yourself or something less, you can quickly build a torsion bar machine from scrap and improvised materials, pos. 2. In principle, filaments can also be obtained on both machines by inserting a bundle of 4 bars half the size into cartridges. But do not think that you can make a good flashlight or basket just by pushing the tailstock with a lever. It will turn out something like the one on the sidebar in pos. 1 and 2. Blacksmiths call such incidents a well-known word, but not used in literary speech. When twisting the filament in a simple torsion machine, the branches of the filament must be spread out in breadth with a hand tool, which is difficult and does not provide the proper quality of work.

Beautiful filaments (pos. 3) are twisted on torsion machines with a fixed tailstock and screw feed of the spindle, pos. 4. Now let's go back to fig. with types of machines at the beginning, to pos. 2 on it. See the thing with the green exclamation mark? This is a replacement spindle. There are 2 of them in the set: a smooth one for spiral twisting along the long axis of the workpiece and a screw one for twisting filaments. In this design, the bed is welded from a pair of channels with a longitudinal gap, and a shoe with a threaded hole for a locking screw is welded to the tailstock. A shoe is needed with a sole from 100x100, because. fixation of the tailstock in the filament mode is frictional and only partly jammed: the locking screw gives only the initial clamping force.

About the torsion bar electric drive

Working on a torsion bar machine with a manual spindle drive is tiring. But the main thing is the stable quality of products such as in pos. 3 fig. with torsion bars, it is even more difficult to achieve. The reason is that it is difficult to create a uniform torque in a circle with your hands, like with any other lever drive. Therefore, a torsion cold forging machine is just the case when the use of an electric drive is justified no matter what. The best option from improvised materials is the axle shaft of the drive axle of a rear-wheel drive vehicle with a gear pair from the differential from the same place, see fig. on right; don't forget the protective cover! Motor - 1.5-3 kW and no more than 900 rpm. Other design options are also possible, see e.g. video clip:

Video: homemade electric cold forging machine

Spiral like a spiral

In some cases, ordinary straight straight ascending spirals are used as an element of artistic forging. It is absolutely unrealistic to make a spring twister machine for this on your own. But remember: there is no need to spring the spirals in the forged pattern and it can be wound from ordinary ductile steel using a simple device (see the figure on the right). The step (ascent) of the spiral is determined by the horn of the gate (filled in red); bending the horn up and down, you can get thinner and thicker spirals. A square bar is taken on a workpiece or a round one, it doesn't matter. You can also twist spirals from a bar twisted on a torsion bar.

Wave and zigzag

Now we have in turn a tool and equipment for wave and zigzag bending of long workpieces. The bending machine and the pull-and-press bending machine mentioned at the beginning are not reproducible with their own hands. In addition, the first allows you to adjust the pitch and profile within relatively small limits, and the second is expensive. However, a universal wave bending machine can still be made with your own hands on the model of what is on the left in Fig. Only rollers will have to be ordered, they must be made of chromium-nickel or tool steel; the rest is from a simple structural one, a sheet (strip) of 8 mm is needed for the brackets and the arc. Limiters are installed in the arc to accurately maintain the wave profile, but the workloads are transferred to it to a large extent; in fact, the arc provides transverse rigidity of the structure.

It is possible to bend only smooth, but very diverse, waves by adding a gate for waves to the snail machine with a rotary plowshare, on the right in Fig. The handles are used the same, because. they are screwed into threaded sockets on the head of the gate. It is desirable to make the root (central) roller separate and fasten it to the frame with sunken bolts. In this case, by placing rollers of different diameters, it is possible to form waves of a variable and asymmetric profile. And if the bypass roller is made adjustable (for which a number of holes are checked in its carrier), then the wave step can also be changed within a fairly wide range.

About connecting elements and painting

Forged parts need to be assembled into a single composition. The simplest way is welding and subsequent smoothing of the seams with a grinder with a cleaning wheel: it is thicker than a cutting wheel (6.5 mm) and can withstand bending forces. But connections with shaped clamps look much more impressive, they are stamped from a strip of 1.5 mm on an inertial stamp; it can also be hot forged quickly and without experience, see below. The clamp blank is made in the form of a U-shaped bracket on a mandrel in the size of the parts to be joined and its wings are bent from the rear in place with a large metalwork hammer or a 1.5-2 kg sledgehammer in a cold way. The finished product is painted, as a rule, with blacksmith's enamels or acrylic paints for metal. Enamels with a blacksmith's patina pigment are more expensive, but better: dried, they are of a noble color, somewhat antique, do not peel off, do not fade, wear and heat resistant

How to get around the stone

Those. a stumbling block in all of the above: shaped tips of rods; without them, a fence is not a fence, a gate is not a gate, and a gate is not a gate. The inertial stamping press (pos. 3 in the figure with machine types) is expensive, but effective. It works on the principle of a flywheel: first, smoothly rotating the rocker (bar with weights), the screw head is pulled back until it stops. Then a replaceable stamp is inserted into the socket, a blank is placed. Then the rocker arm is quickly spun in the opposite direction (this is a traumatic moment!) And it is left to rotate freely - the working stroke has begun. At the end of it, the striker hits the die shank very hard; due to the inertia of the loads, a force sufficient for stamping is developed.

