How to make a plasma cutter with your own hands

How to make a good plasma cutter from an inverter with your own hands: device, types, manufacturing - SibNovStroy

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.

Direct acting devices

Currently, there are many options for manual plasma cutters, as well as many different options for how they work. One such setup is the 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 action device

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.

Hand tool design

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.

Additional items

There are a total of five main elements that must be included in the design of a plasma cutter.

The first and main part is the plasmatron. It is this element that is responsible for performing all the main functions of the cutter.
Next comes the plasma cutter. The design of this element can be done in two ways - direct or indirect. The difference between these designs is described above.
It is also important to have electrodes as consumables for a plasma cutter.
One of the most important parts was the nozzle. The configuration of this particular element allows the master to understand what kind of metal sheet this cutter is intended for cutting.
Compressor. The need for this detail is quite understandable. Since cutting requires oxygen to be supplied under high pressure, the presence of this device is vital for the functioning of the device as a whole.

Parts selection

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 piece is the cable and hose package. Designed to connect all the parts given above.

Operating principle

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:

When the equipment starts up, the current source begins to generate the required voltage, which is transmitted through the cable to the torch-torch.
There are two main elements in a plasmatron (cutter-torch) - a cathode and an anode. An arc will be initiated between these two parts.
A powerful stream of air, which moves under high pressure, and also overcomes special twisted cables, brings the arc out. At the same time, the supplied air greatly increases the arc temperature.
Next, the ground cable comes into play, which is always connected to the device in advance. It creates an arc closure on the working surface, which ensures stable operation of the plasma cutter.
It is important to note that when converting an inverter into a plasma cutter, welding remains possible. That is, the cutter can also be used as a welding machine. In this case, it is best to use argon as the main gas or another inert mixture that can protect the weld pool from environmental influences.

Cutter device

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.

How to make a plasma cutter?

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:

Its power supply must be supplied from a 220V network.
The cutter should operate with a power of 4 kW.
The current adjustment range for a manual device should be from 20 to 40 A.
Idling is also 220V.
The nominal operating mode for a 10-minute cycle should not exceed 60%.

In order to achieve all these parameters, it is necessary to use certain additional equipment.

Plasma cutter diagram

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.

Product circuit operation

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:

The plasma torch has a button that starts the entire workflow. Pressing this button will activate relay P1. The function of this element is to supply current to the control unit.
Next, relay P2 is switched on. It performs tasks such as starting current to the inverter and simultaneously turning on the solenoid valve, which purges the burner. This blowing is necessary in order to dry the burner chamber and clean it of possible debris or scale.
After a three second delay, relay P3 is turned on, which supplies current to the electrodes.
Together with the activation of this relay, an oscillator is started, which ionizes the air between the cathode and the anode, thereby exciting a pilot electric arc.
When the flame is brought to the product, an arc is ignited between the sheet and the plasma torch, which is called the working arc.
At this moment, the current supply that operates for ignition is cut off.
Next, work is carried out on cutting or welding the metal.
Upon completion of work and pressing the button on the plasma torch, relay P4 is activated, which turns off both arcs and also turns on the air supply to the burner chamber for a short period of time to remove burnt elements.

Plasma torch, electrodes, compressor

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.

Source: https://sibnovostroy.ru/stanki/kak-sdelat-svoimi-rukami-horoshij-plazmorez-iz-invertora-ustrojstvo-vidy-izgotovlenie.html

How to make a plasma cutter from a welding inverter with your own hands? Recommendations for production!

Used parts of various machines and tools are great for making useful devices for the household with your own hands. If you have an unnecessary welding inverter, you can use it to make a homemade plasma cutter.

How to turn a metal welding device into a device that can cut durable material will be discussed in detail in this article.

The advantage of a plasma cutter over a gas cutter

One of the simplest devices for cutting metal is a gas cutter. Such a device costs little money and consumables for it are also inexpensive. But when performing gas welding work, too large an area of metal is heated.

For this reason, materials with high thermal conductivity may warp and change color. Both at the point of metal melting and at a considerable distance from the thermal effects of the burner flame.

