How to make spot welding yourself

Do-it-yourself spot welding from a microwave

Do-it-yourself spot welding from a microwave

Surely, those who are interested in welding have seen more than once how a spot welding machine works. With it you can make a lot of useful things for the home, and also easily work with thin metal.

The cost of a factory-made spot welding machine is quite high, about 10 thousand rubles or more. However, if you have an old microwave, you can make such a device at home. All that is required of it is a transformer, which is subject to slight alteration.

In this article from the website mmasvarka.ru, let's look at how you can make spot welding from a microwave with your own hands.

Disassembling a microwave oven for refurbishment

To assemble a spot welding machine, you can use almost any microwave, even if it’s not working. However, the transformer from the microwave must be working, since it is this that will need to be subjected to major changes.

First you need to disassemble the microwave body and get to its internal elements. Inside the device there is a textolite board with a transformer; it is this that will need to be removed from the microwave. Next, you will need to unsolder the transformer and after that, you can begin to remake it.

How to convert a microwave transformer for spot welding

The microwave has a step-up transformer that is capable of delivering 2,500 volts from 220 volts. It is from this high voltage that the magnetron of a microwave oven is powered. For this purpose, the secondary winding of the transformer is made with a large number of turns of thin copper wire; in the manufacture of a spot welding machine, all this is not needed.

Therefore, it will be necessary to remove the secondary winding from the transformer, so as not to damage the primary winding. The complexity of its dismantling depends on the design of the transformer, so you may need a hacksaw, a small chisel and a hammer. It is very important not to damage the primary winding.

The next step in converting the transformer, after the secondary winding is removed, is to wind a new winding, but only with a different wire. For these purposes, you will need a thick copper cable with a cross-section of at least 100 square meters. mm. It is with this wire that you need to wind on top of the primary transformer winding, the secondary winding, at least 3 turns, laid tightly to each other.

After the transformer is rebuilt, the process of making microwave spot welding is still not complete. Now you will need to make electrodes and a machine for ease of welding. To make electrodes, you should take small copper rods, which will be used for spot welding. The rods must be attached to the machine through insulators.

To make electrode holders, you should use two pieces of profile pipe, which are connected to each other by a small canopy. At one end of the holders, electrodes are attached to the pipes, and at the other, a previously converted transformer.

Spot welding is a very useful device for the home, which will definitely come in handy when working with thin metal and products made from it.

Source: https://mmasvarka.ru/tochechnaya-svarka-iz-mikrovolnovki.html

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

DIY spot welding from the microwave! | Master Vintik. Everything with your own hands!

Previously we wrote: what can be done from an old microwave oven. Today, let's take a closer look at how to make a spot welding machine with your own hands from a high-voltage transformer or MOT (Microwave Oven Transformer - microwave oven transformer) from an old, unusable microwave oven. Of course, provided that the high-voltage transformer is working (at least its primary winding), and something else is faulty: magnetron, cable, control board, etc.

For a master, there is a need for spot welding. This spot welding produces a current of up to 800 Amperes, which is quite enough for welding sheet metal up to 1.5 mm.

So, we need an old microwave and the larger it is, the better. Larger microwaves have a higher power transformer. If you don’t have an unnecessary microwave, you can often buy old microwaves cheaply on forums and free bulletin boards, or you can look for them near trash containers or ask at TV repair shops.

Attention! Before disassembling, the microwave must be turned off from the power supply. Next, we disassemble the microwave oven. There are several components inside a microwave oven that are dangerous even when turned off and can cause serious electric shock - these are capacitors (see photo) that can hold a charge for some time. Therefore, we discharge the capacitors by connecting their terminals to each other with a screwdriver. The high voltage transformer is located below.

Of the insides of the microwave, we are primarily interested in the high-voltage transformer.

The transformer consists of a core and two windings: primary and secondary. The primary winding is wound with thicker wire and contains much fewer turns.

The transformer core is held together using two thin welds, as seen in the photo.

How to make a transformer for welding?

There are two options for removing the winding:

1. Disassemble the transformer core.
2. Cut off the winding with a chisel.

Method 1.

You will need a hacksaw or grinder to cut this seam, as well as a hammer and chisel to get to the transformer windings.

Be careful when removing the primary winding from the transformer, as we will need it later.

Try not to bend or scratch it.

The secondary winding can be wound very tightly and is difficult to remove, so if you don’t need it, you can cut it and pull it out in pieces, it will be much easier.

Now, after all the manipulations, you should have in your hands an intact and undamaged primary winding of the transformer and its core, divided into two parts (without glue and paper that held its windings inside).

