A semi-automatic welding machine in the hands of a person who knows how to use equipment is a multifunctional and useful device. Thanks to him, a diligent owner of a suburban area can always produce various metal structures, as well as engage in minor car repairs, without resorting to outside help.
Of course, you can buy a welding unit in the distribution network, since the industry currently offers a huge number of models, but this can seriously hit the family budget. Therefore, craftsmen, having found the necessary parts and assembly scheme, try to make a semi-automatic welding machine with their own hands.
In principle, the circuit itself of such a device is not particularly complicated. With a little knowledge of electrical engineering and the ability to carry out locksmith work, you can safely proceed to the manufacture of a semi-automatic welding machine on your own.
Welding features
The traditional welding machine is a transformer that has a high power secondary winding. Welding ferrous metals and steel with the help of such a device is not particularly difficult, but copper, aluminum and other non-ferrous metals will not be able to weld them.
And this is explained very simply: parts made of non-ferrous metals and alloys oxidize very quickly in the open air, so their connection does not occur. To protect the seam, it is necessary to supply elements to the welding zone that can restrict the access of oxygen.
The best quality of this work can be done by self-made semi-automatic welding machines, which are divided into the following types according to the type of protection:
- Welding takes place under the protection of flux.
- The compound is formed in an inert gas atmosphere.
- The splicing process takes place using an electrode flux-cored wire.
The main condition for a strong and high-quality connection is stable arcing, which is achieved by using direct current.
The device of a homemade apparatus
The principle of operation of a semi-automatic welding machine is based on the conversion of electric current of variable frequency into direct current. Moreover, it is necessary to supply a welding wire and a protective inert gas to the junction.
These operations are carried out by the following main components of a self-made semi-automatic welding machine:
- Inverter device.
- Wire feeder.
- Shielding gas kit.
Despite the apparent complexity of the semi-automatic welding circuit diagram, it is not difficult to make it for a person who is familiar withprinciples of electrical engineering.
Making a Homemade Device
It is recommended to start work on the device of a semi-automatic welding machine with your own hands by planning the location of the main components of the unit. First of all, you need to carefully consider what to make the outer casing of the unit. It should be roomy, easy to open and close for cleaning, and, importantly, light in weight.
The best option is to use a case from an old PC system unit for these purposes. Having pre-cut cooling cutouts is a huge plus.
Also in such a home-made semi-automatic welding machine from a computer, there is already a built-in power supply with a voltage of 12 V, which is necessary to power the wire feed system. If you still could not find the system unit, then a metal box of the appropriate size is quite suitable for the external case.
Welding wire is best used in standard 5kg spools as their inner diameter matches well with the polyethylene pipe used for the pivot.
After analyzing and arranging the elements for the manufacture of a semi-automatic welding machine with our own hands, we proceed to the alteration of the necessary components.
Main components required for the machine
Of course, before you make a semi-automatic welding machine, you need to prepare the necessary components of this device in advance. For these purposes, you needprepare:
- The device that will generate a working current of 150 A is an inverter. For a home-made semi-automatic welding circuit, craftsmen often use a transformer from a household microwave oven.
- Electrical assembly required to control the unit.
- Special purpose burners.
- Sleeve for semi-automatic welding required to supply shielding gas to the welding site.
- Welding wire feed unit.
- Bobbin with wire.
Given that all the equipment is heavy, many welders recommend making a do-it-yourself cart for semi-automatic welding.
Transformer manufacturing
A transformer from a microwave oven is suitable for a semi-automatic welding machine in many technical parameters. This product consists of two coils with copper wire. The primary winding of the transformer remains unchanged.
All operations for the conversion of a welding transformer for a semiautomatic device will be carried out on the secondary winding. To reduce the operating voltage and increase the output current, it is necessary to rewind the secondary winding. In this case, it is necessary to correctly calculate the diameter of the copper wire for the coil, because both increased and decreased output voltage significantly affect the quality of the weld.
Rewinding work must be done with extreme care so as not to damage the insulation of the conductors.
To get stableoutput voltage, the electrical circuit of the supply unit also includes a rectifier bridge, a capacitor and a choke. The use of a capacitor is necessary to smooth out the voltage ripple at the output of the rectifier. The inductor is used to maintain a stable level of operating voltage.
Gas burner
The use of this device is due to the need to supply protective gas to the place where the weld is formed. Most often, this device is purchased in a distribution network, since it is very difficult to make it yourself, especially since it is not necessary to use expensive models for a self-made semi-automatic welding machine.
Too hard hose makes it much more difficult to work with the equipment, while a soft one is capable of bending. Therefore, special attention should be paid to the quality of the sleeve for semi-automatic welding. You can eliminate hose kinks near the joints by inserting additional springs.
Wire feeder
The main condition for creating a high-quality weld is a uniform and continuous wire feed to the welding site. For these purposes, a home-made semi-automatic welding machine is equipped with a wire feed system.
To make a feeding unit you will need:
- Two bearings, one of which is clamping (adjustable).
- Clamping spring.
- Guide roller.
- Electric motor to rotate the shaft.
- Mechanism fastening system.
Foodthe electric motor is carried out from the built-in power source, which is located in the system unit. If the case is assembled from a separate device, it is necessary to assemble an autonomous power circuit.
Mechanism assembly steps:
- On a special metal plate we drill holes for installing bearings, as well as the motor shaft.
- Attach an electric motor on the back of the plate.
- A guide roller is installed on the drive shaft.
- The bearings are fixed at the top and bottom.
Cooling system device
During the operation of the semi-automatic welding machine, the secondary winding of the transformer is heated. Therefore, it becomes necessary to cool the unit. For these purposes, you need to install fans on the sides of the case. They are installed opposite the transformer, while they must be configured to extract heated air.
To improve air circulation, drill 20-50 holes in the casing with a diameter of about 5 mm.
Remember that high-quality and efficient cooling of the electrical part of welding equipment has a positive effect on its performance.
Optional equipment
It is customary to purchase a shielding gas cylinder of a standard type, because when working with gas mixtures, equipment safety measures often come first.
Using carbon dioxide to protect the weldallows the use of fire extinguisher containers as cylinders. In this case, you still have to install a special adapter to connect the gearbox.
To increase the mobility of work, semi-automatic welding machines for summer cottages and suburban areas are equipped with special trolleys. You can buy ready-made products, but experienced craftsmen prefer to make their own carts.
Each specialist can develop the design of this device with his own hands. Materials can also be of various types (channel, round or profile pipe).
Some features of operation
Do-it-yourself semi-automatic welding equipment requires a certain attitude to its efficient operation. Remember that a homemade device is not suitable for professional activities.
It is imperative to clean the equipment from dirt and dust at least once every 3-6 months. With increased use, this operation can be performed more frequently. Experienced welders recommend cleaning equipment after each use.
Of course, modern industry produces a wide range of semi-automatic welding models, but every diligent owner prefers to make this device on his own. This is not only a cost saving, but also an opportunity to make a unit that meets the requirements of the master.
