For various types of work on the creation of metal used a variety of welding machines. One of the most versatile and productive is a semi-automatic. It is distinguished by a high speed of seam conducting, the ability to lay long continuous joints and minimal subsequent processing of the joint for painting. Semiautomatic machines are large and small, expensive and cheap, but the key parameters for their suitability for specific types of work are hidden in their configuration and characteristics. We offer a number of tips from experts on the choice of welding semiautomatic devices for various purposes.
Content:
The best manufacturers of automatic welding machines - which company to choose
When you urgently need to purchase high-quality semi-automatic, then turn to trusted manufacturers:
- Resanta;
- Fubag;
- Inforce;
- Aurora;
- Patriot.
But the capabilities of each individual device are so different from others that it is better to get acquainted with specific models in ranking of the best welding semiautomatic devices. This will help to orient in their advantages and disadvantages, and choose more suitable equipment.
For those who want to understand each characteristic and choose a semiautomatic device, the material below is prepared by itself.
The principle of operation and the device welding semi-automatic
Semiautomatic devices are widespread due to the convenience of working with them. Unlike manual electrode welding, it is not necessary to interrupt it regularly to replace a burnt electrode, and you can stitch a length of 2 m or more.
This greatly accelerates the process of welding structures, especially large ones. If pipes of large diameter are joined, then placing them on rollers will create one continuous circular joint.
A semi-automatic is also convenient due to the standard nozzle length and the distance between it and the seam. Unlike the electrode, which burns decreases and requires control not only of the arc size, but also of the filler element itself, which is inconvenient for beginners, equipment with a wire allows you to maintain a constant distance to the surface to be welded.
Like a semiautomatic machine to many welders and the subsequent minimum processing of seams. They have no slag on the surface and the product can be immediately painted.
The equipment is suitable for:
1. Create tacks;
2. Obvarki;
3. Pulse welding;
4. Carbon steel compounds;
5. Creating seams on stainless steel;
6. Welding iron.
The principle of operation of the semi-automatic is divided into two processes:
1. Electric;
2. Gas.
The first is to generate the required voltage on the inverter or rectifier, where a high current is generated and the volts are lowered. In the case there is a drum with wire and a feed mechanism consisting of support and pressure rollers.
The electric motor starts the rotation and the wire, which serves as an additive element, moves into the burner through a special channel of metal. At the end of the nozzle is the mouthpiece, which receives the voltage. Due to the minimum inlet and good contact, the current with the value “+” is transmitted to the wire.
The second contact with the indicator "-" is connected to the ground cable and attached to the product. Pressing the button on the burner starts the feed mechanism and power. Closing the wire on the product excites an electric arc. Here the second process is connected, without which welding by a semiautomatic device would be impossible.
In parallel with the current, pressing the burner button activates the gas valve and the supply of carbon dioxide or its mixture with argon from the cylinder with a reducer to the burner nozzle. The latter has a tubular outreach, which promotes good distribution of inert gas around the weld pool. This protects the molten metal from interacting with the surrounding air and prevents carbon from being released, which would create pores and weaken the seam.
To ensure this complex process, a semi-automatic device has everything you need:
1. Welding current source;
2. Wire reel;
3. Feed mechanism;
4. Control board with microchips;
5. Sleeve and cable mass;
6. Burner with mouthpiece and nozzle;
7. Gas valve;
8. Balloon and gearbox.
Types of welding semiautomatic devices
Household
These are simple models with low power, which are affordable and convenient to perform work in the country or in the garage.
With their help, you can weld a tank under water or a tank for fuel, put a patch on the car body, make a wicket yourself. Usually such a device is in every authoritative owner in a village or a small town.
Advantages:
- easy to maintain and repair yourself;
- simple device;
- suitable for various works in the yard;
- suitable for beginners;
- a light weight;
- compact size;
- Efficiency of 30-50%.
Disadvantages:
- low power;
- low values for the maximum current strength;
- short cable channel.
Semi-professional
This type of apparatus has increased power, a larger range of settings and advanced possibilities for the creation of metal structures. They are used for private workshops or service stations, where semi-automatic machines work for 4-6 hours every day.
Advantages:
- high build quality;
- varying degrees of protection;
- power from 5 to 7 kW;
- various input voltage options;
- large indicators of maximum current strength;
- Efficiency 60-70%;
- cable length 2-3 m.
Disadvantages:
- more expensive parts;
- big weight;
- It is not always possible to lower the current strength to 10-20 A.
