Thanks for that effort Dave!
I appreciate it.
Now if I could only find my other torches....

Maybe it's on the right side?? If you could, maybe check the right side as well......or look thru? The DIY cart mine is on has support straps on the sides making it a huge pain to open the side covers. I had to cut the left one with a cutoff wheel to open the left cover Plus its buried between an ol...

I misspoke, there is nothing like that under my -left- side cover.
No numbered wires either.
It's never seemed to make any difference which position the knife switch is in,
I've tried it both ways with equal results.

Next I'm trying a different (used) torch.
I think mine is an early '70's model but not sure.

HF is def. maxed....it's dismal at best like all these machines were. When it's acting up I can floor the pedal and that oscillating of the arc/puddle begins. Sadly, it's been an intermittent problem for years. But when it's good, it welds great which is the frustrating part. And it stick welds just...

MinnesotaDave...... I found something interesting in the Miller 330 Tech manual. Page 5 (which is the PDF page 9) Section 2-9. Full Wave / Half Wave Balance. The 4 problems they list with Full Wave seems exactly the same as the problems I am having. 1. Poor cleaning action 2. Porosity 3. Fluctuation...

I'm sorry, who didn't know what square wave was? I know what square wave is......and I know there's no such thing as sinesquare wave as well. I even own a couple O'scopes, and know how to use them. Still trying to figure out how my first post sounded like I was 'converting' an old welder to TIG.... ...

Here's the "Mile Long" part number of this machine: AIRCO AC/DC Heliwelder Model 2A/DDR-224HPA/B-D Same or very similar to a MILLER 300A/BP Bobdhus: I am playing with 6061 1/4" plate. dirtmidget33: What is square sign wave?? It's one or the other, but not both. Do you realize how many...

Thought weak HF was the problem. I got the new caps for the HiFreq. installed... Less spectacular improvements than I was hoping for. HiFreq is 'somewhat' stronger, but on Alu. it still does weird things. It acts 'cold' even on high range. There is not an abundance of cleaning action, and the puddle...

To take it one step further if you're after increased protection, there is a spray clear Circuit Board Lacquer that you can apply a couple thin coats of that does help prevent shorts from metal dust and corrosion from moisture and high humidity. Available from places like Didikey, Newark Electronics...

I did replace the caps in the HF years ago because the HF was weak.
The new ones didn't make a heck of a difference.
But I do not believe that is the problem causing the weird (intermittent) weld problems.

You can actually was down circuit boards with contact cleaner, then gently
blow than dry or let them air dry. Helps with getting the metal grit off of
them. There is specific cleaner for this.

No inverter in this old machine to worry about.....

It does look just like that (only a lot cleaner ) and I do appreciate the link!

Thanks!
D

Thanks guys!
I will check all connections, and see how it goes.
Maybe pressure test the gas system to check for pin holes or cracks.

dk

I think this is my second post. Although I signed up here about 2 years ago, I spend more time on the machine shop forums. Mostly because that's what I do more of....machining. But I have a welder/welding problem that's kicking my butt.... Here it is: Machine: Airco AC/DC Heliwelder Model: 2A/DDR-22...

WOW These 2 videos Jody posted this week are just fantastic I am 52 yrs old, a job shop (machine shop) owner since 1979 and I am just getting back into welding with work from the Gas Drilling industry. These 2 videos are very interesting, and I had no idea about all the movements required to do some...