Semi-automatic welding made with your own hands from available materials. The semi-automatic welding machine can be used for repairing vehicles, constructing a greenhouse frame, manufacturing metal products.
Semiautomatic welding machine is used in different areas: in construction, mechanical engineering, in the manufacture of metal structures and in installation work.
Selection rules
It is recommended to first select a gun and a carbon dioxide cylinder. If desired, a shielding gas is used. Experts recommend considering the operating features of the wire feeding mechanism. Before deciding how to make a semi-automatic welding machine, you should find out its components. Gun and cylinder - necessary elements welding machine. Experts advise to carefully select a gas cylinder. Initially, you can use a carbon dioxide fire extinguisher, but such a replacement is short-lived.
Using a gun, the wire unwinding from the spool is fed to the welding zone. A hose is attached to this device that supplies gas. The substance is supplied to the gun nozzle using an electromagnetic valve, which is activated when the wire in contact with the surface of the gun is closed.
The gun for a homemade welding machine is chosen taking into account personal preferences. Experts do not recommend purchasing cheap devices that have low-quality gas hose. Semi-automatic welding machines can be equipped with a CO2 gas system. In the operation of this equipment, the use of gas is necessary to obtain high-quality seams. Carbon dioxide is supplied to the welding area, which protects it from the effects of nitrogen and oxygen. The seams made with a gas apparatus contain little slag.
Gas welding can be replaced with flux-cored wire. The advantages of this system are the absence of the need to use gas and the speed of the work process, but the quality of the seams is low. Gas protection is necessary if high demands are placed on products.
The apparatus that feeds the wire can be assembled using a windshield wiper motor in cars. A roller is put on the shaft. You can prevent it from sliding along the drive roller if you additionally press the structure with a firmly fixed satellite roller.
Welding, for which semiautomatic welding machines are used, requires the use of a rectifier. It is selected depending on the winding method of the corresponding transformer. Manufacturing a welding machine with 2 windings will require the use of 2 “DL161-200” diodes. The bridge rectifier circuit will require 4 diodes. A capacitor (30000x63V) helps smooth out voltage ripples.
In a chain direct current In order to enhance the stability of the arc after the rectifier diodes, it is necessary to install a choke wound on the transformer core with approximately 20 turns of wire. The core cross-section is 35x35 mm. The diameter of the wire must be no less than that used for the secondary winding in the transformer. The power supply for the electric motor used in the wire feeding mechanism comes from a power supply in which the current is 5 A and the output voltage reaches 12-15 V.
Semi-automatic welding machines are additionally equipped with:
- electromagnetic trigger for switching on;
- solenoid valve for gas;
- wire feeding sleeve.
Additional work
Self-made semi-automatic machines can be of high quality and reliable if all the nuances are thought out. You can regulate the wire feed speed during operation of the welding machine using a variable resistor. The gas supply valve will open synchronously with the device’s transformer turning on after pressing the “Start” button.
The scheme according to which the semi-automatic machine will be made with your own hands can be changed taking into account the available parts.
The rectifiers in the block are located:
- throttle;
- bridge rectifier (200 A);
- an electrolytic capacitor with a capacity of 22,000 µF or more (63 V).
The choke is necessary to filter the variable component of the device. When using the TS-270 transformer, 60 turns of winding are sufficient. To one end of the choke of the welding machine it is necessary to connect the “+” of the rectifier, and to the other end of the “+” of the capacitor and the cable that will supply the “+” of the rectifier, which is equipped with the semi-automatic welding machine, to the wire. The gun must be connected to one of the valve contacts using a wire. The negative of the rectifier and the 2nd contact of the valve must be connected to the product.
Make a semi-automatic welding machine yourself without extra costs possible using an electric valve from a Zhiguli car. By pressing the button, the master will be able to turn on the MPP, the wire will be fed to the head of the gun, closing the circuit of the solenoid valve, which is responsible for the gas supply. The valve supplying the substance and the MPP motor are powered using an additional transformer (200 V). It is recommended to close access to the “filling” of the device so that welding work is safe.
