Looking at the fences, gates, gates of various cottages, a person who has no idea about blacksmith tools or work in a forge asks: where does this money come from? A person who understands blacksmithing will answer him that such things (metal furniture decorations, swings, benches) are made using devices for cold forging.
The cost of cold forging is not too high. This is due to low equipment costs, high efficiency processing. A blacksmith who does this type of work can quickly start making a good profit. Probably, some cottage owners make all the fences and gates themselves, because cold forging can be done in a garage or barn without having any special skills.
The main thing you will need is homemade equipment for cold forging. If you want to make various objects from metal, you will need five to seven types of equipment. You can make three to five cold forging machines with your own hands. Before you start crafting, you need to learn the basics of working in a forge.
Stamping, forging, bending
Cold forging differs from stamping in that the material practically does not flow under the influence of the tool. Look at a beer can or, for example, an aluminum/tin teapot. Their extrusion is carried out in 1 blow of the stamping device.
Cold forging differs from hot forging in that the part is not heated before processing. The workpiece is, as it were, riveted by hitting it many times. The metal structure changes significantly. The surface strength increases, and the middle becomes more viscous. Handicraftsmen really value tires for carriage wheels and parts of rails.
The metal is riveted using a conventional hammer. Making it yourself is easier than making a homemade cold forging machine. However, such forging still differs from cold hardening. When it is performed, the metal structure does not change much.
Currently there are different kinds machines for cold forging. An electric drive is rarely used, because the increase in efficiency it causes often does not justify the difficulty of creating it and the expense of electricity. For cold forging, machines are divided into:
- twisters - form flat spirals and other curls with a narrow middle;
- torsion bars - make it possible to create a screw twist of a rod and parts from volumetric spirals (filaments);
- stamping-inertial - with their help they perform splashing of shaped tips, stamping of decorative clamps to combine patterned parts, extrusion of relief elements on long products;
- bending – processing is carried out by pressing, drawing or a combination of these methods. In the first case, waves and zigzags are made, in the second - rings and curls.
In various books, especially English ones, all homemade machines for cold forging with your own hands, which form products by twisting/curling, are often called twisters. Initially, the twister was used to wind springs. However, it is more correct to believe that a twister is a winding device, and a torsion bar machine is a torsion device.
Gnutiki
In a do-it-yourself cold forging machine, a bender is a device designed to produce zigzag elements. By replacing the roller/wedge, it is possible to change the zigzag angle within a certain range.
A bend for pipes and rods up to sixteen millimeters is cheap. Make it in living conditions difficult because spot processing is necessary. Try using a regular electric drill to make a hole in the wrench. But the load in the bend is much greater. In view of this, it is easier to purchase a flex. It can be used both for forging with your own hands and for producing parts of welded metal structures and bending small pipes.
Twisters
Since ancient times, blacksmiths have made curls according to a mandrel template using a horn gripper-lever. This method is ineffective, but it makes it possible to create various bending mandrels from an ordinary metal strip without much difficulty and a lot of time. The persistent lever horn does not allow the template to move under the pressure of the part. The horn must be sliding and fixed. Processing will proceed more slowly, but with greater accuracy.
Another homemade forming device is a sturdy board with support pins. They can serve as ordinary bolts. It is possible to process a strip of up to six millimeters. It all depends on your physical strength. Bend the strip “by eye”. The process is quite slow, but it is possible to create a wide variety of patterns.
Snails
One of the types of twister (forging machine) is a snail. It is very common among people who do artistic forging. The snail has a simple design and can be created at home. In addition, it is easy to use and multifunctional. The snail machine is ideal for forging. It consists of a bending lever, which is slightly improved and mechanized. This equipment for cold forging of metal is divided into 2 types.
With ploughshare
The operating diagram of this device for cold forging is as follows:
- The snail turns.
- The workpiece is fixed on the device.
- The roller is pressed against the part by means of a spring.
- The cochlea is rotated clockwise (levers are used).
- The fixation is removed, the cochlea rises, and the finished curl is taken out of the device.
The advantages of such a twister are:
- It is possible to process parts without special equipment. This is due to the fact that the vertical load on the floor of the room is quite small.
- The support is quite simple to make; you can weld it from ordinary metal profiles.
- It is possible to work alone. Turn the collar with one hand and press the strip against the ploughshare with the other.
- It is possible to make spirals with five turns.
Lever
Similar manual machines for cold forging have a design similar to a pipe bender. They are less efficient than gated devices. The load is quite large. Because of this, a strong base made of special steel is required. After turning the lever until it jams, you need to move the pressure roller. You can create up to four curls on a snail. This manual do-it-yourself cold forging machine has the following features:
- All elements, with the exception of the pressure roller, can be made of ordinary steel.
- The pressure roller can be a standard roller bearing.
- The machine base can last more than a thousand work cycles.
- Bending can be done either using a template or using spacers.
- It is possible to quickly change the shape of the manufactured product and make reverse folds.
- The end of the workpiece can be fixed by placing it in a template recess. Widening is carried out by welding or bending.
Torsion bars
This cold forging tool makes it possible to increase efficiency and increase the quality of manufactured products. The working force is quite large, so a base is needed high strength. A backbone I-beam frame of one hundred millimeters or a pair of connected channels is suitable. The base must be securely fixed to the supporting surface by means of the paws attached to it.
