alternator welder

[alta780]

i am trying to make a welder from an alternator.i have a bridge diode,and a circut board made to control up to 150 amps.does anyone have an idea or drawing as to how to hook up field power.all of the ones i have read about control current by engine speed or by adjusting voltage going to field.i want to control amperage with circuit board after 12 volts is applied to field.will this work? would i also need an on-off switch on field supply wire.i have read almost every welder alternator write up on the web,most are onboard welders and i want mine to be portable with a seperate engine driving the alternator.i have a 13 hp engine that i will be using.does anyone have a drawing or could make up a drawing with every detail included as i don't read electrical drawings well.Thank-you

 

[HarveyH42]

Do you have a link, schematic, even pictures of what you want to build? I've got a 6.5 Hp Honda lawnmower engine and several spare-part alternators from various vehicles I use to own, the idea is interesting. Been wanting a welder, but not enough to shell out the bucks. I've had a few project ideas lately that need some light welding, usually get my little brother to do it, but would like to be able to fire it up when I get the urge to build.

About all I know about alternators is that the rectifier is built in (usually), and that after your car is running, you can disconnect the battery, and it should continue to run, unless the alternator is bad.

 

[Sceadwian]

Buy one, you can get single phase low duty cycle welders for under 200 dollars, even cheaper if you check e-bay.

 

[Andy1845c]

I have seen these kind of things in old popular mechanics type magizines. I can't put my hand on any of them at the moment though.
I can't help but wonder how it is going to weld though. How low is the duty cycle going to end up being?

This reminds me of when I was thinking of building my own 5000psi hot water pressure washer. I came to realize that I would spend alot and never be totally happy with it, so i just bought one. It works great and I am very happy with it.

What are you going to weld with this welder? For light welding you can't beat a gas sheilded wirefeed (MIG) welder. They have come down in price tremendously. Check out ebay.
I won't go back to stick welding unless I am welding somthing on a plow or dozer or somthing like that.

 

[Hero999]

Buy one, you can get single phase low duty cycle welders for under 200 dollars, even cheaper if you check e-bay.

Are they petrol/diesel powered though?

Perhaps he lives in an area where there isn't enough mains power to run a welder.

 

[alta780]

It will be run by a 13hp gas engine because it needs to be portable.i could go and buy one,but this way i get the satisfaction of building it myself.(and of course with a little help from this forum)i will get it built and it may cost me a few sets of brushes until i get the 12volt field feed figured out as to grounding,insulating and possible putting in resistors.Any ideas greatly appriciated.

 

[Nigel Goodwin]

It will be run by a 13hp gas engine because it needs to be portable.i could go and buy one,but this way i get the satisfaction of building it myself.(and of course with a little help from this forum)i will get it built and it may cost me a few sets of brushes until i get the 12volt field feed figured out as to grounding,insulating and possible putting in resistors.Any ideas greatly appriciated.

Just google it - I did the other day, and one of the top hits was a site explaining exactly how to build one, with lot's of pictures.

However, the pictures of his example welding looked bloody rough! - either the alternator welder is useless, or his welding skills are!