# Tig Welder



## sk1nner (Nov 22, 2015)

I was given a Miller Econotig from work.  It's said to work good.  The only problem is that it runs on 460v single phase,  33 amps of it.   I (obviously) don't have 460 in my garage.   I removed the cover and inside was this diagram 
	

		
			
		

		
	



	

		
			
		

		
	
I'm no electrition so I need some help figuring if I can convert it to 220 single phase.   If this makes sense to anyone please, any info you can lend me is greatly appreciated.    As always, thank you in advance.


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## Hawkeye (Nov 22, 2015)

The drawings themselves don't give an easy solution, but if you open the welder up and look at the main transformer itself, you might find extra wires or terminals coming out of it. If so, it's just a case of moving the second incoming wire to the appropriate terminal. You will be drawing quite a bit more current at 220V, so I'd plan on running a 50 amp welder outlet.

An easy alternative would be to source a 220 - 460 transformer, but it would need to be around 20 KVA to give you full use of the welder. And again, that would need to be fed by at least 50 amps.

If you do find extra taps on the transformer, post a picture so we can better advise you.


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## sk1nner (Nov 22, 2015)

I disn't see any extra wires inside, bUT i can taka a nother look.   What I wonder is in the diagram I see there is a circle with FM inside if it.  What does that mean?  I calculated it out and I would need a 15180VA.  Do you think a 15KVA transformer would be adequate?   I've looked on ebay and I see a whole lot of 460 to 220 step down transformers,  those can be used backwards to increase the voltage right?  Thanks for the info


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## TOOLMASTER (Nov 22, 2015)

is there a sticker on outside with voltage in options


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## sk1nner (Nov 22, 2015)

Unfortunately no.  It says 460 single phase 33 amps


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## TOOLMASTER (Nov 22, 2015)

http://www.manualslib.com/manual/98660/Miller-Econotig.html?page=3#manual


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## David VanNorman (Nov 22, 2015)

If you was able to set it for 220 it would take like 66 amps to run it. I think you might put it on E-bay. It is not for a ham and egger.


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## Hawkeye (Nov 22, 2015)

You would need 15180 watts if it was a resistive load, but, since it is a highly inductive load, the VA should be rated higher.


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## BarnyardEngineering (Nov 23, 2015)

That's why it was free. If it were easily converted to 220V single phase, you never would've had a shot at it unless you're the only one that works at the shop.


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## John Hasler (Nov 23, 2015)

sk1nner said:


> I disn't see any extra wires inside, bUT i can taka a nother look. What I wonder is in the diagram I see there is a circle with FM inside if it. What does that mean?


FM most likely means fan motor.  If I had it I'd seriously consider rewinding the primary for 240.


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## Tony Wells (Nov 23, 2015)

On the main diagram, T1 shows to have a 230 primary. The additional diagram is a supplement where it came factory wired for 460. Probably a different transformer. Before getting too excited about it, I'd get a price on a replacement T1. Yes, probably plenty of money, but cheaper than a whole new welder. Check that PC1 has the same inputs as shown. I would presume so, since there is no other schematic.


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## sk1nner (Nov 23, 2015)

John Hasler said:


> FM most likely means fan motor.  If I had it I'd seriously consider rewinding the primary for 240.


Could you please elaborate on this?  I've done a little bit of research but it sounded like I would need a thicker wire (they say it's magnetic?) And half as many windings.  Does that basically cover it?


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## sk1nner (Nov 23, 2015)

Tony Wells said:


> On the mail diagram, T1 shows to have a 230 primary. The additional diagram is a suppliment where it came factory wired for 460. Probably a different transformer. Before getting too excited about it, I'd get a price on a replacement T1. Yes, probably plenty of money, but cheaper than a whole new welder. Check that PC1 has the same inputs as shown. I would presume so, since there is no other schematic.


From what I've seen it looks to be about $700 .  Would a step down transformer used in reverse work?  They seem to be a lot more affordable.   Thank you


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## John Hasler (Nov 23, 2015)

A step-down transformer in reverse would work.  Be careful working with 480.  It is more than twice as dangerous as 240.