The part (a square-shaped rod) is fixed with chucks and mandrels with sockets. Due to the fact that the rod decreases in length when twisted, the chucks in the spindle element and tailstock must be well secured with screw clamps. The tailstock must be sliding.
If the device is needed to make, for example, a small fence, then you can make a cold forging machine with your own hands from scrap or improvised means.
Electric drive
Work on a torsion bar machine with no electric drive tiring. Good quality is almost impossible to achieve. This is due to the fact that it is difficult to achieve a uniform torque manually. In view of this, it is better to use an electric drive, which must be installed in the forging tool. The drive can be made from available means (axle drive axle of a rear-wheel drive car, gear differential pair). The engine is 1.5-3 kW, 900 rpm. You can familiarize yourself with other options by watching the corresponding videos on the Internet.
Wave and zigzag
How to make a cold forging machine, through which it is possible to create wave and zigzag elements? To do this, you will need rollers made of tool/chromium-nickel steel. Limiters are placed in the arc, making it possible to create an accurate wave profile.
If you install a special gate on the snail, you can create waves. The handles are the same. They are screwed into the threaded sockets on the gate head. It is recommended to place the main roller separately and attach it to the base with head bolts.
Forged products must be combined into one whole. The easiest way is to weld and then smooth the seams with a grinder and a grinding wheel. It is thicker than cut-off and copes with bending forces. Parts that are connected with shaped clamps look much better. Stamping is carried out from a strip of one and a half millimeters. The clamp blank is made in the shape of the letter “P”. Her wings are bent from the back using a hammer. For painting, special enamels and paints for metal products are used. Enamels with pigment are more expensive, but they are not prone to peeling, fading, wear and thermal deformation.
The loads endured by a cold forging press, especially impact loads, are quite high. This requires precise processing of the workpieces. In view of this, it is better not to try to make such a device using a drawing of a cold forging machine. You can only make a manual rolling mill yourself. However, steel rolls, shafts and bearing bushings will still need to be purchased.
If you seriously intend to take up blacksmithing, try making a twister or torsion device. The drawings of a cold forging machine are quite simple; even a person who is very vaguely familiar with blacksmithing can understand them. You can find machine drawings on the Internet or ask friends who are involved in blacksmithing. Of course, the profession of “blacksmith” today is less popular than the same “conductor”, but this does not mean that no one is engaged in blacksmithing at all.
Looking at the fences, gates and gates, as in the figure, in houses that are clearly not of the elite class, a person who has some idea about the equipment of the forge and the nature of the work there may think: where did they get so much money? For someone more knowledgeable in blacksmithing, such a question will not arise: these beauties, as well as the metal decor of furniture, light garden buildings, swings, benches, etc., created by cold forging.
Prices for cold art forging are affordable because production costs and initial equipment costs are low, and labor productivity is not bad for artisanal conditions. Consequently, 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. I made my own: cold forging with your own hands can be done 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 be done even at home conditions.
The basis of a “cold forge” is a cold forging machine. For a complete production cycle, capable of satisfying any conceivable fantasies of yours or the customer, You will need 5-7 types of machines, 3-5 main ones of which you can make yourself. However, in the beginning, before spending money on a machine or materials for it, it is highly advisable to master the basics of blacksmithing. Therefore, further we will also consider some techniques for making artistic forging parts without a machine and equipment for them, which can be quickly made from scrap materials.
Stamping, forging and bending
So what is cold forging? It differs from stamping in that the metal hardly flows or flows weakly under the influence of the working element. 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 stamping press; kettle, etc. products of complex shape - with a composite sliding punch. Get what you need to create such high pressure working force at home is impossible, except in 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 hardening (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.
Steel hardening is carried out with a mechanical hammer. You can do it yourself, and it’s even easier than some types of machines for cold artistic forging. But this publication is devoted specifically to the latter subject, and cold artistic forging is essentially bending (bending) metal: its structure in the part does not undergo significant changes, and changes in the physical and mechanical properties of the metal are not significant for the quality of the final product. Therefore, we will leave cold forging, which is forging, until a suitable occasion, and Let's do forging, which bends. For brevity, let's just call it artistic forging, and where it is necessary to mention hot forging, this will be specifically stated there.
Machines and equipment for cold forging
The main equipment for artistic forging with your own hands consists of several types of hand-operated machines and devices. The electric drive is used infrequently, because the resulting increase in productivity is not always equivalent 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 are working on the “handbrake”. Almost all elements of the products in Fig. at the beginning can be done on the following types of machines:
- Twisters (twists), pos. 1 in Fig. – form flat spirals and other curls with a narrow core (core).
- Torsion machines, pos. 2– allow you to obtain a helical twist of a rod 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 ends (item 1 in the figure below), decorative clamps are stamped to connect the details of the pattern (item 2 in the same figure), a small wave and relief are squeezed out on long parts.
- Bending machines are push, broach and combined, pos. 4. The first ones allow you to get only waves and zigzags; lingering - rings, curls and spirals with wide cores, and the latter - all these types of products.
Note: in 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 torsion machines as torsion bars.
What are flexes?
