The work of cutting metal sheets is not so easy to do without special equipment. Therefore, all home craftsmen who are faced with a similar task should take care to have in their arsenal such a tool as a manual plasma cutting. This equipment is compact in size and allows you to easily cut iron sheets into pieces of a suitable size at home.

This tool has many advantages, the main one of which is that while dividing the workpieces into segments, the owner will not have to subsequently process the edges of the parts. To simplify the work with this equipment, it would be useful every home craftsman get an idea about the existing varieties of these devices, their design, operating principles and selection rules.

Equipment for plasma cutting of metal

The whole variety of such instruments can be classified into two main groups:

• production;
• home use.

The peculiarity of the devices representing the first group are big sizes and significant weight. Their design includes CNC (computer numerical control). This device simplifies the production of parts of various shapes.

Working with such equipment involves developing a layout using special software. It is this that you will subsequently have to focus on while performing the work. After that the file created in the required format is sent to the machine, and there it is already being cut off. It is worth noting that such equipment is not cheap: the price of these units can reach tens of thousands of dollars.

Devices designed for plasma cutting at home have a simpler device. In their execution they have compact block type, which is powered by electricity and is equipped with components such as a hose and tip to produce an electric arc. It is thanks to her that cutting is performed.

The arc also allows you to separate iron sheets and ensure high quality edges. Considering that an unusual tool in the form of a hacksaw or disk is used to cut the workpiece, the owner will not have to waste time and effort on additional grinding of parts. Equipment for home use It is attractive because it can be transported to any place, as well as stored and used for a long time.

The models of plasma cutting devices offered on the market are designed to work with different types of materials, which is determined by the type of gas that is present in the mechanism. Using air-plasma type installations, you can practice cutting blanks from ferrous metals and their alloys. If the task arises of separating parts made of non-ferrous metals and their combinations, it is advisable to use equipment that uses inactive elements such as hydrogen, nitrogen or argon. However, this type of gas cutting is rarely used at home.

Difference between direct and indirect devices

Today you can find various versions of hand-held devices that implement different operating principles. The operation of direct-acting units is based on the use of an electric arc. Last looks like a cylinder, and a gas stream is directly supplied to it. Thanks to this design, the arc heats up to high temperatures of about 20,000 degrees. And at the same time, it is able to effectively cool other elements of the device.

If we talk about indirect installations, then their feature is lower efficiency. This is precisely the reason why they are not used so often.

Speaking about their design, it should be noted that the main goal here is to place the active points of the chain on the pipe or special tungsten electrode. Indirect-action equipment has become widespread for spraying and heating metal devices, and they are not used as cutting equipment. For the most part, with the help of a similar manual mechanism, automotive components are repaired without resorting to removing them from the body.

However, such installations have one common feature: they can only operate with air filters and coolers. The benefit of the former is to increase the service life of the cathode and anode, accelerating the start-up of a mechanism that has been in operation for quite a long time.

As for the second element, it is necessary to increase the operational life of the device operating in continuous mode. Optimally when within an hour of continuous cutting with this machine allocate about 20 minutes for rest. These characteristics are very important and must be taken into account regardless of the type of design of the selected device.

Design of a manual plasma cutter

The ability of such a device to perform its function is ensured by the supply of highly heated air to the metal sheet. At temperatures reaching several tens of thousands of degrees, at which oxygen is heated, the latter reaches the surface under high pressure, which leads to its cutting.

Faster execution of this operation is ensured by taking into account ionization by electric current. The service life of such equipment can be extended provided that the following elements are present in its equipment:

• Plasma torch. It has the appearance of a cutter whose responsibilities include performing basic tasks;
• Plasma cutter. This device can be made in the form of direct or indirect impact;
• Nozzle. This device is superior in functionality to all other pieces of equipment. It makes it clear what kind of cutting complexity a particular model is designed for;
• Electrodes. They are equipped with certain types of devices;
• Compressor. With its help, a powerful air flow is created.

How to make a plasma cutter from an inverter - instructions

If desired, any owner can make such equipment with his own hands. However, in order for a homemade plasma cutter to do its job effectively, all the rules must be followed. In a case like this the inverter will be practically irreplaceable m, since with the help of this device a reliable supply of current will be ensured. Due to this, there will be no interruptions in the operation of the plasma cutter, and it will also be possible to reduce energy consumption. However, it also has disadvantages: it is designed for cutting material of a smaller thickness than when using a transformer.

Selecting elements

If you decide to make a plasma cutter yourself, then you should prepare the necessary materials and equipment:

Assembly

Even before you start assembling a homemade plasma cutter, it doesn’t hurt to find out whether the components you purchased are compatible with each other. If you have never made a plasma cutting machine with your own hands before, it is advisable to seek help from more experienced craftsmen.

After analyzing the power of each element needed, they will give you their recommendation. Definitely worth taking care availability of protective clothing. You will have to use it when the time comes to test the performance of a homemade plasma cutter. If we talk about the procedure for assembling plasma cutting equipment, it includes the following steps:

Regardless of whether you plan to make a plasma cutter with your own hands or buy it in a store, you should first study all the models, get acquainted with the principles of their operation and design options. An important point is the type of material that is planned to be cut using this equipment in the future. You can simplify your selection task if you first watch a video that shows the operating principle of a manual plasma cutting machine and the technology for working with it.

