I'm sure I've seen it done either on here or somewhere else.
I know Shenion built his own pedal so it may have been what he used, searching his threads will find it.
^^ that's where a thanks/like it button would be good!
Several threads on home made pedals about. As said, Shenion built one from scratch and others began with a guitar pedal. In essence they're just a poteniometer and a microswitch, obviously need to know the value of the pot and which terminals of the machine to connect it to. Also need a plug to match the socket on the welder.
Personally, cry once and buy http://www.ssccontrols.com/homepage-TIGweldingcontrols.htm although as TIG pedals go they're far from the most expensive. Best pedal i've ever used, i've been kicking mine around the floor, tripping over it daily and dropping stuff on it and i've not had to post a thread singing the praises of their customer service as it worked when i got it and it still works after 12+ years.
One of those would drive me insane due to the height of the thing. What i love about the SCC pedal is that it's comfortable to use standing or sitting and even pretty comfortable when grovelling around on the floor... slim design and angles/travel that actually suit people with legs of the same length and normal ankle joints.
I have had two SSC pedals ordered from the USA,Sent them an email and got a nice reply from a chap called James Moll, We did the deal via email,He told me that they made the pedals for Lincoln electric.
Many sewing machine pedals are carbon stack type that compresses a bunch of carbon discs. Not suited for much else. I bought a new sewing machine pedal to convert and it was useless.
A guitar pedal would better as it has a pot. You would need to change the pot as the one in the pedal will probably be logarithmic taper instead of linear.
You'll need to get the right pot resistance. New inverters are probably not very particular as they use a voltage input.
Old transformer beasts use heavy-duty rheostats. My Airco uses a 150watt, 25 ohm rheostat that would never fit in a small pedal.
Works well. I had made an amplifier to drive the Airco but it kept burning out. I found the the control transformer was bleeding 180V of the HF signal back into the pedal. I could have got it going but found a Miller RFC23 for a decent price.
I am still in the process of making mine! 3 kids and my job have got in the way !
I have a volume pedal for an electric organ that also has a push tab on the side.
I have the correct size potentiometer as i found the schematic online, and i have managed to get hold of the right plug for the tig, which was the most expensive part at about £40.
I have some flex cable that i am testing it with but i may swap to some SY cable for a bit more protection on the cable, i also have a cherry microswitch to place next to the push tab so i can push that to initiate the arc and then control the amps with the pedal.
The hardest bit is trying to get the control for the potentiometer rigged up as i bought an aluminium timing pulley and some timing belt but need to get it arranged inside the pedal to control it properly.
Its not easy but it can be done, depends if you want it soon or you are prepared to wait to build one.
i was going to build one and get a friend to wire it up but bit the bullet and gotone with the welder was the best £200 spent and know it works straight out of the box.