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## jim18655 (Nov 23, 2015)

Connect as an autotransformer and you only need to carry half the current.


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## John Hasler (Nov 23, 2015)

sk1nner said:


> Could you please elaborate on this?  I've done a little bit of research but it sounded like I would need a thicker wire (they say it's magnetic?) And half as many windings.  Does that basically cover it?


I'd make the existing winding into two paralleled windings.  Exactly how I did it would depend on what I saw when took it apart.


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## Tony Wells (Nov 23, 2015)

Using a stepup transformer is one way to go, but like John says, extra care around 480. It's not forgiving. I'm not really sure how that transformer would be to be sized, with out thinking about it some. You know the demand of the machine, but the transformers I have seen are rated for stepdown use. I suppose energy is energy and the same ratings would apply either way.


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## sk1nner (Nov 23, 2015)

John Hasler said:


> I'd make the existing winding into two paralleled windings.  Exactly how I did it would depend on what I saw when took it apart.


So I could actually use the same wire, just double it up.  That sounds interesting.   I may look into this more.  Thank you.


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## jim18655 (Nov 23, 2015)

Tony Wells said:


> Using a stepup transformer is one way to go, but like John says, extra care around 480. It's not forgiving. I'm not really sure how that transformer would be to be sized, with out thinking about it some. You know the demand of the machine, but the transformers I have seen are rated for stepdown use. I suppose energy is energy and the same ratings would apply either way.



Transformers aren't as efficient in "reverse" as they are in the way they're designed to be used. It has to do with the magnetic flux around the core and the position of the coils.


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## Tony Wells (Nov 23, 2015)

Makes sense.


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## John Hasler (Nov 23, 2015)

sk1nner said:


> So I could actually use the same wire, just double it up.  That sounds interesting.   I may look into this more.  Thank you.


Well, I said *I'd* consider trying it, but I'm an electrical engineer and also a little bit crazy.  Whether or not I actually would try rewinding it would depend on what I found when I took it apart.


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## John Hasler (Nov 23, 2015)

jim18655 said:


> Transformers aren't as efficient in "reverse" as they are in the way they're designed to be used. It has to do with the magnetic flux around the core and the position of the coils.


They work exactly as well one way as the other.


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## sk1nner (Nov 23, 2015)

You have sparked my interest in doing this.   I don't want to mess anything  up, could you give some tips.  I know I will have to be careful with the wire.  But what else should I look for?


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## sk1nner (Nov 23, 2015)

Got a few pics of the inside of the welder.  The main transformer actually has 3 windings on it


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## MozamPete (Nov 24, 2015)

Looking at the first post with the circuit diagrams, I would say the fan motor is 230Vac in both configuration (230V or 460V supply), so if you just disconnected wire '11' from the switch to the transformer and reconnect from the switch to the transformer terminal wire '13' connects to you would get all the correct voltages out of the transformer when running on 230Vac (the 24V control supply, supply to the electrode, etc).  You would probably still only be able to draw the original 33 amp from the supply without risking burning out the transformer primary so would need to de-rate the welder output to around 1/2 current - but you could easily add a fuse or circuit breaker to the input to protect against that and give it a try.


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## sk1nner (Nov 24, 2015)

With wire 13 being 230v, logically wouldn't there be the other end of that wire somewhere?   Or would it actually splice off of the 460 coil winding?


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## MozamPete (Nov 24, 2015)

That's what the circuit diagram is showing, 460v across the entire primary with a tap  off half way for the fan motor (which I'm assuming is 230vac). It is called an auto transformer and can be done with only one winding needed, and also work the other way round - when you put 230v on as show in my markup you will get 460v at the unused end so make sure you insulate it and don't just leave a wire floating around.

As you haven't increased the wire size you as still limited to the original transformer current limit - which is probably something just above the 33A quoted supply requirement, but how much above is unknown unless you can find some actual markings on the transformer.