Average cost of equipment

Available in stores today a large number of equipment for manual cutting of metals, which are offered at different prices. Moreover, the cost of these devices will be influenced by several factors:

You can avoid mistakes at the stage of choosing a tool for cutting metals, provided that you visit several stores and compare the conditions under which they are willing to sell this equipment to you. Considering various models of plasma cutters, you should immediately inquire about the prices of components, which you cannot do without if you have to repair this equipment. On average, the prices of spare parts for plasma cutters, taking into account the thickness of the cut, are in the following range:

• With a thickness of no more than 30 mm – 150–300 thousand rubles;
• With a thickness of no more than 25 mm – 81–220 thousand rubles;
• With a thickness of no more than 17 mm – 45–270 thousand rubles;
• With a thickness of no more than 12 mm – 32–230 thousand rubles;
• With a thickness of no more than 10 mm – 25–20 thousand rubles;
• With a thickness of no more than 6 mm – 15–200 thousand rubles.

Conclusion

Equipment for plasma cutting of metals is a high-tech device that can significantly simplify the work of cutting various metal products. Moreover, it is by no means necessary to purchase expensive equipment in a store; each owner can make this device on his own.

All you have to do is prepare everything necessary equipment and follow the plasma cutter assembly technology exactly. Even a home-made plasma cutter can provide the same quality of cutting steel parts as the equipment offered in stores.

Plasma cutting of sheet metal is usually used in large industries for the production of complex parts. You can cut any metals on industrial machines - regular and stainless steel, aluminum, copper, brass, super-hard alloys. You can also make a plasma cutter with your own hands, and it’s a completely workable design, albeit with somewhat limited capabilities.

It will not be suitable for large-scale production, but cutting out several parts in a metalworking workshop, metalworking shop or at home, in a garage, for example, will always work. At the same time, there are practically no restrictions on the complexity of the configuration and hardness of the metal being processed. Limitations relate to metal thickness, sheet size and cutting speed.

The easiest way to build a plasma cutting machine is based on an inverter welding machine. A do-it-yourself plasma cutter made from an inverter is distinguished by its relatively simple design, operability, and accessibility of main components and parts. Those that cannot be purchased can be made independently in a workshop with average equipment.

A homemade plasma cutting machine is not equipped with a CNC - this is its disadvantage and advantage. The disadvantage is that it is difficult to produce two absolutely precise parts when operated manually. Even small series of blanks will differ in some way.

The advantage is that you don’t have to buy one of the most expensive units. Not every highly qualified engineer can make it, and assembling it from ready-made components is the same as buying a new device. A mobile cutter does not need a CNC due to the other tasks it performs.

The main components of a homemade plasma cutter are:

• DC source;
• plasmatron;
• oscillator
• compressor or compressed gas cylinder;
• connection hoses;
• power cable.

As you can see, the device does not include anything particularly complicated. But difficulties begin upon closer examination of the characteristics of a particular unit.

Current source

The characteristics of plasma cutting require that the current be at least at the level of a medium-power welding machine. This current is generated by a conventional welding transformer and an inverter machine. In the first case, the installation will be conditionally mobile - the large weight and dimensions of the transformer will make it difficult to move. In combination with a compressed gas cylinder or compressor, the system will turn out to be quite cumbersome.

In addition, transformers are characterized by low efficiency, which will lead to increased energy consumption when cutting metal. The circuit using an inverter is somewhat simpler and more convenient to use, as well as more energy efficient. A welding inverter will produce a fairly compact plasma cutter that can easily handle cutting metal up to 25-30 mm thick. It is for these thicknesses that industrial installations are used. the transformer will be able to process thicker workpieces, but this is required less often. All the advantages of plasma cutting are manifested precisely on thin and ultra-thin sheets. This:

• line accuracy;
• smooth edges;
• no metal splashes;
• there are no overheated zones near the interaction between the arc and metal.

A homemade plasma cutter is assembled on the basis of any inverter welding machine. The number of operating modes does not matter - only direct current with a power of more than 30A is needed.

Plasma torch

The second most important element of the plasma cutter. Let's briefly consider the principle of its operation. A plasma cutter consists of two electrodes, one of which, the main one, is made of refractory metal, the second is the nozzle. It is usually made from copper. The main electrode serves as the cathode, the nozzle as the anode, and during operation, the current-conducting part being processed.

In this case, we are considering a direct plasma torch for cutting metals. An arc occurs between the cutter and the workpiece. There are also indirect plasma torches that cut with a plasma jet, but they will be discussed below. The inverter plasma cutter is designed for direct action.

In addition to the electrode and nozzle, which are consumables and can be replaced as they wear out, the plasma torch body contains an insulator that separates the cathode and anode units and a small chamber in which the supplied gas swirls. A thin hole is made in the conical or hemispherical nozzle, through which gas heated to a temperature of 5000-3000 0 C escapes.

