Convert TIG/stick to MIG?

Hey -
So, I have an AHP 200DX (TIG & stick), but there are times when I wish I had a MIG machine. I seriously don't have the room for both.
I understand why MIG is CV and the others are CC, but I'm wondering whether I could whack together a circuit (been a professional circuit whacker for something over 40 years) that would measure the output voltage and convert that to an appropriate signal to apply to the circuit coming from that current adjustment knob.
The circuitry should be pretty simple, and the implementation should, as well. What I don't know is whether this is going to work, and I'm not really in need of yet another project, but if it's as simple as I think it might be...
So does this sound like a thing worth pusuing, or is it just plain nuts?
I await your answers.
Reply to
Jesse Bear
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I'm saying nothing. Creating a welding machine with a sweet characteristic is not easy. The best manufacturers had a reputation for good reason.
Reply to
Richard Smith
Hey -
So, I have an AHP 200DX (TIG & stick), but there are times when I wish I had a MIG machine. I seriously don't have the room for both.
I understand why MIG is CV and the others are CC, but I'm wondering whether I could whack together a circuit (been a professional circuit whacker for something over 40 years) that would measure the output voltage and convert that to an appropriate signal to apply to the circuit coming from that current adjustment knob.
The circuitry should be pretty simple, and the implementation should, as well. What I don't know is whether this is going to work, and I'm not really in need of yet another project, but if it's as simple as I think it might be...
So does this sound like a thing worth pusuing, or is it just plain nuts?
I await your answers.
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I made an adjustable power supply from a 50A buzz box welder transformer on a Variac, an MDQ series bridge rectifier and about 0.1F of capacitance. The output approximates a 1 Ohm source impedance. The rectified no load output is 55V and it drops to about 35V at 20A DC. The 50A rating is of course at a 20% duty cycle. For continuous use the transformer gets as hot as I want to let it at around 22A. R*22^2 is about 20% of R*50^2. It can deliver over 70A for a short while to test circuit breakers.
It can feed a DPS5020 buck converter, which is the regulator section for a 50V, 20A power supply. Although 20A is too low for a MIG welder this topology of rectifying the arc welder transformer and controlling it with a constant current buck converter has worked well for me.
If you can't find or design a large enough buck converter you might be able to design a variable linear voltage regulator that handles the full power of your stick welder. It will need to accept the no-load arc-striking voltage of the transformer or its full load current, but not both at once because of the CC voltage drop.
Measuring a welder's output V-I curve under full load isn't easy. The Harbor Freight carbon pile battery tester has a 12V-specific timer in it and the voltmeter pegs at 16V, though it can pull 500A for a few seconds.
Reply to
Jim Wilkins
I'm saying nothing. Creating a welding machine with a sweet characteristic is not easy. The best manufacturers had a reputation for good reason.
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I have enormous respect for Vladimir Pavlecka, an airplane engineer who invented the Heliarc process as he learned how to use it.
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Reply to
Jim Wilkins
I am going to tell you the answer you specifically said you didn't want. Buy a MIG welder and have both. An adapter box if one exists is likely to be just as big a a small/medium inverter MIG welder.
Everlast, Harbor Freight (currently - the old ones were shit), and USA Welds all seem to have decent import machines if you don't want to spring for a Lincoln or a Miller. There are cheaper machines too, but well...
Reply to
Bob La Londe
I am going to tell you the answer you specifically said you didn't want. Buy a MIG welder and have both. An adapter box if one exists is likely to be just as big a a small/medium inverter MIG welder.
Everlast, Harbor Freight (currently - the old ones were shit), and USA Welds all seem to have decent import machines if you don't want to spring for a Lincoln or a Miller. There are cheaper machines too, but well... Bob La Londe
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I agree. Although I gave you an idea of how to characterize the output of a stick welder, that's only the first and easiest step, and there are so many things to go wrong with MIG that you won't know where to look for the problem. I suggest that you take a night school class to learn from a pro on industrial-grade equipment, then maybe you can get a student discount on a trade-in at a welding shop. That's what I did. The trade-ins had proven too small for commercial work but are fine for a hobbyist who can design to stay within their limits.
After learning on the big machines I repeated the course with my own equipment so the instructor could show me how set and operate it properly. Fortunately I have a small crane that mounts in the bed of the pickup and didn't have to leave it there between classes.
Reply to
Jim Wilkins
I need to add a socket for the pivoting job crane in the back corner of my pickup bed . I already have a "portable" base and a socket in the front corner of my utility trailer .
Reply to
Snag
I need to add a socket for the pivoting job crane in the back corner of my pickup bed . I already have a "portable" base and a socket in the front corner of my utility trailer . Snag
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The crane base was easy to add to my 1991 Ranger by attaching it to the bed bolts I haven't figured out how to move it to a truck without the bolts that install from above. A heavy load on the crane bends the 3/8" bar stock base up as much as an inch and I can't see sheet metal holding nearly as much.