Professional
Such devices are characterized by volumetric cases and large mass. The wire feeder and cable channel they are designed for setting different diameters, which allows welding both thin metals of machine bodies and containers, and thick steel flanges and channels. They are used in manufacturing from engineering to the creation of water treatment systems.
Advantages:
- high power;
- different cable lengths;
- maximum amp setting up to 500 A;
- good degree of protection;
- there are models with carts;
- Efficiency 80-100%;
- idling 50-80 V.
Disadvantages:
- large mass;
- often washing only from 380 V.
Selection parameters of welding machine
Input current
Semiautomatic machines must be connected to the mains. This parameter can be 220 or 380 V, or a combined type.
1. To work in the country you need a model of 220 V, so that the power supply is carried out from an ordinary outlet.
2. Enterprises use 380 V devices, because there is a three-phase network. This gives high performance and the ability to connect multiple units simultaneously.
3. It makes sense to acquire a combined type only with a moving type of work (between workshops and non-production premises), where connection possibilities are not known in advance.
Power
This characteristic affects the ability of the semiautomatic device to boil a certain thickness of the metal and affects the performance. The parameter varies from 3 to 14 kW, and implies that the specified amount of current will be consumed by the equipment in one hour of operation.
The higher the power, the wider the area of use of the unit and the thicker the plates and pipes they can connect to high quality. But the effective power (operating) is slightly lower than the power consumed, so the value is selected with a margin of 20%.
1. To use the equipment in the country, for welding the tank or to patch the car body, low indicators of 3 kW are needed.
2. Gates and doors are made of metal 1.2-1.5 mm, where a characteristic of 4-5 kW is required.
3. Flanges and thick sheets of iron are welded on devices with a capacity of 7 kW and above.
Degree of protection
Each device is endowed with a certain degree of protection against liquid and ingress of mechanical objects inside. For this, IP marking with numbers is used.
In semi-automatic, it can have three options:
1. 21 - only for work indoors and installed on a high stand, strictly in an upright position. Slight dripping of water from above onto the hull is allowed (if the roof leaks a little), which will not harm the device. Suitable for work in the garage.
2. 22 - it is allowed to operate indoors with the installation on a stand and a slight deviation from the vertical (up to 15 degrees), in which water from above does not penetrate inside. They can be used under a canopy or in a private workshop where splashes of rain fly in or the roof leaks. Will be suitable for welding of pipes with water, when using a pedestal or the cart.
3. 23 - such units are protected from rain and even oblique drops at an angle of 60 degrees. They can be used outside in any weather. Will be suitable for open works on the pipeline or the platform near the shop.
Maximum welding current
Each semi-automatic has a maximum indicator for the development of welding current. It is measured in amperes and can be from 110 to 500 A. It is important to determine the thickness of the metal that the device can boil.
If the values are not enough, then the welding seam will not melt deeply, but will lie on the surface. Such a connection will not be sealed and easy to break. But too large indicators when welding thin metals will only lead to the failure of the entire resource of the semiautomatic device and the initial overpayment.
1. To work with car bodies, where the wall of steel is 0.6-0.8 mm, models with an indicator of 110-120 A are sufficient.
2. The manufacture of gates and doors, as well as tanks and containers of metal 1.0-1.5 mm will require values of 160-180 A.
3. Thick-walled pipes and flanges (2-4 mm) are welded with equipment from 200 A.
4. Powerful plates and channels for metal structures need 300-400 A.
Minimum welding current
There is a need for the opposite - it is necessary to reduce the welding current to the minimum values in order to weld a thin product. Here, the capabilities of the devices vary in the range of 10-40 A. If the device is unable to reduce the current to the desired performance, then burnouts will be formed.
Installing additional resistance in the circuit may help, but this will slow down the process (constant adjustment by shifting the end of the cable on the spring) and may interfere under your feet.
1. Work with car bodies requires the lowest limits (10-20 A), since the metal is very thin and holes from the arc are easily formed.
2. For economy in the manufacture of doors, some use thin steel, which is difficult to combine with the frame of the frame, and here it is also desirable to lower the current to 20 A.
3. Boil the sheet-iron tank without a burn-through will turn out on the indicator 30-40 A.
Current adjustment
With the help of a switch on a semiautomatic device, it is possible to change the current strength from maximum to minimum, which allows welding of metal of various thickness. But the method of adjustment itself can have a significant impact on the work performed and performance.
On most cheap models there is a step-by-step circular toggle switch, which adds a current of 10 A at each step. It looks like this: 20-30-40-50-60 ... 110-120-130 A.
