Making my own welding machine?

A post in the transformer thread made me think. I have a very large transformer with many windings. At least a 200 pounds beast.

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I hope that I can find a way for it to reduce voltage to say 30-60 volts or something, on those windings. Maybe rewind it a little bit.

I am going to have a 60 AMP subpanel in my garage soon, I am working on it anyway (compressor needs more juice etc).

Then, to have a rudimentary welding machine, all I need is to add a onboard overcurrent protection device, a rectifier big enough, and welding cables. Am I missing something important? I know next to nothing about welding equipment and wanted to tap into your collective knowledge.

Do welding machines need to be DC powered?

Thanks!

i
Reply to
Ignoramus28225
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Nope you can weld with AC, I think DC is nicer though. Look around on the web there are lots of great DIY welding plans out there and you have a good start with your transformer core.

Reply to
Modat22

Thanks. I will definitely look for it. After I am done with the subpanel and soundproofing my generator, I may start working on a welder. I will create a webpage with progress pictures, just like Idid with my generator repair project. I appreciate your comments.

i
Reply to
Ignoramus28225

That transformer looks like it has pretty beefy secondaries already. When you energize the primary and connect the secondary windings in parallel, what do you get for an open circuit voltage?

Most guys who make welding transformers remove the secondary windings and wind on a few turns of flat copper bar. If you want to convert to DC you may have to spend some serious change to get a rectifier beefy enough to handle the stress of striking an arc. Google for the terms "welder" and "snubber circuit" or something.

And do NOT fall in love with your transformer. In my neighborhood I see 225A AC welders for $50 several times a year, it would be a lot easier for you to start with one of those.

GWE

Reply to
Grant Erwin

I thought that connecting different secondary windings in parallel would be some sort of equivalent of a short.

What size would that bar need to be?

Do I need DC for a welder?

Good point. I might just look for a used welder. Imust say though, that Idid look for one and did not find anything cheap.

i
Reply to
Ignoramus28225

Reply to
Waynemak

Thanks. The arc welder link does not work.

Thanks. I looked on ebay. Is something like this:

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worth anything?

i
Reply to
Ignoramus28225

Where do you live? Have you looked in your local newspaper's classified ads, your local "nickel ads", your local craigslist? - GWE

Reply to
Grant Erwin

Forget the welder...make a TIME MACHINE!!!

Reply to
Tom Gardner

That looks like a constant-voltage or ferroresonant transformer. The presence of the oilfilled caps in the background supports that notion.

If the middle leg (iron) is movable, it might indeed make a good arcwelder with that being the current-control shunt.

Reply to
Don Foreman

Not much.

You want something more along this line....

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I bought one of these locally for $20 a few years ago. Ive outgrown it, but it was a fair machine. The Lincoln 225 is a decent machine as well.

I have both for sale, but shipping would eat your lunch.

Gunner

It's not unwise to remember that Mother Nature is essentially a murderous, sneakly, promiscuous bitch who has been trying to kill you since your conception.

Eventually she will succeed, perhaps with the help of your fellow man.

Life consists in putting off the inevitable as long as possible and taking what good and joy you can before her success.

Whether you attribute that situation to evolutionary forces, a fallen nature after Adam and Eve screwed the pooch, or whatever, it's no less true.

Be friendly, pleasant, unaggressive, and honest toward all and be prepared to ignore, avoid, or even kill anyone who is otherwise toward you. Being ready doesn't mean eager, just ready. What true friends are found in life will undestand and accept that fundamental rule of human interaction." John Husvar

Reply to
Gunner

Thanks, I will look for a cheap local one then.

i
Reply to
Ignoramus28225

i

It might be interesting and rewarding and even educational to build a welder with the transformer you have. It probably boils down to deciding what is more important to you, Building a welding device or Doing some welding. I own several Miller welders MIG, TIG and even one that does both. But, I prefer to use the stick welder I made from scrap. I sure dont suggest the junky-scrap welder I made is superior to the Millers, but, I sure like useing the ugly thing. The design considerations involved with making a decent stick welder are kinda interesting.

Jerry

Reply to
Jerry Martes

I have been having urges to mess around with machinery lately. So, I would not mind making a primitive welder. Any website suggestions?

i
Reply to
Ignoramus28225

"Ignoramus28225" wrote: (clip) I thought that connecting different secondary windings in parallel would be some sort of equivalent of a short.(clip) ^^^^^^^^^^^^^^ If the windings have the same number of turns, and you don't get the polarity reversed, they don't act like a short.

A "stick" welder has to have inductance in addition to the transformer itself, so that while you are welding, the current remains relatively constant. Particularly, while you are striking the arc, you are shorting the welder output. Without the extra inductance, the current would jump way up, possibly sticking the rod and turning it red hot.

I think building a welder is an interesting challenge, but if you try to weld with an unknown and imperfect setup, you won't know which part of the problem is the machine, and which part is you. I agree with the others who say you should start by buying an inexpensive unit.

Do you know about sci.engr.joining.welding?

Reply to
Leo Lichtman

That's why I said "different". They do NOT have the same # of turns.

I had no idea!

i
Reply to
Ignoramus28225

Home Depot sells the Lincoln ac225 arc welder for 279.00 bucks. Cheap for what you can do with it. Of course, if sheet metal or aluminum is your fetish, your screwed without a tig welder..... MLM

Reply to
JohnQ.Public

I am curious, how heavy would be a lincoln 225.

i
Reply to
Ignoramus584

I have a Lincoln 225 [oldie but good] in Eastern TN. The first $50 gets it. I'm having fun with my new Lincoln TIG/Stick.

Reply to
Bugs

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