In technical vernacular, bending machines are called benders. However, in amateur and private metalworking, the name “gnutik” was established for a table-top device for producing waves and zigzags, see fig. on right. By changing the roller or wedge in the bend, you can vary the pitch and height of the wave or the zigzag angle 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: it requires precise processing of special steels. Try using a regular electric drill and a regular metal drill to drill through a regular open-end wrench. And in a bending machine, the workloads are much higher than on its jaws. Therefore, it is better to buy a bender; in addition to forging on the farm, it is useful for the manufacture of elements of welded metal structures, like a pipe bender for small thick-walled durable pipes and in other cases.
Twisters
Since ancient times, blacksmiths have cold-formed curls according to a template-mandrel using a horn lever grip, pos. 1 in Fig. This method is low-productive and not for wimps, but it allows you to quickly and easily make various bending mandrels from an ordinary steel strip: the end (thrust) horn of the lever prevents the template from yielding 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. Depending on how comfortable you are with your home exercise machine, 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 curl steel reinforcement bars into a pattern with their hands.
Snails
The snail twister machine is the most popular among those involved in artistic forging: its capabilities, in comparison with the simplicity of the design, the ease of making it yourself and the ease of operation, are amazing. Actually, the snail machine is a slightly mechanized and improved bending lever, but it did “a little” possible job beginners on it. Snail machines are, in turn, divided into machines with a collar and a rotating plowshare and lever machines with a fixed template and a deflection roller.
Snail with ploughshare
The device of a bending scroll with a plowshare is shown in the diagram below; The technology for working with such a machine is also described there.
Advantages of twister bending machine of this type the following:
- It is possible to work on a scroll with a rotating share and a collar in an unequipped room: the vertical component of the workload is negligible, and its horizontal components are partially transferred to the support.
- Due to previous point supporting structure can be quite simple and light, welded from ordinary steel profiles.
- We can carry out the work process alone: turning the gate with one hand, we press the rod or strip against the template plowshare with the other. As its links bend, they will fall into place on their own.
- Using a cold method, you can twist spirals of up to 5 turns on a snail with a rotary plowshare.
Drawings of a snail machine for artistic forging with a specification of parts are given in Fig. We’ll talk about the dimensions of the links (segments) of the folding share later, but for now pay attention to the steel grades: the share bears heavy loads. If you make it from ordinary structural steel, the template will lead to the middle of the gate or fence section.
Note: For more detailed drawings of a snail machine of a similar design with description and detail, see the link: //dwg.ucoz.net/publ/osnastka/instrument_dlja_kholodnoj_kovki/5. There you will also find drawings of a homemade bender and a device for bending rings.
The material for the folding rotary 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 ploughshare 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 in a well-established and equipped industrial production, therefore, the resources of folding templates for cold forging are generally much less than their material itself would allow. Poor use of material properties is a serious drawback. In addition, for the same reasons, another weak point of the snail-type machine with a collar is the eccentric clamp of the part. Therefore, novice homemade blacksmiths work more successfully with homemade snail machines for artistic forging, made according to a lever design.
Snail with lever
The lever volute for cold forging is designed similarly to the well-known one. A homemade lever-type snail machine with a fixed template is significantly inferior in performance to a snail with a collar. The working load in it is more fully transferred to the base, so 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, a workshop or outdoor production area is required. Work on the lever scroll progresses slowly: after turning the lever until it jams, you need to move the pressure roller. It is possible to curl up to 3-4 turns on a lever volute. Nevertheless, the advantages of a snail lever machine for home craftsmen are significant, especially when working for yourself:
- All parts, except 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 frame made of ordinary steel can withstand more than 1000 working cycles.
- You can bend either according to a template (pos. 1 in the figure below) or using spacers, pos. 2 there.
In addition, the snail lever machine allows you to use technological method, 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. This creates a small reverse bend in the core of the curl. The part looks more impressive and, when working for sale, the product is more valuable.
The lever snail has another rather fat plus: on such a machine you can bend flat curls with a small core from a strip laid flat. The snail with a collar and a rotating plowshare gives up completely here: the workpiece will go in a vertical wave. Wide curls and rings from the strip can be bent flat on a broaching machine with rollers in which grooves are machined, see fig. on right. But the drawing speed, so that the workpiece does not lead, requires a significant one, so you won’t get a narrow curl core.
On a snail lever machine, this problem is solved by installing a pressure roller with a height equal to the thickness of the strip and with a flange (edge), like a railway wheel, only wider. Bending using this method takes a lot of time: the lever must be applied a little at a time, otherwise the inner edge of the workpiece will wrinkle; The flange does not help from this. But it is impossible to obtain a curl from a flat strip with a narrow core in a handicraft production in any other way.
In general, at the start of blacksmithing and artistic activity or making a forged fence, gate, gate, bench, swing, gazebo, etc., arranging a garden for yourself, It’s better to use a snail lever machine for cold forging. Moreover, it can be made from scrap materials without accurate and detailed drawings, see for example. next video.
Video: a simple do-it-yourself artistic forging machine
How to build a curl?
