Just bought a new Miller Dynasty DX before Christmas and have just tried it out.
This new welder seems to make odd ticking noises that sound like internal arcing, especially with HF mode on - Do these welders have an internal spark gap in them for HF? I was using the manuals settings for 1/8 in Aluminum ie AC, HF on, F= 120 Hz, 20 sec preflow, pulser off, 120amps etc. When I shut the machine down, the noises gradually run down, like a rotor winding down(?)
Also, the background of the display flickers while welding which seems worrisome. This machine will likely be going back soon. I could not get a nice bead either like I did with the demo unit in the store - just some sooty mess - seemed like the nice new 60 cu Ft Aluminum argon cylinder was not purged of air when they filled it? It was also only filled to 600 psi (or the valve had leaked it down to 600 psi
Oy Vey - Kinda disappointing after wanting one of these things for over four years. Thanks for any advice, Graham
Thanks for the tip that the gas is likely bad - store said they would refill and even swap the 200DX when they get a new one in after Jan 1st.
Turns out that this 200 DX is arcing inside to the case when HF is on. If I look in the front grill above the gas port, on the right side I can see a sheet discharge. There is no spark gap in the schematic so I think that this is bad.
Two things come to mind - When I called the store, they said check the grounding to earth which I will do, which may be suspect in our old circa
1912 house. There is 240 VAC at the shop plug with proper 120 on each leg.
The other I remember from my high school electronics shop TV repair days (back when they were all CRT`s!) and that is that High voltage supplies with suspect insulation always leaked worst when the air is damp. My garage is unheated and it is a bit damp here in Vancouver BC (!).
When the store re-opens, I`m taking the machine back to swap for another and then I will get back to melting metal in aid of fixing aluminum boats, experimenting with making solar collectors and heat pipes etc.
The noise after turn-off is normal, at least it hasn't caused a problem in the 4 years I've had my welder. I don't believe the noise is due to a spark gap, the HF is electronicly generated in these machines.
I haven't paid much attention to the display while I'm welding, so I can't tell you much about that.
It certainly sounds like you got a bad bottle of gas, maybe they gave you
25% co2 intended for MIG? If you got a sooty mess (with good gas flow) then the gas is wrong and you can't expect a good bead.
I've had no problems with my DX, I've used it more for stick than TIG, maybe 75/25. It has handled 6011, 6013, 7014, 7018 and a couple of other rods with no problems, much to the dismay of a friend withj a different inverter welder which has trouble with some rods. You will need to adjust the Dig control to improve the performance with some rod.
It is a bit difficult to restart certain rod due to the low open circuit voltage, we can thank the safety nannies for this requirement.
I got an air-cooled torch because of cost, if you can afford it go with water cooled if you'll be doing much TIG, especially with heavier aluminum. You'll find the heat on your hand limits you more than the machine duty cycle.
In my experience using them for stick welding, I've never heard or seen one arcing inside the case. I've occasionally seen one that "clicked" during the high-freq tig starts on steel, but those machines usually wound up heading back to the repair shop in fairly short order for one reason or another.
I would definitely take your machine back to the seller and see if they can satisfactorally explain what is happening and / or get it to run right.
Good luck, and let us know what happens! I've been thinking about getting one of these when I finish my shop....
I've been told by "Servicedude" on the Miller discussion board that it is normal to see HF discharge inside a DX200 while the HF is active as there are discharge points inside there.
Made the trek to the dealer to replace the faulty (leaking) Ar tank and to get an assortment of electrodes more suitable for alumimum (Ce and La).
I'm going to call Miller to find out for sure about the spooky internal discharge. Welder seems to be working more or less normally - hard to tell though, as a beginner without much time to fiddle with the knobs and buttons (wife wants that attic rebuilt.....)
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