The next step is to wind the secondary winding of the transformer. To do this, you need to take a copper (required!) cable of approximately the same cross-section as the slots in the transformer core (about 7 mm) and wind two turns.

I then bonded the transformer core to its base using regular 2-part epoxy resin and gently pressing it in a vice and left it to glue.

Once the epoxy has dried, the transformer should look something like this.

Method 2.

It’s also not easy, but the transformer hardware will remain intact, which is important. To do this, you need to remove the winding using a chisel, chisel, hacksaw, etc.

We also remove shunts.

Next, we wind a new winding onto the transformer. It is made from stranded wire with a cross-section of at least 100 mm2 (or a diameter of more than 1 cm). It will be enough to make 2-3 turns. If the wire has too thick insulation, you can remove it and replace it with fabric insulating tape. If two transformers are used at once, then the secondary winding for them is made common, but it is very important to correctly connect the leads from their primary windings.

The voltage at the output of the transformer was just over 2 volts, but the current was about 800 Amperes! This is sufficient current to ensure a strong connection when welding metals.

DIY welding body

Now all that remains is to make a housing for the spot welding machine. You can make it out of metal.

You can make the body out of wood. You can make it based on what you have on hand.

The photo below shows the process of making the case.

Once I had all the body pieces cut out, I carefully rounded the edges using a router bit. You will need to make a notch on the upper arm so that the arm can easily rise up without resting on the body.

On the back panel I cut two holes, one for the switch, the second for the power wire.

I then attached the switch to the back panel and inserted the power cable into the hole. The thickening on the cable prevents it from falling out.

I secured the transformer to a wooden base using regular self-tapping screws. I put a terminal on one of them, which I connected to ground.

I then sanded, primed and painted all the parts. I chose two colors - black for the body, and yellow for the moving parts (levers).

Also, when making spot welding with my own hands, I used:

• Power cable;
• Door handle;
• Switch;
• Copper holders for contact electrodes (2 pcs) (they can be bought in stores selling welding equipment);
• Thick single-core copper wire for making contact electrodes (about 5 mm);
• Wood screws, nails;

After the painted body had dried (I gave it about 2 days), we began the final assembly of the device.

Electrodes for spot welding

The electrodes of equipment for spot welding perform several functions simultaneously: compression of the sheets being joined, supply of current to the welding zone, and subsequent heat removal. Important parameters when choosing an electrode are its shape, dimensions, etc.

It is these parameters that directly determine how high quality the welded joint will be.

The geometric shape of the electrodes can be straight or curly, but preference is given to straight models, as they provide better access to the welding area.

When choosing electrodes for a microwave welding machine, you can simply refer to the corresponding GOST (14111-90), which already specifies all possible diameters of these elements (10, 13, 16, 20, 25, 32, 40 mm).

Homemade electrodes. To make them, cut two pieces of thick copper wire, each about 2.5 cm long. Clamp them into the holders. The electrodes in the holders are tightened using a regular screwdriver. The denser the better.

The electrical part could be considered complete, but for greater safety and convenience, I decided to add another button (microphone), which will be located on the upper lever at a slight angle. Microswitches can also be taken from the microwave. This way, spot welding will only work when the rear panel switch is on and the mic is pressed (in other words, two switches are in series).

You can use a timer to set the welding time. For example:

Note: Remember to carefully insulate all connections!
I screwed the sides with self-tapping screws (6 pieces per side).

I secured the levers in the following way: experimentally (by eye) I installed them one on top of the other, drilled two holes in the side walls (for the lower and upper levers) and inserted an ordinary nail into the hole, the end of which I then bent. The result is a cheap and reliable axle.

I installed contact electrodes at the ends of the levers. For convenience, the top wire goes in one direction, the bottom in the other.

After the contact electrodes burn out, they can be easily removed and replaced with new ones.

To ensure that the upper arm was always raised, I used a regular rubber band.

If, after assembly, the axes of the electrodes do not align correctly with each other, this can be easily corrected by bending them slightly.

Homemade spot welding tests

To use, place thin sheets of metal between the electrodes, then press the button (micric) for 3-4 seconds. A powerful pulse of electric current heats them to the melting point, and the pressure of the electrodes further strengthens the welded joint.

Now you can remove your finger from the button and wait until the weld has cooled down.

The DIY spot welder works so well that after welding these washers together, I could not separate them (I was only able to do this using 2 pairs of pliers).

Attention!