There are plenty of sketches of curls for artistic forging on the Internet, but when you try to adjust their sizes to those required for yourself, it often turns out that the product loses spectacularly due to a seemingly insignificant violation of the proportions. Therefore, it is also desirable to be able to construct forging patterns of curls that obviously have aesthetic advantages.
Templates for cold forging of artistic curls - volutes - are built on the basis of mathematical spirals. The most commonly used is the logarithmic spiral; it is one of the widespread natural forms expressing the fundamental laws of nature. The logarithmic spiral is found in the shell of a snail, in our hearing aids, and in the form of a treble clef in musical notation; in the neck of the violin itself too.
The principle of constructing a logarithmic spiral by points is that when the radius that forms it is rotated, starting from a certain initial R0, by a fixed angle φ, its length is multiplied by the divergence index of the spiral p. For volutes p, as a rule, take no more than 1.2, because a logarithmic spiral diverges (unwinds) very quickly; on pos. In Fig. a logarithmic spiral with p = 1.25 is shown as an example. To make it easier to build a spiral at points with sufficient accuracy for forging work, take φ = 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 plasticity 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 precision specified in advance, you will have to solve cubic and higher-order equations. There are no computer programs for numerical technical calculation of volutes on the Internet, so we will use an approximate method that allows us to get by with one working and, possibly, one test 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 volute for a forging template follows from here:
- 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 left soul hind paw beloved cat;
- Using the data from the table in Fig., we calculate the diameter of the volute b such that it is slightly smaller than the width of the opening under it a, see pos. G;
- We calculate the working initial radius R using the formula for pos. G;
- we build a volute profile on a scale point by point;
- if necessary, we accurately adjust R using the same formula and build the profile of the working template completely.
Note: If you use the table to calculate intermediate values, don’t forget – you need to take them in geometric proportion!
Torsion bars
You can twist rods with a screw for artistic forging without a machine at all, see fig. on right. To prevent the workpiece from bending at the root (clamped in a vice) end, you need to place a wooden block or something like it with a V-shaped cutout at the top under the end of the guide pipe farthest from them; It is better to secure the pipe to this support with a clamp, and secure the stand to the workbench. The pipe should be shorter than the workpiece and approximately 1.5 times wider inside than its largest diameter, because When twisted, the workpiece contracts and expands in width.
A torsion cold forging machine allows you to increase productivity and improve the quality of the resulting parts. The working force in it is transferred to the support to a significant extent, so a strong frame is needed, in the form of a spinal frame made of an I-beam from 100 mm or a pair of welded channels of the same size; the corrugated pipe will apparently be deformed. The frame must be securely secured to the supporting surface using paws from the same profile welded to its ends, pos. 1 in Fig.
The workpiece - a square rod - is held by mandrels-chucks with sockets also of square cross-section; they are visible there in pos. 1. Because When twisted, the rod shortens in length; the chucks in the spindle and tailstock must be securely fixed with screw clamps. For the same reason, the tailstock is made sliding. To allow twisting of 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 smaller, you can a quick fix build a torsion bar machine from scrap and scrap materials, pos. 2. On both machines, in principle, it is possible to obtain filaments by placing a bundle of 4 rods half the size into the cartridges. But don’t think that you can make a good lantern or basket by simply pushing the tailstock with a lever. You will get something like the one in the inset in pos. 1 and 2. Blacksmiths call such incidents a word that is generally known, but not used in literary speech. The branches of the filament, when twisting it in a simple torsion bar machine, must be spread out in width with a hand tool, which is difficult and does not ensure the proper quality of work.
Beautiful filaments (pos. 3) are twisted on torsion bar machines with a fixed tailstock and a screw feed spindle, pos. 4. Now let’s return briefly to Fig. with types of machines at the beginning, to pos. 2 on it. See the thing marked with a green exclamation point? This is a replacement spindle. There are 2 of them in the set: smooth for spiral twisting along the long axis of the workpiece and screw for twisting filaments. In this design, the frame 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 The tailstock fixation in filament mode is frictional and only partially jammed: the locking screw provides only an initial clamping force.
About the electric torsion bar drive
Working on a torsion bar machine with manual drive spindle is tedious. But the main thing is stable quality of products such as in pos. 3 fig. with torsion bar machines, it is even more difficult to achieve. The reason is that it is difficult to create a uniform circle with your hands. torque, like any other lever drive. Therefore, a torsion bar machine for cold forging is exactly the case when the use of an electric drive is justified no matter what. The best option from scrap materials - the axle shaft of the drive axle of a rear-wheel drive car with a gear pair from the differential from the same place, see fig. on right; Just don't forget about the protective casing! 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 smooth, straight, ascending spirals are used as an element of artistic forging. Making a spring twister machine for this on your own is absolutely unrealistic. But let us remember: there is no need to spring a spiral in a forged pattern and it can be wound from ordinary plastic steel using simple device(see picture on the right). The pitch (ascent) of the spiral is determined by the horn of the gate (filled in red); By bending the horn up and down, you can get thinner and thicker spirals. A square bar is taken onto the workpiece or a round one, it doesn’t matter. You can also twist spirals from a rod twisted on a torsion bar.