Technical data of our semi-automatic welding machine:
Supply voltage: 220 V
Power consumption: no more than 3 kVA
Operating mode: intermittent
Operating voltage regulation: stepwise from 19 V to 26 V
Feed rate welding wire: 0-7 m/min
Wire diameter: 0.8mm
Magnitude welding current: PV 40% - 160 A, PV 100% - 80 A
Welding current control limit: 30 A - 160 A
A total of six such devices have been made since 2003. The device shown in the photo below has been in service since 2003 in a car service center and has never been repaired.
Appearance of semi-automatic welding machine
At all
Front view
Back view
Left view
The welding wire used is standard
5kg coil of wire with a diameter of 0.8mm
Welding torch 180 A with Euro connector
was purchased at a welding equipment store.
Welder diagram and details
Due to the fact that the semi-automatic circuit was analyzed from such devices as PDG-125, PDG-160, PDG-201 and MIG-180, circuit diagram differs from a circuit board because the circuit was drawn up on the fly during the assembly process. Therefore, it is better to stick to the wiring diagram. On the printed circuit board, all points and parts are marked (open in Sprint and hover your mouse).
Installation view
Control board
A single-phase 16A type AE circuit breaker is used as a power and protection switch. SA1 - welding mode switch type PKU-3-12-2037 for 5 positions.
Resistors R3, R4 are PEV-25, but they don’t have to be installed (I don’t have them). They are intended for fast discharge choke capacitors.
Now for capacitor C7. Paired with a choke, it ensures combustion stabilization and arc maintenance. Its minimum capacity should be at least 20,000 microfarads, optimal 30,000 microfarads. Several types of capacitors with smaller dimensions and higher capacity were tried, for example CapXon, Misuda, but they did not prove to be reliable and burned out.
As a result, Soviet capacitors were used, which still work to this day, K50-18 at 10,000 uF x 50V, three in parallel. 
Power thyristors for 200A are taken with a good margin. You can put it at 160 A, but they will work at the limit, they will require the use good radiators and fans. The used B200s stand on a small aluminum plate.
Relay K1 type RP21 for 24V, variable resistor R10 wirewound type PPB.
When you press the SB1 button on the burner, voltage is supplied to the control circuit. Relay K1 is triggered, thereby supplying voltage to the solenoid valve EM1 for supplying acid, and K1-2 - for the power supply circuit of the wire drawing motor, and K1-3 - for opening the power thyristors.
Switch SA1 sets the operating voltage in the range from 19 to 26 Volts (taking into account the addition of 3 turns per arm up to 30 Volts). Resistor R10 regulates the supply of welding wire and changes the welding current from 30A to 160A.
When setting up, resistor R12 is selected in such a way that when R10 is turned to minimum speed, the engine still continues to rotate and does not stand still.
When you release the SB1 button on the torch, the relay releases, the motor stops and the thyristors close, the solenoid valve, due to the charge of capacitor C2, still remains open, supplying acid to the welding zone.
When the thyristors are closed, the arc voltage disappears, but due to the inductor and capacitors C7, the voltage is removed smoothly, preventing the welding wire from sticking in the welding zone.
Winding up a welding transformer
We take the OSM-1 transformer (1 kW), disassemble it, put the iron aside, having previously marked it. We make a new coil frame from PCB 2 mm thick (the original frame is too weak). Cheek size 147×106mm. Size of other parts: 2 pcs. 130×70mm and 2 pcs. 87x89mm. We cut out a window measuring 87x51.5 mm in the cheeks.
The coil frame is ready.
We are looking for a winding wire with a diameter of 1.8 mm, preferably in reinforced fiberglass insulation. I took such a wire from the stator coils of a diesel generator). You can also use ordinary enamel wire such as PETV, PEV, etc.