Loads, especially impact ones, in an inertial stamping machine are large, fall on small areas, and the accuracy of manufacturing its parts needs to be high, so it’s better not to try to do it on your own. It is possible to make a manual rolling mill on your own, see fig. on the right, but only partially: special steel rolls, shafts and bearing bushings will have to be ordered, and gears will have to be bought or looked for second-hand. On such a mill, you can only get goose foot and leaf (spear) tips, and it will immediately be clear from their necks that this is machine work.

Meanwhile, the same, and some others, rod tips can be hot forged without being an experienced blacksmith. A good, obviously handmade tip-sheet is forged simply with a sledgehammer and a hammer, and a forging stamp (stamp) for the paws is made from an unusable file in which grooves are selected by a grinder. Do you need a forge for this? For occasional small work, it is not at all necessary; the main thing is to heat the metal. A propane burner is not suitable, the heating must be uniform on all sides and without overburning. So, we come to the conclusion that cold and hot forging do not exclude each other: in order to obtain high-quality products using simple cold forging machines or even improvised means, a small blacksmith's forge made of improvised materials will not even hurt in addition to them.

Stamping, forging and bending

Riveting of steel is carried out with a mechanical hammer. You can make it yourself, and even easier than some types of cold art forging machines. But this publication is devoted specifically to the latter subject, and cold art forging is essentially bending (bending) of metal: its structure in detail does not undergo significant changes, and a change in the physical and mechanical properties of the metal for the quality of the final product is not significant. Therefore, we will leave cold forging, which is forging, until a suitable occasion, and let's deal with forging, which is bending. For brevity, let's just call it artistic forging, and where it is necessary to mention hot forging, it will be specifically mentioned there.

Machine tools and equipment for cold forging

The main equipment for do-it-yourself artistic forging is several types of hand-operated machines and fixtures. The electric drive is used infrequently, because. the resulting increase in productivity is not always equal to the complexity of manufacturing and the cost of electricity. However, we will still remember about the electric drive for home forging machines while we deal with the “handbrakes”. Almost all elements of the products in Fig. at the beginning can be done on the following types of machines:

Twisters (twisters), pos. one in fig. - form flat spirals and other curls with a narrow core (core).
torsion machines, pos. 2- allow you to get a helical twist of a bar and elements from volumetric spirals, the so-called. filaments: baskets, lanterns, bulbs.
Inertial stamping machines, pos. 3- on them, the ends of the rods are splashed into shaped tips (pos. 1 in the figure below), decorative clamps are stamped to connect the details of the pattern (pos. 2 in the same figure), a small wave and relief are squeezed out on long details.

Bending machines are push, broaching and combined, pos. four. The former allow you to receive only waves and zigzags; broaching - rings, curls and spirals with wide cores, and the latter all these types of products.

Note: in the technical literature, especially in English, all machines that form parts by torsion or winding are often called twisters. Initially, a twister is a machine for winding springs. But in relation to artistic forging, it would be more correct to consider winding machines as twisters, and twisting machines as torsion ones.

What are gnats?

In technical vernacular, bending machines are called benders. However, in amateur and private metalworking, the name "gnutik" has established itself behind a desktop device for obtaining waves and zigzags, see fig. on right. By changing the roller or wedge in the bend, it is possible to vary the step and height of the wave or the angle of the zigzag within certain limits.

A bend for rods / pipes up to 12-16 mm is relatively inexpensive, but it is difficult to make it yourself at home: you need precise processing of special steels. Try using an ordinary electric drill with an ordinary drill for metal to drill an ordinary open-end wrench. And in the gyne, the workloads are much higher than on its sponges. Therefore, it is better to buy a bender, in addition to forging on the farm, it will be useful for the manufacture of elements of welded metal structures, as a pipe bender for small thick-walled strong pipes, and in other cases.