The advantage of a plasma cutter is that it is possible to obtain a very thin stream of hot gas, which will affect a small surface area, which will significantly reduce the heating of the part.

Operating principle of a plasma cutter

It is almost impossible to make a plasma cutter yourself without understanding the principle of operation of this device.

THIS IS INTERESTING: How to clean silver spoons at home

The process of plasma formation occurs as a result of:

Supplying electric current to the burner.
An electric arc occurs between the electrodes (cathode and anode) of the burner.
Air under pressure is supplied to the burner and “blows” the arc outward, thereby significantly increasing its temperature.
A ground cable is connected to the metal being cut, so the ionized flame seems to make contact with the surface of the material.

The result is a highly efficient device for cutting various metals. Including those that have increased thermal conductivity.

Watch the video, which shows in an accessible form what plasma cutting is and how it works:

Parts for a homemade device

A do-it-yourself plasma cutter from a welding inverter is made from the following parts.

1. Plasmatron. This detail in the design of a plasma cutter is the most important.

Even if the required electric current and gas pressure are available, an arc cannot be obtained if the internal electrodes are not positioned correctly. And the air supply hole will have the wrong diameter.

Such a part is quite expensive, so home craftsmen prefer to make burners themselves from scrap parts.

Source: https://plavitmetall.ru/oborudovanie/plazmorez-iz-svarochnogo-invertora-svoimi-rukami.html

How to make a plasma cutter with your own hands from an inverter

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.

Features of a homemade device

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.

General design of an inverter plasma cutter

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:

plasma torch - a plasma cutter, thanks to which the main cutting procedure is performed;
compressor - a device through which powerful air flows are supplied, forming a plasma jet;
power source, which is the inverter itself;
cable hoses - allow you to connect individual elements into a complete system.

Plasma cutter device diagram

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.

Selection of structural elements for equipment

To make a plasma cutter from an inverter with your own hands, you need to correctly select the appropriate structural elements:

compressor;
plasmatron;
electrodes;
nozzle;
plasma cutter

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.

Cutter assembly process

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:

The welding inverter should be checked to ensure its serviceability. Then, using a cable, connect the device to the electrode so that an arc can subsequently form during operation.
Provide compressed air supply from the compressor via a cable hose.
Connect the compressor and the plasma torch with a hose, which should ensure the conversion of the air stream into a plasma stream for cutting metal.

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.

Working principle of a plasma cutter

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.

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 device based on an inverter, there is an excellent opportunity to perform not only high-quality metal cutting at home, but also to weld thin metal with an inverter.

"Plasma cutter device"

Source: https://pro-instrymenti.ru/svarochnye/plazmorez-svoimi-rukami-iz-invertora/

DIY plasma cutter from an inverter! Instructions, diagrams and video material!

Making a working plasma cutter from a welding inverter with your own hands is not such a difficult task as it might seem at first glance.

In order to implement this idea, you need to prepare all the necessary parts of such a device:

Plasma cutter (or in other words - plasma torch)
Welding inverter or transformer
A compressor that will create the air jet necessary to form and cool the plasma flow.
Cables and hoses for combining all structural elements of the device into one system.

Plasma cutters, including homemade ones, are successfully used to perform all kinds of work both in production and at home. This device is indispensable in situations where it is necessary to make an accurate, thin and high-quality cut of metal workpieces. Certain models of plasma cutters, in terms of their functionality, allow them to be used as a welding machine. This welding is performed in argon shielding gas.

Return cable and gas hose for plasma cutting!

When choosing a power source for a homemade plasma torch, it is important to pay attention to the amount of current that such a source can generate.

Most often, an inverter is chosen for this, which ensures high stability of the plasma cutting process and allows for more economical use of energy. Unlike a welding transformer, it has compact dimensions and light weight, and the inverter is more convenient to use.

The only disadvantage of using inverter plasma cutters is the difficulty of cutting very thick workpieces with their help.

The photo shows a torch from an ABIPLAS plasma cutter and its components!