1. You cannot short-circuit the electrodes with each other!

2. When welding galvanized metals, zinc oxide fumes are formed, which is harmful. Therefore, it is advisable to carry out welding work in a well-ventilated area.

the process of making a spot welding machine with your own hands:
Another option for spot welding:

Another option for making spot welding:

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Source: http://www.MasterVintik.ru/tochechnaya-svarka-svoimi-rukami-iz-mikrovolnovki/

Description of the process of self-assembly of spot welding

The resistance spot welding machine is very easy to manufacture. It comes in a variety of configurations - from small portable to quite large. Before you begin assembling the structure of a homemade apparatus, remember the Joule-Lenz law, which gives a quantitative assessment of the thermal effect of electric current (Q = I² X R X t).

Given that the amount of heat generated in a conductor is directly proportional to the conductor's resistance, squared current, and time, poorly made connections with thin wires will waste a significant amount of energy. Therefore, special attention should be paid to the quality of the electrical circuit.

In this article we will answer in detail the question: “How to make spot welding at home?”

Due to its simplicity and convenience, spot welding has become widespread

There are three types of resistance welding: spot, seam, butt. A spot welding machine welds parts at one or several points simultaneously. The structure of the welding point depends on the size and shape of the contact surface of the electrode and determines the strength of the connection. A spot welding machine is a type of resistance welding, which is why its technology is based on the thermal effect of electric current.

Brief spot welding technology

Spot welding technology involves several stages. The parts to be joined, aligned in the desired position, must be placed between the electrodes of the welding equipment, pressing them against each other.

The need to press the parts is explained by ensuring the formation of a sealing belt around the molten core. At the moment of the welding pulse, the formed belt prevents the splash of molten metal from the welding zone.

Next, the parts should be heated to a state of thermoplasticity, this is necessary for their deformation. To ensure high-quality precision welding at home, it is necessary to maintain a constant speed of movement of the electrodes, the required pressure value and ensure full contact of the parts being connected.

A spot welding machine heats parts due to a short-term pulse generated as a result of the passage of welding current. This impulse promotes the melting of the metal at the points of contact with the electrode, forming a common liquid core of the parts. The diameter of the formed core reaches 4-12 mm.

Once the current stops, the parts will continue to be held until the molten core cools and crystallizes. Spot welding technology at home is very economical and can provide mechanical strength to the seams. As for the tightness of the seam, this cannot be achieved with such equipment.

Welding processes, the equipment used, as well as safety precautions are strictly regulated by GOSTs. You can check out some of them:

GOST R. ISO 17659-2009 (will help define terms for welding joints);
• GOST 5264-80 and GOST 11534-75 are designed for manual welding;
• GOST 10157-79 and GOST 5583-78 regulate technical conditions;
• GOST 15878-79 regulates structural connections of contact welding;
• GOST 2601-84 (welding of metals, basic concepts);
• GOST 19521-74 - Metal welding and classification.

Homemade spot welding machine design

Such equipment cannot be called powerful. Using it, you can weld a sheet of metal with a thickness of 0.2 mm or steel wire with a diameter of 0.3 mm. Such parameters allow welding thermocouples, as well as welding thin parts made of foil. The welding electrode is made of a gun, since the clamping force of the small-sized parts being welded is small.

Making welding equipment according to this scheme is quite simple. The main equipment unit is the T2 welding transformer. The welding electrode is connected to the secondary winding of the transformer using a flexible cable. As for the larger piece being welded, it is connected to the lower end.

The welding machine is connected to the network using a V5V8 rectifier bridge. The second diagonal of this bridge is designed to turn on thyristor V9; when it opens, voltage is applied to the primary winding T2. In this case, resistance welding pliers act as a gun.

Their technological feature lies in the attachment of a gun to one end of the secondary winding of the transformer, as for the second end, it is attached to the resistance spot welding product itself. Thus, the pliers can perform welding work anywhere on the product using a single electrode. Resistance welding pliers can operate on single-phase or three-phase current.

The transformer from which the resistance welding pliers receive power produces a current of several kiloamperes.

In the handle of the welding gun there is a button S3, when pressed, the thyristor is controlled. When the auxiliary source is connected to the network, capacitor C1 begins charging immediately. Transformer T1 and rectifier bridge V1V4 are an auxiliary source.

Detailed diagram of the point apparatus

The T1 welding machine is turned on by closing the diagonal of the V5V9 bridge with an open thyristor. The thyristor will remain open until capacitor C1 is completely discharged. Variable resistor R1 is provided to adjust the discharge time of the capacitor. To prepare the next welding pulse, button S3 must be released, at which time capacitor C1 will be charged. The next pulse is generated when pressed again.

Transformer T1 can be any low-power one (510 W). The maximum welding duration, with the specified ratings C1 and R1, will be 0.1 seconds.

This provides a welding current of 300500 A, which is quite sufficient when welding small-sized parts.
In this example, the transformer is made of iron.