When work is often done with the same materials, it is possible to set the value to 80 A and to safely begin welding. But if the parts to be connected are constantly changing in thickness and combination method, then it will not always be possible to create an equally good 80 A seam, and a more subtle change in current strength will be required.
In such cases, it is better to acquire digital adjustment in increments of 1 A (10-11-12-13 .... 72-73-74 A). This will help to choose the optimal current in each specific situation.
Idling
When the semiautomatic device is turned on and the welding arc is started, but it does not burn, then it is idling.This is a kind of standby mode, where the device is ready for action. For this, a certain voltage level is maintained on current-carrying parts (from 30 to 90 V), due to which, when the contact closes the wire against the surface, an arc is excited.
The higher the idle value, the easier it is to start the arc and weld. Often, after the end of the seam and a short break, the welder tries to start a new one, but the contact does not close due to the melting at the end of the wire. The worker has to remove this element with side cutters for better contact with the mass, which slows down the performance a little.
1. At the cottage or in the garage, where there is no strict work schedule, you can choose a model with an idling of 30-40 V.
2. For a workshop or workshop, it is desirable to have indicators of 50-60 V.
3. On the production of taking semi-automatic with idle 80-90 V.
Cable channel length
This important element can be 2–5 m long. The filler wire moves along it and inert gas is supplied. The convenience and maneuverability of the welder on various objects depends on its length.
1. If the apparatus is massive and the welded construction is large, then it is inconvenient to constantly move it on a trolley with a balloon. Here, choose a long sleeve in 4-5 m.
2. If the device is small, then it is carried by the handle, and behind it the electric wire and the gas hose only stretch. Then welding can be conducted at a considerable distance and with a short cable channel.
3. When work is carried out in a cabin with a small radius of movement, models with a channel of 3 m will do.
4. For welding on the table enough 2-2.5 m.
Pulse welding capabilities
Some semi-automatic devices have a pulse mode when the program itself supplies current and wire with short breaks, which allows the welder to rearrange the direction of the burner to a new weld area and get uniform tacks of the same length and degree of penetration.
This feature is very convenient when working with thin iron (car body, docking of metal sheets without using a thick base). Buy such models for service stations or create decorative items made of tin with forging.
Burner connector
The welding torch experiences the greatest load during the operation of the semiautomatic device. It is exposed to high temperatures, shocks from falling, splashes of molten metal. The cable channel regularly tread or they cling to the corners of the product. Sooner or later there is a need to replace these elements.
Connector for the burner and cable channel are of three types:
1. Euro;
2. Euro 19 pin;
3. Individual.
It is much easier to choose the first two types, in view of the standard, and even a model from another device or manufacturer can approach them. This is useful for semi-professional and professional activities, where you can not lose weeks in finding and buying a new suitable burner.
An individual connector can also be purchased for domestic needs, because periodic operation does not consume the burner resource so quickly, and buying a new one will not be so urgent.
Work at low input voltage
For full operation of the device, sufficient voltage must be applied to it. This parameter varies from 140 to 220 V.
Some models are able to function only at 220 V, and the fall of the network leads to a weak arc and the inability to weld. Such semi-automatic devices should be bought only where there is a stable voltage or there is its stabilizer.
Units with a value from 140 V are suitable for rural areas or moving activities where network parameters are unknown or voltage often jumps. This is a good option for cottage or garage.
Opportunities for welding without gas
A semiautomatic device with the use of wire must necessarily boil in a protective gas medium, otherwise there will be pores in the seam and it will easily crack under load. But there is a need to create a connection far from the location of the welding station or this joint must be performed at a considerable height.
If in the first case large-scale transportation of the apparatus with a balloon is necessary, then in the second it may be impossible at all. For these purposes, the manufacturers supplied some semi-automatic devices with a universal connector for a conventional electrode holder and an MMA mode, where the gas valve and the rotation of the drum with the feed mechanism are closed, and only resistance welding works.
So you can disconnect the hose, take the device and carrying and seam at any distance from the workplace or height. This will be practical in the country, where you may need to podvarit tank, fence or help a neighbor. Still such models are bought by enterprises in order to cover all the needs of production over a large territory.
Current source
A welding current with the required number of amperes can be produced in an inverter or rectifier. These are various in design and principle of operation of the device. The first are more suitable for beginners, because they have different capabilities and it is easier to ignite and hold the arc.
Rectifier-based semi-automatic machines are easier to maintain and cheaper to repair, making them more attractive for workshops and businesses. But working on them requires a certain amount of experience, which is not suitable for students.