Gas is supplied to the chamber from a cylinder or from a compressor through a hose combined with power cables, which form a hose-cable package. They are connected in one insulating sleeve, or connected in the form of a bundle. Gas enters the chamber through a straight pipe located on top or side of the vortex chamber, which is needed so that the working medium moves only in one direction.

How does a plasma torch work?

Gas, entering under pressure into the space between the nozzle (anode) and the electrode (cathode), quietly passes into the working hole and escapes into the atmosphere. When the oscillator, a device that generates a pulsed high-frequency current, is turned on, an arc appears between the electrodes, which is called a preliminary arc and heats the gas located in the limited space of the combustion chamber. The heating temperature is so high that it turns into another type of physical state - plasma.

This type of material state is distinguished by the fact that almost all atoms are ionized, that is, electrically charged. In addition, the pressure in the chamber increases sharply and the gas rushes out in the form of a hot jet. When the plasma torch is brought to the part, a second arc appears, more powerful. If the current from the oscillator is 30-60 A, then the working arc occurs at 180-200 A.

This arc additionally heats the gas, which accelerates under the influence of electrical forces to an extremely high speed - up to 1500 m/s. The combined effect of the high temperature of the plasma and the speed of movement cuts the metal in a very fine line. The thickness of the cut depends on the properties of the nozzle.

An indirect plasma torch works differently, in which a nozzle acts as the main anode. It is not an arc that escapes from the cutter, but a stream of plasma - a jet that cuts non-conductive substances. Homemade equipment with such plasma torches very rarely works.

Due to the complexity and subtle settings, it is almost impossible to make it yourself, despite the simple drawings that are available on the Internet. He works under high pressures and temperatures and becomes simply dangerous if something is done wrong. You can assemble a plasma cutter according to drawings with your own hands from ready-made parts that are sold in welding equipment stores. But, like most machines and mechanisms, assembly from components costs more than a complete cutter.

Oscillator

This is a kind of starter that serves to start the preliminary arc. For those versed in electronics, its circuit is simple. The functional diagram looks like this:

And the electric one is something like this (one of the options):

You can see how the homemade oscillator looks and works in the video. If you don’t have time to assemble electrical circuits and search for parts, use factory-made oscillators, for example VSD-02. Its characteristics are best suited to work with an inverter. The plasmatron power supply is connected in parallel or in series, depending on the requirements of the instructions for a particular device.

Working gas

Before making a plasma cutter, you should outline the preliminary scope of its application. If you are going to work only with ferrous metals, then you can only get by with a compressor. Copper, titanium and brass require nitrogen, and occurs in a mixture of nitrogen and hydrogen. High alloy steels are cut in an argon atmosphere. In this case, the device is also designed for compressed gas.

Assembling the device

Due to the rather complex and numerous components of a plasma cutting machine, it is difficult to place it in a portable case or box. It is best to use a warehouse cart to transport goods. On it you can compactly place an inverter, cylinders or compressor, cable and hose group. It is very easy to move them within a workshop or workshop. If you need to travel to another site, everything can be loaded into a car trailer.

Do-it-yourself plasma cutter from an inverter is not so difficult to assemble. It is important to provide the following elements:

• plasmatron, i.e. directly;
• power source, which is a welding inverter (a transformer can also be used);
• compressor for supplying a cooling air jet and forming a plasma flow;
• cable hoses for assembling and connecting individual elements into a single system.

Plasma cutters can be used for more than just cutting various parts, but also for welding.

A homemade plasma cutter can be used to perform a variety of jobs. This is not only production, but also household work, for example, processing of various metal workpieces, where precise, thin and high-quality cuts are required. There are models that can be used for welding in a protected gas environment using argon.

When assembling, attention should be paid to the current strength. The value depends on the power source; they prefer to use an inverter. It provides more stable operation, energy consumption is more economical than that of a transformer, although the thickness of the workpieces with which it can work is lower. Why an inverter? The thing is that it is more convenient to use than a transformer. Its weight is less, it is not so massive. Less electricity is consumed, while the efficiency is 10% higher, which has a positive effect on the quality of work.

Schemes for assembly can be used ready-made if the structural elements are purchased all together. You can take it from the Internet, especially when you already have all the parts and don’t need to buy anything. When assembling, attention should be paid to the accuracy and clarity of compliance with the diagram and the connection of individual elements. The nozzle should be long, but not too long, as it will have to be replaced quickly.

Selection of structural elements

Making a plasma cutter with your own hands from an inverter requires the following elements:

1. The power source for the equipment, in this capacity, is the inverter, which supplies current with the necessary characteristics to the plasma cutter. Instead of an inverter, if it is not available or cannot be found, you can use a transformer.
2. If a transformer is chosen instead of an inverter, it is necessary to take into account its heavy weight and too high power consumption.
3. Plasma torch, i.e. plasma cutter, which is the main element of the design.
4. Air compressor and cable-hose package.