The thickness of the set is 70 mm; PEV-2 0.8 wire containing 300 turns was used as the primary winding. The diameter of the stranded wire of the secondary winding is 4 mm.

DIY welding machine

The basis of the welding machine is a three-phase step-down transformer. Without disassembling the core, you need to cut through the copper busbar and remove the secondary windings from all coils. The primary wires remain intact, but the middle wire must be rewound with the same wire, forming taps every 30 turns. There should be 8–10 of them in total.

Using a three-phase multi-core power cable, wind the secondary winding around the two outer coils until they are completely filled. The cable should consist of wires D – 6-8 mm, and one of them should be thinner. It is reliably insulated and can withstand high current.

Due to the flexibility of the wire, winding can be carried out without first disassembling the equipment. You will need approximately 25 meters of cable. If necessary, it can be replaced with a wire of a smaller cross-section; in this case, when winding, the cores must be folded in half.

It will be difficult to cope with such a task alone. It is recommended that two people do the work: one pulls the wire, the other lays the turns. To make terminals, you will need a copper tube D - 10 - 12 mm and 30 - 40 mm long.

One side of the tube needs to be riveted, and a hole D – 10 mm must be drilled in the resulting plate. Wires are inserted into the other side and should be thoroughly cleaned. Using a hammer, you need to crimp the stripped wires.

To improve contact, notches need to be made on the surface of the tube.

The standard screws with nuts located on the top of the transformer must be removed and replaced with two new ones with M10 threads, attach the secondary winding terminals to them. A separate textolite board must be attached to the transformer. This is necessary for the primary winding terminals. Before attaching the board, you need to drill 11 holes D - 6 mm in it. and insert screws with two washers and nuts into them.

This is the aesthetic appearance a do-it-yourself spot welding can have

The electrical holder is a 3/4 pipe 250 mm long, with notches cut out on both sides. To ensure free pressing of the electrode, a piece of steel wire is welded to the holder. A hole is drilled on the opposite side and a piece of the same cable that was used for the secondary winding is connected. The pipe must be hidden with a rubber hose of suitable diameter.

Please note: the welding machine is used for a small amount of welding work, so after working with 10-14 electrodes, it needs to be allowed to cool.

A multi-spot welding machine, unlike a spot welding machine, works with workpieces of certain sizes and shapes. A universal multi-spot resistance welding machine is quite rare. Re-adjusting this device is a rather complex and lengthy process.

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.

How to make spot welding with your own hands - Machine tools, welding, metalworking

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.

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://stanki-info.com/kak-sdelat-tochechnuyu-svarku-svoimi-rukami/

How to make your own spot welding from a microwave transformer

The topic of the article is for handy craftsmen, spot welding - we make the device with our own hands from improvised means. And a used microwave oven will help us with this. Or rather, a high-voltage transformer from it, which is suitable for connecting thin sheet metal at home.

Just don’t have to run headlong into the kitchen to disassemble your microwave. You can ask your neighbors for experimental material, find it at a landfill, or buy it second-hand for cheap.

How to mount a transformer correctly

So, we make spot welding with our own hands from the microwave. We need a transformer that consists of a welded core and primary and secondary windings.

We take it out of the old cracked oven. The desired transformer power is from 800 watts, the more powerful the better.

We will need a core and a primary winding (with a thicker wire). We remove the secondary winding, for example, cut it off with a chisel or saw it with suitable tools.

Sometimes, in the case of a tight fit of the secondary winding, in order to remove it, you have to disassemble the core and then glue it together.

After removing unnecessary junk, we take a copper cable (with a cross-section of 16mm2, determined experimentally) and wind 2 turns in the transformer windows.

We securely attach copper lugs to the ends of the cable.

So, the main part for homemade spot welding from the microwave is ready. We are thinking about the design of the future structure.

Appearance of the device

If the head works and the arms grow correctly, then the entire structure can be made of metal (reliably and beautifully). Let's look at a complex circuit first.

Internal structure of the device:

• transformer from a microwave with a wound copper wire;
• terminals for copper wire;
• 20 ampere circuit breaker for de-energizing the network;
• terminal block for connecting wires;
• computer fan with 12 volt transformer;
• diode bridge with capacitor;
• relay REK 74;
• 2 indicator lights;
• microwave button.

External microwave spot welding design:

• base with side walls;
• closing lid with handle;
• corners with bolts;
• 2 pieces of profile for pliers;
• soldering iron handle mounted on a hexagon while hot;
• spring from carburetor;
• electrodes are attached to the corners.

The angles allow you to change the angle of the electrodes for precise contact. Electrodes can be made from a soldering iron tip with sharp or blunt tips; in the case of welding different materials, it will be possible to change them. At the attachment point, the electrode rod is thinner with a thread cut for the nut.

