DCEP on Dynasty200??

[sssr]

NOOB question(s)...
It has been suggested that to TIG aluminum, you should ball the end of the electrode by running DCEP with modest current. How does this machine switch to DCEP? It appears that DCEP is only available with Stick mode...can you use the TIG torch in this mode? Also, is it possible to stick weld DCEN? If these are dumb...my apologies.
sssr

[HAWK]

SSSR,

DO NOT,NOT, NOT BALL THE TUNGSTEN WITH THE DYNASTY!!! This machine is designed to work with ceriated and lanthanated tungsten sharpened to a point with a small flat on the tip. A ball will only make the machine work harder to accomplish the job, a poor job at that, and possibly burn up the machine.

Hook it up just as the manual shows with the torch on the right dinse connecter and the ground on the left. This will give you DCSP as required for most TIG applications. You can swap leads for DCRP and DCSP when stick welding.

[dyn88]

always read your owners manual before using any new equipment. There could be one sentance in it that you didnt already know and it could be the difference between success and failure.

[sssr]

I can appreciate your concern with my not using it as demonstrated in the manual, but, it does not say to NOT ball the end. As a matter of fact, it shows a tungsten tip balled up next to a tip sharpened for comparision, then simply goes on to say the "idea" tip is sharpened with a flat spot ground on the tip. It does not say that you will damage the unit. BTW, how can it damage the unit?

Back to the original questions, 1) can you run DCEP on TIG and 2) can you run DCEN on stick (short of swapping the leads). TIA.
Chuck

[KB Fabrications]

Chuck,
I am curious as well about the tungsten balling issue. I have tried both ceriated and lanthanated tungstens sharpened the way the manual describes. The ceriated just ends up balling up on its own and disperses an "OK" arc while the tip on the lanthanated kinda falls to the side and the arc becomes erratic.

All that said, I have had the best luck using zirconiated tungsten. I sharpen like the manual and begin welding. The zirc balls up on its own as well but the arc remains tight and focused and the machine welds awesome. I don't see how that could damage it either. Maybe Hawk could chime in about that.
At any rate, I'm waiting on a call from my local Miller rep.

[HAWK]

You can run DCRP or DCEP as you mentioned in the TIG mode, but only by swapping the leads. This will concentrate the majority of the heat on the tungsten electode and its ( the tungsten ) amperage capacity will be dramatically decreased. The same goes for stick: swapping leads is the only way to swap DC polarity.

The balling of tungsten can ruin the machine by overworking the power and polarity switching IGBT's. As additional input power is provided the input bridge and filters capacitors could possibly have a "melt down". The reason for this additional power and overworking is the balled tungsten disperses the arc energy over a wider area than would a properly prepared sharpened tip.

These inverter based power soruces are not designed to run a balled tungsten. There are numerous reasons behind the inverter technology. One if them is the absence of high frequency on AC after the arc is initiated. Since there is no continuous HF, there is one less path for arc stabilization. A concentrated arc is necessary to properly maintain itself with this advanced squarewave design. A pointed and slightly flatted tip really concentrates the arc energy rather than dispersing it.


Double check the manual. The editions I have plainly read to prepare the tungsten with a pointed tip for DCEN welding. The balled and pointed tunstens are shown a page previous to the preparation page and are only illustrating the difference between the two prepared tunsgtens. The manuals do not state the procedure for balling the tungsten as it is not the recommended method. The manuals also discuss polarity and say the machine is set to weld DCEN in the TIG mode and DCEP in the stick mode. There are no references to the polarity switch being able to toggle between DCSP and DCRP. I apologize for any confusion as I have used the terms DCRP/DCEP interchangeably. DCEN and DCSP are also interchangeable terms.

[HAWK]

Kevin,

I wonder if you have a bad run of lantung. I have experienced what you are describing with cheaper grades of tungsten. I only use Sylvania or a German manufacture for unprepared tungstens. I use Diamond Ground products presharpened and flatted tungstens ordered to specs when possible.

Perhaps if your ceriated and lanthanated tungsten is balling or drooping to one side, then the taper is not steep enough to handle the amperage. I weld with the Dynasty 300DX wide open at 300 amps, 72% EN, 110 HZ, 75He/25Ar shield with a 3/32" 2% lanthanated tungsten with negligible tungsten erosion. For this I use a 35 degree taper and a .030" flat. 1.5% lanthanated will perform nearly the same.

Zirconiated tungsten is designed to ball and is intended for critical applications. Critical, in this case, being welds that cannot tolerate the least amount of tungsten comtamination. Zirtung will ball without dropping the ball or spitting tungsten slivers into the weld. It was designed for and has found wide favor among operators of non-inverter based GTAW machines. If you want a transformer based GTAW machine to shine, feed it Zirtung!

[KB Fabrications]

Hawk,
You're right about the zircs, they work awesome on my Lincoln which is why I tried them on the Dynasty. I will play around with the different angles. I have some samples on the way from Diamond Ground and will assess when they arrive. Actually I'm looking at one of the dedicated grinders as well.

Thanks for the help.

[sssr]

thanks for the answers hawk...
my manual does provide preparation procedures for the tungsten as you have said, the ideal for using a balled tip came from reading the fourms and NGs. it seems that many people have good luck with a balled tip, so i simply wanted to try it. also, i would certainly hope that the machine has an overtemp sensor to prevent damage.

the basis for my question came from the fact that it apparently can internally reverse its polarity...it does so when switching from stick mode to tig mode. also, there is a section on programmable start parameters, which allow you to set a start amperage, a time, and a start polarity. i do not understand what this is or how it is used.

anyway, the interest in DCEP on TIG was so i could create the ball tip...not to do any welding. the interest in DCEN on stick welding was because it seems that sometimes DCEN is applicable. hard to believe that they don't give you a "button" for this.

kevin...when you hear back from your supplier, post his response if you dont mind. i am curious too.

chuck

[HAWK]

Hawk,
You're right about the zircs, they work awesome on my Lincoln which is why I tried them on the Dynasty. I will play around with the different angles. I have some samples on the way from Diamond Ground and will assess when they arrive. Actually I'm looking at one of the dedicated grinders as well.

Thanks for the help.

Kevin,

I use the Piranha II. They are hard to beat. They only go up to 3/32", but with a bridgeport lathe and 15 minutes they do 1/8" easy. Actually the original Piranha II ground from .040" to 1/8". The new one only does .040" through 3/32", but ... I'll be glad to send you some samples of my grinds on this machine if you want. [email protected] As for the Lincoln: I had a client with a SQ Wave 175 that simply would not perform on AC. I dropped in an unprepped stick of Zirtung and it balled on its own in less than a minute. The machine welds like magic. Of course they still have some problems, but I contribute it to operator error. The machine is fine.

[HAWK]

sssr,

I did not mention the hidden menus as there are too many paramters to "accidentally" screw up. That goes for anybody. I usually only change parameters such as START polarity and start amperage unless it is a really wierd application.

When changing the internal menu you have to be careful. There are no external indicators for what you have done. As Kevin mentioned the Zirtung balls on its own. However, I would not recommend it for this machine.

Here's a little history. I learned to TIG on an old gray Lincoln Ideal Arc. It was a sinewave machine and loved pure tungsten. I thought thoiated was better than sliced bread. Along came squarewave machines that have been running strong for 25+ years and the advanced squarewave inverter units like the Dynasty have been on the market long enough to kill all the bugs. Cool stuff. Maybe in the future variable polarity plasma arc welding will be affordable for many to use. Right now it is not. However, it is unbelieveable what can be down with so little. Lots of $$$ though.