Cutting sheet metal is a complex process that requires the use of special equipment. A plasma cutter will help you quickly cope with the task, with which you can make parts of any configuration. The industrial unit can work with aluminum, stainless steel, brass, steel, and heavy-duty alloys.
For domestic needs, you can make a plasma cutter from an inverter with your own hands in a home workshop. Despite the fact that the device will have limited capabilities regarding the configuration of the resulting product from metals of different hardnesses, other than the thickness of the material and the speed of its cutting there is no. Depending on the power of the device, the device can be used for welding metals in argon gas.
To make a plasma cutter, you can take a serial welding inverter, on the basis of which you can make drawings and diagrams of a plasma cutter yourself. A productive unit can be assembled from a set of elements:
It is recommended to base the choice of power source for completing a homemade plasma cutter on the strength of the generated current. The positive properties of the equipment include optimal overall dimensions, low weight, and ease of use. A negative factor of the device is the difficulty when working with a thick sheet of metal.
Due to its high technical characteristics, plasma metal cutting, which you can do yourself in a private workshop, has a stable voltage that affects the quality of the cutting. An inverter-based device, has high efficiency, a simple setup circuit, low electrical energy consumption, and helps to perform work on sites with limited accessibility.
In order to make a plasma torch with your own hands, diagrams, drawings and descriptions of which can be found on the world wide web, you need to select replacement plasma cutters that allow you to obtain a cutting jet of the required thickness, improve the quality and efficiency of cutting. The work process requires compliance with personal safety precautions by the operator.
The formation of a stream of compressed air, turning into a jet of high-temperature plasma, is carried out by a specially designed compressor. To supply power from the electrical network and air from the compressor, a homemade plasma cutter from a welding inverter uses a cable and hose package. The hose supplies argon gas through a pipe into the vortex chamber with an outlet in one direction.
A metal cutting device made in a home workshop can perform other types of work. To make a high-performance device from a household direct-acting inverter you will need:
A direct plasma cutter is an element consisting of two electrodes: the main and copper nozzle, or anode. The main electrode, or cathode, is made of a refractory metal; the current-conducting element is the material being processed. Metal cutting is carried out by a plasma arc that occurs between the nozzle and the metal.
In addition to consumables, the inverter plasma cutter has an insulator and combustion chambers for argon. When the oscillator is turned on, the gas, escaping from the hole of the nozzle with a ceramic body under high pressure, is heated to a temperature of + 5000 C, turns into plasma and acts on a narrow strip of metal. When separating elements, a smooth surface is formed at the cut site; the process does not create splashes or torn edges.
If it is not possible to make an oscillator yourself from parts, it can be replaced with a factory-made VDS-02 device. The technical characteristics of the device allow you to connect the device in parallel or in series to the inverter.
To quickly assemble and disassemble the device, experts recommend using terminals or special clamps.
Unlike a conventional welding machine, a plasma cutter assembled by yourself is powered by an ignition control system; the primary spark of the igniter is obtained from the built-in oscillator. After the plasma is formed, the system is turned off using a relay that responds to the amount of current from the load inverter. To form plasma, the pressure of the working medium must reach 2.5 atm, the value of which can be provided by an inverter compressor for cars or with a receiver.
It is recommended to include a gearbox in the equipment package, allowing you to maintain gas pressure at a constant level. The cost of the device will quickly pay off if the device is used when painting an object with a spray gun. Handmade homemade products show good results when working with both sheet metal 1 mm thick and steel blanks up to 20 mm thick. The quality of work will be higher than on a CNC machine.
Working with a plasma-type device differs from welding metals with electrodes. The process of processing a workpiece with a device of the first type consists in the peculiarities of the technological process. For a manual plasma cutter, you will need a supply of gaskets for hoses; the lack of consumables can lead to damage to the unit.
A burner should always be available as a spare element, since the nozzle undergoes rapid heating and cooling when performing tasks. It is also important to have refractory electrodes made of zirconium, thorium, beryllium or hafnium in stock. When using special-purpose electrodes, it should be remembered that when heated, beryllium releases radioactive oxides, and volatile toxic elements are released from thorium.
To cut metal according to the same type of program, it is best to use a plasma cutter of a separate modification, which is equipped with protective covers for the operator’s hands. Operation of the equipment is associated with a threat to the life and health of personnel; only highly qualified specialists are allowed to work with the plasma installation.
A plasma cutting machine is a fairly popular piece of equipment that allows cutting any metals in many areas of production. Plasma cutters are used not only in enterprises. Recently, they have begun to appear in home workshops. But, since almost every workshop already has welding machines, it would be wiser not to buy a ready-made plasma cutter, but to make one from an inverter with your own hands.
In some cases, a plasma cutter is an indispensable tool for processing metal products, since the temperature of the plasma leaving its torch reaches 25-30 thousand degrees. Thanks to these characteristics, the scope of application of plasma cutters is quite extensive:
In addition, plasma cutters (as an alternative to laser cutters) are used as part of automatic lines at large enterprises for cutting parts of various configurations from sheet materials.