Fiberglass - in my opinion, the most better insulation it turns out
We begin winding - the primary. The primary contains 164 + 15 + 15 + 15 + 15 turns. Between the layers we make insulation from thin fiberglass. Lay the wire as tightly as possible, otherwise it won’t fit, but I usually didn’t have any problems with this. I took fiberglass from the remains of the same diesel generator. That's it, the primary is ready.
We continue to wind - the secondary. We take an aluminum busbar in glass insulation measuring 2.8x4.75 mm (can be purchased from wrappers). You need about 8 m, but it is better to have a small margin. We begin to wind, laying it as tightly as possible, we wind 19 turns, then we make a loop for the M6 bolt, and again 19 turns. We make the beginnings and ends 30 cm each, for further installation.
Here is a small digression, personally, for me to weld large parts at such a voltage, the current was not enough; during operation, I rewound the secondary winding, adding 3 turns per arm, in total I got 22+22.
The winding fits snugly, so if you wind it carefully, everything should work out.
If you use an enamel wire as a primary material, then you must impregnate it with varnish; I kept the coil in the varnish for 6 hours.
We assemble the transformer, plug it into a socket and measure the current idle move about 0.5 A, voltage on the secondary is from 19 to 26 Volts. If everything is so, then the transformer can be put aside; we no longer need it for now.
Instead of OSM-1 for a power transformer, you can take 4 pieces of TS-270, although the dimensions are slightly different, and I only made 1 welding machine on it, so I don’t remember the data for winding, but it can be calculated.
We'll roll the throttle
We take an OSM-0.4 transformer (400W), take an enamel wire with a diameter of at least 1.5 mm (I have 1.8). We wind 2 layers with insulation between the layers, lay them tightly. Next we take an aluminum tire 2.8x4.75 mm. and wind 24 turns, making the free ends of the bus 30 cm long. We assemble the core with a gap of 1 mm (lay in pieces of PCB).The inductor can also be wound on iron from a color tube TV like TS-270. Only one coil is placed on it.
We still have one more transformer to power the control circuit (I took a ready-made one). It should produce 24 volts at a current of about 6A.
Housing and mechanics
We've sorted out the trances, let's move on to the body. The drawings do not show 20 mm flanges. We weld the corners, all iron is 1.5 mm. The base of the mechanism is made of stainless steel.
Motor M is used from a VAZ-2101 windshield wiper.
The limit switch for returning to the extreme position has been removed.
In the bobbin holder, a spring is used to create braking force, the first one that comes to hand. The braking effect is increased by compressing the spring (i.e. tightening the nut).
A diagram of a semi-automatic welding machine sent by a site visitor who identified himself as Sanych.
The scheme is very simple, even an inexperienced radio amateur can repeat it.
Actually the scheme (all images on the site are clickable, that is, to enlarge the image, click on it):
PCB topology:
Appearance device:
Internals of the device:
Wire feed mechanism:
Attaching the welding sleeve to the broaching mechanism:
Disassembled burner:
Here is the drawing, body dimensions and component layout:
Many descriptions of semi-automatic machines suggest using a hard welding mode (18-25 volts at the transformer output). But such a mode, as when welding with an electrode, in in this case not comfortable. Anyone who has cooked in a camping store knows that the arc there is crackling - a series of continuous clicks. In my design, the arc hisses gently. It's up to you to decide which mode you prefer.
For the transformer I used four cores from the TS-270 folded together. Total almost 2000 watts. For our trance of power behind the eyes. It’s tempting to use the core from the TS-180, but the wire won’t fit there. I didn’t go into much calculations, since I didn’t intend to squeeze out the greatest power.
I wound the primary (180+25+25+25+25) with 1.2mm wire. For the secondary winding I used an 8 sq. mm bus bar. (35+35 turns). In any case, the number of turns in the secondary will have to be specified in last resort. Therefore, I advise you to make an additional couple of turns in each shoulder.
