Tig pedal help

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Hi quick fix here maybe?Ive  got an old Miller 250 Dial Arc HFits a beast, huge, with water cooled tig torch.The foot pedal is the old two plug  style contactor, no six pin or anything. You literally plug it in.They dont make these things like they used too!!ok heres the problem. The tig works fine, except I noticed after buying this machine used.It has ABSOLUTELY NO FOOT PEDAL SENSITIVITY.JUST ON AND OFF ,  why would there be a foot pedal if there is no amperage sensitivity.So , can this be tweaked fixed or changed? because otherwise its just like a blunt light switch.feel free to email me [email protected] help much obliged
Reply:take a screw driver and open up the foot pedal and post a photo of the inside.usually they have a sliding dimmer switch inside of them, they cost about $4 to replace and another $6 to ship the part to you from mouser inc.they are called potentiometers and if you search my threads you can find a good part number to use.
Reply:Actually, the older 2-plug style of pedal uses a large ceramic rheostat, not a standard potentiometer. Look inside the pedal and see if the rheostat has burnt or broken wires on it. You can get replacements from miller4less.com. If the rheostat looks OK, check the wiring between the rheostat and the plug for continuity.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:Im unsure if your particular welder has this, but most modern tig welders have a contactor AND amp control switch that can be set to "panel" or "remote".You set them both to remote when using a foot pedal.  If you only set the contactor to remote, your pedal will only work as an on/off switch.I've made that mistake myself with mine.TA Arcmaster 300CM3XMT 304S22P12 suitcase feederX-Treme 12VSOptima pulserTA161SMaxstar 150STLHypertherm PM45OP setupStihl 020AVP, 039, 066 Magnum
Reply:so it should definately  have sensitivity right?even the old tig machines like the dial arc i would assume should have sensitivity?why else include a foot pedal.?Ive got a second foot pedal ill try that again.is it possible that its something inside the main machine/?
Reply:The odds are its in the pedal or wiring, if everything on the machine is set right.www.georgesplasmacuttershop.comPlasma Cutter and Welder Sales and Repairs--Ebay storeTec.Mo. Dealer Consumables for the PT and IPT torch's
Reply:I have a Dial Arc 250 HF machine and the RFC 23 foot pedal like yours.  Yes, the pedal throttles the amperage.  Start by opening the pedal box up and ohming the wires and plugs for shorts or open circuits.  If you find a broken wire just hoof on down to the local purveyor of hardware and get a new length of wire.  One is a 2 conductor and the other is a 3 conductor wire, both of which are locally available.  If that is OK then check the carbon brush on the rheostat.  Miller no longer services the part but they are available from other sources.  The contactor switch is a micro switch and is a common available hardware store part for me.  If all that is good make sure you are set for remote operation and understand the adjustment range selection on the panel.  If you do not have it already get the serial number stamped on the face plate and go the Miller website and download the owners manual for your machine.  The instructions are in it.  Might as well get the owners manual for the foot pedal while you're there as well as the resistance values and schematics for the pedal are in it.RogerOld, Tired, and GRUMPYSalesman will call, Batteries not included, Assembly is required, and FREE ADVICE IS WORTH EXACTLY WHAT YOU PAY FOR IT!Dial Arc 250HFThunderbolt 225 AC/DCAssorted A/O torches
Reply:One last thing.  Dialarcs have current ranges low-med-high.  Try to weld on the lowest setting you can (there is overlap) because you cannot go below the low current setting.  The welder will just snap off.  (turn off like a switch leaving a crater in whatever you were welding).   So if you set the output to 10% and the switch to medium, you will get almost no variability.  If you set the output to 90% and the switch to low, you will get much better control.Just a thought.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:Sounds good guysHaven't had a chance to get to the shop and check .But your all making me seem hopeful!By any chance related to this questionCan you add a remote control to the dial arc old style connectorAnd rid your self of the foot pedal ?Is this something I can buy or outright have to make ?