What to choose as a current source for assembling a plasma cutter? The transformer is not the best the best option for a variety of reasons. It's not just his heavy weight, making it difficult to use the equipment after assembly, but also consuming too much electricity. The device turns out to be too expensive. Among the advantages, it should be noted that it is weakly sensitive to voltage changes in the network during operation. Such equipment can cut various workpieces, the thickness of which is significant.

An inverter as a power source is more preferable, it is more economical, and its cost is lower. In addition, the weight of the inverter is much less, and the device is easier to use after assembly. But the thickness of the workpieces cannot be too large. Such plasma cutters can be used in home workshops, in small production, since the power is quite enough for such a “modest” production. There is one more advantage in favor of the first. This is a level of efficiency that is approximately 30% higher for an inverter cutter, the arc is more stable, and the cutting quality is better. Such equipment is also more convenient for working in hard-to-reach places where transformers cannot be used. Plasmatron – main element cutter, its design includes a nozzle, an air supply channel (compressed to ensure cutting), an electrode, an insulator/cooler.

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Plasma cutter assembly

For a plasma torch, you need to select an electrode; it can be purchased from thorium, beryllium, zirconium or hafnium. Such materials are optimal for air plasma cutting. So-called refractory oxides appear on the surface of the electrodes during the cutting process; they prevent the electrode from being destroyed. When choosing, remember that some of these metals are dangerous for the welder. Beryllium causes the formation of radioactive oxides, and thorium causes toxic ones. It is best to use hafnium, it is absolutely safe for the operator.

When assembling, attention should be paid to the nozzle, with the help of which the cutting jet is formed. The jet characteristics, cutting time, and cutting width depend on the nozzle diameter. It is best to use products with a diameter of 3 cm; its length should be significant to ensure a better and more accurate cut. However, you cannot take a nozzle that is too long; it quickly collapses.

A compressor is required to supply air to the structure. The operating features of the cutter suggest that gases will be used for protection and plasma formation, while the work is carried out at a current of 200 A, but no more. To operate the device, compressed air is used; it is necessary to cool the equipment during operation and to form plasma. This option allows you to cut workpieces whose thickness is 50 mm. For industrial equipment, compressed air is not used; oxygen, helium, hydrogen, argon, nitrogen, and their mixtures are used here.

A special cable-hose package is used to connect the power source, plasmatron and compressor. The assembly order is as follows:

1. An inverter (or transformer) is connected by an electrical cable to an electrode to create an arc.
2. Compressed air is supplied through the hose from the compressor, it forms a plasma jet inside the plasma torch.

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How does a plasma cutter work?

After the plasma cutter is assembled, you need to check its performance. When turned on, the inverter begins to supply current to the plasmatron at a high frequency. An arc appears, its temperature at this moment ranges from 6000°C to 8000°C, it ignites between the nozzle tip and the working electrode. Next, compressed air begins to flow into the chamber, it passes through the electric arc from the nozzle, heats up, and increases in volume up to 100 times. The jet acquires conductive properties and is ionized.

The nozzle forms a narrow working flow, the speed of which is 2-3 m/sec. The temperature at this time rises greatly and can reach from 25,000°C to 30,000°C. The output produces high-temperature plasma used for cutting. When the plasma and the part come into contact, the initial duty arc goes out, and the cutting arc is lit, which processes the part locally. The metal melts only at the cut site; all molten metal particles are blown away by the air flow.

Using such a cutter from a conventional welding inverter allows you to get neat cuts in metal workpieces. During operation, it is necessary to ensure that the arc spot is strictly in the center of the cathode/electrode, for which the so-called tangential supply of the working air flow is used. If such an air vortex flow is disrupted during operation, the device will begin to operate unstably, and the quality of the cut will greatly deteriorate. It is important that during operation two arcs do not form at once, in which case the device will simply fail. The plasma cutter should not have too much air flow.

Speed ​​providing good quality, is equal to 800 m/sec, but the current strength should be up to 250 A, not higher.

But we must take into account that air consumption will be increased.

A plasma cutter, the main element of which is an inverter for arc welding, is used for cutting metal workpieces. The assembly is simple; the design includes such elements as a current source, a nozzle, a plasma cutter, and a compressor. When assembling, you should immediately decide on the power source; instead of an inverter, some prefer a transformer. All the advantages and disadvantages of the devices have been described above, you just have to make a choice.

Plasma cutting is actively used in many industrial fields. However, a plasma cutter is quite capable of being useful to a private master. The device allows you to cut any conductive and non-conductive materials with high speed and quality. The technology of work makes it possible to process any parts or create shaped cuts, which is carried out by a high-temperature plasma arc. The flow is created by basic components - electric current and air. But the benefits of using the device are somewhat overshadowed by the price of factory models. To provide yourself with the opportunity to work, you can create a plasma cutter with your own hands. Below we present detailed instructions with the procedure and list of equipment that is needed.

What to choose: transformer or inverter?

Due to the presence of features and parameters of plasma cutting devices, it is possible to divide them into types. Inverters and transformers have gained the most popularity. The cost of the device of each model will be determined by the declared power and operating cycles.