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## RJSakowski (Nov 25, 2015)

According to the manual, there is over temperature  protection circuitry so you could probably still use to full capacity, just derate the duty cycle chart accordingly.  

If the tap for the fan comes out from the winding (and is 230v), you may be able to split the primary winding there and reconnect the two halves as two parallel windings.


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## sk1nner (Nov 25, 2015)

Thank you everyone for the help with this.  You all are a great bunch of guys!


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## sk1nner (Nov 25, 2015)

Yes the fan is 220v.   So I can input 220 to the "fan" lead (#13) and power the welder, this is great news.  I really can't express how grateful I am for the info guys, you saved me a lot of time and money on this.  Thank you!


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## kingmt01 (Dec 23, 2015)

Thanks for asking the question. At the moment I have no use for the info. But I like knowledge & I learned something.


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## Tony Wells (Dec 23, 2015)

I'd be hesitant to actually do that. Main reason being that the 230 tap for the fan is likely to be a few gauges small to use as the input for the primary. Compare it to the incoming wires for the specified 460. I'd think much smaller.


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## kingmt01 (Dec 23, 2015)

Maybe aluminum instead of copper also. Worth a close look.


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## amuller (Jan 26, 2016)

Have you talked to Miller about this?  If you get to the right person they can be very helpful.  From looking at the parts list it appears that there is a different transformer part number for each voltage.  On the other hand, it appears there is a 23o volt winding for the fan motor that would give the correct turns ratio for 230 volt input.  Obviously the fan motor leads would not have the gauge to power the welder, but if that winding is in fact a segment of the main primary winding, and there is access to it at both ends, you might be able to do something--such as use it for a "center tap" and run two sections of the primary in parallel as one does with a dual voltage motor.  Obviously don't mess with something like this unless you know exactly what you are doing at all times (!)  One would need the winding data sheets from Miller, or to strip the transformer down, to really know what's what.


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## amuller (Jan 26, 2016)

Tony Wells said:


> I'd be hesitant to actually do that. Main reason being that the 230 tap for the fan is likely to be a few gauges small to use as the input for the primary. Compare it to the incoming wires for the specified 460. I'd think much smaller.


Now, having done a post, I see this issue already addressed.  Sorry about that.


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## sk1nner (Feb 6, 2016)

Ok I finally had some time in the shop to work on this.  I cut the end off of the 230 tap on the coil, I found that there is 2 wires coming from the coil.  I used my multimeter and it appears that the main 460 coil is made up of 2 separate coils joined in the "center" at the 230 tap.  If this is correct could I connect the 2 coils up in parallel?  I would then have a coil that winds on top of the other coil.  As it came from miller the 2 coils are wired in series making the whole thing 460.


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## amuller (Feb 6, 2016)

For whatever reason, I can't see your pics except as the thumbnails.  

If you have access to the center tap at the full gauge of the primary winding, there is a very good chance that you can run the two windings in parallel and be fine.  It could be that the leads from the terminal block to the switch and then to the primary winding were sized for 460 and would be undersized for 230, so this is something to check.


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## sk1nner (Feb 6, 2016)

I edited the post, can you see the pics now?


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## amuller (Feb 6, 2016)

No, can't even see the thumbnails now.


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## sk1nner (Feb 6, 2016)




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## sk1nner (Feb 6, 2016)




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## sk1nner (Feb 6, 2016)




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## sk1nner (Feb 6, 2016)




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## sk1nner (Feb 6, 2016)

My biggest concern is having a coil wrapped over the other coil.  Can that cause any issues?   From what I've read coils change voltage through induction?  Will the "outer" coil cause any problems with the "inner" coil?


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## TOOLMASTER (Feb 6, 2016)

Had to break mine open yesterday..it is the 220 version


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## sk1nner (Feb 6, 2016)

Any more pics?  Thanks for the help everyone.


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## TOOLMASTER (Feb 6, 2016)

thats all i took


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## sk1nner (Feb 6, 2016)

Thank you


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## John Hasler (Feb 6, 2016)

sk1nner said:


> Will the "outer" coil cause any problems with the "inner" coil?