Wave and zigzag
Now we have tools and equipment for wave and zagzag bending of long workpieces. The flex and push-pull mentioned at the beginning bending machine are not reproducible with your own hands. In addition, the first allows you to adjust the pitch and profile within relatively small limits, while the second is expensive. However, you can still make a universal wave bending machine with your own hands, similar to the one on the left in Fig. You only have to order rollers; they must be made of chromium-nickel or tool steel; the rest is made of simple construction; for the staples and arch, a sheet (strip) of 8 mm or more is needed. Limiters are installed in the arc to accurately maintain the wave profile, but the workloads are transferred to it to a significant extent; in fact, the arc provides lateral rigidity of the structure.
You can bend only smooth, but very diverse, waves by adding a gate for waves to a snail machine with a rotating plowshare, on the right in Fig. The same handles are used, because they are screwed into threaded sockets on the head of the gate. It is advisable to make the main (central) roller separate and fasten it to the frame with bolts with countersunk heads. In this case, by placing rollers of different diameters (diameters), it is possible to form waves of variable and asymmetrical profile. And if the deflection roller is made adjustable (for which a number of holes are checked in its carrier), then the wave pitch can 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– welding and subsequent smoothing of the seams with a grinder with a grinding 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; You can also hot-forge quite quickly and without experience, see below. The clamp blank is made in the form U-shaped bracket on a mandrel to the size of the parts to be connected and bend its wings from the rear in place with a large plumber's hammer or a 1.5-2 kg sledgehammer in cold conditions. They paint ready product usually with blacksmith's enamels or acrylic paints on metal. Enamels with pigment from forge patina are more expensive, but better: when dried, they have a noble, somewhat antique color, do not peel off, do not fade, are wear- and heat-resistant
How to get around a stone
Those. the stumbling block in all of the above: shaped ends of the rods; Without them, a fence is not a fence, a gate is not a gate, and a wicket is not a wicket. An inertial stamping press (item 3 in the figure with types of machines) is expensive, but effective. It works on the principle of a flywheel: first, by smoothly rotating the rocker arm (bar with weights), the screw firing pin is pulled back until it stops. Then a replacement stamp is inserted into the socket and the blank is placed. Next, they quickly spin the rocker in the opposite direction (this is a dangerous moment!) and leave it to rotate freely - the working stroke has begun. At the end of it, the striker hits the stamp shank very hard; Due to the inertia of the loads, a force sufficient for stamping is developed.
The loads, especially impact ones, in an inertial stamping machine are large and occur over small areas, and the manufacturing accuracy of its parts needs to be high, so it’s better to do it yourself and not try. It is possible to do it manually yourself rolling mill, see fig. on the right, but only partially: rolls made of special steel, shafts and bearing bushings will have to be ordered, and gears will have to be bought or looked for used ones. On such a mill, you can only produce goosefoot and leaf (spear) tips, and from their necks it will be immediately clear that this is machine work.
Meanwhile, the same, and some others, rod tips can be hot-forged without being an experienced blacksmith. A good, clearly handmade tip-sheet is simply forged with a sledgehammer and a hammer, and the forging stamp (stamp) for the legs is made from an unusable file, in which grooves are selected with a grinder. Do you need a forge for this? For episodic small work not at all necessary; the main thing is to heat the metal. A propane torch is not suitable; heating should be uniform on all sides and without burnout. So, we come to the conclusion that cold and hot forging are not mutually exclusive: in order to obtain high-quality products using simple cold forging machines or even with improvised means, it wouldn’t hurt to add a small forge from scrap materials.
Creation forged products produced by hot and cold processing. The latter method does not require special skills, but its implementation requires special devices. There are various drawings of cold forging machines, many of which are suitable for creating a tool yourself.
Manufacturing Features
Forged are formed metal elements as a result of deformation, while in the process of work must be taken into account performance characteristics material.
The structure of the metal crystal lattice consists of grains having irregular shape. The tool used for forging affects it and leads to a change in the appearance of the part. The selection of machine drawings is of particular importance, since the workpiece must retain its previous properties.
Homemade cold forging machine: manufacturing rules
There are certain rules, compliance with which ensures obtaining the desired result:
- Creating a suitable configuration is possible using several tools.
- Before production begins, the parameters of the formed products are calculated.
- The rods used for workpieces can have different diameters, which are selected taking into account the degree of complexity of the equipment and subsequent operation.
- It can only be processed because other types do not have the necessary plasticity.
"Gnutik"
For cold forging, you can make it yourself, just understand the intricacies of using the tool and select a suitable drawing. "Gnutik" is necessary for creating corners of various configurations. Its main structural elements are a driving stop and two shafts placed on a steel plate.
Homemade cold forging of this type must be created in accordance with certain features. For example, the deformation angle must initially be determined. It is also possible to add an additional bending element; if used, a third rotating shaft is mounted.
The tool is made of special steel, since it bears heavy loads during the process. It is worth noting the possibility of collecting various parts, including wavy ones.
"Twister" and "Snail"
Today, artistic forging is not complete without screw-shaped parts. Their creation is ensured by manual cold forging machines called “Twister”. They have characteristic feature, which consists in scrolling the rod along its axis. The tool consists of a movable and a fixing part. The rotary handle deforms the workpiece, which is fixed between the main parts of the structure. It is worth noting that the spiral is formed from the side of the product fastening, and the applied forces can be reduced with proper calculation of the lever that exerts pressure. This device allows you to produce parts for metal fences and window grilles.
