How to make spot welding from a welding machine

Homemade spot welding: how to assemble the device at home (instructions and diagram)

It is not difficult to make homemade spot welding yourself.

Similar mechanisms are produced in several variations:

1. Portable
2. Compact
3. Dimensional

Welding process: manufacturing diagram

When assembling the device yourself, it is necessary to take into account the Joule-Lenz law (Q = I² X R X t), which states: thermal energy is released in conductors in a certain amount in proportion to their resistance, the coefficient of current strength in time and squared.

Experts advise paying due attention to the homemade mechanism, taking into account the large loss of energy in thin wires, and using a high-quality electrical circuit.

Types of contact welding:

In spot welding, the device technology is based on the thermal effect of current. This ensures welding of the part at one or several points.

The size and structural features of the electrode contact surface differ. This affects the strength level of the connections.

We list several existing stages in spot welding technology:

1. The mating components are connected and placed between the electrodes of the device. The components should be positioned tightly against each other. This will ensure the formation of a sealing belt near the molten core, which will prevent hot metal from splashing out during the pulse.
2. The next step is heating the parts. They become thermoplastic, which makes it possible to modify them. It is possible to make high-quality welding at home, the main thing is to follow the key principles of the technology: maintain the speed of movement of the electrodes, a constant pressure value and a tight connection of all parts.

When current passes, a pulse is generated, which heats the welding machine and allows the metal to melt at the points of contact with the electrodes.

Then a common core of liquid consistency 4-12 mm in diameter is formed. After the current is applied to the parts, they will hold securely until the core cools and its further crystallization.

Domestic use of homemade spot welding allows you to ensure mechanical strength of metal seams without high costs, but does not allow you to create hermetic seams.

The state standard regulates safety precautions, work processes and welding equipment.

Welding machine at home

A homemade device can be assembled from scrap materials

There is no need to use a homemade spot welding machine for high power: the device can work with metal wire 0.3 mm in diameter; with steel sheet 0.2 mm thick.

The configuration allows you to weld the thinnest foil components and weld thermocouples.

The electrode is produced from a pistol with light force, which is necessary for pressing small objects.

The technology for producing homemade spot welding is not complicated: the electrode is connected with a flexible cable to the secondary transformer winding, and the most massive part should be connected to the lower end.

Here you will need rectifier bridges; the thyristor is connected to the second part of the bridge. Opening the first part facilitates sufficient voltage from the transformer to the primary winding.

The welding gun is replaced with a gun and the first element is connected to the end of the secondary winding on the transformer. In this case, the second end is securely attached to the device.

Single-phase or three-phase current powers the clamps, which allows them to function. The transformer feeding the clamps supplies a current of several kA.

The thyristor is controlled by pressing a button on the pistol handle. The capacitor is charged when an additional source (rectifier bridges or transformers) is connected to the network.

The thyristor closes, the mechanism turns on and remains open until the capacitor is discharged.

The length of time during which the capacitor can discharge is regulated by a variable resistor. The button is pressed - the next pulse is generated and the capacitor is charged. When you press the button again, the process starts over again.

The duration of the process in a homemade device does not exceed 0.1 second due to the value of the resistor and capacitor, the welding current is 300-500 Amps, while the power is low - 5-10 Watts. These parameters are sufficient for working with small objects.

Homemade spot welding can be created from a steel transformer with a kit thickness of 70mm. For the primary winding, PEV-2 0.8 wire with 300 turns is used, for the secondary winding, a stranded wire of 4 mm in diameter is used.

Production of welding equipment: instructions

The simplest homemade spot welding

According to experts, a three-phase step-down transformer should be chosen as the basis of the equipment.

The secondary windings are removed from the coil, the primary wires and core are left in their original form, the middle wire is wrapped in the same material with 8-10 turns at the output.

To independently produce welding equipment, you need a 25 m cable, a copper pipe 10-12 mm in diameter, a metal disc and a grinder.

It is necessary to ensure that both coils located at the edges are filled by carefully winding the secondary winding using a multi-core three-phase power cable. The flexible wire winds without the need to disassemble the equipment.

The parameters of the wires in the cable are 6-8 mm in diameter. One of them should be thinner, but with good insulation and resistant to current power. For the production of the device 25 m of cable. If necessary, it can be replaced with wires with a smaller cross-section.

It is more efficient to do this work together: one person will do the pulling of the wire, the second will do the laying of the turns. To make a terminal, you need a copper pipe 30-40 mm long and 10-12 mm in diameter.

One part of it is separated, which forms a plate in which a hole up to 10 mm in diameter is made; pre-stripped wires are inserted into the other part. Experts advise crimping the wires with a hammer.

Contact will improve if several notches are made on the outside of the pipe.

New fasteners with M10 threads replace the existing screws and nuts at the top of the transformer, to which the terminals from the secondary winding are then attached.

It is necessary to make 11 holes (no more than 6 mm in diameter) in the textolite board for screws with nuts and washers; and firmly attach it to the surface of the transformer. These components will provide the output of the primary winding.

The electric holder is made from ¾ pipe 25 cm in length. It is necessary to make recesses in the corners, and weld a small piece of metal wire to the holder.

A hole is made on the reverse side and a piece of cable is connected, as with the secondary winding. Then you need to insulate the pipe with a rubber hose.

Electrodes for spot welding

Do-it-yourself spot welding done at home is suitable for a small amount of work. It is recommended to let the device cool down after working with 10-14 electrodes.

The difference between multi-point equipment and its analogues is the work with metal workpieces of a certain shape and size.

Multipoint devices are rare, but are universal for contact pairing of elements. Only experts can re-adjust it.

Contact welding of parts is impossible in the absence of electrodes made of alloys with a high level of thermal conductivity.

Electrodes favor the compression of metals and conduct current to the surface of the elements. The level of heat concentration depends on the tips - thin mechanisms wear out quickly and need constant sharpening.

There are several forms of manufactured tips.

It is possible to extend the life of the tips by following the tips below:

• Electrodes are selected according to the criteria of the metal used in the work;
• Ensure their safety as much as possible;
• For heavy welding, use more massive tips;
• Use a water jacket.

Experts advise not to file the tips due to the appearance of unevenness, which will generally negatively affect the quality of work.

Source: https://prosvarku.info/apparaty/samodelnaya-tochechnaya-svarka

Do-it-yourself spot welding: diagrams, principle

Spot welding machines are not used as often in everyday life as arc welding machines, but sometimes it is impossible to do without them. Considering that the cost of such equipment starts from $450-$470, the profitability of its purchase is questionable.

Household spot welding machine CBA-1.5AK

The way out of this situation is resistance spot welding with your own hands. But, before we tell you how to make such a device yourself, let's look at what spot welding is and the technology of its operation.

Briefly about spot welding

This type of welding is contact (thermomechanical). Note that this category also includes seam and butt welding, but it is not possible to implement them at home, since complex equipment will be needed for this purpose.

The welding process includes the following steps:

• the parts are combined in the required position;
• they are secured between the electrodes of the device, which press the parts;
• heating is performed, as a result of which, due to plastic deformation, the parts are firmly connected to each other.

A production spot welding machine (such as the one shown in the photo) is capable of performing up to 600 operations within a minute.