Watch the video to learn how to make this type of spot welding yourself.

I understand that not everyone will make such a design. Therefore, we will consider simpler options for a do-it-yourself spot welding machine.

Simple welding machine body

A wooden structure is the simplest design that anyone can make. The photo below shows design ideas.

Let's take the last option as a basis: take a tape measure and take the dimensions of the prepared microwave transformer. Based on the measurements taken and our idea, we prepare wooden blanks for the device.

We make the upper lever (do-it-yourself spot welding pliers) with a recess. This is if you make a device with a closing lid. If the device is planned to be open, then a recess is not needed.

On the back wall we cut out suitable holes for the power button and wiring.

For beauty lovers: the blanks for the device can be painted in your favorite color.

Also, for do-it-yourself spot welding you will need the following materials:

• switch;
• handle for closed structure;
• circuit breaker (micrik);
• power cord.

Take these accessories from the disassembled microwave.

Also needed:

1. electrodes can be made from a soldering iron tip or thick copper wire;
2. copper holders for attaching electrodes (you will have to buy);
3. self-tapping screws for assembling the structure.

We insert the prepared electrodes into the holders and clamp them with a screwdriver.

We secure the back wall with the screwed switch and power cord to the main board with self-tapping screws.

We also attach the microwave transformer with self-tapping screws to the base of the device. We screw one of the screws with a grounding wire, which we connect to the switch.

Also, we run a wire from the switch to the transformer, and we lead the second wire from the transformer to the circuit breaker, which we borrowed from the microwave.

You can do without a circuit breaker installed in series in the electrical circuit. It serves for convenience and is installed on the upper arm of the spot welding machine.

Using wooden blanks and self-tapping screws, we close the electrical part. The top board must have a handle for carrying the device.

Device levers

Next, we think over the design and attach the levers (pliers) for spot welding with our own hands. First, we drill holes for self-tapping screws at the ends.

We attach the electrical circuit breaker to the upper lever with a convenient slope.

We insert the pliers into the device and determine the attachment location by eye. We drill through holes in the side walls and levers, and secure them using metal rods.

Using self-tapping screws, we attach the holders with contact electrodes to the end part of the pliers.

After assembly, the electrodes usually face in different directions; we bend them with our hands to center them.

To raise the upper arm, we screw it into it and into the body of the device using a self-tapping screw, not completely, and attach a spring or a tight rubber band to them.

Trying a welding unit

Our spot welding is ready, we are testing the machine. Turn on the power and press the breaker with your thumb.

Sparking appears between the electrodes, but this cannot be done.

Thin sheets of metal can now be reliably joined with our device. If you have a vehicle, then homemade spot welding for welding a car will make it easier to repair the body.

To do this, we made the levers removable; just pull out the metal rods and remove the pliers to weld large-sized metal and you can crawl into hard-to-reach places.

Also, there is a plus in removable electrodes, which are easy to replace if necessary.

will tell you about the correct winding of a transformer and show the entire process of assembling a resistance welding machine.

Source: https://plavitmetall.ru/svarka/tochechnaya-apparat-svoimi-rukami.html

How to make spot welding yourself

Translated by Creator for mozgochiny.ru

In this brain project, I want to tell you how to make a resistive spot welding machine with your own hands

I plan to use it to weld nickel plates to an 18650 battery, but depending on the position of the electrode holder, the machine can be used to weld sheet metal and other metal objects. Now let's start making the device!

Step 1: Disassembling the microwave

Warning!
There is a danger inside the microwave oven. A large capacitor may be charged and is a potential source of dangerous or fatal electrical shock. Therefore, you should discharge it as quickly as possible by short-circuiting the capacitor terminals using the metal blade of a screwdriver.

So, remove the microwave cover to get to the electronic components of the device. Discharge the capacitor as stated earlier and begin dismantling the microwave parts.

Find a transformer that should look something like the one shown in the photo. Unscrew the nuts and it should come out quite easily.

I also removed some limit switches that will be used later and some power cables.

Step 2: Removing the Secondary Winding

It is necessary to rewind the secondary winding if we need to get more current and less voltage. The primary winding is where the power is supplied and the secondary has a thinner winding wire with red wires attached.

Fewer turns of wire increases the current but decreases the voltage, and more turns increases the voltage but decreases the current. We do not need the secondary winding of the transformer, so it must be carefully removed. Be careful not to damage the primary winding.

Step 3: Adding a New Winding

The new winding will provide the necessary current for the operation of our welding machine. Choosing a thick cable will allow you to reduce the number of turns from thousands to just a few and still provide the required current load. A thick cable has good insulation, which will not melt when heated, as in a thin cable.