When assembling a homemade plasma cutting unit, you can use ready-made diagrams that are easy to find on the Internet. In addition, there is a video on the Internet on how to make a plasma cutter with your own hands. When using a ready-made diagram when assembling such a device, it is very important to strictly adhere to it, and also pay special attention to the correspondence of the structural elements to each other.

Schemes of a plasma cutter using the example of the APR-91 device

As an example when studying the electrical circuit diagram, we will use the APR-91 plasma cutting device.

Schematic diagram of the power part of the plasma cutter! Schematic diagram of the plasma cutter control Schematic diagram of the oscillator!

Details of a homemade plasma cutting device

The first thing you need to find to make a homemade plasma cutter is a power source that will generate electric current with the necessary characteristics. Typically, inverter welding machines are used for this, which is explained by a number of their advantages.

Due to its technical characteristics, such equipment is able to provide high stability of the generated voltage, which has a positive effect on the quality of cutting.

Working with inverters is much more convenient, which is explained not only by their compact size and light weight, but also by ease of setup and operation.

The principle of operation of a plasma cutting device!

Due to their compactness and low weight, inverter-based plasma cutters can be used even in the most difficult places, which is impossible for bulky and heavy welding transformers. The big advantage of inverter power supplies is their high efficiency. This makes them very energy efficient devices.

In some cases, the power source for a plasma cutter can be a welding transformer, but its use is fraught with significant energy consumption. It should also be taken into account that any welding transformer is characterized by large dimensions and significant weight.

The main element of an apparatus designed for cutting metal with a plasma jet is a plasma cutter. This piece of equipment ensures cutting quality as well as efficiency.

The size and shape of the plasma jet depends entirely on the diameter of the nozzle!

To form an air flow that will be converted into a high-temperature plasma jet, a special compressor is used in the design of the plasma cutter. Electric current from the inverter and air flow from the compressor enter the plasma cutter using a cable hose package.

The central working element of a plasma cutter is a plasma torch, the design of which consists of the following elements:

Nozzles
Channel through which a stream of air is supplied
Electrode
An insulator that simultaneously performs the cooling function

THIS IS INTERESTING: How to restore chrome plating

Plasma cutter design and tips for making it

Replacement nozzles for plasmatron

Some of the above materials, when heated, can release compounds hazardous to human health; this point should be taken into account when choosing the type of electrode. Thus, when beryllium is used, radioactive oxides are formed, and when thorium evaporates in combination with oxygen, dangerous toxic substances are formed. A completely safe material for the manufacture of electrodes for a plasma torch is hafnium.

The nozzle is responsible for the formation of the plasma jet, with the help of which cutting is carried out. Its production should be given serious attention, since the quality of the work process depends on the characteristics of this element.

Plasma torch nozzle design

The most optimal is a nozzle with a diameter of 30 mm. The accuracy and quality of the cut depends on the length of this part. However, a nozzle that is too long should also not be made, since in this case it will quickly collapse.

As mentioned above, the design of a plasma cutter necessarily includes a compressor that forms and supplies air to the nozzle. The latter is necessary not only for the formation of a jet of high-temperature plasma, but also for cooling the elements of the apparatus. The use of compressed air as a working and cooling medium, as well as an inverter that generates an operating current of 200 A, allows you to effectively cut metal parts whose thickness does not exceed 50 mm.

Gas selection table for plasma cutting of metals!

To prepare a plasma cutting machine for operation, you need to connect the plasma torch to an inverter and a compressor. To solve this problem, cable hose packages are used, which are used as follows.

The cable through which the electric current will be supplied connects the inverter and the plasma cutting electrode.
The compressed air supply hose connects the compressor outlet and the plasma torch, in which a plasma jet will be formed from the incoming air flow.

Main features of the plasma cutter

To make a plasma cutter using an inverter to make it, you need to understand how such a device works.

After turning on the inverter, electric current from it begins to flow to the electrode, which leads to the ignition of an electric arc. The temperature of the arc burning between the working electrode and the metal tip of the nozzle is about 6000–8000 degrees.

After the arc is ignited, compressed air is supplied to the nozzle chamber, which passes strictly through the electrical discharge. The electric arc heats and ionizes the air flow passing through it.