Equipment for machine spot welding

Process technology

To heat the parts to the required temperature, a short-term pulse of high-power electric current is applied to them. As a rule, the pulse lasts from 0.01 to 0.1 seconds (the time is selected based on the characteristics of the metal from which the parts are made).

When pulsed, the metal melts and a common liquid core forms between the parts; until it hardens, the welded surfaces must be held under pressure. Due to this, as it cools, the molten core crystallizes. A drawing illustrating the welding process is shown below.

Spot welding process illustration

Designations:

• A – electrodes;
• B – parts to be welded;
• C – welding core.

Pressure on the parts is necessary so that, when pulsed, a sealing belt is formed along the perimeter of the molten metal core, preventing the melt from flowing outside the zone where welding occurs.

To provide better conditions for crystallization of the melt, the pressure on the parts is gradually removed. If it is necessary to “forge” the welding site in order to eliminate inhomogeneities inside the seam, increase the pressure (do this at the final stage).

Please note that to ensure a reliable connection, as well as the quality of the seam, it is first necessary to treat the surfaces of the parts in the places where welding will take place. This is done to remove oxide film or corrosion.

When it is necessary to ensure reliable connection of parts with a thickness of 1 to 1.5 mm, capacitor welding is used. The principle of its operation is as follows:

• the capacitor block is charged with a small electric current;
• the capacitors are discharged through the parts being connected (the pulse strength is sufficient to ensure the required welding mode).

This type of welding is used in those areas of industry where it is necessary to connect miniature and subminiature components (radio engineering, electronics, etc.).

Speaking about spot welding technology, it should be noted that it can be used to connect dissimilar metals together.

Examples of homemade designs

There are many examples on the Internet of creating machines that produce spot welding. Here are some of the most successful designs. Below is a diagram of a simple spot welder.

An example of a device circuit diagram

For implementation we will need the following radio components:

• R - variable resistance with a nominal value of 100 Ohms;
• C – capacitor designed for a voltage of at least 25 V with a capacity of 1000 μF;
• VD1 – thyristor KU202, the letter index can be K, L, M or N, you can also use PTL-50, but in this case the capacitance “C” must be reduced to 1000 μF;
• VD2-VD5 – diodes D232A, foreign analog – S4M;
• VD6-VD9 – D226B diodes, they can be replaced with a foreign analogue 1N4007;
• F – 5 A fuse.

It is necessary to make a digression to tell how to make the TR1 transformer. It is made on the basis of Sh40 iron, with a set thickness of 70 mm. For the primary winding you will need PEV2 wire Ø0.8 mm. The number of turns in the winding is 300.

To make a secondary winding, you will need a Ø4 mm stranded copper wire. It can be replaced with a tire, provided that its cross-section is at least 20 mm2. The number of turns of the secondary winding is 10.

do-it-yourself resistance welding

As for TR2, any of the low-power transformers (from 5 to 10 W) will be suitable for it. In this case, winding II, used to connect the backlight lamp “H”, should have an output voltage within 5-6 V, and winding III – 15 V.

The power of the manufactured device will be relatively low, ranging from 300 to 500 A, maximum pulse time up to 0.1 sec (provided that the ratings “R” and “C” are the same as in the diagram shown). This is quite enough for welding steel wire Ø0.3 mm or sheet metal if its thickness does not exceed 0.2 mm.

Let us present a diagram of a more powerful device, in which the welding electric current of the pulse will be in the range from 1.5 kA to 2 kA.

Circuit diagram of a device with a pulse strength of up to 2 kA

We list the components used in the circuit:

• resistance ratings: R1-1.0 kOhm, R2-4.7 kOhm, R3-1.1 kOhm;
• capacitances in the circuit: C1-1.0 µF, C2-0.25 µF. Moreover, C1 must be designed for a voltage of at least 630 V;
• VD1-VD4 diodes - D226B diodes, replacement with a foreign analogue 1N4007 is allowed, instead of diodes you can install a diode bridge, for example, KTs405A;
• thyristor VD6 - KU202N, it must be placed on a radiator with an area of ​​at least 8 cm2;
• VD6 – D237B;
• F - 10 A fuse;
• K1 is any magnetic starter that has three pairs of working contacts, and the winding is designed for ~220 V, for example, you can install PME071 MVUHLZ AC3.

Now we’ll tell you how to make transformer TR1. The LATR-9 autotransformer, such as shown in the photograph, is used as a basis.

Autotransformer used as a basis

The winding in this autotransformer has 266 turns, it is made with copper wire Ø1.0 mm, we will use it as the primary. We carefully disassemble the structure so as not to damage the winding. We dismantle the shaft and the movable roller contact attached to it.

Next, we need to isolate the contact track; for this purpose, we clean it from dust, degrease it and varnish it. When it dries further, we insulate the entire winding using varnished cloth.

As a secondary winding we use copper wire with a cross-sectional area of ​​at least 80 mm2. It is important that the insulation of this wire is heat resistant. When all conditions are met, we make a winding of three turns.

Setting up the assembled device comes down to calibrating the scale of the variable resistor that regulates the pulse time.

We recommend that before starting welding, you experimentally establish the optimal time for the pulse. If the duration is excessive, the parts will be burned, and if it is less than necessary, the strength of the connection will be unreliable.

As already written above, the device is capable of delivering a welding electric current of up to 2000 A, which allows you to weld steel wire Ø3 mm or sheet steel, the thickness of which does not exceed 1.1 mm.

Source: https://www.asutpp.ru/tochechnaya-svarka-svoimi-rukami.html

Do-it-yourself spot welding - simple detailed instructions for building the machine

In domestic applications, spot welding is used less frequently than arc welding. There are cases when it is difficult to do without it, but if we take into account the price of such devices, the feasibility of purchasing it is called into question. In this case, you can find another way out and look at an example of how to make spot welding with your own hands. For a radio amateur at home, constructing such a device is not difficult. But first you need to understand the features of its work.

How resistance welding works

This is a thermomechanical type of welding. Before starting work, the welded parts are arranged in the desired position. Next, each part of them is fixed between hardware electrodes, under their action the parts are compressed.

The current passing through the electrodes heats the parts, and an alloy is formed at this point. It is the connecting element of two parts. Devices of this type in production have high productivity. They are capable of making 600 weld points in a minute.

But in order for the surfaces to become hot and begin to melt, an electric current of enormous strength is supplied to them. Such an impulse leads to almost instantaneous melting of metals. Its duration depends on the type of metals being fused. Typically the time range is 0.01-0.1 seconds.

In this case, the molten metal surfaces form a welding drop between themselves, which must harden. To do this, the welded parts are kept compressed for some time. The molten drop at this moment forms a kind of crystal lattice.

Pressure plays an important role in this process. It prevents the molten drop from spreading over the area of ​​the parts, thus being held together at one point. The compression force is gradually reduced, then the weld is better set. This work requires clean surfaces of the parts.

Therefore, before work, the intended location of the weld is treated with a special solution. This removes corrosion elements and other oxide films. The result is a high quality seam.

Homemade device designs

Let's look at the structure of a spot welding machine using an example. Let's prepare radioelements and other details:

• Electrical converter;
• Copper cable with a cross-sectional diameter of at least 10 mm;
• Copper type electrodes;
• Breaker;
• Several tips;
• Bolts;
• Frame.