Afterwards it will be easier to rewind without disassembling the transformer. The rectifier is assembled using a full-wave circuit. You can read about the benefits of such a construction on the same website. I installed a paired biscuit as a current switch. Both diodes are on a small radiator. It is advisable to take a capacitor of at least 30,000 microfarads.
The filter choke on the core is from TS-180, with the same shank, 70 turns. To turn on the power part, any sufficiently powerful contactor (KM-50D-V, KP-50D-V) is suitable. I installed TKD511-DOD - what was there. Store prices for contactors are sky-high, but practice shows that you can buy them on the market for 50-100 rubles. These relays are designed for 27 volts, but even from 15 they operate reliably.
The benefits of using a contactor are obvious - high switching power with a minimum operating current (300-400 mA). The wire drawing and gas supply circuit does not need description. Everything should be clear from the photographs. I consider delay and brake circuits unnecessary. Although it's a matter of taste. Ultimately, you can roll your “brainchild” on rails.
Power transformer TS-40, rewound to an output voltage of 15 volts. Roller of the broaching mechanism with a diameter of 25-28mm. has a guide groove 0.5 mm wide and 1.0 mm deep. It is attached to the conical motor shaft with a native nut. My device has a roller with a diameter of 26mm. To ensure optimal wire feeding, the regulator circuit produces about 6 volts. If this does not fit into the lower limit, then you need to select a zener diode with a lower operating voltage.
The handle-holder is machined “on the knees” from two plates of PCB 10mm thick. Seating processed using a drill with drills and an end mill. The protective hose in the handle, as in the device, is held in place using spacer sleeves. There are small grooves on the mating parts. The body is made of sheet iron 1mm thick with double bends at the edges. The entire structure is mounted on rollers for ease of movement.
The device operated in this configuration for more than ten years. With its help, many cars have been repaired. The issue of additional cooling arose only after two three years, when I started cooking more serious things.
The cooling fan must be installed on the rear wall opposite the power transformer. In normal mode, current consumption is approximately 5-6 amperes.
I hope it helped someone. Good luck!
Did you like the article? If it's not difficult, please vote:If you decide to assemble a semi-automatic welding machine with your own hands from an inverter, diagram and detailed instructions will become indispensable companions on the way to achieving your goal. The easiest way is to purchase factory semi-automatic devices such as Kedr 160, Kaiser Mig 300 with the required Ampere rating. But many people strive to do everything themselves. It's not that easy, but if you want to, you can achieve a positive result.
Mig, Mag, MMA welding requires the use of appropriate devices. Mig Mag is a semi-automatic welding process that is performed in an inert argon gas environment. Sometimes carbon dioxide is used for Mig Mag welding. MMA welding is called manual arc processing with electrodes on which a special coating is applied. If you are working with stainless steel, then MMA welding is carried out only with direct current.
Since we are talking about how you can assemble a full-fledged semi-automatic machine based on an inverter with your own hands, you are not interested in MMA, but in Mig Mag welding.
To assemble a homemade device, a worthy analogue for the Kedr 160, Kaiser Mig 300, with your own hands, you will need a diagram, video instructions and the necessary design elements of the semi-automatic device. These include:
- Inverter. Determine its welding ability by selecting the supplied current. Typically, craftsmen assemble devices capable of delivering 150 Amps, 170 Amps or 190 Amps. The higher the Amps, the higher the ability of your welding device;
- Feeding mechanism. We will tell you about it separately;
- Burner;
- Hose for supplying electrodes;
- A spool of special wire. This attachment is easily attached to the structure in any way convenient for you;
- Control unit for your welding unit.
Now regarding the feed mechanism for a semi-automatic machine and some important points.
- It is responsible for supplying electrodes using flexible hose to the welding point.
- The optimal feed speed of the electrode wire corresponds to the speed of its melting at welding work oh with your own hands.