It is necessary to distinguish between concepts such as plasma cutting and plasma welding. The latter is available only on expensive, professional equipment, the cost of which starts from 100 thousand rubles.
There are various methods, as well as drawings and diagrams, according to which you can make a plasma cutter. For example, if it is made on the basis of a transformer welder, then the plasma cutter diagram provided below is suitable, which describes in detail what parts are needed to manufacture this module.
If you already have an inverter, then in order to convert it into a plasma cutter, you will need a little modification, namely adding an oscillator to the electrical circuit of the device. It is connected between the inverter and the plasma torch in two ways, as shown in the following figure.
The oscillator can be soldered independently according to the diagram provided below.
If you make a plasma cutter yourself, then choosing a transformer as a current source is not recommended for several reasons:
Despite this, the welding transformer also has positive qualities, for example, insensitivity to voltage changes. It can also cut thick metal.
But advantages of an inverter plasma cutting machine in front of the transformer unit there is:
Therefore, it is preferable to make a plasma cutter from a welding inverter than from a transformer.
To assemble a device that will make air plasma cutting of metals possible, you will need to have the following components available.
After all the necessary elements have been prepared, you can begin assembling the plasma cutter:
After assembling all the elements, you can begin equipment testing. To do this, connect the ground cable to the part or metal table on which it is placed. Turn on the compressor and wait until it pumps the required amount of air into the receiver. After the compressor automatically turns off, turn on the inverter. Bring the torch close to the metal and press the start button to create an electric arc between the torch electrode and the workpiece. Under the influence of oxygen, it will turn into a stream of plasma, and metal cutting will begin.
In order for a homemade plasma cutter from a welding inverter to work effectively and for a long time, you should listen to the advice of specialists related to the operation of the device.
As for safety rules, work should be carried out in special clothing that protects against splashes of hot metal. You should also wear chameleon welding goggles to protect your eyes.
The operating principle of most plasmatrons with a power ranging from several kW to several megawatts is practically the same. An electric arc burns between a cathode made of a refractory material and an intensively cooled anode.
A working fluid (WM) is blown through this arc - a plasma-forming gas, which can be air, water vapor, or something else. Ionization of the RT occurs, and as a result, we obtain the fourth aggregate state of matter, called plasma.
In powerful devices, an electric magnet coil is placed along the nozzle; it serves to stabilize the plasma flow along the axis and reduce wear of the anode.
This article describes the second design, because The first attempt to obtain stable plasma was not particularly successful. Having studied the Alplaza device, we came to the conclusion that it is probably not worth repeating it one by one. If anyone is interested, everything is very well described in the instructions included with it.
Our first model did not have active anode cooling. The working fluid was water vapor from a specially constructed electric steam generator - a sealed boiler with two titanium plates immersed in water and connected to a 220V network.
The cathode of the plasmatron was a tungsten electrode with a diameter of 2 mm, which quickly burned out. The diameter of the anode nozzle hole was 1.2 mm, and it constantly became clogged.
It was not possible to obtain stable plasma, but there were still glimpses, and this stimulated the continuation of experiments.
In this plasma generator, a steam-water mixture and air were tested as the working fluid. The plasma output was more intense with water vapor, but for stable operation it must be overheated to a temperature of several hundred degrees so that it does not condense on the cooled plasmatron components.
Such a heater has not yet been made, so experiments so far continue only with air.
Photos of the insides of the plasmatron:
The anode is made of copper, the diameter of the nozzle hole is from 1.8 to 2 mm. The anode block is made of bronze and consists of two hermetically sealed parts, between which there is a cavity for pumping coolant - water or antifreeze.
The cathode is a slightly sharpened tungsten rod with a diameter of 4 mm, obtained from a welding electrode. It is additionally cooled by the flow of the working fluid supplied under pressure from 0.5 to 1.5 atm.
And here is a completely disassembled plasmatron:
Power is supplied to the anode through the cooling system tubes, and to the cathode through a wire attached to its holder.
Launch, i.e. The arc is ignited by twisting the cathode feed knob until it comes into contact with the anode. Then the cathode must be immediately moved to a distance of 2..4 mm from the anode (a couple of turns of the handle), and the arc continues to burn between them.
Power supply, connection of air supply hoses from the compressor and cooling system - in the following diagram:
As a ballast resistor, you can use any suitable electric heating device with a power of 3 to 5 kW, for example, select several boilers connected in parallel.
The rectifier choke must be designed for a current of up to 20 A; our example contains about a hundred turns of thick copper wire.
Any diodes are suitable, designed for a current of 50 A and above, and a voltage of 500 V.
Be careful! This device uses transformerless mains power.
The air compressor used to supply the working fluid is a car one, and a car glass washer is used to pump the coolant through a closed circuit. Power is supplied to them from a separate 12-volt transformer with a rectifier.