Assembling the device

These are the main design details. Now let's look at a diagram for manufacturing a spot welding machine. There are quite a few of them on the Internet. And each has its own set of radio components. But the main similarity of all the schemes is their simplicity and low power.

Therefore, homemade devices are suitable only for small household work. They will be able to weld thin sheets of iron, or wire strands. For the printed circuit board you will need the following elements:

• Variable resistor – 100 Ohm;
• Capacitor – 1000 mKF, from 25V;
• Thyristor;
• A pair of diodes - D232A;
• Several diodes - D226B;
• Fuse – F (fuse type).

The next stage of assembling a do-it-yourself welding machine is to construct the TR1 transformer. It is based on Sh40 iron, the required plate thickness is 70mm. The design has two windings. A PEV2 conductor with a cross-section of 0.8 mm is used for the primary winding. Next, 300 turns are wound.

The secondary winding is made with a multi-core copper cable with a cross-section of 4 mm. The number of turns does not exceed 10.

For the second transformer TR2, no manual work is required. It can be replaced with any weak converter with a power of 5-10V. Its secondary winding should have no more than 5-6V output. The third winding should output up to 15V.

By completing this assembly, you can get a device with a power of up to 500A. The pulse duration will not exceed - 0.1 sec, but only if the values ​​of the resistance and capacitor coincide with those in the diagram. The power of homemade spot welding will allow you to weld metal sheets with a thickness of no more than 0.2 mm, as well as steel wire with a diameter of 0.3 mm.

Types of homemade spot welding machines differ mainly in power. Some models are capable of delivering current up to 2000A, which allows welding steel sheets up to 1.1mm thick and steel wires up to 3mm in diameter.

DIY spot welding photo

Source: https://tytmaster.ru/tochechnaya-svarka-svoimi-rukami/

Do-it-yourself spot welding from an inverter

Do-it-yourself spot welding from an inverter - is it a myth or reality? It is not at all easy to answer this question clearly. You can find many articles on this topic on the Internet.

Their authors, as a rule, deal with the problems of altering electrical and electronic components. The question of how to create the necessary working pressure on the electrodes seems to fade into the background.

But it is, in fact, key, since we are talking about an effort of tens and sometimes hundreds of kilograms. Well, okay, let's take it in order.

Opening opportunities

The advantages of resistance welding are sufficient to make it attractive to those who intend to launch mass production of products or repair equipment at a professional level.

• Good quality welded joint. It is ensured by the stability of the parameters of the welding current and pressure exerted on the parts being joined.
• High speed of the process. It takes seconds to apply a suture. This is especially important when it comes to performing a large amount of work.
• Operational simplicity. A properly manufactured resistance welding machine does not require special skills to use, and even a semi-skilled specialist can master the process.
• The use of a spotter is justified when repairing automobile bodies. This device simplifies not only the welding process, but also the straightening of damaged parts.

The main obstacle to widespread adoption of the technology is the high cost of equipment. This gives many people the idea of ​​making a resistance welding machine on their own.

Do you need an inverter?

In fact, using an inverter for these purposes is unjustified. After all, for resistance welding there is no need for direct current. If you have a ready-made welding inverter, the task of installing control circuits and manufacturing transformer coils of the required parameters is only slightly simplified. With the same success, you can make equipment, as they say, from scratch.

It is not worth starting to solve such a problem without the necessary theoretical knowledge and practical skills. In words it all looks relatively simple. But if you know how to solder and know how to rewind the transformer coils correctly, you can try it. To do this you will need certain materials and tools.

• Copper wire of a certain cross-section. Its cross-section and quantity can only be determined by performing preliminary calculations.
• Material for making a tire. At worst, you can get by with the same wire, but it is more advisable to purchase a ready-made product.
• Varnish to create an insulating layer on the wires and good insulating tape.
• Multimeter for taking the necessary measurements.
• Soldering supplies – soldering iron, flux, solder, etc.

Of course, you will have to purchase a ready-made welding inverter.

Transformer manufacturing

Figure No. 1 schematically shows the possible ratio of turns of the primary and secondary windings of the transformer necessary for resistance welding. A large number of outputs on the secondary winding is necessary in order to be able to roughly adjust the current parameters. But the presented circuit requires adjustment depending on the required current parameters. You can't do without preliminary calculations.

Theoretical and practical assistance

The number of turns can be calculated using this formula: N = 50/S. Where N is the number of turns, S is the core area in cm2. To simplify the task, it is recommended to use a ready-made calculator program. They can also be found online. For example, the OER program.

This will help avoid mistakes and simplify the task. Since we are talking about designing equipment based on a ready-made inverter, you should first measure the parameters of the primary coil, make calculations, and only then begin manufacturing the secondary winding.

Carefully!

Care must be taken to ensure that both windings are grounded. After all, the resulting current power will be very high, and contact with live parts can be fatal.

Carefully insulate and cool well

When winding wire onto a coil, be sure to apply insulating varnish to its surface and lay the turns as tightly as possible. Otherwise, interturn short circuits and wire burnout due to overheating cannot be ruled out. Transformer cooling comes to the fore. For some reason, the authors of many articles are silent about this.

It is possible that the installation of an additional cooling system consisting of radiators and fans blowing them will be required. If this is not taken care of, the equipment will simply fail due to overheating or even become a fire hazard. As an option, it is possible to install ready-made cooling systems used in electrical and electronics.

Control system installation

When installing the control circuit, it is recommended to use ready-made elements. They are already in the factory inverter. This will greatly simplify the assembly process and make the device convenient to use. But the capacity of its standard capacitors may not be enough.

In this case, they will have to be replaced with parts that match the parameters. The current parameters in the resistance welding machine are adjusted in stages. Its accuracy will depend on the number of pins of the secondary winding and their pitch.

This is necessary if equipment capable of operating in different modes is required.

It is important!

Installation of circuit components should be done using soldering. Detachable connections are not capable of providing the required heat transfer mode. Their use makes sense only in cases where frequent replacement of any parts is expected.

Making pliers

Only when the transformer is ready does it make sense to start making contact clamps. Their design primarily depends on the nature of the work for which the equipment will be used. The gripper design will depend on its drive system and the expected size of the parts to be connected. An important part of the pliers are the contact tips.

If the thickness of the sheet being welded is small, it is quite acceptable to use copper tips from a soldering iron. It is better if you purchase and install ready-made tips - they are available for sale and are convenient because they have a special shape that is well suited for the job.

But if we are talking about a steel sheet of 0.5 mm or more and it is intended to apply connecting seams of considerable length, it is recommended to equip the tips with rollers.

Providing clamping force

Next we will have to solve the most practically difficult problem. The fact is that if you intend to create pressure on the welding tongs manually, it is better to refuse making resistance welding. The efficiency of such a device will be low. The applied force at the welding site must be uniform and very significant.

In industrial settings, hydraulic or pneumatic systems are used for this. Making such a device yourself is extremely problematic. It makes more sense to purchase a ready-made booster, since they are available for sale.