Reply:ok well.its gots sensitivity.dont shoot me please.it was just a matter of changing the range.never occured to me that the range setting was the problem.now its at medium and has a bit more play.any ideas on the remote start for foot pedal free?
Reply:If you just want remote start without amperage control, wire any SPST switch to a plug that matches the 2-conductor connector on the machine. If you want a full-function remote with amperage control you will need a rheostat with similar ratings to the one inside the foot pedal. It will be about the size of your fist. Expensive new if you can find it, but commonly available surplus.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:Sorry could you go at that a little slower ?What exactly is this kind of switch ? And where can it be purchased graingers ?Now obviously this being an old machine . I assume its not going to have any kind of rampUp or ramp down with the switch . Do you think this will be a problem . Obviously the gas solenoid will still function well.If you could give just a little more detail would be really helpful . Not the brightest here .  Also .Do you think a switch would work like this for tacking and short welds ? Because I see even the modern tig welders some have on off switches .Thanks Craig usher
Reply:The remote contactor in your foot pedal works, OK.  Yes it is the two wire plug.  Buying another switch won't solve any thing.  The rheostat in the RFC is a wire wound unit and they rarely wear out the windings.  May need cleaned and a replacement wiper brush but real life experience tells me you probably have a broken or shorted wire in the three wire circuit (remote amperage control).  Make sure you have the panel switches in the correct positions first. My machine set for welding steel.RogerOld, Tired, and GRUMPYSalesman will call, Batteries not included, Assembly is required, and FREE ADVICE IS WORTH EXACTLY WHAT YOU PAY FOR IT!Dial Arc 250HFThunderbolt 225 AC/DCAssorted A/O torches
Reply:Miller also has a remote box called the RHC-3. It is a remote device, just like the pedal, except it is contained in a box that you manually turn the dial to reduce amps.  I have one and it works fine but I never use it.The rheostat control inside the RHC-3 is the exact same rheostat that is inside the welding machine.  When I bought my DialArc the rheostat was bad.  I simply order three RHC-3 boxes on eBay, I think I got two for $50.00 and one I paid more like $60.00.  Changed out the rheostat and welder works.  I also had two extra rheostats. I saw four or five RHC-3 units on eBay the other night for $25.00 each.The rheostat on my welder uses three wires.  I wonder if the pedal connector on your machine is only designed as high frequency On/OFF?On another note, on the DialArc remote, it only adjusts amps as a percentage of the amp setting you have on the welder.Last edited by MWalden; 08-28-2013 at 12:23 AM.
Reply:RiverThank you for your expertise .It seems the issue I believe was more of a setting thingI had my machine set like yours . Exact . But at the higher amperage .And I was getting the cut off like a previous poster had described .After moving the switch to mid range I did notice some sensitivity . Not much comparedTo a nice new maxstar 15Os . But maybe these old things just ain't as sensitive .So three questions for the masters .1. Since I did notice sensitivity after switching the range . Do y'all still reccomend I Open up the pedal and check for shorts ? Maybe it could operate even better ?2. The idea of the remote switch was a separate . Thing.I would like to make that tig machine operate with a thumbstart on the torch and be able not to use the foot pedal.So . With that idea . I would set amperage at the machine . Or remotely with a rh-3 And then use the switch on the tig like an on off . Unfortunately I'm guessing no ramp up or down.Let me know your thoughts . Joining this forum was the best thing I ever dun.Please don't hate me for being not so keen on this . I am not a master like y'all
Reply:Meant to say roger damn I phone tiny keys
Reply:You might want to punch in the circuit breaker above the AMPERAGE switch just to make sure the REMOTE AMPERAGE CIRCUIT is getting power.  Never had mine pop, but they put it there for a reason. Worth checking.RogerOld, Tired, and GRUMPYSalesman will call, Batteries not included, Assembly is required, and FREE ADVICE IS WORTH EXACTLY WHAT YOU PAY FOR IT!Dial Arc 250HFThunderbolt 225 AC/DCAssorted A/O torches