As practice has shown, this design also turned out to be experimental. Finally got stable operation within 5 - 10 minutes. But there is still a long way to go to complete perfection.
Replaceable anodes gradually burn out, and it is difficult to make them from copper, and even with threads; it would be better without threads. The cooling system does not have direct contact of the liquid with the replaceable anode, and because of this, heat transfer leaves much to be desired. A more successful option would be with direct cooling.
The parts were machined from semi-finished materials at hand; the design as a whole was too complex to be repeated.
It is also necessary to find a powerful isolation transformer; without it, using the plasmatron is dangerous.
And finally, some more pictures of the plasmatron when cutting wire and steel plates. Sparks fly almost a meter :) 
As a rule, sheet metal is cut by plasma in large production facilities, and this is done when manufacturing parts of complex configurations. Industrial machines cut any metals: steel, copper, brass, aluminum, super-hard alloys.
It is noteworthy that it is quite possible to make a plasma cutter yourself, although the capabilities of the device in this case will be somewhat limited. In large-scale production, a homemade manual plasma cutter is unsuitable, but it will be possible to cut out parts in your workshop, workshop or garage.
There are practically no restrictions regarding the configuration and hardness of the workpieces being processed. However, they relate to cutting speed, sheet size and metal thickness.
DIY plasma cutter It’s easier to make using an inverter welding machine as a basis. Such a unit will be simple in design, functional, with accessible main components and parts. If some parts are not for sale, you can also make them yourself in a workshop with moderately complex equipment.
The homemade device is not equipped with a CNC, which is its disadvantage and advantage at the same time. The disadvantage of manual control is the impossibility of producing two completely identical parts: small series of parts will differ in some way. The advantage is that you don’t have to buy an expensive CNC machine. For a mobile plasma cutter, CNC is not needed, since the tasks performed on it do not require it.
The main components of a homemade unit:
So, there are no complex elements in the design. However, all elements must have certain characteristics.
Plasma cutting requires that the amperage be at least equal to that of a medium power welder.
A current of such strength is generated an ordinary welding transformer and an inverter machine.
In the first case, the structure turns out to be conditionally mobile: due to the large weight and dimensions of the transformer, its movement is difficult. Together with a compressed gas cylinder or compressor, the system becomes cumbersome.
Transformers have low efficiency, which results in increased energy consumption when cutting metal.
The circuit with an inverter is somewhat simpler and more convenient, and even more profitable in terms of energy consumption. The welding inverter will produce a fairly compact cutter that will cut metal up to 30 mm thick. Industrial plants cut metal sheets of the same thickness. A plasma cutter on a transformer can cut even thicker workpieces, although this is not required so often.
The advantages of plasma cutting are visible precisely on thin and ultra-thin sheets.
A homemade cutter is assembled on the basis of an inverter welding machine of any type. It doesn’t matter what the number of operating modes is, you only need a direct current of more than 30 A.
The second most important element is the plasmatron. A plasma cutter consists of a main and an additional electrode, the first is made of a refractory metal, and the second is a nozzle, usually copper. The main electrode serves as the cathode, and the nozzle serves as the anode, and during operation this is the current-conducting part being processed.
If we consider the plasmatron direct action, the arc occurs between the workpiece and the cutter. Indirect plasma torches cut with a plasma jet. The inverter device is designed for direct action.
The electrode and nozzle are consumables and are replaced as they wear out. In addition to them, the housing has an insulator that separates the cathode and anode units, and there is also a chamber where the supplied gas vortexes. In a nozzle, conical or hemispherical, a thin hole is made through which gas escapes, heated to 3000-5000°C.
Gas enters the chamber from a cylinder or is supplied from a compressor through a hose, which is combined with power cables, forming a package of hoses and cables. The elements are connected in an insulating sleeve or connected by a harness. Gas enters the chamber through a straight pipe, which is located on top or on the side of the vortex chamber, which ensures the movement of the working medium in only one direction.
Gas entering under pressure into the space between the nozzle and the electrode passes into the working hole and is then released into the atmosphere.
When the oscillator is turned on - a device that generates a pulsed high-frequency current - a preliminary arc appears between the electrodes and heats the gas in the limited space of the combustion chamber. Since the heating temperature is very high, the gas turns into plasma.
In this state of aggregation, almost all atoms are ionized, that is, electrically charged. The pressure in the chamber rises sharply, and the gas rushes out in a hot stream.
When brought to the part plasmatron, a second, more powerful arc occurs. If the oscillator current is 30-60 A, the working arc occurs at a force of 180-200 A.
It additionally heats the gas, which accelerates under the influence of electricity to 1500 m/s. The combined effect of high temperature plasma and speed of movement cuts the metal along the finest line.
The thickness of the cut is determined by the properties of the nozzle.
