lift tig cut off pedal

[BrokenBiker]

thinking of getting a bottle of argon and a valved torch set up for my inverter when im paid next month...

have done lift tig before but want to have another go and try to learn it a bit better as i do eventually want to buy a tig welder.

i have seen some videos where people use homemade pedals to terminate the arc so you dont lose shielding.

anyone on here made one and have pics of it?

i will probably go with a ply wood pedal affari with some decent heavy contacts on it

 

[WorkshopChris]

Seen one used on welding trick and tips on youtube just had a quick look think it was this one.

Scratch Start Tig Welding Tips

Worth keeping a look out on ebay for a Murex open circuit voltage reduction unit. They sometimes come up cheap. I have one on my list of projects to mod to allow the torch trigger or a foot switch to turn power on and off to scratch start with my welder generator and big kemppi dc set.

 

[BrokenBiker]

i was also wondering about making a switch to mount on the torch to kill the arc but i dont want to faff with the internals of the welder while its still under warranty...

 

[WorkshopChris]

nice big contactor and a plastic box at its most basic wouldn't need much to add a few timers for post & pre flow with a gas solenoid as well.

 

[Richard.]

You should never lose shield. It takes a little practice but you simply flick off quickly to extinguish the arc then go back to it quickly keeping the valve open and post flow the run. Scratch start is an art to starting and stopping effectively but it is a very usable process in capable hands.

 

[BrokenBiker]

You should never lose shield. It takes a little practice but you simply flick off quickly to extinguish the arc then go back to it quickly keeping the valve open and post flow the run. Scratch start is an art to starting and stopping effectively but it is a very usable process in capable hands.

might give that a try before building a pedal then...when i tried it before i could never get back onto the weld to keep it shielded enough

 

[Richard.]

The trick is in the flick away. If you move away to break the arc too slowly you extend the arc length and allow oxides to get in putting soot and contamination over the end of the run. Break away quickly with a flick then get straight back on it with the post flow.
Starting can also catch people out. I don't scratch it or stab or even hold it down and lift off, I again adopt a flick type method where I very gently flick the point on the work. Be gentle and snappy because the last thing you want is the tungsten sticking to it and breaking the point off on the job which is common and very easy to do. It takes practice but you'll soon get the knack. Some people strike off the rod with the rod touching the job to prevent contamination. I personally don't prefer that way but you might do so try a few things out. I think it's a great process and enjoy coming back to it when I get chance.

 

[choco]

Would this be helpful?
http://lcdvision-schweisstechnik.de/DC-TIG-HF-Unit

 

[BrokenBiker]

that would enable me to use HF instead of lift which isnt a bad option actually...the valved torch set up is around 80-90 quid i think but that unit is quite a bit more advanced than a simple valved torch and not a lot more money either

 

[Richard.]

90 quid for a valved torch? Your kidding ain't ya.

 

[choco]

Cheap chinese but it's an option

 

[BrokenBiker]

thought it was 90 but weldequips one is 78 and includes an argon reg too http://www.weldequip.com/tig-conversion.htm

 

[Richard.]

Sounds about right. You can get valved torches on there own for £50.

 

[BrokenBiker]

Sounds about right. You can get valved torches on there own for £50.

Yeah, last time I did it I bought a stupidly cheap torch, seperate leads, Rev and gas hose as I thought it would work out cheaper, and it did, came to about 65 quid...until I tried to turn the gas valve off after welding and it snapped...ended up having to buy another torch for about 40 quid so put it well over the price of weldequip...

 

[KemppiFrog]

Would this be helpful?
http://lcdvision-schweisstechnik.de/DC-TIG-HF-Unit

Thanks for that. Just a bit surprised their English is not a bit better.

Just a thought? With my valved torch, it would be easier to put the diy footswitch on the earth cable.

 

[choco]

This isn't a pedal stop switch but an amp setting pedal. Handy enough to do. If you buy the cheap chinese pedals they are about 40 euro.

http://weldingweb.com/showthread.php?271071-Everlast-PowerArc-140st-Pedal-Modification-DIY

 

[KemppiFrog]

Had a spare moment this evening, so thought I would see what was in the parts bin. Folded up two bits of ally treadplate and drilled them for a hinge rod. So that's the treadle bit. Some brass flat and a bit of Tufnol made up the 'blade' bit of the switch, hinged off the same rod as the casing. Found a spare earth cable with a dinz connecter, so that will be the connection to the welder. I will take a pic.

 

[chriso]

Got my pedal from Amazon

 

[KemppiFrog]

Got my pedal from Amazon

10 amp rating is not a lot for welding. Liable to weld the contacts together.