“Snail” is the simplest homemade machine for cold forging, which ensures the formation of spirals with the required number of turns. It is the most popular and can be adapted to produce the desired product. The tool is equipped with a manual or electric drive, the type of which is selected in accordance with the intensity of use.
Homemade cold forging machine: preparation of materials
First you need to draw a spiral with an identical pitch of all turns. In this case, you need to start from the workpieces used, since the stroke width, as a rule, is within 15 mm, while the tool is intended for rods with a cross-section of 10 mm. Free space is necessary for maneuver, since when the workpiece is fully compressed, bending will become impossible.
Next, you need to cut a plate measuring 20x20 cm from a steel sheet. Despite its small dimensions, it will ensure optimal workflow. In accordance with the length of the expected “snail”, a steel cut is made. The strip must be bent using pliers, placed on the plate and outlined with a bright marker on all sides.
Next, a part of the rod is cut off with a length equal to the width of the steel strip. The main thing is that it does not exceed this parameter, as this can lead to injuries during the bending process. The rod is necessary to secure the material at the first stage of creating the product in order to prevent free movement at one point.
A part with a length of 10 cm is cut off. It will combine the sheet and the base on which the fixation will be made. Because of high degree Loads should only be applied to thick-walled materials. After all the main elements have been prepared, you can assemble a homemade cold forging machine, the drawing of which is presented below.
Assembly of the structure
The steel “snail” is divided into turns, the first of which will hold the workpiece, and the others will contain the turns of the rod themselves. The central part is welded to the base, and the resulting seam should not have even the slightest defect. The pieces of rod are welded to the main part of the strip, the distance between them should be 3 cm. Care must be taken when forming the seams, and then knock them down with a hammer.
Then installed in necessary places strip sections and are outlined with a marker. The resulting circles are needed to form holes. They must perfectly match the diameter of the legs to ensure easy installation and removal.
The final stage is welding profile pipe in the lower part, as well as a fixing element next to the “snail”. Photos of homemade cold forging machines made in a similar way are presented above.
Blacksmithing is hard physical work that requires special equipment combined with specialized knowledge and experience of the master. However, to make some artistic elements, you simply need to bend the blanks at the desired angle. Metal deformation can be performed without heating mechanically; cold forging machines are used for this. What features do such units have will be discussed in this article.
Selection of tools and materials for forging. Tips for beginning metal artists. Description of the forging process, features and warnings.
The main working force required to deform the material will be taken by the support, so the base of the future machine must be strong. An I-beam or a pair of channels welded together are suitable for this purpose. Stability of the base will be added by paws made of a similar profile, welded to general design. Next, you can start making other components - the tailstock and spindle.
In each of the components of a homemade cold forging machine with your own hands, the cartridges intended for placing workpieces in them must have strong screw clamps (for the purpose of reliable fixation). Due to the reduction in the length of the workpiece when twisting, the tailstock is always sliding. It is possible to construct a headstock from a vice, securing them to the base with bolts of a standard size of at least M16. On the same axis with the clamping unit, a bushing is installed for the moving part of the machine, in which holes for the clamping bolts are pre-drilled.
The moving part of the spindle is rotated by a handle consisting of 4 levers that have sufficient length, to dampen the force applied for rotation. You can add rubber grommets to protect your hands from slipping.
The main difference in assembling a universal homemade cold forging machine is the design of the moving part. It should provide for screw feed when making lanterns and baskets and be fixed during normal twisting of the metal. Therefore, the moving part is equipped with a set of two spindles - smooth and screw. In this design, the sliding headstock requires a locking screw for fixation.
Helpful advice! If it is necessary to make a workpiece that is not twisted along its entire length, but only in certain areas, limiters are added to the design of the machine. They are made like a tailstock - with screw clamps and the ability to slide.
Working on a torsion bar machine is physically tiring, and it is difficult to obtain high-quality products in large quantities. Therefore, introducing an electric drive into the design would be an appropriate solution.
How to make a cold forging machine
The bending machine is monumental, massive, simple in design and assembly, but difficult to find and fit parts. Its purpose is to bend workpieces at different angles, so the force on all components will be equally large, which means that the requirements for assembly parts are high.
A thick steel frame is selected for the base of the machine. It is worth considering that the machine will be mounted on a table. Usually the fasteners are made with a bolted connection, for example, like a vice. There is a guide in the center of the frame that will be movable. It is driven by an eccentric mechanism, which, in turn, is fixed to the base frame. Additionally, three stops are installed, creating a kind of “fork” - these are the working elements of the structure. Depending on the bend profile, they are changed: round rollers - for making waves, “hammer” - for forming corners.
Working elements are made only from structural steel. Their strength is the reliability of all equipment. Processing and fitting of such products require exclusively professional equipment. Therefore, if there are difficulties in ordering, purchasing or manufacturing the main components, then it would be advisable to buy a machine for cold bending forging in a store. Its cost is low, but it can be additionally useful for bending pipes.
Do-it-yourself snail machine for cold forging: design options
The algorithm for assembling a homemade cold forging machine with your own hands is quite simple and understandable. Only when creating a snail, three options for a design idea are possible, and even then they are very approximate. Each master sees the execution of a curl or spiral, as well as the sequence of bending the workpiece in his own way.