As a result, its volume increases hundreds of times, and it becomes capable of conducting electric current.

Using a plasma cutter nozzle, a plasma jet is formed from a conductive air flow, the temperature of which actively rises and can reach 25-30 thousand degrees.

The speed of the plasma flow, due to which metal parts are cut, at the exit from the nozzle is about 2-3 meters per second.

The moment the plasma jet makes contact with the surface of the metal part, electric current from the electrode begins to flow through it, and the initial arc goes out. The new arc that burns between the electrode and the workpiece is called cutting.

A characteristic feature of plasma cutting is that the metal being processed melts only in the place where it is affected by the plasma flow. That is why it is very important that the place of plasma exposure is strictly in the center of the working electrode.

If we neglect this requirement, we may be faced with the fact that the air-plasma flow will be disrupted, as a result of which the cutting quality will significantly deteriorate.

To meet these important requirements, use a special (tangential) air supply principle to the nozzle.

It is also necessary to ensure that two plasma flows do not form simultaneously, instead of one. The occurrence of such a situation, which leads to non-compliance with the modes and rules of the technological process, can lead to failure of the inverter.

Basic parameters of plasma cutting of various metals.

An important parameter for plasma cutting is the air flow speed, which should not be too high.

Good cutting quality and speed are ensured by an air jet speed of 800 m/s. In this case, the current flowing from the inverter unit should not exceed 250 A.

When performing work in such modes, one should take into account the fact that in this case the air flow used to form the plasma flow will increase.

Making a plasma cutter yourself is not so difficult; to do this, you need to study the necessary theoretical material, watch a training video and select all the necessary parts correctly.

If you have a similar device at home, made on the basis of a factory inverter, it can perform not only high-quality metal cutting, but also plasma welding!

If you do not have an inverter in use, you can make a plasma cutter using a welding transformer as a basis, in which case you will have to come to terms with its large dimensions and considerable weight. Also, a plasma cutter made on the basis of a transformer will not have very good mobility and moving it from place to place will be problematic!

Source: https://kavmaster.ru/plazmorez-iz-invertora-svoimi-rukami/

Do-it-yourself oscillator for a plasma cutter: diagram, video, homemade for plasma

page » DIY » Plasma cutter » Oscillator

An oscillator for a plasma cutter is a device for non-contact initiation of an arc and stabilization of its combustion. It receives these options thanks to the conversion of electricity parameters.

Homemade oscillator for a plasma cutter: a little theory

The appearance of the electronic unit of a factory-made oscillator is shown in the figure.

Welding oscillator brand VSD-02, used to stabilize the arc. East. http://met-all.org/oborudovanie/svarochnye/svarochnyj-oscillyator-svoimi-rukami.html.

Modern oscillators are divided into two classes of action:

continuous action . This class adds a high frequency current (150-250 KHz) and a high voltage value (30,006,000 V) to the welding current. Under such conditions, the arc will ignite even without the electrode touching the surface of the workpieces being connected. Moreover, it will burn very steadily even at low welding current values (due to the high frequency of the current generated by the oscillator). And, what is also important, electricity with such characteristics is not dangerous to the health of the worker working on this device;
pulse . The electrical circuit of this class may provide for its parallel or serial connection.

Examples of electrical circuits are shown in the figure.

Parallel and serial connection of the oscillator. East. http://met-all.org/oborudovanie/svarochnye/svarochnyj-oscillyator-svoimi-rukami.html.

Devices that are connected to the electrical circuit of the plasma cutter in series are more effective. This is explained by the fact that their circuit does not use high voltage protection as unnecessary. The use of an oscillator, in addition, allows you to expand the options of the plasma cutter and process “problem” metals or alloys:

aluminum;
“stainless steel”, etc.

DIY oscillator for plasma cutter

An oscillator, which is easy to make with your own hands if desired, most often refers to continuous-action devices. Let's look at the design of the gadget.