Inverters are lightweight, compact in size and consume minimal electricity. Disadvantages of the equipment include increased sensitivity to voltage changes. Not every inverter is able to function within the specific conditions of our electrical network. If the device’s protection system fails, you must contact service center. Also, inverter plasma cutters have a rated power limitation of no more than 70 amperes and a short period of switching on the equipment at high current.

A transformer, traditionally, is considered more reliable than an inverter. Even with a noticeable drop in voltage, they lose only part of the power, but do not break. This property determines the higher cost. Plasma cutters based on a transformer can operate and be switched on for a longer period of time. Similar equipment is used in automatic CNC lines. The negative aspect of a transformer plasma cutter will be its significant weight, high energy consumption and size.

The maximum metal thickness that a plasma cutter can cut is from 50 to 55 millimeters. The average power of the equipment is 150 - 180 A.

Average cost of factory devices

The range of plasma cutters for manual cutting of materials is now truly huge. Price categories are also different. The price of devices is determined by the following factors:

• Device type;
• Manufacturer and country of production;
• Maximum possible cutting depth;
• Model.

Having decided to explore the possibility of purchasing a plasma cutter, you need to be interested in the cost of additional elements and components for the equipment, without which it will be difficult to fully operate. Average prices for devices, depending on the thickness of the metal being cut, are:

• Up to 6 mm – 15,000 – 20,000 rubles;
• Up to 10 mm – 20,000 – 25,000;
• Up to 12 mm – 32,000 – 230,000;
• Up to 17 mm – 45,000 – 270,000;
• Up to 25 mm – 81,000 – 220,000;
• Up to 30 mm – 150,000 – 300,000.

Popular devices are “Gorynych”, “Resanta” IPR-25, IPR-40, IPR-40 K.

As you can see the price range is wide. In this regard, the relevance of a homemade plasma cutter is increasing. Having studied the instructions, it is quite possible to create a device that is in no way inferior in technical characteristics. You can select an inverter or transformer at a price significantly lower than the prices presented.

Operating principle

After pressing the ignition button, the source of electricity starts, supplying high-frequency current to the working tool. An arc (pilot) occurs between the tip located in the cutter (plasma torch) and the electrode. Temperature range from 6 to 8 thousand degrees. It is worth noting that the working arc is not created instantly; there is a certain delay.

Then compressed air enters the cavity of the plasmatron. This is what a compressor is designed for. Passing through the chamber with a pilot arc on the electrode, it is heated and increases in volume. The process is accompanied by ionization of the air, which transforms it into a conductive state.

Through a narrow plasma torch nozzle, the resulting plasma flow is supplied to the workpiece. The flow speed is 2 – 3 m/s. Air in an ionized state can heat up to 30,000°C. In this state, the electrical conductivity of air is close to the conductivity of metal elements.

After the plasma contacts the surface being cut, the pilot arc is switched off and the working arc begins to operate. Next, melting is carried out at the cutting points, from which the molten metal is blown with supplied air.

Differences between direct and indirect devices

There are various types of devices that differ in operating principles. In direct acting equipment, the operation of an electric arc is assumed. It takes on a cylindrical shape and is directly connected to the gas stream. This equipment design makes it possible to provide a high arc temperature (up to 20,000°C) and a highly efficient cooling system for other components of the plasma cutter.

In indirect-acting devices, operation is assumed to be less efficient. This determines their lower distribution in production. The design feature of the equipment is that the active points of the circuit are placed on special tungsten electrodes or a pipe. They are used more often for heating and spraying, but are practically not used for cutting. Most often used in car repairs.

A common feature is the presence in the design of an air filter (extends the life of the electrode, ensures quick start-up of the equipment) and a cooler (creates conditions for long-term operation of the device without interruption). An excellent indicator is the possibility continuous operation devices for 1 hour with a 20-minute break.

Design

With the proper desire and skill, anyone can create a homemade plasma cutter. But in order for it to function fully and effectively, it is necessary to observe certain rules. It is advisable to try on an inverter, because It is he who is able to ensure a stable current supply and stable arc operation. As a result, there are no interruptions and electricity consumption will be significantly reduced. But it is worth considering that an inverter-based plasma cutter can cope with a thinner metal thickness than a transformer.

Required components

Before starting assembly work, it is necessary to prepare a number of components, materials and equipment:

1. Inverter or transformer with suitable power. To eliminate error, it is necessary to determine the planned cutting thickness. Based on this information, select the right device. However, taking into account manual cutting, it is worth choosing an inverter, because... it weighs less and consumes less electricity.
2. Plasma torch or plasma cutter. There are also some peculiarities of choice. It is better to choose direct action for working with conductive materials, and indirect action for non-conductive materials.
3. Compressed air compressor. It is necessary to pay attention to the rated power, because it must cope with the load imposed and match the other components.
   Cable hose. Required for connecting all components of the plasma cutter and supplying air to the plasma torch.

Selection of power supply

The operation of the plasma cutter is ensured by the power supply. It generates the specified parameters of electric current and voltage and supplies them to the cutting unit. The main supply unit can be:

• Inverter;
• Transformer.