When making resistance welding with your own hands, it is easier to use amplifiers driven by compressed air. In this case, for their operation it will be enough to connect a conventional pneumatic compressor. It is optimal if the maximum force on the contacts reaches 100 kg or more.

To change the pressure, you can use a separate regulator, or integrate it into the overall control system of the device.

Gas supply

To optimize welding conditions and improve the quality of the connecting seam, it is worth taking care of the gas supply to the working area. In the case of steel, this should be carbon dioxide. The selection of nozzle and its location depend on the size of the pliers, contacts and working area. The supply hose is secured so as not to interfere with the operation of other components of the device. It must be made of non-flammable, heat-resistant material and equipped with a control valve.

Concern for reliability and safety

For efficient operation of the equipment, as well as to ensure safety standards, all components of the device must be carefully secured and insulated. It is recommended to use dielectric materials with good heat resistance and mechanical strength as a basis. It is also necessary to take care of integrating protective fuses into the electrical circuit. It is important to follow all recommended safety precautions when working on equipment.

Weigh everything properly

Planning to make a resistance welding machine with your own hands. First, objectively evaluate your knowledge and capabilities, as well as the entire scope of upcoming work. This will avoid wasting time and money.

It will be a shame to realize somewhere in the middle of the journey that everything was in vain, and it would have been easier to buy ready-made equipment.

But if everything works out, you will be rewarded with significant monetary savings and the pride of knowing that you were able to cope with a difficult task.

Source: https://svarkalegko.com/oborudovanie/izgotovlenie-tochechnoj-svarki-iz-invertora.html

How to make a spot welding machine with your own hands

Home plumbing work is part of the life of a business person. One of the most popular home devices is spot welding. It assumes the presence of a factory or homemade welding device. It is not difficult to create a similar device that will be used for spot welding with your own hands; you only need desire and some available tools.

Features and principle of spot welding

Let's start studying the question of how to make spot welding with our own hands with the principle of operation.

Today, spot welding is in demand not only in everyday life, but also in production, as it can solve even the most difficult tasks. In industry, as a rule, devices operating in automatic mode are used; in domestic conditions, a semi-automatic welding machine is used for spot welding.

Spot resistance welding in production is necessary to weld sheet blanks from ferrous and non-ferrous metals. It is used to weld products from profiles of different thicknesses and configurations, as well as intersecting metal workpieces. Under some conditions, it is possible to achieve a high-speed operating mode of up to 600 points per minute.

Many people are interested in the question of how to make spot welding at home? In the home environment, spot welding is used to repair household utensils and, if necessary, to weld electrical wires.

The spot welding procedure includes several stages:

• the workpieces are combined in the required position;
• fasten the parts directly between the clamping electrodes of the installation;
• the surfaces are heated, during which the parts are deformed and they bond with each other.

There is another point connection technology - laser welding. It is capable of performing tasks involving high precision work and extreme soldering strength.

It turns out that the principle of spot welding is the excessive heating of working metal surfaces, which results in their fusion and a single structural new formation.

The main role in the welding process is played by the impulse response of the current, which creates the necessary heating of the metal area. An equally important characteristic is the exposure time and the holding force of the parts. Thanks to these parameters, the metal structure crystallizes.

The main advantages of electric contact welding from a welding machine are:

• profitability of use;
• strong seam;
• simplicity of equipment;
• homemade spot welding can be created at home;
• possibility of automation in an enterprise environment.

The only flaw in the point connection of parts is considered to be a leaky connection.

The main requirements for welding equipment are:

• the ability to change the process time;
• creating pressure in the working area, reaching the limit at the end of the heating process;
• the presence of electrodes with high energy and heat conductivity.

For household use, electrolytic copper and its mixture of EV grade are suitable. It is worth noting that the area of ​​the contacted area of ​​the electrode must exceed the joint (seam) to be welded by 2.5 times.

Assembling a welding machine yourself

To spot weld parts, it is necessary to create appropriate equipment. A homemade do-it-yourself spot welding installation can have any shape - from portable varieties to large-sized models. In practice, desktop versions are usually used, used for joining various metals. Before you create spot welding from an inverter, you should familiarize yourself with the materials that will be needed during manufacture.

• energy converter, that is, a transformer;
• electrical cable with insulation with a cross-section of 10 mm;
• copper electrodes;
• breaker;
• tips;
• bolts;
• available tools and materials for creating a frame base or welding pliers (blocks of wood, recycled materials, plywood).

1 — modified OSM-1.0 transformer; 2 — conductor (duralumin rod with a diameter of 30, L300, 2 pcs.); 3 — liner (steel rod with a diameter of 10, L30, 2 pcs.); 4 — electrode (copper rod with a diameter of 12, L50, 2 pcs.); 5 — brass washer (2 pcs.); 6.12 — M6 screws; 7 handle; 8 - eccentric; 9 — cheek (2 pcs.); 10 - spring; 11 — output of half of the secondary winding (4 pcs.); 13 — textolite bushing (with a groove for the end loop of the spring); 14 — M8 bolt (6 pcs.); 15 — textolite washer (4 pcs.); 16 — insulating coating (varnished fabric or protective adhesive tape on a fabric basis, 2 pcs.); 17 — transformer casing.

Installation diagrams

The main types of welding device assembly schemes are simple projects with a minimum amount of required materials. It is worth noting that the manufactured equipment will not be powerful, that is, this spot welding scheme is intended only for domestic use. Its purpose is to weld small sheets of iron and electrical wires.

To understand how to do resistance welding, remember the school curriculum, namely the physical rule “Joule-Lenz Law”: when electricity passes through a conductor, the amount of thermal energy created in it is directly proportional to the resistance of the conductor, the time of exposure and the square of the electric current. Conclusion, if the current was initially large (for example, 1000 A), then with a weak connection and small wires more energy will be consumed (several thousand times) than with a lower electric current (10 A). That is, the quality of the assembled electrical circuit plays an important role.

The formation of an electrical pulse between two sections of metal products is considered a basic part of the operation of a welding installation. This will require a small energy converter. The product to be welded must be connected to the lower winding of the device, and the metal electrode to the secondary.

It is worth noting that it is unacceptable to directly combine the converter with the power source. For this purpose, a bridge with an electronic switch (thyristor) is provided in the electrical circuit. To create the required pulse, the device must be supplied with auxiliary power, which includes an energy rectification bridge and a transformer. The electric current will be concentrated in a capacitor, whose role is to generate a pulse.

In order for a home-made resistance welding machine to work, you need to press the “pulse button” on the handle of the gun to open the capacitor-resistor circuit diagram. As a result of these manipulations, a discharge will occur through the metal rod. To reinforce the theoretical material, it is recommended to watch the training video, which explains in detail about spot welding. This allows you to visually understand how this is all done correctly.

Homemade device from a microwave oven

Since it is not always possible to allocate an extra amount of money for spot welding machines, you can make it yourself. This will require a fairly powerful microwave oven.

Transformer assembly

You only need one part from the microwave - a high-voltage transformer for spot welding. This part requires only a core (magnetistor) and a primary (lower) winding. To remove unnecessary areas, you can use a hammer, grinder or hacksaw.

After removing the transformer secondary winding, it is necessary to create a homemade transformer for resistance welding. To do this, you should use a copper cable with a diameter equal to the opening of the transformer. It is necessary to make two turns.

