I'm in the process of developing an on board welding using a fat alty, its gonna be mig/stick and tig with hf start.
I've seen various designs around, but very few that are proper good ones.
There is some electronics in the design, but as little as possible.
I have done some work on the hf start system for tig mode, it creates very high voltage (from a car ignition coil) at high frequency and iniates an arc for the heavy current to flow along, heres some work so far:


Theres a couple of boards, the one at the back is partly the hf start, it adds the high voltage to the output of the alty to create the initial arc, the fat black wires are inline with the electrode, the next bit to go on is the field controller for the alty, so that I can have constant voltage or current, and of course adjustable power.
Not sure what to do about the wirefeed for mig mode yet, whether to make one with a wiper motor, or salvage one from a knackered set.

Cool.

Cheers

Blippie

What a good idea.
I assume you know about the PTO driven generators and welders that are available?
If you get this to work you could sell it as a kit, a bit more use than on board air
Keep up the good work

Is your landy that rusty that you need to be welding it while you're driving?

Yeah snot and run.

Still lookin for a fat alty, any offers?

Many moons ago you could buy these out the box , that was a big alternator with a change over switch . Plug your welding cables in , flick over the old school switch arm and away you go worled really well to .

keep us posted on your progress tho