It is necessary to approach the choice of power supply taking into account the features of the devices described above.

Plasma torch

A plasma torch is a plasma generator. This is a working tool in which a plasma jet is formed that directly cuts materials.

The main features of the device are:

• Creation of ultra-high temperature;
• Simple adjustment of current power, start and stop of operating modes;
• Compact dimensions;
• Reliability of operation.

Structurally, the plasma torch consists of:

• Electrode/cathode containing zirconium or hafnium. These metals are different high level thermionic emission;
• The nozzle is basically isolated from the electrode;
• A mechanism that swirls plasma-forming gas.

The nozzle and electrode are consumables of the plasma torch. If a plasma cutter processes a workpiece up to 10 millimeters in size, then one set of electrodes is consumed within 8 hours of operation. Wear occurs evenly, which allows you to change them at the same time.

If the electrode is not replaced in a timely manner, the cutting quality may be impaired - the geometry of the cut changes or waves appear on the surface. The hafnium insert in the cathode gradually burns out. If it has a production of more than 2 millimeters, then the electrode can burn and overheat the plasmatron. This means that electrodes replaced at the wrong time will lead to rapid failure of the remaining elements of the working tool.

All plasmatrons can be divided into 3 volume groups:

• Electric arc - has at least one anode and cathode, which are connected to a direct current power source;
• High-frequency - there are no electrodes and cathodes. Communication with the power supply is based on inductive/capacitive principles;
• Combined - operates when exposed to high-frequency current and arc discharges.

Based on the arc stabilization method, all plasmatrons can also be divided into gas, water and magnetic types. Such a system is extremely important for the operation of the instrument, because it forms a compression of the flow and fixes it on central axis nozzles

Currently, various modifications of plasma torches are available for sale. You may need to study the offers and buy a ready-made one. However, making your own at home is quite possible. This requires:

• Lever. It is necessary to provide holes for wires.
• Button.
• An appropriate electrode designed for the current.
• Insulator.
• Flow swirler.
• Nozzle. Preferably a set with different diameters.
• Tip. Splash protection must be provided.
• Distance spring. Allows you to maintain a gap between the surface and the nozzle.
• Nozzle for removing carbon deposits and chamfering.

Work can be carried out with one plasma torch due to replaceable heads with different diameters that direct the plasma flow to the part. It is necessary to pay attention that they, like the electrodes, will melt during operation.

The nozzle is secured with a clamping nut. Directly behind it there is an electrode and an insulator that prevents the ignition of the arc in the wrong place. Next, a flow swirler is placed to enhance the arc effect. All elements are housed in a fluoroplastic casing. You can do some things yourself, but others will have to be purchased at the store.

The factory plasma torch will allow you to work without overheating for a longer time due to the air cooling system. However, for short-term cutting this is not an important parameter.

Oscillator

An oscillator is a generator that produces high-frequency current. A similar element is included in the plasma cutter circuit between the power source and the plasma torch. Capable of acting according to one of the following schemes:

1. Creation of a short-term impulse that promotes the formation of an arc without touching the surface of the product. Externally, it looks like a small lightning bolt supplied from the end of the electrode.
2. Constant voltage support with high value voltage superimposed on the welding current. Ensures the preservation of stable arc maintenance.

The equipment allows you to quickly create an arc and start cutting metal.

For the most part they have a similar structure and consist of:

• Voltage rectifier;
• Charge storage unit (capacitors);
• Power unit;
• Pulse creation module. Includes an oscillatory circuit and a spark gap;
• Control block;
• Step-up transformer;
• Voltage monitoring device.

The main task is to modernize the incoming voltage. The frequency and voltage level increase, reducing the period of action to less than 1 second. The work sequence is as follows:

1. The button on the cutter is pressed;
2. In the rectifier, the current is leveled out and becomes unidirectional;
3. Charge accumulates in capacitors;
4. Current is supplied to the oscillatory circuit of the transformer windings, increasing the voltage level;
5. The pulse is controlled by a control circuit;
6. The pulse creates a discharge on the electrode, igniting an arc;
7. The impulse ends;
8. After stopping cutting, the oscillator purges the plasma torch for another 4 seconds. Due to this, cooling of the electrode and the treated surface is achieved.

Depending on the type of oscillator, it can be used in different ways. However general characteristic is to increase the voltage to 3000 - 5000 volts and frequency from 150 to 500 kHz. The main differences are in the intervals of action of the high-frequency current.

For use in a plasma cutter, it is advisable to use an oscillator for non-contact ignition of the arc. Similar elements are used to work in argon welders. The tungsten electrodes in them will quickly become dull if they come into contact with the product. Including an oscillator in the apparatus circuit will allow you to create an arc without making contact with the plane of the part.

Using an oscillator can significantly reduce the need for expensive consumables and improve the cutting process. Properly selected equipment in accordance with the planned work allows you to increase its quality and speed.

Electrodes

Electrodes play an important role in the process of creating, maintaining an arc and direct cutting. The composition contains metals that allow the electrode not to overheat and not prematurely collapse when working with an arc at high temperatures.