An indirect plasma torch works differently. The role of the main anode in it is played by the nozzle. Instead of an arc, a plasma jet erupts from the cutter, cutting non-conductive materials. Homemade equipment of this type works extremely rarely.
Due to the complexity of the plasma torch design and fine adjustments, it is almost impossible to make it in artisanal conditions, although drawings are not difficult to find.
It works under high temperatures and pressures and becomes dangerous if done incorrectly!
If you don’t have time to assemble electrical circuits and search for parts, take factory-made oscillators, for example, VSD-02. The characteristics of these devices are most suitable for working with an inverter. The oscillator is connected to the plasmatron power circuit in series or in parallel, depending on what the instructions for a particular device dictate.
Before you start making a plasma cutter, consider the scope of its application. If you have to work exclusively with ferrous metals, you can get by with just one compressor. Copper, brass and titanium require nitrogen, and aluminum is cut in a mixture of nitrogen and hydrogen. High-alloy steels are cut in an argon atmosphere; here the machine is also designed for compressed gas.
Due to the complexity of the device design and the numerous components that make it up, the plasma cutting machine is difficult to place in a box or portable case. It is recommended to use a warehouse cart to move goods. The trolley will compactly accommodate:
Within a workshop or workshop there will be no problems with moving. When the device needs to be transported to any site, it is loaded into a passenger car trailer.
Plasma cutting is a method of processing metal empty parts with a plasma stream.
This method allows you to cut metal because it is enough to be done in such a way that the material is electrically conductive.
Compared to similar methods, plasma cutting of metals allows for a faster and higher-quality process without the use of massive rollers and special additives.
In this way, it is possible to process a variety of metal sheets, pipes of different diameters, shaped and sorted products.
During processing, a high-quality cut is obtained, which requires minimal cleaning effort.
Even with the help of this technology, various imperfections can be eliminated from the metal surface such as bulges, seams and irregularities and prepare for welding, drilling and other operations.
Plasma cutting of sheet metal is an extremely effective method.
Unlike other methods, it can be used to process ferrous and non-ferrous metals. For this reason, there is no need to prepare the surface and clean it of contaminants, which could make it difficult to ignite the arc. In the industry, the main competitor to this method is laser processing, which has even greater precision but also requires significantly more expensive equipment.
At home, there are no equivalent competitors to the plasma device.
Plasma cutting is carried out using a special device, which has dimensions similar to those of a conventional welding machine. At first these devices were large in size, but as they were improved they became smaller.
The device is connected to a 220V power supply for household appliances and 380V for industrial applications.
During the production process, cutting is carried out using CNC machines, which consist of one or more torches with mechanisms for moving them.
The machine can implement measures according to a specific program, which greatly facilitates the work of several sheets in the same cut.
To create a plasma jet, you need to connect the system to a compressor or air line.
The compressed air supplied to the device must be free of dirt, dust and moisture. For this purpose, air filters and dehumidifiers are installed in front of the device. Without such devices, wear of electrodes and other elements will accelerate faster. Liquid-cooled plasma torches also require plumbing.
Manual cutting of steel pipe
Circular cutting of steel pipe
self-propelled vehicle
Air plasma cutting technology achieves quality edges (no sucking or grating) and no warping (also on low-thickness sheets).
This allows subsequent welding of the cleaned metal without pre-treatment.
Manual cutting of metals on a sample
Plasma cutting of steel in everyday life is carried out with devices along which the length of pipes reaches 12 m.
Manual devices have a cutting head equipped with a motorized handle. Such devices use air cooling because it is simpler in design and does not require additional refrigeration units. Water cooling is used in industrial installations where plasma cutting of steel sheets is more efficient, but the cost of the devices is higher.
Oxygen plasma cutting requires a special electrode and nozzle, which has a significant temperature effect as a consumable.
First, an auxiliary arc begins, which is excited by the discharge caused by the DC generator. Thanks to the arc, a plasma torch 20-40 mm long is created.
When the torch touches the metal, a working arc appears and the auxiliary bow is turned off.
Thus, the plasma acts as a guide between the device and the workpiece. Arisen arc is self-sufficient, creating plasma due to the ionization of air molecules.
Plasma cutting using working fluid at temperatures up to 25000 ° C.
Plasma cutting and welding can be done in workshops and workshops, as well as outdoors.
This method may not be as efficient as a gas power plant for renovation and construction work without a central system for electricity and compressed air. In this case, a sufficiently strong generator is required to provide power to the device and the compressor.
Similar to gas flame cutting, this method can be used to process empty pieces of different sizes and shapes.
Plasma cutting of large diameter pipes does not create any problems: it is performed manually or using self-propelled machines. The fixed burner rotates outside the tube. The use of self-propelled machines ensures precise and smooth cutting. Work with formed and sorted rolled products can also be automated in industrial settings.
Devices for the initial ignition of the arc are divided into two classes: ignition of the arc from a short circuit and by breakdown of the electrode-product gap with high-voltage pulses.