Like any creative process, making a snail for cold forging with your own hands begins with the basics - designing the key components of the machine. In this case, these are the frame, tabletop and main shaft with a rotation lever.
The frame or table for the snail must be made of metal. Wood is completely unsuitable for this design: prolonged and heavy loads will destroy it after several uses. The material used would be a corner, thick-walled pipes or a channel. For the tabletop you will also need metal - a sheet with a thickness of at least 4 mm: the thicker, the more reliable. The shaft and lever are the main assembly that will force the metal workpiece to bend according to a given pattern. The lever is connected on one side to a roller that bends the workpiece, and on the other to the main shaft.
According to the type of design, snail machines come in three variants:
- monolithic with a fixed bending template;
- with removable bending structures that allow you to create different types of curls;
- with collapsible curl designs and rotating table top to obtain complex profiles high precision bending.
Drawings of a cold forging machine for a snail with your own hands
Many craftsmen who take on the manufacture of machines for the first time neglect the design stage, build templates “by eye”, and develop and modernize components directly during the assembly process. A drawing of a snail for cold forging with your own hands should be done at the preparation stage. It will help to avoid some subtle nuances during assembly, and will also significantly reduce the manufacturing process time.
It is not necessary to follow the drawings made by another master. Availability of manufacturing materials or assembly conditions may vary, and it is likely that the vision finished design may also be different.
One of the design options :
1 - snail ploughshare; 2 - base of the machine; 3 - pressure roller; 4 - lever for controlling the pressure roller; 5 - fastening the base; 6 - finger for fixing the plowshares; 7 - groove for the pressure roller; 8 - control lever axis; 9 - spring for pressing the roller; 10 - clamp for the workpiece; 11 - driving ploughshare of the snail; 12 - main axis; 13 - levers
Diagram of a snail machine for processing products using cold forging
A drawing is especially important for constructing curl patterns with your own hands. A video of cold forging equipment will help you correctly calculate and build a proportional spiral. This stage is necessary so that the curl made on a homemade machine has an aesthetic appearance.
Helpful advice! Templates for the snail are built according to the rules of mathematical spirals, taking into account the number of turns, their density, the width of the opening for equipment on the machine and the initial radius of the entrance to the curl.
Making a snail: how to make a machine with your own hands
A monolithic machine is the most simple design snails. The spiral pattern is applied directly to the tabletop. Then, following the drawing, several pieces are cut out of thick metal. They are welded to the tabletop, following the previously applied markings. Work on a snail of this type progresses slowly, but the machine allows you to bend both workpieces of symmetrical diameter and strips of metal that are laid flat, without vertical deformations.
A monolithic machine can have Alternative option designs when the base is not made fixed, but can be rotated. A worm mechanism is used for a given rotation and to facilitate physical labor.
How to improve a snail cold forging machine with your own hands
A homemade snail does not have to contain only simple elements. You can immediately assemble an improved model. For example, what to do if curls are needed different forms, and with different patterns of spirals? It would be impractical to assemble a separate machine for each sample. Therefore, instead of a tightly welded single template, a number of removable options with different patterns are created on the tabletop. Adjustments are made to the design that allow you to change the template, secure it stably, while maintaining the overall reliability of the machine.
The most professional of the snail models is a machine where the table top rotates and the curl template is made from several collapsible segments. It is worth noting that all sections are made with high accuracy. It is difficult to implement this in a home workshop, so the production of the unit is ordered in workshops or at a factory. The curvature of the template is changed using adjusting screws, and a number of holes are made on the surface of the tabletop that will fix the template segments in a given position. You can bend any type of curl using this method.
Making a cold forging machine with your own hands, the drawing of which will help you complete this task, is quite simple if you understand the principle of its operation and design features. It is important to calculate everything carefully and take measurements. It is possible that someone will be able to come up with their own new options or improve existing models.
Homemade machines for cold metal forging with your own hands: video instructions
Cold forging is impossible without special forging equipment. Let's look at the types of devices and the figures that can be obtained with their help. We have prepared drawings and thematic videos for you. We will also consider the sequence of making a cold forging machine with your own hands.
If you are just going to organize a cold forging workshop and want to avoid large expenses, then self-production machines and devices will help you create your own small business without excessive costs.
Basic devices and machines
Cold forging machines are mainly designed for arc or angle bending, as well as twisting. They can be manual or electrically driven.
The main types of machines and devices for cold forging:
- Gnutik
- Twister
- Snail
- globe
- Wave
- Flashlight
Device "Gnutik"
Purchased or self-made “Gnutik” - universal device, allowing you to get an arc or angle from a rod. It consists of a base with a slider, on which a stop with an angle (90° or another as necessary) and two cylindrical fixed stops are fixed. By moving the slider and the angle stop, the rod bends at an angle. To obtain an arc, a third cylinder is provided, rotating on the side opposite to the angle stop.
The device can be made on a horizontal or vertical platform.
Axonometry of the "Gnutik" device - vertical arrangement
To scale the dimensions, here is a drawing of the bottom bar of this “Gnutik”.