When purchasing electrodes for a plasma cutter, it is necessary to clarify their composition. Beryllium and thorium contents create harmful fumes. They are suitable for work in appropriate conditions, with adequate protection for the worker, i.e. additional ventilation is required. Because of this, for application in everyday life it is better to buy hafnium electrodes.

Compressor and cable - hoses

The design of most homemade plasma cutters includes compressors and hose lines to direct air to the plasma torch. This design element allows you to heat the electric arc up to 8000°C. An additional function is to purge the working channels, clearing them of contaminants and removing condensate. In addition, compressed air helps cool the components of the device during long-term operation.

To operate the plasma cutter, it is possible to use a conventional compressed air compressor. Air exchange is carried out by thin hoses with suitable connectors. An electric valve is located at the inlet, which regulates the air supply process.

An electrical cable is placed in the channel from the apparatus to the burner. Therefore, it is necessary to place a hose with a large diameter here, which can accommodate the cable. The passing air also has a ventilation function, as it is able to cool the wire.

The mass must be made of cable with a cross-section of 5 mm2. There must be a clamp. If there is poor ground contact, switching the working arc to the standby arc will be problematic.

Scheme

Now you can find many schemes using which you can assemble a high-quality device. The video will help you understand the symbols in detail. A suitable schematic drawing of the equipment can be selected from those presented below.

Assembly

Before starting the assembly process, it is advisable to clarify the compatibility of the selected components. If you have never assembled a plasma cutter with your own hands before, you should consult with experienced craftsmen.

The assembly procedure assumes the following sequence:

1. Prepare all assembled components;
2. Electrical circuit assembly. In accordance with the diagram, an inverter/transformer and an electrical cable are connected;
3. Connecting the compressor and air supply to the apparatus and plasma torch using flexible hoses;
4. For your own safety net, you can use an uninterruptible power supply (UPS), taking into account the battery capacity.

Detailed equipment assembly technology is presented in the video.

Checking the plasma cutter

After all nodes are connected into a single structure, it is necessary to test for functionality.

Please note that testing and working with the plasma cutter must be carried out in protective clothing using personal protective equipment.

It is necessary to turn on all the units and press the button on the plasma torch, supplying electricity to the electrode. At this moment, an arc with a high temperature should form in the plasmatron, passing between the electrode and the nozzle.

If the assembled plasma cutting equipment is capable of cutting metal up to 2 cm thick, then everything is done correctly. It should be noted that a homemade device made from an inverter will not be able to cut parts with a thickness of more than 20 millimeters, since there is not enough power. To cut thick products, you will need to use a transformer as a power source.

Advantages of a homemade device

The benefits provided by an air plasma cutting machine are difficult to overestimate. It is capable of cutting sheet metal accurately. After work, there is no need to further process the ends. The main advantage is the reduction in work time.

These are already compelling reasons for assembling the equipment yourself. The circuit is not complicated, so anyone can cheaply remake an inverter or semi-automatic device.

In conclusion, let us draw your attention to the fact that it is necessary for an experienced specialist to work with a plasma cutter. It's best if it's a welder. If you have little experience, we recommend that you first study the technology of working with photos and videos, and then begin to complete the assigned tasks.

Plasma cutting is very widely used in various sectors of construction and manufacturing. The ease of use and quality of the final result of this processing method have gained enormous popularity among specialists. That is why many novice craftsmen and even individual teams often ask the question of how to make a plasma cutter from an inverter with their own hands, since the original device is quite expensive and everyone wants to save money by using existing equipment.

Purpose

First of all, this device allows you to quickly cut various metals. This is very convenient when creating all kinds of designs without using another tool. Also, a manual plasma cutter can use different electrodes with which welding is performed.

The process of joining metals using a unit involves the use of the soldering method. Therefore, the main advantage of such equipment is that thanks to it it is possible to join completely different metals using high-temperature solder.

The use of such a tool in blacksmithing deserves special attention. The fact is that it can be used to harden, anneal, thermally clean and weld ferrous and non-ferrous metals together. Therefore, its presence in such production is a necessity, which allows you to save a lot of time.

Design features

When assembling a plasma cutter from an inverter with your own hands, you need to know its structure and equipment. However, it is immediately worth noting the fact that some parts are much easier to purchase ready-made than to create yourself.

A typical apparatus consists of a plasma torch, which is also very often called a “cutter,” an air compressor and a hose and cable package.

• A power source is required to supply the device with a certain amount of current. In fact, it is the heart of the device, and its technical characteristics depend on it.
• No less important is the cutter or plasma torch itself. It has a certain design, which differs significantly from similar products on the market. It is immediately worth noting that when creating a plasma cutter from an inverter with your own hands, it is better to purchase this particular part in a store. This will greatly facilitate operation and solve a lot of problems with replacing some elements.
• A compressor in a device operating using a current of no more than 200 A is necessary to supply air, which performs cooling functions and allows you to create a dense plasma beam. For more powerful installations, argon, helium, hydrogen, nitrogen, oxygen and their mixtures are used.
• The cable-hose package serves as a connecting element through which electric current flows from the power source and air from the compressor to the plasmatron.