First install the primary winding, followed by 2 shunts on each side and then wrap a couple of turns of blue cable on top. Be sure to leave enough cable length to attach the welding electrodes.

Step 4: Completing the Transformer Fabrication

Our super powerful transformer is almost ready. The top part needs to be welded back. Alternatively, you can use a 2-part epoxy to glue it in place. There is a choice, use the method that suits you best!

Step 5: Electrode Leads

Now we need to attach the ends of the cable to the copper bushings that will be used for welding. I turned the copper bushings on a lathe. But you can use copper clamps from a hardware store for this purpose. I have also attached a CAD file for making the electrode clamp.

Step 6: Welding Holder

I will use a welder to weld the nickel plates to the battery. For this purpose, I will place two welding electrodes side by side, although you can easily place them opposite, like in a traditional welder. I designed and laser cut a fiberboard base for the holder that will hold the switch and electrode leads.

Step 7: Completing the Project

The transformer is supplied with a dangerous voltage of 230 V, so it is very important to close the transformer. A laser cut enclosure can be perfect for this purpose. Make sure all live parts are covered. This will ensure your safety when working with the device.

To connect the phase and neutral to the primary winding of the transformer, use the existing contact plates. I recommend installing a switch between one of the power cables to easily turn the device on and off. I used the switch from the microwave.

Your device is now ready. Time to start spot welding !

(Az Source)

Source: https://steelfactoryrus.com/kak-sdelat-tochechnuyu-svarku-svoimi-rukami/

How to make a spot welding machine with your own hands at home: features of the device

Sooner or later, many people have a desire to purchase their own welding machine. But, unfortunately, such equipment is highly expensive, so many people prioritize making a homemade device. With the help of freely available diagrams, drawings and other step-by-step guidance, the upcoming event can become very simple and understandable .

Currently, resistance spot welding is in great demand and is used in a wide variety of human activities. The tool is indispensable when repairing or producing metal parts. It can also be used for the manufacture of metal stairs, gates, individual structural elements and other parts.

The operating principle of resistance welding is as follows: the electric current present in the key unit is capable of heating individual parts of a steel workpiece that are connected to each other. In this way, a special welded joint is formed - a seam. The quality of the result is determined by the type of material from which the product is made, as well as the density. In addition, when carrying out welding activities, you should pay attention to the following features:

1. The welding circuit must have low voltage levels - from 1 to 10 watts.
2. The welding process continues for several seconds.
3. The welding pulse is characterized by high current strength.
4. The smaller the melting zone, the higher the welding quality.
5. The weld must cope and withstand heavy loads.

The final result of welding activities depends on the correct observance of such rules . Making a device with your own hands is quite difficult. In order for the task to be completed successfully, it is necessary to precisely learn a number of specific instructions and technological recommendations.

A simpler solution is to build a variable current . Such a device is capable of controlling the welding process by changing the duration of the welding pulse that hits the workpiece. In addition, in order to successfully complete the task, it is necessary to equip a clock relay, which can be controlled automatically or manually.

Important design properties

The key component of a spot welder is the welding transformer, which is often found in microwave ovens, televisions and other equipment. Rewinding of the winding is carried out only after determining the ratio of the required current and voltage, during the supply of which welding occurs.

To choose the appropriate device control option, you need to correctly assemble the basic mechanisms . It is no secret that structural parts are selected taking into account the power and parameters of the transformer.

In the manufacture of resistance welding systems, the relationship between the type of application and the properties of the material that can be processed is taken into account. In most cases, welding pliers are attached to the main device.

When performing any assembly work, be extremely careful and thorough. The build quality must be maximum , otherwise further operation may become problematic. Wires are selected with the appropriate diameter and cross-section. If the circuit reliability is not good enough, the intensity of the required electric current will not be stable. In addition, there is an increased risk of sparks causing workers to stop welding.

To make resistance spot welding yourself, carefully study the corresponding diagrams. The most popular of them is effective in situations where it is necessary to process metal sheets with a thickness of one millimeter or wiring and rods with a diameter of up to 4 millimeters.

In this case, it is necessary to take into account the following features:

1. For welding, you should acquire equipment with an alternating voltage of 220 W.
2. As for the output voltage type when idling, it is 3-7 V.
3. The maximum welding current reaches 1.5 thousand amperes.

The entire design is characterized by a circuit diagram, which consists of power parts, an automated switch and a control circuit. If dangerous situations arise while performing a task, all you have to do to prevent them is press the switch. The first node is equipped with a transformer for welding T2 and a non-contact thyristor switch of a single-phase type, which connects the primary winding to an electrical power source .