- The quality of the seam you make with your own hands depends on the wire feed speed.
- It is recommended to make a semi-automatic machine with the ability to adjust the speed. This will allow the semi-automatic machine to be adapted to different type electrodes used.
- The most popular electrode wires have a diameter from 0.8 to 1.6 mm. It must be wound on a reel and charged the inverter.
- If you provide fully automatic feeding, you will not have to do it yourself, and therefore the time spent on welding activities will be significantly reduced.
- The control unit is equipped with a control channel, which is responsible for stabilizing the current.
- The behavior of Amperes, that is, the current of a semi-automatic device, is regulated by a special microcontroller. It performs its work in pulse-width operating mode. The voltage created in the capacitor directly depends on its filling. This affects the welding current parameters.
Preparing a semi-automatic transformer
In order for a self-made semi-automatic machine to work no worse than a welding machine like Kedr 160, Kaiser Mig 300, you need to understand the features of transformer preparation.
- Wrap it with a copper strip. Its width should be 4 cm and thickness - 30;
- Before this, the strip is wrapped with thermal paper. Suitable material used in cash registers. It is not difficult to purchase such paper;
- In this case, the circuit does not allow the use of ordinary thick wiring, otherwise it will begin to overheat;
- The secondary winding must be made by using three layers of tin at once;
- PTFE tape is used to isolate each layer of sheet metal from each other;
- At the output, you will need to solder the contact ends from the secondary winding with your own hands. This is necessary in order to increase current conductivity;
- Be sure to include a fan in the inverter housing. It will serve as a blowing mechanism that reduces equipment overheating.
Inverter setup
There are no problems with the operation of Kedr 160 and Kaiser Mig 300. Cedar 160 and Kaiser Mig 300 are factory equipment that have excellent specifications. These semi-automatic machines function perfectly and allow you to get required amount Ampere - 160 Ampere, 170, 190 Ampere, etc. It all depends on how you configure the device.
But if you decide to remake the inverter and make it a semi-automatic device, then the idea of buying Kedr 160, Kaiser Mig 300 should be thrown aside.
After completing work with the transformer, you should move on to the inverter. If you do correct settings the inverter itself, alteration will bring the desired result. Therefore, a homemade semi-automatic machine will function no worse than a ready-made Kedr 160 or Kaiser Mig 300 device.
- Be sure to provide high-efficiency radiators used for rectifiers (input and output) and power switches. Without them, the device will not be able to work properly.
- A temperature sensor should be installed inside the radiator housing, which heats up the most, to trigger it in case of overheating.
- Connect the power part to the control unit and plug it into the working network.
- When the indicator is activated, you should connect an oscilloscope to the wires.
- Find bipolar impulses. Their frequency ranges from 40 to 50 kHz.
- The time parameters between pulses are adjusted by changing the input voltage. The time indicator must correspond to 1.5 μs.
- Make sure that the inverter produces square wave pulses on the oscilloscope. The edges should not exceed 500 ns.
- When the device has passed the test, connect it to the power supply.
- The indicator built into the semiautomatic device should produce 120 Amperes. Parameters can reach up to 170, 190 Amperes. But if the device does not show given value, you will have to go in search of reasons low voltage in the wires.
- Typically, this situation occurs when the voltage is less than 100 V.
- Now we test the semi-automatic welding machine, starting the device with variable current. At the same time, constantly monitor the voltage on the capacitor.
- We complete the testing by checking the temperature readings.
- Check how the device behaves when loaded. Similar initial tests should be carried out with the Kedr 160 and Kaiser Mig 300. Although the Kedr 160 and Kaiser Mig 300 are factory semi-automatic machines from trusted manufacturers, it will never be superfluous to make sure of their professional suitability.
- To check homemade inverter or Cedar 160 with Kaiser Mig 300, you need to connect a 0.5 Ohm load rheostat to the welding wires. Make sure this element can withstand a load greater than 60 Amps. The current parameters are monitored with a voltmeter.