No.


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## sk1nner (Feb 6, 2016)

So I can wire the 2 coils (one wound over the other) in parallel, and my welder *should* be good to go at 230 ? I'm sorry to keep asking, I just don't want to damage anything.   Thank you.


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## sk1nner (Feb 6, 2016)

Should I be worried about coil resistance,  or will it be correct when paralleled?


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## amuller (Feb 6, 2016)

I can see lot of pics now.  No idea what changed.


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## British Steel (Feb 8, 2016)

Hi Skinner,

You need to be sure you have the coils in the right phase:

from the "start" of the 460v winding, at the 230v tap you need to wire the newly-free end that connects through to the "finish" end to the "start" wire, then the other new end (which will show continuity through to the "start") connects to the finish - so both windings coil the same way around the transformer core.

I've attached a Crap-o-CAD that should explain it better!

You can do a Proper Test to confirm if you're unsure, attach a small AC transformer to the secondary (arc) side of the transformer, not too many volts (you'll get quite a voltage increase), maybe 3v AC - 6v AC but with a few amps behind it (a good rating would be whatever the welder's minimum AC weld current is), and put the meter on AC on the mains side windings.

Connect what you think are the "starts" of the windings together, you should see little or (ideally) no AC voltage across the two "finishes" - if you see more than a few volts, swap one winding end-for-end and test again, if you suddenly have no volts showing - perfect, or you didn't join the wires up... If you have a lot more AC volts showing, swap it back how it was before!

Once you've got them what should be the right ways around, the 3v - 6v of AC into the secondary winding should deliver maybe 25 - 30v AC from the primary side as a final check.

As someone said, bear in mind that at full chat it's going to pull DOUBLE what it would on 460v, so size for 60+ amps - or keep the wick turned down!

Dave H. (the other one)


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## sk1nner (Feb 8, 2016)

That is very useful information.  That is how I thought it should be hooked up, but I'm no electrition so I didn't want to assume.  I figured I needed the "start" of each winding together and each "end" together.  Thank you for the help.  I like the idea of  the low voltage back feed test.   I just need to figure out a power supply for it.  I have plenty of dc power supplies but  not sure about a ac, I'll figure something out.  Once again thank you to everyone that had offered help.


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## sk1nner (Feb 9, 2016)

Do you think I could use a dc power source?   I've looked at every thing I can around the house and garage,  I don't have any ac supplies.   I was thinking if dc would work a 9 volt battery might work.


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## sk1nner (Feb 10, 2016)

IT LIVES!  I wired the coils the way David H showed.  I checked the voltage on the secondary coil and it's at about 26 volts.  Thank you EVERYONE, for the advice.   Now to get the regulator working and my bottle filled and I can lay down some beads.


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## 89yjsahara (May 27, 2016)

Can you post pics or explain how you hooked the wires up for 230? I get the basic idea but do not want to let the magic smoke loose or possibly zap myself.


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## sk1nner (May 28, 2016)

Please note this is how I did it on my Miller Econotig that was 460 single phase.  I can not guarantee this will work with all Econotig's or any other welder.

The coil had 2 input leads.  We will call them A and B. It also had a center tap for the cooling fan to relieve 220 volts.  We will call that C.
What worked for me is I cut the connector off of C.  When I did that I found that it was actually 2 leads joined with the connector.  They are now called C1 and C2.

I used my meter to determine which wire (C1 or C2) was on the same coil as lead A.  And made sure that I had the proper one for lead B.  The way my welder was made they manufactured the 460 coil from a pair of 220 coils wired in series.  I rewired the coils (and the fan) in parallel.
When it was all said and done I  (after making sure I had the correct leads selected) wired lead A and C1 along with a fan lead to one side ofor the switch and lead B and C2 along with the other fan lead to the other side of the switch.

This worked for MY welder, I can not guarantee this will work on any other welder.

If you need it can make sure short video next week showing what I did.  I hope my rambling makes sense.