In order to connect the two parts of the core you will need epoxy resin.

Next, you should test the output voltage from the device. The optimal value is considered to be 2 volts, and the current strength is about 850 amperes.

The base is done, now we need to work on the body of the homemade installation. For this purpose, various polymers are used, for example, plastic or wood. The back area of ​​the point installation housing should contain several openings. One opening will serve as the key for the device, and the other will supply electricity.

If wood is used instead of plastic, then first you should perform several preparatory operations, namely sanding, impregnation and varnishing. To create a homemade working machine for spot welding with your own hands, you will need:

• welding installation power cable;
• Door knob;
• switch;
• copper holders;
• large diameter electrical wire;
• consumables (screws, nails).

After the body section has dried, it is necessary to assemble the installation and combine all the associated parts. After this, the copper wire is cut into 2 parts, each of which is approximately 25 mm. These elements will perform the function of electrodes.

To fix them, just use a standard screwdriver. Then you need to install the system key; a thick electrical cable will prevent it from slipping out.

To fix the transformer to the structure body, you can use self-tapping screws, but do not forget about grounding one of the terminals.

To increase the safety of using the welding device, it is recommended to install an auxiliary switch. Small nails and other fasteners are also used to secure the working arms. Contact metal rods are attached to the end parts of the handles. To raise the upper handle, a standard polymer is used - rubber.

Creation of electrodes

Elements used for do-it-yourself spot welding must meet certain requirements, namely resistance to operating temperatures, good electrical conductivity and ease of machining.

Copper wires with a cross-section of 15 mm or more are perfect for this. The basic principle is that the cross-section of the electrode should not be less than the diameter of the wire. If you don’t mind, you can use the tips of 2 soldering irons, which will definitely last a long time.

Controls

The do-it-yourself resistance welding has a simple device. There are only two control systems - a switch and a handle. The spot welding switch is fixed in the primary winding circuit.

This is necessary because there is more current in the secondary winding, and the switching system will create additional resistance. The switch is installed on the lever, so it will be more convenient to work.

That is, you can turn on the electricity with one hand, and hold the materials being welded with the other.

It is worth noting that turning the welding current on and off must be done only with the electrodes compressed, because otherwise a spark will appear, leading to their burning. It is also recommended to use a fan to cool the device.

If such a cooling system is not available, then the temperature of the energy converter, metal electrodes, electrical wires should be constantly monitored and additional breaks should be created to prevent overheating.

Today, purchasing a welding machine for spot welding is not a problem if you have the money. Any specialized store will offer a range of installations for point joining of parts, with different capacities and manufacturers.

But for home craftsmen it is not always possible to select the required parameters, so making a spot welding machine with your own hands will be the optimal solution. All necessary supplies can be borrowed and found at home.

A do-it-yourself spot welding installation does not fail and works perfectly, thereby providing the required minor repairs to metal products.

Source: https://oxmetall.ru/svarka/kak-sdelat-apparat-dlya-tochechnoj-svarki-svoimi-rukami

Do-it-yourself spotter from a welding machine

A spotter is a welding unit used specifically for organizing spot welding, and also allows you to work on straightening thin sheet workpieces.

This type of welding is especially common in workshops whose employees are engaged in straightening work that requires preliminary disassembly of the body.

Using a spotter allows you to avoid the mandatory dismantling of the load-bearing parts of the car and straighten surfaces without using a reverse hammer (figure below).

Using a reverse hammer

In this case, the welding procedure is used for the purpose of point-fixing an additional holder on the restored surface, by pulling which it is possible to straighten the existing dent.

Spot Welding Properties

The design of this device is somewhat different from typical units with a continuously burning arc. You can make a spotter from a welding machine with your own hands only if you know the basic principles of the formation of the operating current. The fact is that with the contact welding method, heating occurs not by melting the metal, but by concentrating heat in a point zone between the workpiece and the electrode.

In the case of an incorrectly selected resistance welding mode (with a lack of experience on the part of the operator), sticking of the electrode is often observed, which can lead to unpleasant consequences in the form of a short circuit or even breakdown of the unit. That is why the spot welding machine is manufactured so that the welding time is strictly limited and does not exceed a second.

In addition, such a device is designed for small values ​​of effective voltage (since ignition of the arc is not required in this case) and for significant operating currents. In this regard, the transformer (CT) included in its composition must also withstand high current loads, sufficient for high-quality heating of the welding site.

Features of the conversion

DIY digital TV antenna

You can make a spot welding machine with your own hands without unnecessary effort if you use the option of converting it from an unnecessary welding device. When preparing for work, you will need to pay attention to the following points:

• For an ordinary CT, the voltage when operating at idle (no-load), as a rule, is selected to be no more than 70 Volts;
• In a situation with a spot welding unit, this figure should not exceed 6 Volts;
• To implement this condition, a new secondary winding will be required, designed for a reduced output voltage.

Note! You can also make a new low-voltage coil by winding it over the existing secondary winding (if space allows).

Otherwise, it is better to unwind the old “secondary” and use its wire to form a new working winding.

Before doing spot welding with an updated transformer, it is advisable to familiarize yourself with the existing types of these electrical products and try to choose the most suitable one.

Core types

DIY crafts: DIY electrical

The cores used in welding transformers can have several different designs (picture below).

Among them, the following types of CT stand out:

• With the so-called “W-shaped” or armored core;
• With a rod base (in the shape of the letter “O”);
• And finally, with a core made in the form of a torus.

Of all the listed options, the most suitable for the purposes under consideration is a transformer with a toroidal core, which has small dimensions and relatively light weight (see the figure below).

Toroidal transformer

Additional Information. The cross-section of such a core in any transformer will be determined by the expected welding current.

For do-it-yourself spot welding to work properly, the output current of the unit must be at least 1000 Amperes. The latter means that a sufficiently thick wire must be used in the CT output winding. This requirement is fully satisfied by the selected version of the toroidal core, since there is plenty of space for placing the output winding in it.

Selecting parameters

DIY wind generator from a car generator

When remaking a CT, the main attention should be paid to the parameters of the secondary winding, which determine the output characteristics of the device (its load current, in particular). In this case, it is important to select a bus cross-section that would provide a current density of about 8 A/mm² (with a cross-sectional area of ​​about 120 mm²). Since it is very difficult to handle such a thick busbar when winding on a torus, they are most often limited to a value of 80 mm².

Note! The specified cross-section can be obtained by putting together several wires of slightly less thickness.

To facilitate the conditions for converting a CT into a point unit, it is advisable to pre-calculate the amount of wire required for rewinding it. After this, it will be possible (based on the space occupied by the winding) to decide whether it will fit into the free space remaining on the torus or not.

Important! In the case where the new winding does not fit into the torus, the old secondary coil will have to be completely disassembled (dismantled).

To make it easier to handle new wires during the winding process, it is recommended to wrap them with fabric-based insulating tape. To determine the exact number of turns that affect the output voltage, we recommend using the test winding method with a small-section wire in insulation.

Since the winding in this case is not connected to the load, the cross-section of the test wire is not very important. Experience has shown that during rough tests it is sufficient to use no more than 10 turns. After winding them, the transformer should be connected to the network and the voltage produced by the test coil should be measured, after which it is divided by the number of turns. The result is a figure indicating the number of turns required to produce one volt of output.

