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Four Microwave Welding Machine

A full-fledged welding machine can be assembled from four microwaves. Find them in our time is not difficult, models may vary. The design is not complicated, you do not have to disassemble the transformer cores. Such a home-made welder is quite capable of providing a current of 200 A, which is excellent enough to maintain stable arc burning.

It will be required to assemble the device


  • Four transformers from microwave ovens.
  • A wire with an outer diameter of 7 mm, with an inner diameter lived 4.5 mm (16 sq. Mm.) - 13 meters.
  • Network wire 1.5 sq. mm - 2 meters.
  • Electrode holder and ground clip.

Welding Machine


We disassemble the microwave ovens and remove the transformers from them. None of them will be needed. On average, each transformer has a power of 800-1000 watts. All of them are step-up, which means the secondary winding has a greater number of turns. Usually it is on top, but there are exceptions, so be aware.
Four Microwave Welding Machine

We cut it off with a grinder on both sides. This can be done with a hand hacksaw.
Four Microwave Welding Machine

On the one hand and on the other.
Four Microwave Welding Machine

To remove the central part, we use a drill. we drill a hole and knock out the remains of the wire. There is also a third between these two massive windings. It consists of several turns and serves to glow the cathode of the magnetron. We also delete it, it is not needed.
Four Microwave Welding Machine

Transformers are prepared for further winding. But before that, I recommend checking the resistance of all windings - it should be approximately equal for all four. And it will not be superfluous to also check the short circuit to the core, you never know ...
So we secure ourselves and check whether we have damaged the windings under mechanical stress. Or if someone did this before us if you found these microwaves in an unknown state.
Four Microwave Welding Machine

Take a wire of 16 squares and a length of about 13 meters.
Four Microwave Welding Machine

With this wire we wind the windings on all transformers in series and in one direction. A total of 32 turns should be obtained, 8 for each transformer.
Four Microwave Welding Machine

There should be approximately one meter ends of the wire for connecting the clamp and holder. We place transformers in the form of a square.
Four Microwave Welding Machine

We connect all network windings in parallel to each other. The most important thing is to connect everything correctly, otherwise the transformers will work in antiphase.
Four Microwave Welding Machine

Turn on the network. We measure the voltage at the output. It should be approximately equal to 30-32 V. If it is radically different - check the inclusion of all windings.
Four Microwave Welding Machine

Check with a tick ammeter short circuit current. Of course, it is problematic to measure it, since the wire heats up sharply, but the device shows 326 A. The current during arc burning will naturally be less.
Four Microwave Welding Machine

The welding machine is almost ready. Take a wooden plank and screw all the transformers to it with screws.
Four Microwave Welding Machine

From a round stick and thick steel wire we will make a handle for carrying.
Four Microwave Welding Machine

To the output wires of the secondary winding, we fasten the purchased electrode holder and ground clip. And to the input of the primary windings we attach a network plug.
Four Microwave Welding Machine

Welder Testing


We take the electrode three
Four Microwave Welding Machine

We will try to weld a piece of thick steel to a steel corner.
Four Microwave Welding Machine

The arc burns quite steadily.
Four Microwave Welding Machine

Everything was welded well.
Four Microwave Welding Machine

We weld two steel thick studs.
Four Microwave Welding Machine

I am not a professional welder, so it turned out not quite evenly. The main thing is that everything is working properly.
Four Microwave Welding Machine

Four Microwave Welding Machine

This welding machine does not have current control, there are other disadvantages, but it will do for home use. Bye! See you soon!

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Comments (1)
  1. Sergey K
    #1 Sergey K Visitors May 29, 2018 18:28
    5
    A little homework was late in time, so for 15-20 years ... Nowadays, inverter welders cost from 50 bucks! And this includes wires, albeit short, holders and clamps, and most importantly the ability to adjust the welding current. And reliability, well, probably will be at the level of this crafts.

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