In general, the oscillator consists of the following main components:

oscillatory circuit. It plays the role of a spark generator of damped oscillations. The oscillatory circuit consists of the following components:
- storage capacitor;
- inductor . Its role is usually performed by the winding of a high-frequency transformer;
arrester;
choke coils;
high frequency transformer

If you have the necessary tools, skills in working with electronic equipment and the desire to assemble an oscillator for a plasma cutter with your own hands, then you will have to assemble and configure the above components.

Scheme

To make it clear what you will create, we will tell you in general terms about the principle of operation of the oscillator. The mains voltage after the step-up transformer is supplied to the capacitor of the oscillating circuit and charges it. When the capacitor is charged to the optimal value provided for by the parameters of the electrical circuit, it is discharged through the spark gap (air gap breakdown).

The appearance of a homemade arrester is shown in the figure.

Homemade single spark gap. East. http://met-all.org/oborudovanie/svarochnye/svarochnyj-oscillyator-svoimi-rukami.html.

The pulse that appears at this moment on the spark gap excites oscillations in the oscillatory circuit (oscillations represent the exchange of energy between the capacitance of the capacitor and the inductance of the winding of the high-frequency transformer). In the oscillatory circuit, damped high-frequency electrical oscillations arise, corresponding to its resonant frequency.

At the moment of resonance, a high voltage is generated on the capacitor plates of the oscillating circuit (the value depends on the quality factor “Q” of the oscillating circuit), which is supplied to the cutter through the separating capacitor and the coil winding and ignites. The parameters of the separating capacitor are selected in such a way that its reactance prevents the passage of low (mains) frequency current and does not interfere with high frequency.

Here is one version of the circuit diagram of a homemade oscillator.

Source: https://plazmen.ru/svoimi-rukami/plazmorez/oscillyator/

The principles of making a plasma cutter with your own hands

Creating a plasma cutter with your own hands is very profitable due to its simple design and the use of available components. They are inferior in functionality to industrial models, but allow you to perform basic types of metal cutting with no less efficiency and quality.

DIY plasma cutter

What is a plasma cutter used for?

A plasma cutter allows you to process various metals at temperatures of 25–30 thousand degrees with high speed, accuracy, and quality. It is a direct competitor to laser processing, but has a simpler design and is unpretentious in maintenance, operation, and repair.

Plasma cutting is used for cutting metal workpieces into shapes of varying complexity. Due to the protective gas atmosphere, complex metal compounds are not formed during heating, the properties of which differ from the required ones.

Inverter or transformer

To obtain plasma, you need to connect high-quality power sources. These can be transformers or inverters.

It is profitable to make a plasma cutter from an inverter due to its compactness, accuracy of current and voltage adjustments, control of electrical parameters, and economical energy consumption. It is limited in current to 70A, but has enough power to handle typical metalworking jobs.

The disadvantage of the inverter is the high requirements for power quality, which does not allow their use in networks with voltage fluctuations without connecting to stabilizers.

Transformers do not have the disadvantage of an inverter, are more reliable in operation, and are unpretentious in maintenance. But at the same time they have large dimensions, weight, and high power consumption. The current limit reaches 180 A, depending on the number of turns and the diameter of the wire used.

Inverter for plasma cutter

Design

The design of a plasma cutter consists of the following components:

A plasma torch designed to form a plasma jet. It has a complex design and is made of refractory metal. It is necessary to select the following parameters: nozzle diameter, cutter length, angle of compressed air supply into the plasma formation area.

Source: https://metalloy.ru/obrabotka/rezka/plazmennyj-rezak-svoimi-rukami

Do-it-yourself plasma cutter from an inverter: drawings, manufacturing instructions:

Do-it-yourself plasma cutter from an inverter - video, drawings, diagrams

For cutting sheet metal, various mechanical devices are used, as well as electric welding or a gas cutter. But besides these methods, there is an effective way to cut metal - a plasma cutter. A factory-made installation is quite expensive, but it can be replaced with a homemade plasma cutter from a welding transformer.

Features and purpose of a plasma cutter

Inverter plasma cutting is used to perform work in both home and industrial environments. There are several types of plasma cutters for working with different types of metals.