As for the second scheme, it requires the implementation of a characteristic winding on the welding transformer using certain turns. On the primary winding there are lead-out sections, which are intended to adjust the output welding current taking into account the ratio of the secondary winding. Thus, the permanent connection of the network circuit remains at the first pin, and the operation of the power supply is regulated through the others.

An important part of the system marked M TT4 K is distinguished by mass production. This module contains a thyristor switch that switches the load through contacts 1 and 3. The device can operate under loads with voltages up to 800 watts and currents up to 80 amperes. The composition of the scheme includes:

1. power unit.
2. chain for setting the mechanism.
3. relay k1.

Any transformer system with a power of up to 20 watts is used as a source of electrical power for welding equipment. At the same time, it is used when operating on a nominal network of 220 V. As for the voltage that is supplied on the second version of the winding, its indicators reach 22 V. To rectify the intensity of the current supply, you can install a diode bridge . The option of using any other nodes with similar parameters is also not excluded.

Device features and design

Currently, there are several functions of the control circuit. If it is necessary to turn on k1 for a given period of time, you need to set this period correctly, determining the specific time for applying electronic pulses to the elements being welded.

The electrical circuit design contains capacitors: from c1 to c6 with characteristic electrolytic properties. Their voltage is 52 V. In addition, it is necessary to use a capacitor with a capacity of 46 μF .

The main power unit of the mechanism is the transformer. It acts as a converter from one type of electricity to another. In this case, it is customary to use a 2.5 A magnetic wire.

It is better not to use the old winding, but to install rings made of electrical cardboard at the end of the magnetic wire. They are folded along the inner and upper edges. The next step is to wind the magnetic circuit with lattic fabric in three or more layers.

To successfully complete the winding, you should use the following wires:

1. primary winding with a diameter of 1.5 millimeters, which is impregnated with a varnish composition.
2. the second version of the winding with a diameter of about two centimeters, which is equipped with multi-core insulation of organosilicon origin.

When making the first winding, it is important to arrange intermediate type terminals. Then the winding is impregnated with a special varnish, and a cotton tape , which is also impregnated with a varnish composition. Then the process of secondary winding begins, as well as further impregnation with varnish.

If you want to make homemade spot welding, you must take a responsible approach to the design of the pliers. Today, two types of such elements are used:

The first solution is characterized by ease of operation, as well as high-quality and reliable insulation, which is due to firmly connected node sections. True, such pliers are characterized by one drawback - in order to provide clamping force, you need to apply physical force.

The version of external pliers is particularly easy to use and compact in size. To control the efforts of the pliers, it is enough to change the length of their extension behind the device. Bolts, bushings and washers are installed at the connections of such parts for more reliable waterproofing.

When making parts, it is customary to use copper rods or beryllium bronze . You can also use a tip from a soldering machine with high power ratings. As for the diameter of the electrode, it must match the diameter of the wire to which it is connected.

In order for the welding cores to have good quality, the ends of the electrodes are narrowed and made small.

Microwave spot welding

It's no secret that purchased models are very expensive, so it makes sense to give preference to homemade solutions. To make a productive installation, you can use a large microwave oven. It is the dimensions that determine the power of the future device .

If you don't have a microwave, try looking for one at a flea market or buying one from your neighbors. Such a purchase will not be a big investment. In the future, all that remains is to disassemble the microwave and remove the high-voltage transformer from it.

Be careful, because even in a disassembled state without a direct connection to the electrical network, individual components of the equipment may be electrocuted.

The main parts of the transformer are represented by a core and two types of winding - primary and secondary. To connect the core, you can use two thin welds. Get rid of them in advance, which can be done with a hammer and a hacksaw. You can also use a grinder, which will allow you to get to the transformer windings without damaging them. To remove the secondary winding, just cut the secondary with careful movements.

Ultimately, you will have access to the core from the transformer, which consists of two parts.

The next step is to carry out the secondary winding of the transformer part. Here you will need to use a copper cable with the same cross-section as the transformer slot. It is necessary to wind about two turns. Using standard two-part epoxy resin, join the two halves of the core together. To make the process especially successful, try fixing them in a vice.

Don't forget to check the voltage level at the output of the transformer mechanism. It should not exceed the 2 volt mark. In this case, the minimum current value varies within 850 A.

Then you need to start manufacturing the body of the welding material. At this stage, you can use wood or high-strength plastic. There are several holes on the back panel. One of them is responsible for the electrical supply, and the second is for turning the system on and off.

Conclusion

If the body part is dry, you can proceed to assembling the device by connecting the working units together. Then you need to cut two pieces of copper wire with a size of about 25 millimeters.

They act as electrodes, which are fixed in the holder using a regular screwdriver. Then you need to secure the switch with a thick cable, which will prevent it from falling out. The transformer is fixed using ordinary self-tapping screws.

