I have a 250 amp Airco TIG machine that was probably made in the late 60's. It works awesome and I have never had any problems with it. I start the arc with a high frequency switch that is located on the torch itself. I recently was given a nice Linde water cooler attachment, torch and foot pedal assembly. I was wanting to hook everything up, but my machine has only one plug with two prongs for the high frequency start, and the foot pedal cord has four prongs, two for the high frequency, and two for the amperage control. My question is if anyone knowsif I can wire in the correct plug that will allow the foot pedal to be used?
I never used a foot pedal. If your settings are on the money and you get your puddle right why would you want to continually go in and out of the temperature zone with a pedal. Most do it to form the little separate dimes that seem to be the trend. You can do beautiful welds and never use a foot pedal. I understand they have a use to begin and end a weld, but I think that is what they were designed for, not to go plop, plop, with little weld dimes. You have been welding fine without the pedal and wonder why you want it.
I wanted the foot pedal for aluminum, because I notice that you need alot of heat to get started, but once the piece heats up, you need to back off on the amperage.
I agree the foot pedal is great for exactly that, increase to start, ease up to finish a weld. All the foot work in between I think is not necessary. If someone prefers that technique, that is up to them. The foot pedal also is a pain when you are down low welding or some place that require you to be an acrobat to reach the pedal. I just always used speed, up or down, to control the heat, not the pedal.
BUT WHEN I have to be an ACROBAT, I OFTEN have had to velcro the foot pedal box to one leg,...and push the pedal with my KNEE../ the original question was about HOW to make the electrical connection.. for me, I would have to know HOW the existing plug was wired, and then compare. oftentimes some of the power units can have a seperate "finger" .....added on..... the foot pedal that you can then touch with the side of your shoe....
Contact Airco and get an owner's manual if you don't have one. Maybe it can answer your question. I've gotten manuals for equipment as old as my 1950 Johnson saw. It was only good thing Clinton ever did. They have to provide you with manuals so you know how to operate the piece and don't get hurt. It will probably be a photocopy.
I learned on a scratch start TIG and have used one hundreds of times in plants while welding stuff that had to be welded in place (repairs, new installations, etc.). That being said, a foot pedal is something I do not do without if I don't have to. It is not really used to "pump" the pedal like you see a lot of guys doing. You can still lay a row of dimes without doing that method. I'm not knocking that way to weld, if it works for others, fine. I just know you can make dimes without doing that simply by controlling your tig torch and filler rod. The guy that taught me could make the most beautiful welds I've ever seen (even on out-of-position welds) and he didn't "pump" the pedal. Foot pedals are important for several reasons but the most important are: 1) They allow you to more accurately control your heat input. Upon start up, you can go "full throttle" and start your bead. Because there is heat build up in the workpiece, as you are welding you can "throttle down" on the heat input thus maintaining the same amount of heat input to the part. This is more evident in the last part of the weld. Look at your HAZ with a scratch start TIG and you will see what I mean. 2) Foot pedals are very important in the prevention of crater cracks. Crater cracks are caused by several things but one of the reasons is because of breaking the arc too quickly like it is done with a scratch start TIG. If you use the foot pedal to "throttle down" on your amperage then you can help prevent crater cracks (along with back traveling, maintaining sufficient post flow, etc.). Can you make good TIG welds without a foot pedal? Yeah. But you can make MUCH better welds with one. And I'm not just talking about appearance. A higher quality weld can be made with a foot pedal than without it.
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