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Reply to
Jim Wilkins
Maybe in a way similar to the way removable 5th wheel (gooseneck plate also) rails may be installed. A heavy angle bracket is bolted through the frame. Then the rails are bolted through the bed and through the angle bracket. All (most) of the stresses are on the frame this way.
Hmmm... maybe I should make a pickup crane plate that pins to the rails in my 3/4 ton truck. Nah. Just another thing in the way 99.9% of the time in the shop when its not being used. Just like my gooseneck hitch plate and my fifth wheel hitch.
Reply to
Bob La Londe
Maybe in a way similar to the way removable 5th wheel (gooseneck plate also) rails may be installed. A heavy angle bracket is bolted through the frame. Then the rails are bolted through the bed and through the angle bracket. All (most) of the stresses are on the frame this way.
Hmmm... maybe I should make a pickup crane plate that pins to the rails in my 3/4 ton truck. Nah. Just another thing in the way 99.9% of the time in the shop when its not being used. Just like my gooseneck hitch plate and my fifth wheel hitch. Bob La Londe
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When the truck was new I fitted PT blocks into the stake pockets and cross-drilled them for 7/8" aluminum pins through the pockets' lower rope tie holes, then drilled and tapped the wood and pins for vertical 3/8" SS eye bolts. Rubber grommets pushed onto the eye bolts seal to the separate bed liner to keep rain out.
Later when I needed a ladder rack the eyes served as the attachment. The rack is made of PT 2x4 legs and a 4x4 cross rail. The bottoms of the legs were slotted to fit over the stake bed eyes and cross drilled for attachment eye (tie off) bolts that pass through centering bushings in the stake eyes. Since the truck is old enough to have rain gutters on the cab roof a pair of canoe racks on them serves as the front of the ladder rack. The forward eyes hold diagonal braces for the rear uprights made from 1" conduit, as smaller conduit failed my 750 Lb proof test.
I mounted the rack in the forward bed eyes to winch a garden tractor up ramps into the bed. I think it could be guyed and tilted back enough to lift a load past the rear bumper, or certainly to slide it up ramps.
I keep looking for a new truck that can do what the 91 will, with its 7' bed.
Reply to
Jim Wilkins
I'm going to be pulling the bed off while I re-gear the rear axle , finish the exhaust system , and do minor body work to the bed . There WILL be thought given to adequately supporting the jib crane for intended loads . Plus 100% for a safety factor . This just gets better and better , who on Earth would suspect an old beat up truck of being a hot rod if there's a jib crane standing in the corner of the bed ?
Reply to
Snag
If nothing happens to my current truck I would like to just keep maintaining/repairing it until I die or don't need a truck anymore. 2007 Duramax Diesel 4x4 Crew Cab. Fills any need for a multi passenger sedan. Hauls or tows almost anything I need to haul or tow. Has so much torque I sometimes forget I am towing until I pass somebody and see the trailer dragging along in the rear view mirror. I have been using the newer Jeep for a daily driver and light towing to save the truck for things that need it. The truck isn't to bad in the sand either, though it does need an air down in places the Jeep will just float over. Its a good reminder "that the more off road capable is your truck the longer you have to walk to find a tractor." I've been considering removing the AT tires and switching it back to highway touring tires for the marginally better mileage.
Reply to
Bob La Londe
If nothing happens to my current truck I would like to just keep maintaining/repairing it until I die or don't need a truck anymore. 2007 Duramax Diesel 4x4 Crew Cab. Fills any need for a multi passenger sedan. Hauls or tows almost anything I need to haul or tow. Has so much torque I sometimes forget I am towing until I pass somebody and see the trailer dragging along in the rear view mirror. I have been using the newer Jeep for a daily driver and light towing to save the truck for things that need it. The truck isn't to bad in the sand either, though it does need an air down in places the Jeep will just float over. Its a good reminder "that the more off road capable is your truck the longer you have to walk to find a tractor." I've been considering removing the AT tires and switching it back to highway touring tires for the marginally better mileage. Bob La Londe CNC Molds N Stuff
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Mechanics tell me they are very busy keeping older vehicles in service.
I stocked up on the common maintenance items, plugs, filters etc, but I'm finding that other parts are no longer available from the dealer, like my 2000 car's harmonic balancer and alternator mounting bracket, or hugely overpriced such as lower window trim moldings (water seals) for over $100 apiece.
If the part failed from age on my car I can't expect a junkyard or eBay one to be better.
Reply to
Jim Wilkins
I've had bad luck with junkyards. One that is still in business locally often wants more than new price for a part. The one I liked went out of business not long after the owner died.
I suspect you could make an alternator bracket.
