Hello everyone, as I know very little about the electronics and principles involved etc. I need to ask you experts, is it possible to use a MIG welder for cutting in place of a plasma cutter? In other words make some kind of conversion to achieve this.
Thanks,
Tony

You can't do that. A plasma cutter uses a high voltage to initiate the arc (about 300V open circuit voltage) and delivers a constant current. A MIG welder has a much lower open circuit voltage and is a constant voltage power supply.

Thanks Jeff, I just wondered because I have seen 3 in 1 machines advertised where you can change over at the flick of a switch.
Never mind I will just have to bite the bullet and buy a plasma machine.

I thought your question was "can I take a MIG welder I have now and use it for a plasma cutter", which can't be done. There are welding power supplies out there that can run in both CC and CV mode (constant current for TIG/Stick and Constant Voltage for MIG). I've not seen one of the 3-in-1 power supplies in person so I cannot comment on how they work.