Bottom bar
This device is universal. With the help of attachments you can not only bend, but also cut and punch holes. But this will be the next step.
Getting an arc on "Gnutik"
Getting an angle on "Gnutik"
This is what a homemade “Gnutik” looks like:
Twister device
“Twister” is a tool for twisting rods, mostly square, along the longitudinal axis. This simple device can be manual or electric. Operating principle: both ends of the rod are secured, then one fastening begins to rotate, twisting the metal to the required shape.
Appearance of a purchased manual “Twister”
Look at the photo of a homemade “Twister” with an electric drive, assembled using used electrical equipment:
There is a special machine for making “Lanterns” and “Cones”, but for starters you can also use a “Twister”, as shown in the video (English, but everything is very clear).
Video: how to make a blank for “Flashlight” on “Twister”
Device "Snail"
The Snail Tool is designed to create curls (or spirals) and “currencies” (S-shaped pieces). There are various designs.
One of the design options: 1 - snail ploughshare; 2 - base of the machine; 3 — pressure roller; 4 — lever for controlling the pressure roller; 5 — fastening the base; 6 — finger for fixing the plowshares; 7 — groove for the pressure roller; 8 — control lever axis; 9 — spring for pressing the roller; 10 — clamp for the workpiece; 11 — leading ploughshare of the snail; 12 — main axis; 13 — levers
The result should be something like this:
Another lightweight design for bending rolled products with a cross-section up to 12 mm:
1 - cochlear segment; 2 - eccentric; 3 - handle; 4 - base; 5 — guide runners; 6 - axis; 7 - slider; 8 — axle nut; 9 — roller mounting axis; 10 - roller; 11 — drive axis; 12 — eccentric guide; 13 - central segment of the cochlea; 14 — eccentric wing; 15 — main leg; 16 — connecting pin of cochlea segments; 17 — adjustment screw; 18 - connecting ear of cochlear segments
Often the “Snail” device is made on a support, especially if you need to bend thick rolled products.
Several useful videos on homemade machines"Snails."
Making a snail
Machine operation
We will talk more about such designs below.
"Globe" device
Such a device is similar in appearance to a school protractor and is designed for making arcs with a large bending radius from a strip, square, circle or hexagon. First, one end of the workpiece is fixed with a bend, then it is bent along its entire length according to the template. The principle of operation is somewhat similar to the operation of a canning machine.
Appearance of the device
Video of work at Globus
Using exclusively muscular strength, arc large diameter can be made on a template screwed or welded to a workbench. It is good for bending strips, thin-walled pipes, etc.
Sample
Device "Wave"
You can produce wavy products from a round, square, hexagonal cross-section or tube using the “Wave” device. The deformation of the workpiece occurs between vertical rolls by scrolling.
Wave device and resulting products
Device in action
Flashlight device
This machine produces blanks for “Lanterns” or “Pine Cones” elements, which can consist of 4, 6, 8 or more rods. According to the principle of operation, the machine is similar to the “Twister”, but here the workpieces are bent around the guide shaft, which forms a more correct and accurate configuration of the product.
Flashlight device
Operation of the device for making “Flashlight”
Device for cold forging of the “Clamp” element
The cold forging element “Clamp” is designed to fix other structural elements together.
The device for bending the “Clamp” can be made according to the attached drawings.
Devices for making crow's feet
“Crow's foot” - flattening with the application of beautiful notches at the ends of the workpieces to make the structure more elegant or to reduce the thickness for various joints.
The ends of the elements are decorated with “houndstooth”
This operation can be performed using a machine with a die or fixture and a heavy forging hammer on an anvil. We provide both options in the form of videos.
Machine for making " crow's foot»
Tools for forging crow's feet
Detailed stamp making process
Below is a rolling machine to perform the same operation.
Machine for rolling "crow's feet" (the distance between the rollers is adjustable).Materials for a rolling machine: gears and shafts - spare parts from a used combine
Operating principle
Making a "Snail" with a drive
The electrically driven "snail" facilitates the production of curls and "currencies". This is especially valuable when the work is not “for the soul”, but for production large quantity similar products on the production line when working to order.
Below are the stages of assembling a machine for bending a rod with a maximum cross-section of 10x10 mm. The 0.5 kW/1000 rpm engine operates at the limit of its capabilities. Performs 6 shaft revolutions per minute. The snail segments are machined from a round blank St.45 without heat treatment, 25 mm high and 20 mm thick. The volute is mounted on a shaft on bearings from the rear wheel of a motorcycle - 7204. The support roller is firmly fixed in the groove. Pulleys are installed between the engine and the gearbox.
Below are drawings of the cochlea segments.
Snail element 1
Snail element 2
Snail element 3
Snail centerpiece
For a more massive rod (from 12 mm), the motor power should be more than a kilowatt. The photographs below show a machine with a 2.2 kW, 1000 rpm motor, giving a shaft output of about 10 rpm. This is already a machine for professional use. A used gearbox was used, the matrix was cut from a 30 mm thick workpiece - the most labor-intensive process.
For cold forging you will also need an anvil and a hammer. A forge is not needed, it is only required for hot forging.
Advice! Before starting work, draw a sketch future design real size. This will help you adjust the elements and not get confused during assembly.