Q. I have a Miller 330A/BP TIG machine, and have trouble with a stable arc on aluminum less than .090" thick, both with 1/16" and 3/32 pure tungsten. Is this to be expected with this machine, and would there be much improvement with a Syncrowave machine, or would it be necessary to move up to a Dynasty in order to see a significant improvement? Would there be a noticeable difference with either of these machines on steel, as compared to the one that I am using, and what would those differences be? Is there an add-on accessory for the 330A/BP that would help the arc stability on thin aluminum? Also, I have an Airco machine that looks very similar to this Miller, was it made by Miller, and are they different internally? (Submitted by: John Russell from Richland, MI)


A. Great question John. The 330 ABP was a great TIG unit in its day. The problem with arc stability on low end is that the unit is a sinusoidal unit, meaning the AC output is the same shape as the AC input. It's rounded something like "~". The Syncrowave has a modified output AC wave shape called squarewave. The reason it's more stable is because the switch from positive to negative on the AC is straighter and faster through the zero axis. This causes a more stable arc and eliminates arc wonder. The Syncrowave would be a fine improvement to your shop. The Dynasty is the next step in arc shaping and pinpointing. It takes a little more set up skill but the results are unmatched. MILLER did make some of the Airco units. The chance of it being one of ours is pretty high.