Since in this case it is necessary to obtain 6 Volts, multiplying the number obtained from the test connection by 6, we obtain the required number of turns.

In order to make a new device with your own hands, you must first calculate the amount of wire required for rewinding the CT. After this, it will be possible (based on the space occupied by the bus winding) to determine whether it will fit into the free space remaining on the torus.

Winding diagrams and placement

The connection diagram and the order of placement of the “secondary” depend on the type of core selected. Given the toroidal base of the CT that we have declared, it is more convenient to divide it into two half windings connected in series (3 Volts each).

In order to increase the load capacity (increase the welding current), you can make two windings of 6 Volts each and connect them in parallel. In this case, the output voltage will not change, and the load current can be doubled. This design option allows us to solve the problem of the large cross-section of the secondary bus, which can then be reduced by half.

Various types of connections of such windings are shown in the picture below.

Secondary connection circuits

The order in which they are connected is very important to obtain the required output parameters, and mistakes made in this case can lead to completely different indicators. So, in particular, if you make a mistake during installation and turn on two windings in opposite directions, as a result they will be short-circuited to one another and will produce zero voltage at the output, which is equivalent to a short circuit.

At the ends of ready-made secondary windings, special tips should be equipped by crimping.

Control circuit

To control the welding process, short pulses are used, generated in a special electronic circuit. When manufacturing a spotter based on an old unit, it is also necessary to provide a control unit that allows switching a significant output current.

To solve this problem, manually generated pulses are applied to the primary winding of the CT (the simplest control circuit is shown in the figure below).

The disadvantages of such management include:

• Using the button shown in the figure, the mains voltage is switched, which is extremely dangerous;
• When mechanical contacts open, strong sparking occurs;
• Even if you replace the mains switch with a traction relay from the starter, controlled by a push-button mechanism, then such a circuit, despite the improvement, will still be unfinished.

Note! To implement the traction principle, it is allowed to use a combination of “powerful starter plus automotive relay” (and the latter can be of any brand).

When this combination is selected, the relay is activated when a voltage of 12 Volts is applied, and its switching causes the power contactor to operate. However, this control option is not without drawbacks, since in this case it is not possible to precisely control the impact interval (pulse width).

For those who know the basics of electronics and know how to handle a soldering iron, a more complex in design, but reliable in operation, electronic control circuit will be suitable (see photo below).

Thyristor control circuit

Here, operating pulses are supplied to the input winding of the CT from an electronic device - a thyristor, which opens when voltage is applied to its control electrode. The capacitor (C1) included in its circuit, with the button contact open, is charged through the elements V1-V4 of the diode bridge. When the button is pressed, the capacitance is discharged through resistor R1 and directly through the thyristor control electrode circuit, which causes it to turn on.

The electronic device will remain on until the capacitor is completely discharged (this interval can be adjusted with variable resistor R1). For the subsequent start operation, the button must first be released and then pressed again (its shutter speed determines the welding interval).

Transformer T1 can be of any type (with a voltage on the secondary winding of 12 Volts). The parameters of the thyristor must satisfy the operating conditions, that is, allow it to operate at voltages up to 400 Volts and currents of at least 50 Amperes. An electronic product of the T132-50 brand is quite suitable for these purposes.

In the final part of the review, we would like to remind you that welding equipment of the “spotter” type is most often in demand for body repair and similar work with sheet metal. In this regard, when choosing the output power of a home-made unit, it is necessary to take into account the thickness of the sheet material with which you will mainly be working.

Source: https://amperof.ru/elektromontazh/spotter-iz-svarochnogo-apparata.html

Homemade contact welding with your own hands from an inverter

Reading time: 9 minutes

Now on the Internet you can find dozens of articles and instructions on how to make resistance welding from an inverter with your own hands. Some people think that a resistance welding machine should be assembled from an inverter, while others say that this is a waste of time and effort. In fact, both are right. But the first ones forget that the main characteristic of resistance welding is not only an electrical impulse, but also a clamping force. Without it, it is impossible to form a weld point.

Based on this, it becomes clear that attention needs to be paid not to WHAT the contact welding is made of, but to HOW the clamping force will be provided. However, let's talk about everything in order. In this article we will tell you in detail how to assemble a resistance welding machine with your own hands from an inverter-type device, and whether an inverter is needed at all in this situation.

This article is intended for practicing masters, and does not contain detailed explanations, which are already clear. If you are a beginner, then read other articles on our website in which we talk about the resistance welding machine.

Assembling a resistance welding machine

Do-it-yourself contact welding from an inverter is easy and quick to assemble if you have the appropriate skills and knowledge in the field of electrical engineering. Once again, this article is not intended for a beginner. There will not be long explanations of each step here. We are only sharing our experience in assembling resistance welding. If you have never held a soldering iron in your hands and do not know how to wind a transformer, then first study the theory. And only then start assembling the device.

Required tools and parts

To wind the transformer you will need copper wires. We'll talk about the cross-section later. But you can independently calculate the required wire cross-section using formulas that are available on the Internet.

You will also need various little things like an on/off button, they will be used for the control circuit. You will also need available materials to make levers and electrodes. We will talk about them in detail throughout the article. Don’t forget about insulating materials, you can’t do without them.

Tools you will need are a soldering iron, solder, and a chisel/hacksaw.

Inverter: necessary or not?

We believe that resistance welding from an inverter is not the best solution. Moreover, all you need from the inverter itself is a transformer. Some craftsmen manage to use electronics, but they still need to be painstakingly refined. Therefore, it is easier to do everything from scratch using new components, rather than trying to disassemble the inverter into molecules.

You can take a transformer from an inverter or make one yourself. But we recommend using microwave ovens because they are cheap, easy to upgrade, and perfect for our purposes. Further recommendations will be given based on the fact that for assembly we will use a microwave transformer.

Welding transformer

So, we agreed that we would assemble resistance welding from a microwave transformer. Assembly from an inverter is impractical, it is tedious and ineffective. Therefore, all further recommendations will be related specifically to the microwave transformer. Be careful.

Let's start with selecting a transformer. You will not need any transformer, but only the option with a power of 1 kW and above. These are installed in fairly powerful microwave ovens with many functions. You can take a transformer of lower power, but then your machine will not be able to weld even 1 mm thick metal. And if you want to make a very powerful device, you can take two transformers of 1 kW each and connect them.

Let's assume that you have a transformer. Now we need to remove the secondary from it, later we will wind it ourselves. It is very difficult to remove the secondary with bare hands; it is better to use a hacksaw or chisel. If the secondary is tightly glued, then you can first drill it out and then saw it off with the same hacksaw or beat it with a hammer.

You should still have the core and the primary. Typically, microwave transformers have a primary made of thicker wire, so you definitely won’t confuse it with the secondary. Also remove shunts, if present. Try not to damage the primary when dismantling unnecessary parts.

Next, we proceed to winding a new secondary. We used the copper wires mentioned above. We recommend choosing wires with a cross-section of 100 mm2 or more. These are quite thick wires, but this is the optimal cross-section in our case.