Ignition by short circuit is carried out by short-term contact of the electrode and the product and their subsequent separation. The current through the microprotrusions of the electrode heats them to boiling temperature, and the field that arises when the electrodes are separated provides the emission of electrons sufficient to initiate the arc.
With this ignition, transfer of electrode material into the weld is possible. To eliminate this undesirable phenomenon, ignition should be carried out at a low current not exceeding 5-20A. The ignition device must provide a low short-circuit current, maintain the current at this level until the arc is formed, and only then smoothly increase to the operating level.
(UDG-201, ADG-201, ADG-301).
Basic requirements for gap ignition devices (arc exciters or oscillators):
1) must ensure reliable arc initiation;
2) must not endanger the safety of the welder and equipment.
Exciters can be designed to initiate a DC or AC arc. In the latter case, a number of specific requirements are imposed on the exciters related to the moment of ignition of the arc. The circuit diagram of the OSPZ-2M oscillator is shown in Fig.
Rice. 5.5. Schematic diagram of the OSPZ-2M oscillator. F1 – fuse; PZF – noise protection filter; TV1 – step-up transformer; FV – spark gap; Cg – capacitor of the oscillatory circuit; Cn – decoupling capacitor; TV2 – high voltage transformer; F2 – fuse.
Capacitor Cr is charged from the voltage of the secondary winding of step-up transformer TV1.
After charging it to the breakdown voltage of the spark gap FV, an oscillatory circuit is formed, consisting of a capacitor Cr and the primary winding of a high-voltage transformer TV2.
The oscillation frequency of this circuit is approximately 500 - 1000 kHz.
From the secondary winding, this voltage with a frequency of 500 - 1000 kHz and a value of about 10,000 V is supplied to the electrode-product gap through a separating capacitor Cn and fuse F2.
In this case, a spark appears in this gap, which ionizes the gap, as a result of which an electric arc is excited from the power source. After the arc is excited, the oscillator automatically turns off.
Please note that the oscillator has high voltage.
It is not dangerous for humans due to the low power of the source. However, if the source circuit contains semiconductors (diodes, thyristors, etc.), then their breakdown by the oscillator voltage is possible.
To avoid this, the oscillator must be connected to the source using protection systems (Fig. 5.6).
Connection diagram of the oscillator to the power source.
The choke is protected by DZ for the high frequency of the oscillator, has a very large inductive reactance and does not allow the oscillator voltage to pass to the source.
The protective capacitor SZ, on the contrary, has a very low resistance for high frequency, protecting the source from the high frequency and high voltage voltage of the oscillator. The decoupling capacitor Cp protects the oscillator from the power supply voltage.
Plasma cutters are widely used in enterprises working with non-ferrous metals. Unlike ordinary steel, which can be cut with a propane-oxygen flame, stainless steel or aluminum cannot be processed in this way, due to the greater thermal conductivity of the material.
When attempting to cut with a conventional flame, a wide part of the surface is exposed to heat, which leads to deformation in this area. A plasma cutter is capable of point heating of metal, producing cutting with a minimum cutting width.
When using filler wire, the machine can, on the contrary, weld non-ferrous types of steel. But this equipment is quite expensive.
How to assemble a plasma cutter yourself from a welding inverter? On what principle does the device work? What is the equipment layout? Is it possible to make a cutter gun yourself, or is it better to buy this item? The following discusses the answers to these questions, including a topical video.
You can make a plasma cutter from an inverter with your own hands if you have a good understanding of the operating principle of the device and the elements involved in the process. The essence of the functioning of a plasma cutter is as follows:
The temperature of the arc, due to acceleration by air flow, can reach 8000 degrees, which allows you to instantly and precisely heat the required section of the metal, performing cutting, and without overheating the rest of the product.
Plasma cutters differ in power and configuration. Small models are capable of cutting metal about 10 mm thick. Industrial machines work with steels up to 100 mm thick. Often these are large machines on brackets, onto which steel sheets are fed by hoists.
A plasma cutter made at home will be able to cut stainless steel and other metals up to 12 mm.
They can make shaped cuts in sheet iron (circles, spirals, wave-like shapes), as well as welding alloy steel with filler wire.
The simplest homemade plasma cutter should have four component parts:
Assembling the product must begin by finding a suitable power source. Industrial models use powerful transformers that produce high current and are capable of cutting thicknesses over 80 mm. But at home you don’t have to work with such values, and such a transformer will make a lot of noise.
As a current source, you can take a regular inverter, which costs four times less than the simplest plasma cutting machine. It will outperform the transformer by producing a stable voltage at a high frequency.
Thanks to this, the stability of the arc and the required cut quality will be ensured. The inverter will also be convenient due to its small size, in case of on-site work with a plasma cutter.
Light weight will make it easier to transport the device to the desired location.
The plasma cutter from the inverter, in finished form, must meet a number of key requirements:
To achieve these parameters, the product must be equipped with additional equipment, strictly according to the scheme.