There are:

Plasma cutters operating in an environment of inert gases, such as argon, helium or nitrogen.
Instruments operating in oxidizing agents, such as oxygen.
Equipment designed to work with mixed atmospheres.
Cutters operating in gas-liquid stabilizers.
Devices operating with water or magnetic stabilization. This is the rarest type of cutter, which is almost impossible to find on the open market.

A plasma cutter or plasmatron is the main part of plasma cutting, responsible for direct cutting of metal.

Disassembled plasma cutter.

Most inverter plasma cutters consist of:

nozzles;
electrode;
protective cap;
nozzles;
hose;
cutter heads;
pens;
roller stop.

The operating principle of a simple semi-automatic plasma cutter is as follows: the working gas around the plasma torch is heated to very high temperatures, at which plasma appears that conducts electricity.

Then, a current passing through the ionized gas cuts the metal by local melting. After this, the plasma jet removes the remaining molten metal and a neat cut is obtained.

Based on the type of impact on metal, the following types of plasmatrons are distinguished:

Indirect action devices.
This type of plasmatron does not pass current through itself and is suitable only in one case - for cutting non-metallic products.
Direct plasma cutting.
Used for cutting metals by generating a plasma jet.

THIS IS INTERESTING: How to clean copper products at home

The design of a plasma cutter and recommendations for working with it vary greatly depending on the type of device.

Working gas

Even before choosing a specific design for manufacturing a plasma cutter, you should decide on the scope of use of such equipment.

If you plan to use the device exclusively for working with ferrous metals, you can exclude gas cylinders from the circuit and use only a compressor with compressed air.

If you plan to use such equipment for brass, titanium and copper, then you need to choose a plasma cutter with a nitrogen cylinder. Aluminum cutting is performed using a special gas mixture with hydrogen and nitrogen.

Advantages and disadvantages of plasma cutting

Plasma metal cutting has advantages over other methods:

the ability to cut any metals and alloys;
high processing speed;
clean cut line without sagging or drips of material;
processing is carried out without heating the parts being cut;
Flammable materials such as oxygen and natural gas cylinders are not used.

The disadvantages of plasma cutting are:

complexity and high cost of installation;
each operator with a plasma torch requires a separate transformer and control panel;
cutting angle no more than 50°;
a lot of noise when working.

Making a plasma cutter from a welding inverter yourself

For those who like to constantly make useful and beautiful things from metal, in addition to welding, they periodically need to cut metal. You can make a plasma cutter from a welding inverter with your own hands.

You should not buy additional expensive equipment that will rarely be used. A plasma cutter can be made from a transformer, but it will be heavy and energy-intensive.

What is it needed for?

Each specialist periodically has to cut out parts from a sheet. To do this by machining means turning a lot of metal into chips. It makes no sense to buy expensive equipment just to use it once a week for a few minutes. The solution is to make a plasma cutter yourself. You can remake different types of rectifiers:

inverter;
transformer;
rectifier.

Any device will work. The best option for those who like to tinker is to make a homemade plasma cutter from a welding inverter. When using gas cutting, productivity is lower and the cutting width is larger.

The thickness of the cut sheet on household equipment with current up to 200A is limited to 40 - 50 mm. This power is enough for building a house and working in a home workshop. The semi-professional inverter is adjustable for thicknesses up to 100 mm.

For light and powerful equipment, it is enough to connect a compressor and replace the usual holder with a plasma torch, made with your own hands and purchased ready-made . The equipment equipment is easily changed, and inverter plasma cutters turn into ordinary devices on which welding is performed.

Operating principle of the burner

Do-it-yourself plasma cutting occurs by converting the air flow passing through an electric arc into plasma with a temperature of 3000 - 6000⁰C. The metal is instantly melted in a limited area and blown out. The operating principle is similar to gas cutting.

Plasma formation

The inverter produces high DC current. An arc forms at the end of the electrode. Gas enters the nozzle under pressure. It runs in a spiral around the electrode. A vortex is formed, moving at high speed. Cold air enters the holder. Moving around the electrode, it cools it and at the same time heats itself. It comes into the arc already warmed up.