Moreover, you only need to make 3-4 turns for the entire winding. If you can wind more, you will end up with a more powerful device. But we recommend stopping at 3 turns.

This is the best option for a homemade homemade machine that will not weld metal that is too thick.

Device controls and levers

The control system can be assembled using electronics from an inverter, but this is really difficult and expensive. It’s easier to assemble everything from scratch and not have to worry about the inverter circuit. Moreover, you only need an on/off button. You can also add current control, but we didn't do that. After all, our goal is to assemble the most inexpensive and at the same time working device.

As a switch, you can choose any one you like. It must be installed in a circuit with the primary winding. And don't even think about installing a switch with a secondary winding, it's a bad idea. There is too much current on the secondary and it can simply melt the contacts at the switch.

To assemble the levers, you can use a metal pipe (be sure to insulate it) or a wooden blank. In general, you can use any available materials. But make sure that they do not conduct current on their own. In our case, the current will pass to the electrodes through wires attached to the levers. Such levers will be a kind of handles that you will grab, pressing the electrodes to the metal.

Source: https://svarkaed.ru/oborudovanie-dlya-svarki/apparaty/samodelnye/camodelnaya-kontaktnaya-svarka-svoimi-rukami-iz-invertora.html

How to make a spot welding machine: resistance welding technology and assembly diagrams

Spot welding is a subtype of resistance welding. In this type of welding, metal elements are fastened in one or more places.

This surface welding method has high production technology and a variety of applications in various industrial fields, and can be used in the production of electronic devices, automobiles, ships, aircraft and other industrial production fields.

When using this type of welding, a very high strength of connection between structural parts is achieved. The degree of strength at the junction is determined by the efforts to squeeze the surfaces of the fastened elements and the physical force of the device's electric current.

In modern production, different versions of these devices are used, from stationary machines to easily transportable devices. As an example, the picture shows a photo of a manual spot welding machine.

Hardware Features

This type of welding is based on the method of heating a metal part (plate) with an electric current pulse. To ensure the welding effect, the parts (elements) are strongly pressed together.

At the point of greatest compression, parts are spot welded by passing an electric charge between the electrodes of the device. At the point of contact, a molten point of metal no larger than twelve mm in size is formed.

Spot welding methods

This type of welding is conventionally divided into two methods: soft and hard.

Soft mode. In this mode, when welding, the parts are gradually heated using a low current. It takes about three seconds to weld metal surfaces in this mode.

In this mode, the power consumption of the machine (device) is reduced. The mode is usually used when welding metals with hardening properties.

Hard mode. It is determined by a short duration of high electric current and powerful squeezing of the welded elements at the welding point. The density of consumed electric current in this mode reaches 300A per 1mm2. The welding process takes up to one and a half seconds.

The main disadvantage of this method is the large demand for electricity (machines) and large overloads of the industrial network. The advantage is minimal time for welding surfaces.

This mode is usually used when welding surfaces with good thermal conductivity, high-alloy steel or bonding surfaces of different thicknesses.

Welding options

Types of spot welding are determined by the number of joint pixels formed at a time. The following types are used in production: single-point, two-point and multi-point types.

The single-point type is used when joining several sheets, while the quality of welding decreases with each layer of sheets (parts). The two-point type of welding is used when connecting parts with wide surfaces.

The multi-point type is used to fasten various stamped structures. It can be bilateral or unilateral, it all depends on the placement of the electrodes in relation to the nodes being fastened.

This type of welding can also differ in the cycles of electrical pulses. The cyclicity depends on the thickness of the parts being welded.

For a metal surface up to five millimeters thick, one pulse of electric current is sufficient, but for large thicknesses, several short-term electrical pulses are necessary. When welding metal elements of great thickness and hardness, cycles with increased compression are used.

Welding methods

There are several methods for spot welding:

Spot - welding of elements occurs in one or many places. It is used in instrument making, the automotive industry, and the construction of sea, river and aircraft vessels.

Provides welding of steel sheets up to twenty millimeters thick.

Relief method - structural elements are welded in one or several prepared places. The difference between this method and the previous one is due to the shape of the fastened elements at the welding site.

Seam method - the welded elements are fastened with a series of welding seams. A seam can consist of individual weld pixels or overlapping ones. Used for the manufacture of various tanks requiring a high degree of tightness.

Docking - elements are welded along the adjacent contact area under high temperature. They are used in laying pipelines and making anchor chains for ships.

Design Features

Greater spot welding capabilities are in demand in industrial production. For their implementation, production machines and hand-held portable units have been created.

When solving problems of welding metal elements, you need to remember that this process depends on the metal from which the product is made and its density.

Requirements for technology for performing this type of work:

• ensuring low voltage, no more than 10W;
• ensuring a short transit time of the electrical pulse at the welding point;
• providing high electric current at the welding site;
• ensuring a minimum melt area in places where the structure is fastened;
• ensuring high quality weld strength.

A modern spot welding machine can have different designs. In modern production, transformer or capacitor spot welding machines are used.

Transformer machines must carry out high-temperature heating of the surfaces being welded. The performance of welding equipment in everyday life can be ensured by an electric current of up to 5 kiloamperes, and in industrial equipment from three hundred to five hundred kiloamperes.

Industrial machines use powerful transformers. The main disadvantage of such devices is the lack of a uniform load, which leads to large overloads of the industrial network and frequent breakdowns.

Capacitor machines load electrical networks measuredly. The use of capacitors in machine tools allows you to avoid sudden overloads of the industrial electrical network.

Manual capacitor welding machines have minimal dimensions and are widely used to solve everyday problems. Their advantages are small dimensions and operability when connected to a household power supply.

Advantages:

• there is no need to purchase welding materials;
• ease of manufacture;
• ease of operation;
• cleanliness and neatness of seams or weld points;
• compliance with environmental requirements;
• min power consumption;
• high performance.

We make the welding ourselves

This type of welding tool is not a cheap tool. It is more practical to make a spot welding machine with your own hands.

The main element of such a device is a transformer (used in various household appliances). To provide the necessary electric current for this type of work, it is necessary to rewind its windings. During the creation of the 1st winding, intermediate terminals are also prepared. The wire on the windings must be impregnated with varnish and wrapped with special paper.

The components of the device are selected according to the parameters of the transformer. Its design depends on the parts (surfaces) to be worked on. Electrical elements must be designed with a high degree of reliability.

Pincers can be of two types: stationary and remote. Stationary ones are simpler to manufacture; they are firmly fastened together and reliably insulated. Remote ones are more suitable for use when performing various types of work. They can be easily installed and removed. It is convenient to bring them to the place of direct welding.

When using external pliers, it is necessary to ensure their reliable connection to the device itself and their waterproofing. To make electrodes, you can use copper rods, bronze or an old soldering iron tip.

The electrical diagram for connecting such a device can be easily found on the Internet.

Safety precautions

To ensure their own safety, the worker must know and comply with the safety instructions for spot welding:

• To prevent electric shock, ground the unit;
• Before starting work, be sure to check its serviceability;
• use personal protective equipment for hands, eyes and body;
• exclude high voltage supply to the device controls
• use only wires of the specified cross-section in the device;
• carry out work in a room with well-equipped ventilation or use special masks to protect the respiratory system.
• locks and toggle switches (buttons) for turning on or off must be in working order, clearly visible and easily accessible;
• During work, the area of ​​the clamping mechanisms must be covered with a shield.

