Redneck Tig foot pedal with a SSR?

[kf4zht]

I am getting more into TIG welding, but don't have any money for a real TIG machine so I have been using a torch off a Harbor Freight AC/DC buzzbox. This works fine for the basic work I am doing but it would be nice to not have to leave the torch hot and turn the gas off by hand.

My idea was to build a box with a footpedal that controls a air solenoid and a relay. The relay would simply disconnect the power feed going to the welder. Basically if I hit the footpedal the welder comes on and the argon flows.

I was looking at solid state relays, I can get one rated well over the welders draw cheap, but I didn't know if there was any reason why you couldn't use a SSR for this type of purpose.

 

[goneflyin2002]

Hey sounds like a fun thing to try.
Course the only big drawback is not having the 'throttle' action of the tig pedal.
But anyway, try to rig it up so that the gas comes on first for about 5 seconds, maybe a 2 stage pedal?
A SSR might work, but the load is pretty spiky i would imagine- a SSR might not like that but if it's cheap, go for it.

 

[goodspeed]

I'm in the same boat with a lincoln dc tig. If you come up with something workable, I'd like to see it.

 

[Zeke]

Really your only option with a foot pedal or not is a scratch start. You won't have the HF for a pedal start and you won't have the circuitry for a lift start. So all you're doing is controlling the gas with your foot and, like you said, killing the tungsten when not welding.

However, your cooling fan will cease to run when you lift your foot off what is essentially a deadman's switch. No reason not to be creative, but I think the gain is going to be minimal. With a gas control on the torch, you can create your own pre and post flow, both good things.

Where are you going to tap into for low voltage? If you kill the power to the unit, your power source is going to have to be independant.