Twisters

From time immemorial, blacksmiths have twisted curls cold according to a mandrel template with a horn lever grip, pos. 1 in fig. This method is unproductive and not for squishy people, but it allows you to quickly and easily make a variety of bending mandrels from an ordinary steel strip: the end (thrust) horn of the lever does not allow the template to move under the pressure of the workpiece. It is advisable to make the middle (bypass) horn sliding with fixation: the work will go slower, but, especially in inexperienced hands, more accurately.

Another simple device for manual shaped bending is a strong board with support pins - spacers, pos. 2; ordinary M8-M24 bolts are suitable as them. Depending on how friendly you are with a home simulator, you can work with a strip of up to 4-6 mm. They bend the strip by eye, the work goes slowly, but you can draw patterns up to Ilya Muromets on a horse in full armor or Buddha in a lotus flower. The latter, perhaps, is completely handmade: people who have fully mastered hatha and raja yoga are able to twist steel fittings into a pattern with their hands.

snails

The twister machine - a snail is most popular among those involved in artistic forging: its capabilities, in comparison with the simplicity of design, availability for do-it-yourself manufacturing and ease of use, are amazing. Actually, the snail machine is a slightly mechanized and improved bending arm, but such a “little” made it possible for beginners to work on it. Snail machines are divided, in turn, into machines with a gate and a rotary share and lever machines with a fixed template and a bypass roller.

Snail with a plowshare

The device of a bending snail with a plowshare is shown in the diagram below; the technology of working with such a machine is also described there.

The advantages of this type of twister bending machine are as follows:

It is possible to work on a snail with a rotary share and a gate in an unequipped room: the vertical component of the working load is negligible, and its horizontal components are partially transferred to the support.
Due to the previous point, the supporting structure can be quite simple and light, welded from ordinary steel profiles.
We can carry out the working process alone: turning the gate with one hand, with the other we press the bar or strip to the plowshare-template. As it bends, its links will fall into place on their own.
In a cold way, on a snail with a rotary share, you can twist spirals up to 5 turns.

Note: more detailed drawings of a snail machine of a similar design with a description and detailing, see the link: //dwg.ucoz.net/publ/osnastka/instrument_dlja_kholodnoj_kovki/5. In the same place you will find drawings of a homemade bender and devices for bending rings.

Snail with lever

The lever snail for cold forging is designed similarly to everything known. A home-made lever-type snail machine with a fixed template is significantly inferior in performance to a snail with a collar. The workload in it is more fully transferred to the base, therefore, a strong frame made of special steel or a thick plate of ordinary steel, securely fixed to the supporting surface, is required. As a result, an open-air workshop or production area is required. Work on the lever snail is moving slowly: turning the lever until it is jammed, you need to move the pressure roller. It is possible to curl on a lever snail up to 3-4 turns. However, the advantages of a lever snail for home craftsmen are significant, especially when working for yourself:

All parts, except for the pressure roller, can be made of ordinary steel.
It is possible to use a standard roller bearing as a pressure roller.
The use of the material properties of the parts is almost complete: the template and the bed made of ordinary steel can withstand more than 1000 work cycles.
You can bend both according to the template (pos. 1 in the figure below), and along the spacers, pos. 2 there.

Video: do-it-yourself artistic forging machine is simple

How to build a curl?

The principle of constructing a logarithmic spiral by points is that when the radius forming it rotates, starting from a certain initial R0, by a fixed angle φ, its length is multiplied by the spiral divergence index p. For volutes p, as a rule, they take no more than 1.2, because the logarithmic spiral diverges (unwinds) very quickly; on pos. In fig. for example, a logarithmic spiral with p = 1.25 is shown. To make it easier to build a spiral point by point with sufficient accuracy for blacksmithing, take φ = 45 degrees.

based on the available material, we determine R0;
we take the number of turns of the volute w according to the principle: as God puts on the soul of the left hind paw of his beloved cat;
using the data of the table in Fig., we calculate the diameter of the volute b such that it is slightly less than the width of the opening under it a, see pos. G;
we calculate the working initial radius R according to the formula in pos. G;
we build a volute profile on a scale by points;
if necessary, we fine-tune R according to the same formula and build the profile of the working template finally.

Note: if you will calculate intermediate values from the table, do not forget - you need to take them in geometric proportion!

torsion bars

About the torsion bar electric drive

Video: homemade electric cold forging machine

Spiral like a spiral

Wave and zigzag

About connecting elements and painting

How to get around the stone

According to the common (but, alas, technically illiterate) expression "cold forging" (from the English cool forging), equipment designed to perform such plastic deformation processes includes devices that perform such operations as volumetric bending, twisting, flattening, etc. P. This is especially often necessary when working on the manufacture of elements of artistic forging of metal - spirals, volutes, snails, monograms, etc., which do not require subsequent connection to each other.