At the exit, the gas stream becomes thin. When connected to a hot arc, the air is heated by it and turns into plasma, increasing in volume by 20 - 30 times . Rotation of the flow around the electrode makes the jet thin.

cutting

A homemade plasma torch is brought to the metal. Hot plasma quickly melts metal in a small area. The air flow blows out the melt, forming a hole. When the cutter moves, a narrow strip of sheet cut through remains behind it.

A thin, neat cut is obtained by placing the plasma cutter from the inverter at a right angle to the surface being cut. The greater the angle of inclination, the wider the cutting strip .

To gouge the surface of a part, a home-made plasma cutter for metal is tilted towards the surface to be removed at an acute angle of 5 - 10⁰. The flame heats the top layer, the air blows out the liquid metal.

Indirect

A plasma cutter, assembled with your own hands from an inverter, can work on the principle of indirect action. The minus is applied to the tip. The arc occurs regardless of the presence of a conductive part. An indirect cutter can be used to cut any materials, including plywood, plastic, and plexiglass . The plasma jet is formed thinner.

The complexity of making an indirect plasma torch with your own hands is demonstrated by diagrams and drawings . It is necessary to place air cooling in a small tip about 20 mm long and reliably isolate the parts from each other.

Source: https://svarka.guru/oborudovanie/vidy-apparatov/plazmorez-iz-invertora.html

Do-it-yourself plasma cutter: homemade plasma cutter from a welding inverter

Plasma cutters are widely used in workshops and enterprises related to non-ferrous metals. Most small businesses use a homemade plasma cutter.

A plasma cutter performs well when cutting non-ferrous metals, since it allows local heating of products and does not deform them. Self-production of cutters is due to the high cost of professional equipment.

In the manufacturing process of such a tool, components from other electrical appliances are used.

Making a plasma cutter with your own hands

DIY plasma cutting can be done at home. The prohibitive cost of professional equipment and the limited number of models on the market force craftsmen to assemble a plasma cutter from a welding inverter with their own hands.

A homemade plasma cutter can be made provided you have all the necessary components.

Before making a plasma cutting installation, you need to prepare the following components:

Compressor.
The part is necessary to supply air flow under pressure.
Plasmatron.
The product is used for direct cutting of metal.
Electrodes.
Used to ignite an arc and create plasma.
Insulator.
Protects electrodes from overheating when performing plasma cutting of metal.
Nozzle.
A part whose size determines the capabilities of the entire plasma cutter, assembled with your own hands from an inverter.

Source: https://tutsvarka.ru/oborudovanie/plazmennyj-rezak-svoimi-rukami

How to make a plasma cutter with your own hands - Metals, equipment, instructions

Unlike a welding transformer, an inverter is compact, light weight and high efficiency, which explains its popularity in home workshops, small garages and workshops.

It allows you to cover most needs for welding work, but for high-quality cutting you need a laser machine or plasma cutter.

Universal welding machine

Laser equipment is very expensive, and a plasma cutter is also not cheap. Plasma cutting and welding of thin metal has excellent characteristics that are unattainable when using electric welding. At the same time, the power unit of a plasma cutter and a welding machine for electric arc welding have largely the same characteristics.

There is a desire to save money and, with a little modification, use it for plasma cutting. It turned out that this is possible, and you can find many ways to convert welding machines, including inverter ones, into plasma cutters.

A plasma cutting machine is the same welding inverter with an oscillator and a plasma torch, a work cable with a clamp and an external or internal compressor. Often the compressor is used externally and is not included in the package.

If the owner of a welding inverter also has a compressor, then you can get a homemade plasma cutter by purchasing a plasma torch and making an oscillator. The result is a universal welding machine.

DIY plasma torch

When making a plasma cutter from a welding inverter with your own hands, the most difficult part of the work is the production of a high-quality cutting head (plasma torch).