Transformer or inverter

Typically, a metal plasma cutting installation uses an inverter or an inverter as a power source. Both of these options are great for DIY, but before you make a choice, you need to know what the differences are between them and how this affects technical specifications final product.

• A typical plasma cutter made from a welding inverter is the most effective and economical. Its efficiency is 30% greater than that of units using a transformer, and it produces a stable arc. However, such a device can only perform strictly defined tasks, working with materials of a certain thickness.
• When using a transformer, you need to remember that this product is quite bulky and requires space for placement. At the same time, its power makes it possible to work with large parts of fairly large thickness. That is why it is installed in stationary premises or on special mobile platforms.

Considering these features of both units, it is best to create a plasma cutter from an inverter, connecting a ready-made power source and other parts with your own hands in a certain sequence.

Necessary equipment

First of all, you need to purchase all the necessary elements. However, it is immediately worth noting the fact that in order for the installation to be of high quality and practical, many of them will have to be purchased ready-made.

Inverter

This unit can be taken from a ready-made welding machine. Its cost is relatively low, although it can be considered the most expensive investment in this project. Typically, when choosing this device, specialists focus on a certain power. It is determined based on the volume of work and its specifics.

Some experts prefer to create an inverter themselves, selecting parts for specific needs or using existing materials. However, as practice shows, it is much easier to use a ready-made unit, since it is more reliable, and certain standards were used in its manufacture.

Cutter

When creating a homemade plasma cutter, craftsmen often make the mistake of trying to completely create the cutter itself, to which current and air will be supplied. The fact is that this product consists of a handle, supply elements and a nozzle. Moreover, with intensive use, the latter wears out very quickly and needs periodic replacement. That is why it is recommended to purchase a factory nozzle, and the remaining elements can be made independently. However, professionals believe that it is not worth spending a lot of effort and money on creating this element yourself, since it is much easier to purchase it ready-made.

Compressor

Typically, a plasma cutter, the instructions for which suggest the use of inert gas or oxygen, is preferred to be connected to cylinders with special mixtures. The fact is that they make it possible to obtain the densest plasma beam and create the best cooling. However, for domestic use it is easier and more economical to use a conventional compressor.

It is immediately worth noting the fact that this unit can be created independently, using an ordinary cylinder as a receiver. The compressor itself can be taken from a ZIL car or from a refrigerator. However, it is very important to adjust the pressure correctly. Usually specialists do this experimentally directly during work.

Cable-hose package

This equipment can be purchased either as a set for a specific unit, or separately from each other. The fact is that it consists of hoses that are designed for the pressure required for operation, and a cable of a certain cross-section. It is worth remembering that the conductor is selected according to the power of the inverter itself, since otherwise it will overheat and there may be a risk of fire and even electric shock.

Assembly

The entire manufacturing process consists of connecting the plasma cutter nozzle to the compressor and inverter. This is what a cable-hose package is used for. It is best to use special terminals and clamps here, which allow both assembly and disassembly very quickly. This approach makes it possible to obtain a compact device that can be conveniently transported to the place of work, which is very much appreciated by specialists.

• Considering that the principle of operation of a plasma cutter is based on the use of gas, it is worth taking care in advance of the availability of spare gaskets that are used when connecting hoses. This is especially important if the unit is constantly disassembled and transported. A simple lack of this element can stop all work.
• It is also very important to have a spare nozzle for your cutter. This part most often fails during prolonged use because it is exposed to high temperatures and rapid cooling.
• It is important to remember that inverters can be quite expensive, and the price depends on its power. Therefore, before purchasing it, it is worth deciding on the output characteristics and needs for which the device is being created. This will help you save a lot and get a unit that is ideal for specific jobs.
• To operate such a tool, you will need to purchase special electrodes made of refractory metals. Materials made of thorium, hafnium, zirconium or beryllium are best suited for these purposes. However, it is worth remembering that some metals, when heated, emit harmful substances and can harm the welder. For example, thorium is very toxic, and beryllium forms radioactive oxides. This is why it is easier and safer to use hafnium.
• It's important to remember that working temperature plasma in such units reaches 30,000 degrees. Therefore, when working, you must strictly follow safety rules so as not to harm yourself or others or cause a fire. That is why only qualified specialists are allowed to work with such a tool.
• During operation, the vortex air flow must not be disturbed. Otherwise, two arcs may form, which will completely disable the device. Taking this into account, experts prefer to use factory cutters, believing that it is better to spend money once than to constantly repair the inverter itself.
• When performing the same type of work, you can make certain modifications to the device. For example, some craftsmen make a special protective cover for the hand or modify the nozzle. However, it is worth remembering that all these additions should not affect the operation of the equipment itself and should not violate safety rules.

Conclusion

Having considered the question of how to make a plasma cutter using an inverter, you can understand that almost all the necessary equipment will have to be purchased from various manufacturers. In fact, the manufacturing itself is an elementary assembly. However, even with this approach, you can save significantly, since a full set of a new unit will cost several times more.