Compliance with these safety measures will ensure the health of the employee and others and will allow the required amount of work to be completed accurately and on time.

Photo instructions on how to make a spot welding machine

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Source: https://instrumentgid.ru/instrukciya-kak-sdelat-apparat-tochechnoj-svarki/

How to make a spotter with your own hands according to drawings

A spotter is a modification of a welding machine that is used to perform car body repairs. Such work, as a rule, requires special knowledge of the structure of the car. Certain places in it often cannot be leveled from the inside. This is where this device helps. Due to the high cost of factory models, craftsmen are often interested in how to make a spotter with their own hands from a welding machine.

Spotter, its application and design

This tool is used to level out car dents when repairs from the outside are not possible. It can heat up part of the metal, and the damage to the body will be minor.

In particular, it is used for the following purposes:

• body straightening;
• leveling the surface of the body without the need to disassemble it.

The enormous and irreplaceable benefit of this device lies in its use for leveling body parts when access to certain parts is limited due to the specific structure of the car.

When straightening damaged parts of the body, a special device fastener is welded to the deformed surface and then pulls it out.

It should also be noted that the spotter is capable of heating the metal during operation, and this facilitates rapid leveling, obtaining rigidity and the desired shape.

There are several schemes by which the device can be assembled. For such purposes, not only a welding machine can be used, but also an old battery, microwave oven, inverter or transformer. It is not difficult to make a welding machine from a battery with your own hands.

The work of this design consists of point-by-point pulling of the damaged part according to the principle of a hammer.

It looks like this:

• the return hammer of the device is fixed to the body using a welding pulse;
• The handbrake of the device must be pulled along the guide towards you, while the support washer remains in place.

The simplest spotter has 2 modes:

• temporary, when a ring is fixed to the surface;
• welding - light welding of the electrode to the surface is used when the device is attached to the car.

Inverter based spot welding

Do-it-yourself contact welding from an inverter is the most common type of homemade spotter for straightening. There are many ways to assemble this device.

This type of spotter is very similar to resistance welding and is its modification. But its design has a distinctive feature - it does not contain pincers. That is why it can be considered an analogue of electric arc welding, in which current passes through the car body. One welding contact is attached to the surface, and the second is the nozzle and rod.

Inverter device

The main part of the device is a gun, which can be made from a similar device for construction glue or from semi-automatic welding. Many people are interested in how to assemble a puller with their own hands. The scheme is quite simple.

Source: https://pochini.guru/instrument/spotter-po-chertezham

Assembling a spot welding machine with your own hands

In stores, spot welding machines are not cheap, but this tool is useful in the household of every real man. Therefore, many decide to make this equipment themselves, using available materials.

The finished device will allow you to quickly and reliably connect various metal elements. Thus, repairs of various structures can be carried out at home, saving on the services of a professional.

The main advantage of making it yourself is significant cost savings on purchases.

Work principles

The scope of resistance welding is very wide. It can be used both to repair old metal structures and to create new ones. Such a device will allow you to easily cope with the manufacture of gates, stairs, and structural elements made of metal.

The operation of the device directly depends on the electric current, which heats some areas of the steel parts in contact with each other to a certain temperature. At this moment, a welded joint is formed, which experts call a seam. In this case, the metals are connected to each other by melts of each other at point contact. The quality of the work performed directly depends on the type of metal and its density.

You must also follow these rules:

• The welding circuit must have a low voltage (up to 10 watts);
• The welding process should last a few seconds;
• High-quality welding is characterized by a minimal melting zone;
• High current strength of the welding pulse;
• The seam obtained after welding must withstand heavy loads.

Compliance with all the above rules guarantees an excellent result. It’s not difficult to make a spot welding machine with your own hands, but you need to carry out all the steps in accordance with the recommendations of specialists.

Manufacturing of the device

A high-quality welding machine consists of two main parts - a contact block and a welding pulse source. The latter gives an impulse automatically. The current should be within 200 A for 0.03-0.1 s when powered from a regular electrical outlet. Some users advise choosing a device that allows you to adjust the current to work with different types of metal of different thicknesses.

The contact block must be characterized by the following basic requirements:

• Good pressing of welding surfaces;
• Using a point electrode, it is necessary to supply a welding signal;
• Holding workpieces after removing the impulse until complete hardening.

Most often you can find the following solutions:

• the workpieces are clamped between the electrodes;
• use 2 different electrodes: point and flat;
• one of the workpieces is the bottom electrode.

Manufacturing

You can make a high-quality spot welding machine yourself. To do this, you can use a welding pulse source that uses the principle of capacitor discharge. The circuit of such a source is quite simple.

Welding machines with this type of power supply can weld thin sheets of metal (up to 0.5 mm).

The required current is released at the output of the secondary winding. The capacitors are discharged onto the primary winding, which contributes to the generation of the desired signal. Capacitor discharges are controlled by thyristors. The accumulation of charge occurs from the switched on auxiliary circuit of the transformer. It is necessary to use diodes that rectify the electrical signal.

How to make a device?

This device can be assembled from available materials. First of all, you need to assemble it from the inverter. You need to prepare:

• transformer and capacitors for welding;
• diodes and chokes.

Using all of the parts listed will help avoid lengthy setup.

Most often, men make such devices for spot welding batteries from parts of an unnecessary microwave. It may already be at your home, or you can borrow it from friends. The spot welding produced from such parts is characterized by a power of about 800A.

To make such a machine for resistance spot welding, it is better to choose a large microwave. After all, such models have a powerful transformer. And this is the basis of future equipment.

The transformer is a core with two windings. It is held in place by welded seams, which must be removed with a hacksaw or grinder. Be careful, because the winding should not be damaged. Afterwards, the core needs to be divided into 2 parts, cleaned of glue and paper.

We wind the second winding of the transformer. To do this, use a cable that fits into the slot of the transformer, which is wound into 2 turns.

The transformer is attached to the base with epoxy resin, compressed with a vice.

The secondary winding allows you to increase the power of the device.

Transformer circuit

After the windings are connected, the current strength can be checked. It should not exceed 200A. If the value is higher, voltage surges may occur, which can lead to negative consequences.

The voltage should go to the first winding. The output voltage should not exceed 2 volts.

To make a battery with your own hands, you need to pay special attention to the body of the future equipment. Wood is used for this. There must be holes in the back of the device that will be responsible for power supply and shutdown.

The body of the welding machine, made of wood, must be sanded and varnished.

Then they make the device with their own hands. Connect all the parts, prepare copper wires that will serve as electrodes. You can use an ordinary screwdriver to secure them. For high-quality fixation, the transformer can be attached to the housing with self-tapping screws. Remember about safety, grounding must be placed on one of the terminals.

The design of this spot welding machine should include an additional switch secured with self-tapping screws to the body. Thus, you can benefit from a welding machine with your own hands. This means saving money on purchasing a new device and earning money from doing simple work.

Source: https://electrod.biz/vidy/tochechnaya/apparat-dlya-tochechnoy-svarki-svoimi-rukami.html