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## sk1nner (May 28, 2016)

You have to make sure you wire the "beginning" of each coil together and the "ends" of each coil together.  Failure to do so can result in damage to the welder.


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## 89yjsahara (May 29, 2016)

Thank you. That's what I was thinking but wanted to be sure before I did it. It worked perfectly.


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## markba633csi (Jun 16, 2016)

As RJ said, you could conceivably cut and rejoin the windings to get the full power of the transformer- here is a markup of your schematic showing the basic idea. Splitting the winding and putting the two halves in parallel. Forgive my sloppy picture editing attempt lol.  Imagine that the two windings are the same number of turns (which they probably are already) so you just have to find the point on the winding where the fan connects and make the cut, then reconnect using solder and big copper lugs.  Need a big soldering iron or torch, that wire is fat.
Mark S.


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## markba633csi (Jun 16, 2016)

Not sure if that pic worked, may have to change the format


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## markba633csi (Jun 16, 2016)

Here's a schematic of the change (sounds like you got it working fine already)


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## zackdillon (Mar 21, 2017)

Hello!
  I have reciently acquired the same 460v econotig that's discussed in this thread.
I'm going to follow these footsteps and re-wire for the 230v my garage has.
Before I do I'd like to know how your rewired econotig performs.
 Did the rewire drastically reduce it's duty cycle?
Any pitfalls I should watch for?
I've used a tig once in highschool and probably won't know if my econotig is functioning correctly (at first).
Can't wait to burn some holes!


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## sk1nner (Mar 21, 2017)

Unfortunately I haven't had much shop time to mess with the tig.  I don't see why it would alter the duty cycle any.  The few times I have used it, it did seem to work well.  I would recommend upgrading the power cord for the welder (something I still need to do).  It seems to be a regular 220v welder after the changes are made.  Good luck, be careful to not mis-wire the transformer!


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## markba633csi (Mar 21, 2017)

Zack: sk1nner has done this on his machine and says it works well- check page 2 of this thread it's like my markup drawing above.  There are two 230v coils in series in the 460 volt unit, you just separate the windings at the fan connection point and connect them in parallel and in phase.  Need about a 60 amp service to feed it.  Use care. 
Mark S.


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## zackdillon (Mar 21, 2017)

Great!
Thanks guys!
I wired a 50 amp plug for my arc welder last summer. It (unfortunately)  didn't occur to me i would ever need more than 50a.
I ran a 200a service into my garage so I'll run a bigger line if need be.
Think I'll try it on the 50. Worse case is I trip the breaker..... rite?
The drawings are very helpful, thanks!
I need to pick up Argon, tungston and rod tomorrow, then I get to learn how to use this tool.   Definitely MY idea of a good time!


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## FOMOGO (Mar 22, 2017)

I would think that for 90% of what you will ever do 50 amp should be just fine. I have a 220v single phase, 300 amp out machine that calls for 100 amps in and works just fine on a 50 amp circuit for most jobs. It will be getting the full 100 amps in the new shop. Mike


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## zackdillon (Mar 23, 2017)

Sucess!
It seems to operate correctly.

The unit didn't come with a foot operated remote, it came with a hand operated dial and on/off remote box. 


After using this setup for a few minutes it became obvious to me the wisdom of having a foot switch. 
I think I'll make a foot operated on/off switch that'll plug into this box.
I remember my dad's "55" chevy dumptruck had a foot operated starter switch. Or maybe use that same style switch that older cars had for hi/low beams. 
Anyone have ideas?
Thanks.


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## brino (Mar 23, 2017)

zackdillon said:


> I remember my dad's "55" chevy dumptruck had a foot operated starter switch. Or maybe use that same style switch that older cars had for hi/low beams. Anyone have ideas?



Hi Zack,

The two examples you mention are just simple switches with contacts.
The TIG pedal requires a variable resistor (aka potentiometer, "pot", rheostat) to vary a small voltage to the machines control port that then varies the welder output current.