Tools and materials

If you make a plasma cutter with your own hands, it is easier to use air as a working fluid. For production you will need:

a handle in which the cable and air supply tube should fit;
plasma cutter torch start button;
insulating sleeve;
plasma cutter torch electrode;
air flow swirl device;
a set of nozzles of various diameters for cutting metals of various types and thicknesses;
protective tip against splashes of liquid metal;
a limiting spring to maintain the same gap between the plasma cutter torch nozzle and the metal being cut;
chamfering attachments.

Plasma cutter consumables in the form of nozzles and electrodes should be purchased at a welding equipment store. They burn out during the cutting and welding process, so it makes sense to purchase several pieces for each nozzle diameter.

The thinner the metal to be cut, the smaller the plasma cutter torch nozzle hole should be. The thicker the metal, the larger the nozzle opening. The most commonly used nozzle is the one with a diameter of 3 mm; it covers a wide range of thicknesses and types of metals.

Assembly

The plasma cutter torch nozzles are attached with a clamping nut. Directly behind it there is an electrode and an insulating sleeve, which does not allow an arc to occur in an unnecessary place in the device.

Then there is a flow swirler that directs it to the desired point. The entire structure is placed in a fluoroplastic and metal case. A pipe for connecting an air hose is welded to the outlet of the tube on the plasma cutter torch handle.

Electrodes and cable

The plasma torch requires a special electrode made of refractory material. They are usually made from thorium, beryllium, hafnium and zirconium. They are used due to the formation of refractory oxides on the surface of the electrode during heating, which increases the duration of its operation.

When used at home, it is preferable to use electrodes made of hafnium and zirconium. When cutting metal, they do not produce toxic substances, unlike thorium and beryllium.

The cable from the inverter and the hose from the compressor to the plasma cutter torch must be laid in one corrugated pipe or hose, which will ensure cooling of the cable in case of heating and ease of operation.

The compressor at the outlet must have a reducer to obtain normalized pressure at the plasma torch.

Options for direct and indirect action

The design of a plasma cutter torch is quite complex; it is difficult to do at home, even with various machines and tools, without a highly qualified worker. Therefore, the manufacture of plasma torch parts should be entrusted to specialists , or even better, purchased in a store. The direct action plasma torch torch was described above; it can only cut metals.

There are plasma cutters with indirect action heads. They are also capable of cutting non-metallic materials. In them, the role of the anode is played by the nozzle, and the electric arc is located inside the plasma cutter torch; only the plasma jet comes out under pressure.

Despite the simplicity of the design, the device requires very precise settings; it is practically not used in amateur production.

Refinement of the inverter

To use an inverter power source for a plasma cutter, it needs to be modified. You need to connect an oscillator with a control unit to it, which will serve as a starter that ignites the arc.

There are quite a lot of oscillator circuits, but the principle of operation is the same. When the oscillator is started, high-voltage pulses pass between the anode and cathode, which ionize the air between the contacts. This leads to a decrease in resistance and causes an electric arc.

Then the gas electric valve is turned on and under pressure air begins to pass between the anode and cathode through an electric arc. Turning into plasma and reaching the metal workpiece, the jet closes a circuit through it and the mass cable.

A main current of approximately 200 A begins to flow through the new electrical circuit. This triggers the current sensor, which turns off the oscillator. The functional diagram of the oscillator is shown in the figure.

Functional diagram of the oscillator

If you have no experience working with electrical circuits, you can use a factory-made oscillator of the VSD-02 type. Depending on the connection instructions, they are connected in series or in parallel to the plasmatron power circuit.

Before making a plasma cutter, you must first determine what metals and what thickness you want to work with. A compressor is sufficient to work with ferrous metal.

Cutting non-ferrous metals requires nitrogen; high-alloy steel requires argon. In this regard, you may need a trolley for transporting gas cylinders and reduction gears.

Like any equipment and tool, a welding machine with a plasma head requires certain skill from the user. The movement of the cutter should be uniform, the speed depends on the thickness of the metal and its type.

Slow movement results in a wide cut with jagged edges. Moving quickly will result in the metal not being cut through in all places. With proper skill, you can get a high-quality and even cut.

Source: https://spb-metalloobrabotka.com/kak-sdelat-plazmennyy-rezak-svoimi-rukami/