How to make a plasma cutter is well shown in some videos on the network. There you can also find important diagrams according to which the device is assembled. To read symbols, basic electrical engineering skills and the ability to understand symbols are required.
The plasma cutter circuit ensures that the device can actually perform the work. This happens as follows:
Plasma cutting and welding is performed with a torch (plasma torch). It can have various modifications and sizes. It is quite difficult to build a model that runs on water at home, so it is worth purchasing such a “gun” in a store.
It is much easier to make a plasmatron with an air system. Homemade versions of the plasma cutter are most often just like this. To assemble it yourself you will need:
Welding and cutting with the same device can be carried out on different thicknesses of metal thanks to the replaceable elements of the plasma torch head.
For this purpose, a variety of nozzles are provided, differing in the diameter of the outlet opening and the height of the cone. It is they who direct the formed plasma jet to the metal. Nozzles are purchased separately in the store.
It is worth buying several pieces of each type, because they will melt, which will require replacement over time.
The nozzles are secured with a special clamping nut, the diameter of which allows the nozzle cone to pass through and clamp its wide part. Immediately behind the nozzle there is an electrode and an insulating sleeve that prevents the arc from igniting in an unintended place.
Afterwards, there is a mechanism for twisting the air flow, which enhances the effect of the arc. All this is placed in a fluoroplastic case and covered with a metal casing.
Some of these items can be made yourself, while others are better purchased at the store.
A store-bought plasma torch may also have an air cooling system, which will allow the device to operate longer without overheating. But if cutting will be carried out for a short time, then this is not necessary.
Electrodes play an important role in ensuring the arc burning process and cutting with a plasma torch. Beryllium, hafnium, thorium and zirconium are used in their manufacture. Due to the formation of a refractory surface film, the electrode rod is not subject to overheating and premature destruction when working at high temperatures.
When buying electrodes for a homemade plasma cutter, you should find out what material they are made of. Beryllium and thorium produce hazardous fumes and are suitable for use in special environments that provide adequate protection to the welder. Therefore, for home use it is better to purchase hafnium electrodes.
Most homemade plasma cutters include a compressor and air supply paths to the burner in their design.
This is an important part of the device, allowing the temperature of the electric arc to develop up to 8000 degrees, and ensuring the cutting process.
Additionally, the compressor blows through the channels of the equipment and the plasma torch, draining the system of condensate and removing debris. The possibility of compressed air passing through the burner helps to cool the working parts.
You can install a simple compressor in your plasma torch, which is used when painting with a spray gun. Connection to the device is made with a thin hose and an appropriate connector. An electric valve is installed at the inlet to regulate the air supply to the system.
The channel from the plasma cutter to the torch already contains an electrical component (a cable for powering the electrode), so a thicker hose is used, for example from an old washing machine, inside which the electrical wire is placed.
The supplied air will simultaneously cool the cable. The mass is made from wire with a cross-section of more than 5 mm square, with a clamp at the end. If the ground contact is poor, the pilot arc will not be able to switch to the working arc.
Therefore, it is important to buy a clamp that is strong and reliable.
It is quite possible to assemble a plasma cutter at home using a video and purchased components. A working inverter and circuit will serve as the basis for realizing the goal. And the above tips will help you better understand the process and purpose of each element in the assembly.
Making a plasma cutter from an inverter with your own hands is a task that almost any good owner can do. One of the main advantages of this device is that after cutting with such a device there will be no need for additional processing of the edges of metal sheets.
Currently, there are many options for manual plasma cutters, as well as many different options for how they work. One such installation is a direct action cutter. The operation of this type of device is based on the use of an electric arc.
This arc has the form of a cylinder to which a gas stream is supplied. It is due to this unusual design that this device can reach a colossal temperature of approximately 20,000 degrees.
In addition, this device is capable of not only developing enormous temperatures, but also quickly cooling other working elements.
Indirect installations are not used as often as direct ones. The thing is that they are characterized by a lower efficiency, that is, efficiency.
The design of these tools is also quite specific and consists in the fact that the active points of the circuit are placed either on a pipe or on a special tungsten electrode.
These devices have become quite widely used when it is necessary to spray or heat metal parts. However, this type of equipment is not used as a plasma cutter.
Most often they are used to repair automotive components without removing them from the body.
The peculiarities of the operation of such cutters also include the fact that they can only work if there is an air filter, as well as a cooler. The presence of air filters in this device ensures a longer service life of elements such as the cathode and anode, and also affects the acceleration of the process of starting the mechanism.
In order to ensure that a plasma cutter from an inverter performs all the necessary functions with your own hands, you need to understand the basic principle of operation. The entire functionality of the device depends on the supply of highly heated air from the cutter to the sheet of metal.
The temperature conditions that need to be created are several tens of thousands of degrees. When oxygen is heated to such limits, it is supplied under pressure from the cutter to the surface that needs to be cut. It is this work process that is fundamental.
