I recently purchased an old aircraft generator that was once used as a welder generator on a home made setup. It is made by Bendix and is rated at 24 Volts, 200 amps. It was originally set up to run from the power takeoff of a farm tractor through a Model "A" Ford transmission. I am planning on using a 16 HP Briggs & Stratten horizontal shaft engine to drive it. It also had an old flathead ford V-8 generator rigged on it to exite a field in the welder generator, and I have it. Does anybody out there have any ideas or suggestions for me on how to rig this thing up? I have a general idea how to wire it but, maybe some of you out there have done something like this before and can give me some suggestions.
Thanks,

 

Ive never done anything like that but,im a union ironworker,know a good bit about welders,for one thing,just my opinion,your probably gonna end up spending some money on the machine to make it work right,if your just looking for a good DC welder to have around,get a lincoln buzz box,240 volt,can weld 1/8 th 7018 just fine & only costs round 200$-250$ brand new.
That old generator probably not gonna hold a good consistent heat,makin it very hard to get a good consitent weld & heat,another thing,generators usualy require alot of power(torque) to run off of an engine,the briggs & straton probably wont have even close the power to do so under a load
Like i said,ive never done that kind of thing,i might be wrong about the generator but these are some things to think about

Good Luck

 

Larry,

A buddy of mine uses an aircraft generator for a welder. He runs it off a PTO for welding in the field. I've never used it myself but he seems to really like it.

Randy

 

mantta--If they were using a PTO from a John Deere farm tractor to drive the gererator I am willing to bet that the engine out of that was a diesel, to pull 200 amps out of a DC motor/generator would require some serious torque. You are better off buying a welder.

 

I have an old cast iron Briggs that is 16 HP with an 1 1/8" horizontal shaft. I am going to give it a try. This engine was used on a 10 KW generator before and it sould do it for the small jobs that I do. I may not get 200 amps out of it but I will not need that much anyway.

 

Locate the exiter field leads .
Positive polarity =X, F1,or +
Negative polarity= XX, F2 or -

Use a 12 volt battery. Connect the negative field lead to the neg
terminal on the batteryscratch the positive field wire across the positive terminal of the battery several times.


Then start the motor. I think the phrase is called flashing the field. Not to be confused with polarizing. Old tractors that have sat for a while its often necessary to do this to get the alternators producing a charging current. Same with old generators - which sounds like what you have.

Call a generator repair shop if there friendly and have a minute to spare they'll tell you how to do it with what equipment you have. They might recommend a reduction in rpm 2:1.
Good luck.

 

I have the wiring and an exiter generator and rheostat to control the field voltage in the generator. It was all connected up and I drew a diagram of how it is wired so that is not a problem. Thanks for the input!

 

hello,
i have wanted to make a welder from a generater. could you send me a copy of the wiring diagram, please???

i can provide mailing address if needed.
thank you
chuck

 

Let me try to draw it up for you on my paint program and I will e-mail it to you if you give me your e-mail address.

 

hi,
that would be great! i would appreciate it. maybe i can return the favor sometime.
thank you
chuck

 

I use a regulated 24 volt battery charger to drive a Miller wire feeder. You can do a lot on the cheap. Keep going!

 

hi mike w,
how do you do that?? could you give me details please??
thank you
chuck

 

read a good article on converting a altenator into a welder and was wondering if anybody has done this for there garage? and if so would the electric motor fron a furnace blower be big enough to spin it? any ideas
thanks

 

An electric motor from a furnace is not what you are looking for, you need horsepower that is high enough that you will not have a speed variation under a load when welding. A gasoline or diesel engine is your best bet.

 

"Flashing the field" is the correct term, but it may not be necessary. Generators depend on residual magnetism in the field to start the generating process. The residual magnetism may get lost if the generator sits for a long time or is subject to rough handling.

Alternators use field windings to create the magnetic field, so flashing is never required.

Be careful when flashing the field. When the circuit is broken and the magnetic field collapses, it will send a tremendous jolt back through the leads. Same basic principle as an ignition coil, but with a much larger wallop. Wear rubber gloves, rubber boots and eye protection. You don't want to be the spark plug.

Also, small occasional-use welders use 8 to 10 HP gas engines. An engine-driven welder big enough to earn a living doing iron work (structural) usually has a 16-20 HP engine. The big rigs used by pipeline welders are around 35 HP.

Your 1/4 or 1/3 HP furnace fan motor isn't going to cut it. FWIW, the first industrial arc welders were MG (motor-generator) sets. An electric motor turned a DC generator to produce DC welding current. They also required flashing if the field was lost. They were very inefficient compared to transformer-based machines, but were wonderful to weld with because they were pure smooth DC. Rectifying AC to DC is good, but pure DC is a welder's dream.

Cheers,
Eric