homebuilt arc welder

Personally, I'd shop for a used Lincoln 225 or something. You can get 'em for $50-75 if you play your cards right.

GTO(John)

I would buy an old lincoln it will cost you less, have better resale and weld nicer. I built my own welder from a GM alternator that works good and is portable.

Very cool.

I have never built one, but often wondered what it would take to scale one up as others have done. My dad was a welder - some of the welding rods they used were HUGE - like cigars. I dont know how many amps.

Great foundry stuff. You should look into investment casting / ceramic shell.

If you spill liquid metal on the cement it will go BOOM. But you probably know that -

I've seen your sight many times before - very impressed. Keep up the good work.

The stacked microwave transformers are a cute solution to finding a transformer, but I'm puzzled by the heat control circuit. If this is a "scrap bin" project, what's it doing with an International Rectifier thyristor pack in there ? They cost as much as a stick welder does !

Personally I cannibalise microwave transformers to get iron sheet for cabinetry and sword furniture.

cabinetry and sword furniture.

what's that? could you send me a pic?

Peter

Sorry, don't have any pics of my stuff to hand

Searching for "tansu" and "tsuba" ought to give you an idea though.

-- Smert' spamionam

Howdy folks,

On the subject of building a welder from scratch.

My Yahoo site has a good degree of detail on this subject, and is centered around the machine that I call the "AmpTramp".

She weighs 1 Tonne, and is a fully automatic welder, compressor, AC mains supply, self propelled, trailerized system. This system can provide a steady 240Amps of welding current, 6000Watts of AC power, and 120 PSI of air, all at the same time. Further, it has it's own drive system that allows it to travel, independently, to the work site. As added benefits, my 'Tramper' can rewind it's own welding cables, and is operable by way of a tiny remote control transmitter. The whole thing, is powered by a Diesel engine - as I don't have mains power here on the farm. Building it, was an interesting challenge - as I had to develop a method for welding it all together - - without mains power :)

I know Yahoo Groups are a bit of an inconvenience to join up with, but I would like to assure you that it is worth a look:

You'll find circuit diagrams, descriptions, pictures and videos of my machine in action.

I hope you'll come and visit.

Best wishes,

Steve.

Never built a whole arc welder, but I did build a balance control. The square wave Lincoln cost another $1000 over the Lincoln idealarc TIG 250 that I bought and I didn't want to spend that. My balance control uses 2 monster SCR's and a synchronous trigger circuit. I also built it to pulse the weld current, and I can adjust the duration & rep rate of the pulse. While I was at it, I put in a feature similar to electronic light dimmers which allows me to control the number of degrees in the 60 Hz cycle which current flows.

JM

Never built a whole arc welder, but I did build a balance control. The square wave Lincoln cost another $1000 over the Lincoln idealarc TIG 250 that I bought and I didn't want to spend that. My balance control uses 2 monster SCR's and a synchronous trigger circuit. I also built it to pulse the weld current, and I can adjust the duration & rep rate of the pulse. While I was at it, I put in a feature similar to electronic light dimmers which allows me to control the number of degrees in the 60 Hz cycle which current flows.

JM

How much did it cost you in parts to build? Do you have any plans written down that you would like to share? Now all that "magic box" needs is to add some HighFreq and remote current control. Well maybe a gas solenoid. ;^)

You can post files other than text here in the dropbox.

It is sketched out on several peices of paper and not self explanatory, but if I can get the time perhaps I'll try to sketch it out. I did make a PWB for it so I suppose it wouldn't be difficult for someone to make a duplicate. The control circuit parts are probably less than $20 in parts, but the humongo 300-continuous-amp SCR's were about $35 each and it requires 2.

JM