Maximum wire diameter
On semiautomatic machines, you can change the spool with wire and install another one, but this requires a permutation and a cable channel, as well as rollers with grooves on the feeder. Not all models have a wide range to replace such parts, so you should carefully choose the device, taking into account future work.
The thicker the metal, the larger the diameter of the wire needed to melt and create a good connection.
1. Boil pipe butt well on wire 1.0 mm.
2. Gates and doors are also produced on this parameter.
3. Flanges and plates 5–7 mm thick require the installation of a wire diameter of 1.2 mm.
4. More powerful metal structures need 1.6 mm.
Minimum wire diameter
For welding of thin sides, it is necessary that the apparatus has the possibility of moving the rollers and the cable channel to smaller values. Work with a thick wire will lead to rough seams and inaccurate type of connection.
1. For welding tanks and tanks using wire 1.0 mm.
2. Creating centrifuges and other devices for agricultural activity or ventilation requires a 0.8 mm wire.
3. Welding of machine cases is carried out using a diameter of 0.6-0.8 mm.
Machine weight
The weight of the welding machine can vary from 13 to 120 kg. This affects mobility and the need for additional equipment.
1. Light models (from 13 to 20 kg) are suitable for giving and a garage, so that you can cook on the spot without a problem or move to the right part of the yard, but you will need a long gas hose and carry.
2. Devices of 25-40 kg are placed on a stand and are more suitable for stationary use (next to the table), since the transfer is difficult and requires the assistance of a second person (due to size).
3. Models from 50 kg and above must be installed on the cart to which the cylinder is also attached. This allows you to roll the entire complex on the territory, provided concrete floors or tiles, which is practical for service stations and production workshops.
Burner cooling
In the process of conducting the seam, the conductive parts of the mouthpiece and the nozzles are heated by the arc and electricity. More on them constantly splashes molten metal. If you continue to cook without stopping, then the handle of the burner can heat up and bite the welder’s hand, as well as deform.
In most cases, manufacturers are counting on air cooling of the apparatus (fan in the case) and natural evaporation of temperature from the surface of the burner. This allows you to use the device in accordance with its efficiency (35-60%) and requires interruptions in work.
To protect the user and increase the duration of welding, some models are equipped with water cooling.For this, a system is provided for placing the cable in a hose with circulating fluid, which is distilled from the reservoir in the housing with a small pump.
1. Air cooling is suitable for semi-automatic in the country, service stations or workshops for the production of doors. Here, welding work alternates with the stripping and preparatory work, and the equipment will have time to cool.
2. To work outside, in frosty weather, ethyl alcohol is added to the liquid to prevent freezing. Such a cooling system is suitable for enterprises and manufactures where semi-automatic devices are involved for 8-10 hours per day and welding is carried out at maximum currents.
Which welding machine to choose
1. For elementary work in the country (fence, tank) you will need household equipment with an input voltage of 220 V, a maximum rate of 120 amps, air cooling, a minimum welding current of 30 A, the ability to cook continuously for 4 out of 10 minutes, weighing 11 kg, 3 kW, individual burner connector and IP21 degree of protection. Sleeve length is enough for 2 meters.
2. To cover the needs of the workshop for the production of doors and gates, an inverter-type semiautomatic device of 220 V is needed, with a current of 230 A, a Euro burner connector, the ability to work at reduced voltage, 70% of capacity, a minimum current of 20 A, and a weight of 13 kg, and the ability to connect MMA , air-cooled and cable channel 2.5 m. Device power 4.8 kW, wire diameter range from 0.8 to 1.2 mm.
3. A model with an inverter with a power of 4 kW, a maximum current of 190 A, and a minimum of 10 A, having a pulse mode and an MMA connection, with a Euro connector, air-cooled, with a capacity of 60%, and a wire diameter of 0.6-1 , 0 mm, 3 m sleeve, incoming voltage of 140-220 V.
4. To work with thick pipes and flanges in the enterprise, you need to have a semi-automatic with a rectifier of 380 V, with a current of 300-400 A, a minimum value of 50 A, with a capacity of 80-100%, protection degree IP23, water-cooled, 4 m sleeve, MMA capability , idle 70 V, Euro connector, power of 7.8 kW.
How much is automatic welding
1. The model for domestic needs is estimated at 15,000-18,000 rubles.
2. For a workshop for the manufacture of doors and gates the device costs 20000-30000 rubles.
3. Welding of thin metal to the service station will require you to buy a semi-automatic for 19,000-27,000 rubles.
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