Tig welding arc problems pic enclosed

[Johnnyutah66]

Glad you sorted it, pretty poor for a brand new machine though, if you need any more advice with settings etc, just ask.

R tech said it must have happened in transit, I'm not so sure about that mind you. So much for the test certificate that came with it.

 

[julieanncharters]

R tech said it must have happened in transit, I'm not so sure about that mind you. So much for the test certificate that came with it.

tiddly winks were having a firm lashing when yours was assembled then
mine going to have to go back to r tech again still got hit and miss hf start even though they said it was a loose pcb connection causing it

 

[Dr pepper]

What does ac balance do?, does it alter the upper and lower shape of the waveform, or does it make the ac more negative or positive.

 

[shenion]

What does ac balance do?, does it alter the upper and lower shape of the waveform, or does it make the ac more negative or positive.

Most TIG is DC, electrode negative. That puts most of the heat in the weld pool.

Aluminum requires an alternating current to clean the oxides. On the negative cycle, the electrons supposedly break up the oxides and then on the positive cycle, it is lifted away.

You can use DC, electrode positive on aluminum but most of the heat is dissipated by the electrode. So, you need a huge electrode and it is difficult to focus.

AC balance alter the +/- cycles either by changing the duty cycle (ratio of positive current tine verses negative current time) or changing the ratio of the positive and negative currents.

You can lower the positive cycles until you get only as much cleaning as needed. That will give you more heat without using a larger electrode. Will increase penetration some.

 

[Dr pepper]

I understand the fact that electrons flow from the neg electrode (I know this from thermionics).

Sounds like 'ac balance' is also called 'clean' on other sets, am I correct?
I understand your desciption of the output cycle, didnt know that positive pulses lifts away the cack on the weld, thats interesting.
On a square wave set the low cycles would need to have the opposite polarity by the sound of it, my chinese machine has an ac postion on its mode switch, however I reckon its just pulsed dc, the electronics dont look like the polarity can be reversed on the output (just a rectifier on the output of the transformer, no mosfets), bit of a con if thats the case.
Obviously there is a bit more to a rig that can output true a/c.