Emergency welding with modified alternator

Did ya mean zis vun??

Unipower 185

Hi Pop,

Well this certainly brings back memories.

The welders you are thinking of are called AutoArc and were built by Goddards Auto Electrics in Western Australia many years ago.

We have had many of these in our family and I still think they were one of the best bits of gear you could fit to your car if you were travelling in remote areas. The first ones were quite primitive but as the years went by Goddards released the final models that were full of printed circuit boards etc.

I still have one in a box in the shed that I look at every now and then and wonder if it is worth going to the effort making it fit the 80 series. They have a 120amp alternator and a tiny pulley on the front to get it spinning fast to deliver the current. The alternator is very heavily wound.

I think the problem was as engine bays became more limited in space and replacing the existing alternator was not an option due to electronics and sensors etc, rhen the market for AutoArcs became limited to those with older vehicles.

When it came to welding with an AutoArc I dont know what it was but you couldnt do anything wrong. It was a very smooth weld and the rod would sing when you were running a weld. Penetration was great and was varied using the revs of the engine.

When throwing the AutoArc knifeblade switch the other way it would run the power to the 240 volt outlet. This worked well but was 240v DC so was ok for motors and elements etc but I would not run anything with electronics off it.

My brother was a plumber and I was a carpenter both with F100's and I would often use the AutoArc for small jobs when working in the bush. From memory it would run a 1500 watt motor continuously and a 3000 watt motor intermittently. I had no problems running my 12cfm compressor even with the start up current. I normally had the car engine on about 1200 rpm but occassionally up to 1500rpm for a heavy welding job. No problems running power saws, drop saws, grinders etc.

I am preparing for a trip to the cape next winter and I think i will fit the AutoArc to the Landcruiser as I quite like having the ability to weld a trailer if need be on the side of the road. AutoArcs somehow also allow you to weld your own vehicle too. I think the battery is isolated from the alternator when the switch is thrown.

I hope some of this info is helpful and if there is anything else you would like to know give me a yell and hopefully I can help.

BW

Here's the website http://www.unipower.com.au/index2.asp

Pop,

I'm very keen on them as well. Great looking set-up. Could you post the info to the forum if you get a price from them as to how much the 185 unit costs.

Thanks

Mick

A refreshing and interesting thread. We had a bloke break the yoke on a scraper some years back. Next thing a Tojo turned up, stitched the whole lot together, and off it went. I found it amazing that a (superficially) bleep -ant welder could do that. Must be expensive gear, yes?
(And no, I don't mean to imply that the scraper went back to work - it went to sick bay. /.....and we paid the medicals.)
I remain impressed by the performance of that unit, dead set.
Jeff H.

I've been doing a bit of digging around on the net and it is possible to build your own version pretty cheaply.
Going this route though you need to be able to mount and drive a second modified alternator in the engine bay.
Unless you want to use it regularly I think I'll stick with batteries and the leads off the stick welder which hopefully you never have to use.

Some years back I found a unit called Red Back which was an alternator set up that Telstra was using in cruisers and other 4 bys in the bush and they were made by a chap in Alice Springs .
A firm in Melbourne used to fit Telstra vehicles and had a surplus of them.
I bought one and made up a frame and fitted it to a 6.5HP Tecumseh vertical shaft .
It produced 240V DC , 120A of 12V Charge and 150A for welding.
The welding was a bit hairy but it glued things together and the 240 was regulated by revs.
A variable speed drill didnt like the 240DC and that cost a bit but the unit is still in the shed is superceded by an inverter welder.
The alternator had six winding and a bridge rectifyer.
Ian