It is also important to take care of the grounding, which is fixed to one of the terminals.

If you carefully follow all the recommendations and step-by-step instructions, the process of assembling the welding machine will be successful. In this case, you can reduce all costs, depriving yourself of the need to buy expensive professional equipment.

Source: https://tokar.guru/svarka/izgotovlenie-tochechnoy-svarki-svoimi-rukami.html

How to make spot welding from a microwave or battery with your own hands

Arc welding machines are used in everyday life. Such devices are easy to find on the open market, and they have a relatively low cost. However, situations arise when resistance welding may be necessary. This device has a fairly high cost, and its purchase may not be profitable. To save money, spot welding is done by hand.

Features and principle of operation

Spot welding works using a powerful short-term electrical pulse supplied to the electrodes from an inverter. The parts are heated to their melting temperature, then they are connected to each other. At the junction site, a strong weld remains between the two electrodes. The peculiarity of the work is that the place of spot welding is limited by the diameter of the electrode used.

Before combining the two metal parts, they are pressed tightly against each other. After resistance welding, they need to be kept under pressure.

Spot welding allows you to weld metal in small areas of a car body during body work, solder wires and small parts together, and repair electronics.

How to make spot welding with your own hands from a microwave

A mini resistance welding machine is made with your own hands from some microwave spare parts. For a homemade unit you will need to remove the following components:

1. Transformer.
2. Switch.
3. Power cord.

Removing the transformer

The separation of the transformer from the microwave is carried out according to the following algorithm:

• The microwave oven is disassembled.
• All fastenings are removed.
• The transformer is removed from its seat.
• The microwave parts necessary to create a device for spot welding are dismantled.

The extracted transformer has a power of 700-800 watts. This is enough to ensure the connection of metal sheets up to 1 millimeter thick. To manufacture a more powerful spot welding machine, this part is being modernized.

On a transformer, the primary and secondary windings differ in thickness and number of turns. The secondary winding is removed from the part using a chisel and hammer. In this case, all operations are carried out carefully, otherwise the magnetic circuit may be damaged. In this case, the transformer will be damaged.

Instead of the dismantled winding, use a wire whose thickness is at least 1 cm. 2-3 turns need to be wound around the core. This simple upgrade allows you to increase the output voltage to 1000 A.

For a spot welder with increased power, two connected modernized transformers are used.

Transformer Upgrades

When creating spot welding from a microwave, it is necessary to upgrade the welding transformer:

• When dismantling the secondary winding, limiting shunts can be found. They are also removed.
• The fewer turns of the new secondary winding are created, the lower the resistance of the wire will be, and the greater the current. The cable should not be excessively long.
• When winding a new secondary winding wire, difficulties may arise due to the thick insulation. Care should be taken to replace the standard rubberized insulating layer with electrical tape that has a fabric backing. Such a wire should provide an output voltage of 2V and a short-term current of 800A.
• The performance of the point device depends on the correct connection of the two transformers. The elements are connected in a circuit. It is necessary to correctly connect the primary and secondary windings of the transformers. This can be done using special markings. If they are missing, then measurements must be taken using a voltmeter.
• The design of a spot welding machine used in home workshops involves the creation of a device with a power of no more than 2000A. Otherwise, there will be a load on the home network, which will lead to power outages. This circuit also involves checking the current strength and the presence of short circuits using an ammeter.

After creating the electrical part, install the grounding and switch of the spot welding machine. The part is taken from the microwave. Next, the body, levers, holders and electrodes are made.

Making the holder

A homemade spot welding machine is equipped with control levers. They can be made from high-strength plastic or wood. To lift the levers, use a regular rubber band; fasteners for electrodes are installed at the ends of the parts. The holders are not screwed to the device, and this is due to the fact that in some cases, to perform contact welding, you will need to use each element separately. The levers are fixed with a screwdriver or nail.

Battery spot welding

When creating spot welding, car batteries are also used. This device is used when soldering batteries and connecting small parts when repairing electronics. The design of the resistance welding machine consists of a power source, a relay, a special block and two copper wires. The working ends of the wires are stripped and act as electrodes.

Electronic repairs and complex body work involve the use of spot welding. The welding seam is strong, and the small working area allows resistance welding of small parts.

However, a serial resistance welding machine is quite expensive. It is cost-effective to create spot welding from a microwave or welding machine with your own hands.

If you follow all the nuances of design and safety precautions, you will get a functional device capable of fastening sheets of metal up to 5 millimeters thick.

Source: https://InfoKuzov.ru/material-instrument/kak-sdelat-kontaktnuyu-svarku