Hi, I have just the other day made a video showing how to set your wire speed etc.
A mig welder is a CV, constant voltage power supply. You set the voltage with the knob on the front of your machine. Then you adjust the wire speed to suit.
Select you voltage of a voltage/wire speed chart.
It's how you mix the voltage setting and the wire speed that gives you the amperage.
http://www.learn-how-to-weld.com/mig-welding/how-to-set-your-mig-welding-volts-and-wire-speed.html