- If checking the semi-automatic device shows that the specified current value and the controlled value are different, the resistance will need to be changed. Do this until you achieve a positive result.
Assembling a device that will act as a full-fledged analogue for the Kedr 160 and Kaiser Mig 300 is not so simple, but it is possible. You yourself determine whether the semi-automatic device will produce 120 or all 190 Amperes. Make choosing a factory model easier. But their price is appropriate. The price of the same semi-automatic Kedr 160 Mig is from 27 thousand rubles. But the decision is yours to make.
Welding metal products can help a good owner at any time. Therefore, a welding machine can be considered an indispensable thing in household. With such a device you can perform small renovation work on one's own. Most often welding work is required in rural areas, where there may be a need to repair fences, build a greenhouse or create any other metal structure.
Buying a new factory semi-automatic can cost a pretty penny, so every owner at some point has a dilemma about what to do, buy new device or make a semi-automatic welding machine with your own hands.
The easiest way is to make a semi-automatic machine from an inverter with your own hands. If the household has a regular inverter, making a semi-automatic machine will not be difficult; you just need to follow the manufacturing instructions and purchase a few additional parts.
But it should be noted that to perform similar works you need to have basic knowledge of electrical engineering and simple physical laws. At the same time, it is important to conscientiously approach the manufacture, assemble necessary tool and don’t give up what you started.
The device of a homemade semi-automatic welding machine
The circuit of a semi-automatic welding machine is quite simple, and is not much different from a conventional welding machine. The device of the semi-automatic welding machine is distinguished by the fact that instead of classical electrodes, which need to be changed during the welding process, filler wire is used. This feature lies in the fact that there is a welding wire feeding mechanism installed there, which feeds it into the welded area gradually and continuously. This allows you to carry out welding work continuously, producing the most even and uniform seam.
At the same time, the resistance of such a device is significantly lower in comparison with an arc one, so you can repair a semi-automatic welding machine with your own hands without special effort and tools.
When feeding wire, an area of molten metal is formed in the welding zone, which instantly connects the surfaces, literally gluing them together, forming the highest quality, high-strength weld.
Using a homemade semi-automatic welding machine, you can weld almost all types of metal products, including stainless steels and non-ferrous metals. Moreover, the technique of performing welding work is quite simple and can be easily mastered on your own with the help of training materials. But you can also take special courses where you will be taught welding techniques, told about the specifics and the slightest features using a semi-automatic machine. By attending courses, even a beginner who has never dealt with welding machines of any kind can learn welding.
Roughly speaking, a semi-automatic welding machine consists of three parts: an electric one, responsible for supplying current, a wire mechanism, responsible for supplying filler wire, as well as a torch, necessary for creating a gaseous environment using a special nozzle.
The gas environment is necessary to create a protective inert cloud that prevents the oxidation of the molten metal. Carbon dioxide is most often used for these purposes. Gas cylinder connects to the device through the input connector.
In some cases, the use of a cylinder is not necessary, since filler wire with a special coating can be used, which creates a self-protective environment. Ease of use and the absence of the need to use a cylinder made the semi-automatic machine with such wire especially popular among home craftsmen.
The principle of operation of the device is quite simple: alternating current is supplied from the electrical network, which is converted into direct current. This function is performed by a special module in conjunction with a transformer and rectifiers.
When performing welding work, it is important to ensure that the balance of current, voltage and filler wire feed speed is maintained. Changing the balance in either direction can result in a poor-quality seam. To maintain balance in such cases, a power source with a rigid current-voltage characteristic is used. This allows you to adjust the voltage and current supplied depending on the feed speed of the filler wire, which allows you to achieve the highest quality connection.
Required tools and materials
To make a semi-automatic machine from an inverter, you need to prepare the following equipment:
- Inverter. When choosing this component, it is important to pay attention to such an indicator as the strength of the generated current. It is important that its level is not less than 150A.
