Home Made Mig welder.

  1. DJDAudio Member

    Posts: 4
    This web site has been a great resource for me being a DIY welder so Here is my Mig welder I built because I felt it would be a fun project. and I feel you will become a better user of a product after you know how it works.


    The gun is a 600amp Tweco gun I got of eBay for $24

    The Feeder is a Lincoln LN-9 Wire feeder ( or so I was told) bought it for scrap on eBay for $20
    Here are the specs on it

    Feeds up to 3/32" ( 2.4mm ) solid and .120" ( 3.0mm ) flux-cored wires, from 50 - 600 inches per minute ( 1.27 - 12.7m/min ) wire feed speed.

    Had to make a variable speed 90VDC motor driver for it. But works great.
    Also made the spool holder for 10lbs spools but have a small one on it now to test.

    The feeder was junk when I got it. after some TLC and a little home brew refurbishment i think it looks good as new,

    The bungee is my tension system for now haha.

    Oh and I have in it 0.035 flux wire now. ( I have a regulator just need to make a bushing to alow the gas to enter the gun socket.

    The transformer is from an industrial UPS system it is 1’square and about 80lbs and can produce almost 500amp at 40VAC

    Right now it is running at 50amp 220V and is about 200amp output DC or AC.
    The Diodes I got of Ebay for $10 They are 600amp. Stud mount about 1" stud.


    I made my own bridge plates from 1/4" The unit even after 30 min of welding remains just luke warm.

  2. weldequip Member

    Posts: 5,074
    That's a fair spec.machine & probably wouldn't be commercially viable!
    Well done.
  3. MigTig

    MigTig Maintenance Welder

    Posts: 303
    East Sussex
    600a diodes.. Crikey, nice work there..
    If only I understood electronics a little more
    Robert Vanneste likes this.
  4. Alex Member

    600 amp diodes are a lot of money.

    $10 each and they look brand new, thats a deal.

    Nice work.

    How do you adjust the voltage
  5. DJDAudio Member

    Posts: 4

    They are brand new and was a deal of a lifetime I have been looking for diodes on ebay for the past 2 years So it was about time to find a deal.

    I adjust voltage with a home made saturable core reactor IT is the large variable transformer in the front of the welder. the large one will adjust heat and the small one is wire speed. both are 100% adjustable to any power level wanted even down to 1amp (best guess) :) I think all welders should have this feature it is to often you get stuck between power levels.
  6. Alex Member

    I know what you mean about having a fully variable primary tapping, its only maybe upto 20 amps 220V on an average machine so no biggie.

    But inverters are becoming more increasingly popular and they are fully variable, so I dont see it happening on welders commercially produced in the future.
  7. timinder Member

    Posts: 55
    Have you got any pics of welds you've done with it?
    Robert Vanneste likes this.
  8. DJDAudio Member

    Posts: 4
    Please don't laugh I am a first time welder with no training :welder:


    Flux core makes a huge mess of the weld so I had to wire wheel the welds just for you to see them haha

    I am impressed it does a great job with thick metal.
  9. DJDAudio Member

    Posts: 4
    Almost all welders are iverter now the old big heavy transformer welders are dead... I like how the old ones seem to be bullet proof haha.

    For an inverter welder you need an electronics lesson just to fix them.
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