Other parts can often be found from places like O'Reill, LMCtruck, GM PArts Direct (often has parts the dealer says they can' get) Ford parts Direct, etc...
Recently I found complete water pump kits for a long discontinued outboard sourced from China. Perfect fit. A truly American made outboard.
And now its time for a story. When I first got my current truck I managed to break the tiny lower mirror. At the local dealer they told me I had to buy the complete mirror assembly. $400 and change. It wasn't $500, but after taxes it might have been. That really bothered me, but I did some searching, joined a Chevy forum, and searched out various sources to discover there was a GM PART NUMBER fora replacement kit for that manually adjusted lower mirror. Out of curiosity I went back to the dealer, talked to the same parts guy at the counter, and asked him to show me the screen with the mirror. There it was plane as day. The separate parts kit I'd found elsewhere. You know how they will have an arrow and circle to show a parts group. There it was. I thanked him and left. Then I ordered the parts kit from GM Parts Direct. It came in original GM packaging pretty inexpensively.
We all know dealerships are expensive of course, but that just irked me. Not only the markup, but attempting to sell me parts I didn't need.
Some years ago doing a restoration (work, not show) on a 1978 F250 I ordered some parts from LMC Truck that arrived in original Ford packaging.
When I was getting my first car going (1967 Ford Cortina GT) I had difficulty finding original import parts, and when I did find them they were crazy expensive. When the generator died I replaced it with a GM single wire alternator... and made my own mounting brackets. I was 16 with almost none of the skills I have today. Piece of steel, torch, vise, and a hammer. Ok, I might have used a drill press too. It looked like crap, but it worked and it didn't eat belts.
You can keep things running if you want to. Its getting harder with the much more complex modern systems, but its still possible. My dad took another approach. He has a couple Dodge Cummins trucks he likes. There is a complete engine in a crate in his shop as a spare. LOL.
With the Internet and on-line sources like YouTube I can find help with almost any mechanical task.
Reply to
Bob La Londe
I suspect you could make an alternator bracket.
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I eventually found wrenches that fit onto all three of its barely accessible bolts and removed them in only half an hour, 1/12 turn at a time. A website showed which parts to remove or loosen (the brake booster) to clear enough space to remove the alternator upwards. The bracket cleaned up well, even the sliding bushing. Only the alternator pivot bolt was severely rusted in place, enough that it twisted off, but it was in stock. I'd sprayed LPS-3 on everything I could reach, unfortunately the alternator is hidden above an inboard CV joint.
That CRV gave me 20 years of almost trouble free service. Years 21 and 22 have been difficult, mainly from road salt rust.
I figured a trick to make driving up onto ramps easier. I position the ramps against the front wheels and chocks against the front of the rears, measure how far the front wheel hub will move to be centered on the ramp top, then move the chocks that far forward so they stop the car when the front wheels are in place.
Previously I had slammed on the brakes when the car was in place, and blew out a rust spot on a brake line, under a shield that had trapped salty water. I suppose there's no better place than my driveway to have a brake failure.
Reply to
Jim Wilkins
I've got a whole array of special wrenches I've torch bent, cut and ground for use with special applications. One of the first I recall was for snugging up one (just 1) of the mounting bolts (nuts?) for the carb on my dad's Ford Grenada. I cry when I think about it now. It was just a True Value brand Master Mechanic wrench, but they were still made in the USA back then. Probably the last of the decent quality affordable American made wrenches. Now you either get screwed by Mac or SnapOn or you buy Chinese.
P.S. Don't bother mentioning SK. They are decent and I think still made in USA, but they have gotten expensive. My favorite small socket set is an SK I bought back in the early 90s from a local tool store. I bought three of them, and an employee got away with one. I still have the other two. One stays in my Jeep, and one lives on my front work bench.
P.P.S. I remember folks coming in my dad's hardware store. We had three lines of hand tools. Master Mechanic, Challenger, and Proto. Hardly anybody bought Proto after they learned Challenger (cheaper) was made by Proto. We sold a lot of Master Mechanic. I even managed the store for a year or so, and I don't remember ever having anybody bring one back. In fact upon reflection of the tools I've broken the only Master Mechanic I recall breaking was a socket I ground down to fit a low clearance application. Many years later, long after it had done the job I ground it for. I've lost a few on the other hand. I think the brand is still around, but it hasn't been made in USA since the 80s. I don't buy them.
Reply to
Bob La Londe
Thats the first time I have heard any mention of Proto tools in about 30 years.
I have a 1/2 inch drive extension bar from them which is only 2 inches long, which is really handy in certain applications.
I was once told that they had the dubious distinction of being even more expensive (in the UK) than Snap-On tools.
Were they owned by Ingersoll Rand at one time ?
Reply to
Abandoned_Trolley

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