Metal sheets are cut using highly heated oxygen under high pressure.
In order to speed up this process, it is necessary to take into account ionization by electric current. It is also important to note that you can increase the service life of a plasma cutter made with your own hands from an inverter if the device contains some additional parts.
There are a total of five main elements that must be included in the design of a plasma cutter.
In order to make a plasma cutter with your own hands from an inverter, you need to decide which elements to create it from.
The part that will create the necessary power for cutting can be an inverter or transformer. When choosing this element of the device, it is very important to understand exactly what thickness of metal will need to be cut.
It is the thickness of the metal that will be the fundamental factor that will influence the choice of this part. Since a manual cutter is being assembled, it is, of course, better to purchase a welding inverter.
Its power is slightly less than that of a transformer, but it is much lighter and will save a large amount of electricity.
The second important detail will be the choice between a plasma cutter or a plasma point. The main selection criterion here will be the same factor as when selecting a welding inverter, that is, the thickness of the metal.
However, one more nuance needs to be taken into account. Direct impact equipment is designed to work with elements capable of conducting current.
An indirect element is most often installed if it is necessary to do without things that use current in the work.
Another important element is the compressor. Its choice is already simpler, since the only important requirement is power, which must fit the previously selected parts.
The last part is the cable and hose package. Designed to connect all the parts given above.
In order to create a good working tool of this type, it is very important to understand the operating principle and design of the plasma cutter. This device works as follows:
Since the temperature of the arc is artificially increased by supplying hot air, its temperature in a homemade plasma cutter can reach 8,000 degrees. This is a very high temperature indicator, which allows for spot cutting of metal without heating other parts of the sheet.
Like any other technical devices, plasma cutters made from an inverter with your own hands will differ from each other in their power, which will determine how thick a sheet of steel the device can cut. Hand cutters can most often cut sheets up to 10 mm thick. Industrial units are capable of handling metal 100 mm thick.
A homemade plasma cutter made on your own will be able to cut sheets with a thickness of up to 12 mm.
Such products can be used for figure cutting, as well as welding alloy steels with filler wire. The simplest cutters include four main parts - power source, plasma torch, compressor, mass.
Assembling this device should always start with the power source. In industrial units, a transformer is used to achieve more power and, therefore, cut thicker metal.
For a manual home cutter, a regular inverter is perfect, as it can provide such indicators as stable voltage and high frequency.
The advantage of using an inverter will be its light weight, which will make the device more convenient for transportation, and it is also quite capable of ensuring stable burning of the torch arc and the quality of the cutting itself.
In addition, the inverter must meet several more requirements:
In order to achieve all these parameters, it is necessary to use certain additional equipment.
In order to make a working device, it is necessary to consult the diagram of this device. You can easily find such a diagram on the Internet, but you still need to read it. To do this, you need to have the most minimal knowledge in electrical engineering. It is the correct assembly according to the diagram that ensures the actual operation of the unit.
Do-it-yourself assembly of a plasma cutter according to the drawing is the most important process that will ensure stable operation of the device in the future. The finished and correctly assembled circuit looks like this:
Cutting or welding of metal is carried out by an element such as a plasma torch. Making it water-based on your own is very problematic, and therefore it is better to buy it. Plasmatrons with an air system are most often made with their own hands.
For this, a compressor is required, which is responsible for blowing and heating the arc to the required 8,000 degrees. This element also performs a cleaning function in the cutter, drying it and clearing it of unwanted elements and debris. As a compressor, you can use a part used in a conventional spray gun.
An important part of a homemade cutter will be the electrodes used. When purchasing them, it is important to clarify what material they are made of. Beryllium and thorium emit harmful fumes when used. It is better to use them only in a special environment where human safety is guaranteed. The best choice for a home cutter would be hafnium electrodes.
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 of having in their arsenal such a tool as a manual plasma cutting machine.
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.
The whole variety of such instruments can be classified into two main groups:
A feature of the devices representing the first group is their large size 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.
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.
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:
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.
If you decide to make a plasma cutter yourself, then you should prepare the necessary materials and equipment:
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.
Today, stores offer a large amount of equipment for manual cutting of metals, which are offered at various 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:
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.
To do this, it is enough to prepare all the necessary equipment and strictly follow the plasma cutter assembly technology. Even a home-made plasma cutter can provide the same quality of cutting steel parts as the equipment offered in stores.
Home craftsmen who process metal products often need to cut one or another metal workpiece. For these purposes, you can use an angle grinder (grinder), oxygen cutter or plasma cutter. In order not to purchase an expensive cutting device, it is best to make a plasma cutter with your own hands from an inverter.
A homemade plasma cutter can easily perform various jobs. It can be used not only for industrial purposes, but also for everyday tasks, for example, for processing metal products, where the cut must be as precise, thin and high-quality as possible.
