Need help on making a circut for a homebuilt welder.

Discussion in 'The Projects Forum' started by Dmm1542003, Sep 7, 2012.

  1. Dmm1542003

    Thread Starter New Member

    Sep 7, 2012
    Im trying to build a 220amp alternator welder and im getting kinda confused on the control board for it. what i want to be able to do is to make one board. (trying to save money.) i want to be able to switch between arc,mig,tig. also i want to be able to set both the voltage and current. also at the end of the electrode holders their will be something to control voltage and current. with a switch to switch between the two settings. also on the electrode holder their will be a button switch to enable electricity to the electrode. the mig will be push button to allow wire feeding + to turn on and off the gas. same with the tig but a foot pedal. i want this welder to be 100% duty cycle. i have a adruino microcontroler to help out with the mig and tig. the arc will only need a current and voltage regulator. but im not sure how to control the current do i need a rheostat in parrel to control current and one in series to control voltage? And would it be easier to control voltage and current with the field power or after.
  2. williamj

    Active Member

    Sep 3, 2009

    Just from reading your post I think you need to take a step back and do some research.

    Acr, Mig and Tig are not seperate forms of welding. Mig and Tig welding are each a different form of arc welding. Switching between Mig and Tig welding is not done at the flip of a switch.

    Once you understand the differences between the two, come back and ask again.

    just my opinion
    shortbus likes this.
  3. Dmm1542003

    Thread Starter New Member

    Sep 7, 2012
    When i refer to arc what im meaning is stick welding. and yes i know that these are just different forms of arc welding but they each require more to the circut. such as mig has a wire feed rate which also controls current and a voltage control setting. also voltage varies to keep the wire at the correct distance for welding also has a Ohm control that sets the distance of the wire electrode on how far it comes out of the gun. And then for tig
    has frequency settings and so on. I think you misunderstood what im trying to do. check out that better describes it but i need to go through the steps in designing the board so i better understand it myself. BTW this is not a modification to a car/truck this will be a portable all purpose welder.
    Last edited: Sep 11, 2012
  4. shortbus

    AAC Fanatic!

    Sep 30, 2009
    Its more than that. Stick and TIG use a "constant current source". MIG and flux core need a "constant voltage source". To make a welder, especially an alternator/generator type to do both is in the end going to do neither well.

    This is a big undertaking to do, especially if you have no prior electronics back round.
  5. Dmm1542003

    Thread Starter New Member

    Sep 7, 2012
    I do have some background in electronics,but i still think im a novice at it.Ive taken a class at collage and have done other electronic projects and read some of the material on this site.Thanks for trying to help but i think the blacksmiths that i work with know more about this.
    Last edited: Sep 12, 2012
  6. Levi Thomas

    New Member

    Sep 19, 2012
    I'm a forty year welder with a lot of repair experience in MIG And TIG(Heliarc), machines. You would definitely need to have two separate machines. For a 100% duty Tig machine you need a low pressure water supply to cool the welding torch, do not use an air cooled TIG torch. You do not need a high frequency supply as it is on only for a few seconds anyway (this applies to welding steel and stainless only) you'll have to scratch start the tungsten electrode. The classic factory setup for saving money is just clamp your TIG torch on your Arc welding machine and rent a bottle of Argon or Helium or a combination of Argon/Helium, "no CO2 please." Tap into your city water supply and make sure your pressure is restricted to 20 psi, anything higher will burst the plastic lines on the torch. You might enjoy a good challenge but I would avoid trying to build a constant voltage machine 'MIG'. The wire feeder is controlled by the rpm of the drive motor in the gun or in the machine.
    It always comes down to buying a reliable used machine and spending money fixing it up. Please avoid water pumps for TIG as they are very expensive and are a repair nightmare. High frequency supplies were originally designed so the welder would not receive a shock from his torch.
  7. KirkMc

    New Member

    Jun 12, 2013
    I am in the process of converting a 200 amp alternator into a stick welder. I think I want to have a variable current limit.