Compiling the terms of reference for a cold forging machine

The initial data for the design (if none of the options for the finished drawings of this equipment and fixtures suits you) are:

The limiting cross-sectional area of the original blanks (for example, it is very difficult to manually process a steel bar with a cross-sectional size of more than 12–16 mm).
Technical capabilities - in order to make the main parts of the required equipment yourself.
A list of forging operations - bending, upsetting, upsetting - that must be performed for subsequent artistic processing of metal.
The degree of complexity of the tool and fixtures that will make the required cold forging machine versatile.
The need for a drive (a manual cold forging machine is much easier to make than with an electric drive).

In order to carry out most of the operations for the manufacture of the necessary equipment yourself, the drawings should provide for the largest possible percentage of blanks and assemblies that require normalized rolled metal - channel, angle, thick strip, etc.

Types of home-made equipment and tools for plastic metal processing

It is quite difficult to make a completely unified cold forging machine with your own hands. But it is possible to provide in the drawings for the presence of interchangeable nodes, the fastening of which will be carried out on a common frame base. The most requested tools include:

twister- a device that performs spiral twisting of a part of a steel rod in the direction of its longitudinal axis;
Gnutik- a device that bends workpieces from profiled rolled metal to the required angle (including the implementation of spatial bending elements on metal);
Snail- a node that performs spiral twisting of a part of the workpiece with a constantly decreasing radius;
Sample- a tool with which a circle of the required diameter is made from a bar on a cold forging machine;
Kern- a tool for applying volumetric embossing on metal, as well as stamped impressions on flat surfaces.

A set of such equipment actually makes it possible to perform the vast majority of work on volumetric deformation of steels and non-ferrous alloys using cold forging machines.

The capabilities of the machine with a manual drive will allow volumetric deformation of mainly highly ductile metals and alloys - low-carbon steel, some brands of brass, copper, aluminum. From such elements it is possible to make details of forged railings, fences, stands, arbors.

Cold forging machine design steps and preparatory procedures

To make a cold forging machine, you will need the following drawings:

Drawing of the frame base of the bed for the installation of the unit;
Assembly drawings of each of the necessary devices;
Drawings of interchangeable parts of the machine.

As a working tool and starting materials for manufacturing, you need:

Plate steel (or strip) from medium-carbon steel grade not lower than steel 35;
Thick-walled pipe of square cross-section;
Portable cutting machine or grinder;
Tool for working with fasteners (wrench, pliers);
Household welding machine;
Frazier;
Manual bending unit;
Measuring and marking tool (square, caliper, caliper).

Before starting the manufacture of individual elements of the cold forging machine, it is useful to perform all the intended actions on the drawing, drawing all the main movements of the individual components and parts that make up the cold forging machine. It is especially useful to do this before making a replaceable working tool (for a snail, a core, a bend). It is also worth considering the possibility of using standard components: for example, a bench vice, or a caliper from a small decommissioned lathe.

To ensure the high quality of finished products, the roughness parameters of the tool must be one grade higher than the products that will be made on it. Therefore, after the production of welding operations, cuts, etc., the working finishing surfaces must be carefully sanded. When all the necessary components of the cold forging machine are made, it is useful to heat-treat the working replaceable tools. Hardening to a hardness of 40…45 HRC will significantly increase the durability of the fixtures used. It is worth recalling that after hardening the products are somewhat warped, and therefore need subsequent editing. However, it is better to order hardening and tempering transitions in specialized companies that have the necessary equipment.

How to make and assemble individual machine components and tools for it

As an example, a step-by-step instruction is given for obtaining the Twister fixture, which is intended for uniaxial longitudinal twisting of a steel billet from a square cross-section bar. Similarly, and in the same sequence, operations will be performed with respect to other parts of the cold forging machine - snail, core, template, bend, etc.

The reference workpiece for this device should be an I-beam or a channel with thick shelves. A wide thick-sheet strip is attached to it by welding, to which a bench vise can be attached. The fixed part of the twisted bar will be clamped in them. The vice should be fixed especially securely - with a minimum of four bolts with a diameter of M16 or more. To increase the clamping area of the rod, corrugated plates made of thick steel are welded to the vise jaws. From the opposite end of the I-beam, guide rollers are installed, to which a clamping unit for the moving part of the workpiece will be subsequently attached. It can be made from a steel sleeve, along the generatrix of which it is necessary to provide three holes for clamping bolts located at an angle of 120 ° with a diameter of 2 ... 3 mm smaller than the side of the square of the twisted element. The bolts must be hardened, made of quality steel, and also have a flat end. Both clamping devices must be located coaxially, which is checked using a level, bench square, caliper.