When manufacturing equipment, it is important to provide the appropriate current strength. This indicator is determined by the power source, in this case the inverter. Thanks to it, relatively stable operation is ensured; compared to a transformer, energy is consumed more economically, despite the fact that the thickness of the products with which it can work is several times smaller.
Another feature of the inverter is ease of use. It is compact and light weight. In addition, with low power consumption, its efficiency is almost ten percent greater than that of a transformer. All these nuances have a positive effect on the quality of his work. The only disadvantage of using an inverter plasma cutter is the difficulty in cutting workpieces of considerable thickness.
To assemble the design of homemade devices, you can use ready-made diagrams that are presented on the Internet. It is also important to prepare all components in advance. During the assembly process, you should follow the sequence of actions specified in the diagram as accurately as possible, paying attention to whether the structural elements correspond to each other.
To manufacture a functional plasma cutter from a welding inverter, it is necessary to correctly select the main structural elements that will ensure the uninterrupted operation of this equipment. To create a full-fledged unit, you must have:
Homemade plasma cutters from an inverter allow these types of equipment to work according to their main purpose, supplying a heated air stream to a metal product. Temperature values can exceed 1000°C, as a result of which oxygen is heated and directed at a certain pressure to the surfaces being treated. This process facilitates the cutting of metal structures. To speed up this procedure, it is necessary to provide additional opportunities for ionization of the medium through electric current.
Let's consider the circuit of one of the plasma inverters using the APR-91 equipment as an example. Its power part has the following design principle.
To make a plasma cutter from an inverter with your own hands, you need to correctly select the appropriate structural elements:
First of all, you should provide for the presence of an inverter welding machine, which will serve as a power source. Thanks to it, the supply of electrical voltage to the device should be ensured, in a given range of values. If there is no inverter, then you can use an ordinary transformer instead.
The selection of a plasma torch must be especially careful, since it is the main structural element. The air compressor must have enough power to cut thick workpieces.
It is also necessary to provide a good length of hoses, as this will allow you to carry out work at any convenient distance. In addition, appropriate electrodes should be selected for the plasma torch, which are made from suitable materials. Such reliable components include electrodes made of thorium, beryllium, hafnium and zirconium. They have positive characteristics due to the fact that when heated, a refractory oxide film is created on their surface. This provides high protection and prevents tool breakage.
The nozzle and its technical characteristics affect the achievement of the overall result and the quality of the work process. The best option is a nozzle diameter of 30 mm. The length of the nozzle affects how well and accurately the cut is made. The longer the better, however, excessive length can lead to rapid wear and premature replacement.
The operation of the plasma cutter is ensured by a compressor, pumping a stream of air under pressure. At the same time, it not only supplies air flow, it also provides an additional cooling system.
It is quite easy to make a plasma cutter from a welding inverter with your own hands if you have the appropriate tools and materials for this. After the selection and preparation of the elements has been completed correctly, you can begin assembling the device itself. The connection of the compressor, plasma torch and inverter is carried out using a special cable-hose package. When performing the assembly process, you need to adhere to the correct order in connecting all components; this is done in several steps:
Immediately after assembly, it is important to check that the equipment is working and, in the event of a malfunction, replace non-functioning elements or reconnect interconnected elements.
When the equipment is turned on, high-frequency current voltage must be supplied to the plasmatron. At the same time, an arc is ignited, which heats up to 6000-8000°C. An air flow occurs in the nozzle, passing through a section of the electric arc. After this, its volume increases up to a hundred times. The electric arc begins to ionize.
The resulting substance is removed through a nozzle, which forms a narrow jet for cutting. The jet is supplied at a speed of 3 m/s. At this point, the temperature increases to 25000-30000°C, which leads to the formation of a plasma flow. When the plasma and the metal surface come into contact, the pilot arc is extinguished and the cutting arc is ignited. A strong air flow blows away any remaining molten metal parts from the surface of the part. As a result, a neat seam is ensured.
When cutting, it is extremely important to ensure that the arc spot is located exactly in the center of the electrodes. To maintain a stable state, the device uses a tangential air supply. If even minor disturbances occur with the air flow during operation, the accuracy of processing will be significantly reduced.
You should also pay attention to avoid the formation of two plasma flows. During normal operation, only one thread is allowed. This situation may arise due to non-compliance with technological standards during operation, and this entails damage to the inverter.
One of the important parameters that allows you to perform plasma cutting correctly is the speed of the air stream. A high-quality cut and the speed of its production are achieved at an air flow speed of 800 m/s. The current supplied from the inverter should not be more than 250 A. When working in such modes, it should be remembered that there is also an increase in air flow, which forms the plasma flow.
It is not difficult to make a plasma cutter from a welding inverter yourself if you follow the necessary theoretical material, make the correct selection of components and carry out their proper connection. Thanks to such a universal inverter-based device, there is an excellent opportunity to perform not only high-quality metal cutting at home, but also.