My Everlast TIG pedal uses a rack that has an arc that mates with a small spur gear on the pot's shaft. Something like that should be build-able.

Good luck, and please let us know what you come up with!

-brino


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## Rustrp (Mar 23, 2017)

sk1nner said:


> Unfortunately no.  It says 460 single phase 33 amps


When the machine was ordered the option of selecting the input power source was 220 0r 440. The circuit breaker amperage rating to operate the machine at 100% duty is 33 amps or 60 amps if your source was 220. Your option would be a buck/boost transformer. The 33 amp input is required for the stick (SMAW) process or the TIG process if you were welding heavy aluminum. You could get by with a transformer with lower amperage ratings if you TIG only.

PS. I just saw the date on this thread so using the machine as TIG only with the diagram shown by MozamPete works for you. How is the maching working?


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## zackdillon (Mar 23, 2017)

So far its working great. Im learning how to tig, but now I can run a bead without too much fuss.
The machine seems to do fine with 50a 230v. I bet it'll give me trouble when I try thick aluminium...... one way to find out rite?

Bruno, my plan is to wire a on/off foot switch and use the remote I have for amperage control. Not ideal, I know but we'll see.
It's frusterating (at first) fliping the switch when I'm ready to draw an ark with gloves on torch in one hand, filler rod in the other AND shake my head to drop my helmet into place without accidentally touching my electrode to the work piece.  Lol!  About the third time I had to clean and re-sharpen my tungsten I was beginning to get irritated.  
I could go buy a foot pedal, but thats no fun!  My thought is to "move the on-off switch in the remote to the floor using an automotive starter or similar switch where i can toggle it with my foot, while keeping the control dial on the bench.
A helmet with auto darkening is in my near future too.
THANKS! For all the help!


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## zackdillon (Mar 24, 2017)

Rustrp said:


> When the machine was ordered the option of selecting the input power source was 220 0r 440. The circuit breaker amperage rating to operate the machine at 100% duty is 33 amps or 60 amps if your source was 220. Your option would be a buck/boost transformer. The 33 amp input is required for the stick (SMAW) process or the TIG process if you were welding heavy aluminum. You could get by with a transformer with lower amperage ratings if you TIG only.
> 
> PS. I just saw the date on this thread so using the machine as TIG only with the diagram shown by MozamPete works for you. How is the maching working?


Interestingly, This machine came from Miller wired for 460v single phase. 33amp.


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## British Steel (Mar 24, 2017)

Zackdillon wrote:

Bruno, my plan is to wire a on/off foot switch and use the remote I have for amperage control. Not ideal, I know but we'll see.
It's frusterating (at first) fliping the switch when I'm ready to draw an ark with gloves on torch in one hand, filler rod in the other AND shake my head to drop my helmet into place without accidentally touching my electrode to the work piece.  Lol!  About the third time I had to clean and re-sharpen my tungsten I was beginning to get irritated.
I could go buy a foot pedal, but thats no fun!
_________

Keep an eye open for a broken guitarist's wah-wah or volume pedal, strip out the board and there's a nice rack and pinion waiting for you to swap out the potentiometer - you can also fit a microswitch to turn the arc on when you rock it forward pretty easily!
______________
A helmet with auto darkening is in my near future too.
THANKS! For all the help
______________
Best and fastest improvement I ever made to my welding, even a cheap auto is worth having! (Mine was intercepted before it went into the plastics bin at my local recycling centre, cracks patched with "bumper repair" plastic filler - you don't get cheaper than that  )

Dave H. (the other one)


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## Rustrp (Mar 24, 2017)

zackdillon said:


> I bet it'll give me trouble when I try thick aluminium...... one way to find out rite?


Take the load off the machine and just preheat any aluminum over .125". Just use a propane torch or a neutral oxy/acety flame. 

I'm not sure what you mean by wiring in a foot pedal for remote amperage control. The machine is wired for a foot pedal and $300 for a new pedal would be money well spent to improve your welding , but I think you could get something for half that or less if you check out ebay.


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