- Wire feed mechanism for semi-automatic machine. It is he who will be responsible for the continuous supply of filler wire, which should lie evenly, without jerking or slowing down.
- Burner. This component is responsible for melting the filler wire.
- Supply hose. Through this hose the filler wire will be supplied to the work area.
- Gas hose. Necessary for introducing a shielding gas, usually carbon dioxide, into the welding area to protect the weld from oxidation.
- Coil. The filler wire must be located on the reel, with which it must be fed without delay.
- The electronic unit. It is necessary to control the operation of a semi-automatic machine; with its help, the current supply, voltage and speed of work are regulated.
Most components can be found High Quality without much effort and use them without significant changes. But Special attention It is worth paying attention to the feed mechanism. To ensure that the welding work meets all requirements, the wire feed through the flexible feed hose must be carried out in accordance with its melting rate.
Considering the fact that a semi-automatic machine can be used for fastening various metals, welding speed and type of filler wire can vary significantly. That is why it is very important to be able to adjust the speed of the feeding mechanism.
The choice of wire depends on the purpose of welding work and the metal being processed. The filler wire differs not only depending on the material, but also on the diameter. You can usually find wire in diameters of 0.8, 1, 1.2, and 1.6 mm. The corresponding wire must first be wound onto a reel. The quality of the finished seam directly depends on the quality of this preparatory work.
The coil is then secured using a special mount or homemade design to the device. During work, the wire is automatically unwound and fed into the work area. This allows you to significantly simplify and speed up the connection process metal elements using welding, making it more efficient and easier for beginners.
The control unit consists of a microcontroller necessary to stabilize the current. It should be noted that it is this component element that is responsible for the ability to adjust the current during work.
Creating a semi-automatic welding inverter
Before using the inverter as the basis for a semi-automatic welding machine, you need to perform some manipulations with its composite transformer. It needs to be remade, and converting an inverter into a semi-automatic device does not require special knowledge and effort; it is easy to do, following only a few rules.
All you need to do is apply an additional layer to it, which should consist of copper strip and thermal paper. Please note that in no case should you use conventional copper wire, since during operation it can overheat and damage the entire device.
Small manipulations also need to be carried out with the secondary winding. According to the instructions, you need to apply three layers of tin, insulated with fluoroplastic tape. The ends of the existing and applied windings should be soldered. Such a simple manipulation will significantly increase the conductivity of currents.
It is very important that the inverter is equipped with a fan, which is necessary to cool the device and prevent overheating.
Wire feeder
A wire feeder for a semi-automatic machine can be purchased at almost every electrical equipment store. But it can also be produced independently from available materials. For these purposes, experts recommend finding motors from car wipers, a pair of suitable plates, bearings and a roller with a diameter of 2.5 cm, which must be installed on the motor shaft. Bearings are in turn installed on the plates. The resulting structure is pressed against the roller using a spring.
The wire wound on the roller is pulled between the bearing and the roller. All components are mounted on a plate, the thickness of which should not be less than 1 cm, made of durable plastic. The wire outlet must coincide with the attachment point of the supply hose.
Preparing the transformer
Preparation of the transformer consists of creating an additional winding, installing the necessary components and test connection to the network. The assembled welding machine must function normally, not overheat after connecting to the network, and, what is very important, fully respond to current adjustment.
It is also very important to check the insulation and apply more if problems are identified. Then check the operation of the feeding mechanism, the speed and uniformity of the wire feed.
After preparing and checking the working units, you can proceed to the work.
Power supply
The power supply for semi-automatic welding can be various source, such as the previously mentioned inverter, rectifier and transformer. Electricity goes to welding machine from a three-phase network. Recommended for production homemade apparatus use an inverter.
If you follow the appropriate recommendations and choose high-quality components, you can get a high-quality, home-made device that will serve your household for many years and will become a real assistant when performing minor home repairs.