AC DCEN/DCEP independent current control on PP256?

I just got my power pro 256 and its great.

I'm wondering if there is anyway to independently control the current levels for the DCEN and DCEP portions of the AC waveform while in AC mode, like millers advanced squarewave technology.

For instance, you could Tig weld aluminum in AC mode, and adjust it to 240 amps for the DCEN part of the waveform, and 110 amps for the DCEP part of the waveform, which would allow you to weld 1/4" aluminum with a 3/32" tungsten instead of a 3/16" tungsten. Much less heat, and much more precise arc because of the smaller electrode!

I'm pretty sure the PP256 does not have this feature.

BUT, is it modifiable somehow to have this feature? (I'm an EE)

Maybe you should sell an upgrade kit or something.

ACannell,

No that is not a current or modifiable feature of the 256 or the 250EX. Only the Dynasty 350 and up have this feature, not the 200.

First,
You must understand what AC bias does, in practical terms while you are welding. In essence, it controls penetration and cleaning, same as the balance control of + vs. - stages of the AC cycle. This is in many respects doing the same thing as the balance control. It can offer a little additional "fine" tuning of the properties, but is definitely a redundant feature from a practical application standpoint.

Some of our new product legislated for next years production will have this feature...but it is a bonus feature, not anything that would prevent making a high quality weld or limit the adjustability of the welder in the slightest.

Quote:

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Originally Posted by performance

ACannell,

No that is not a current or modifiable feature of the 256 or the 250EX. Only the Dynasty 350 and up have this feature, not the 200.

First,
You must understand what AC bias does, in practical terms while you are welding. In essence, it controls penetration and cleaning, same as the balance control of + vs. - stages of the AC cycle. This is in many respects doing the same thing as the balance control. It can offer a little additional "fine" tuning of the properties, but is definitely a redundant feature from a practical application standpoint.

Some of our new product legislated for next years production will have this feature...but it is a bonus feature, not anything that would prevent making a high quality weld or limit the adjustability of the welder in the slightest.

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Okie dokie. I got all this started in my head from the miller tig handbook. Maybe I mis-interpreted it, as follows:

On page 4 of chapter 6 of their TIG handbook, here: http://www.millerwelds.com/resources...Book_Chpt6.pdf

They have two tables showing machine and electrode setups for aluminum. The first table was just "AC", without even listing balance control. There, it says you need a whopping 5/32" to 3/16" electrode, at 250+ amps.

The table below it is for "advanced squarewave", and it says, for the same weld, you need only a 3/32" electrode. It shows AC balance settings, and also the independent current control setting.

So I think what you are saying is that the AC balance alone gets you almost all the way there, and I think I forgot that the first table doesnt even have AC balance.

So what electrode sizes do you recommend for 1/4" aluminum?

3/32 should be about right.

Yes. That is what I am saying. Just as adding pulse to AC can do some of the same things as well as the AC bias...think about it...You are pulsing between two different current values, even though the heat may be concentrated differently. They do have distinct action on the arc, but they can be used to get similar results.

I have been through the gamut trying to find the proper balance settings and electrode size for aluminum and to weld a corner joint in 1/4 inch aluminum I had to step way up to 5/32.

Quote:

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Originally Posted by Wrenchtamer

I have been through the gamut trying to find the proper balance settings and electrode size for aluminum and to weld a corner joint in 1/4 inch aluminum I had to step way up to 5/32.

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Please describe your problems! Everyone here can learn from you!

well I was having a rather persistent problem with tungsten melting and splitting when welding in ac. For a while I was afraid it was a problem with the unit. It's hard to know because the guys here at everlast are about the only ones who have any familiarity with this style of machine. there is one welding suplier here who is fairly educted about inverter based AC/ advance squarewave welders and he was a little help but basically no matter what I was having the tungsten melt in the torch. I could not accomplish anything with a 1/16 electrode. I get a momentary puddle and then there goes my tungsten. Everybody says you shoud use pure tungsten for aluminum but as we know, pure tungsten is not recomended for our machines. So I stepped up to 3.32 2% ceriated and was finally abe to run some surfaace beads on some 1/16 architectural angle. I had been trying t weld my friend's ladder jack back together since I got the machine... On and off I finally got fusion on that corner joint by stepping waaaay up to a 5/32 electrode. I'm not sure if this is normal for the machine or not. I posted in the help forum and they just told me to watc the video at jody's site. I wish somebody in tech support could gie us a definitive step by step test tomake sure the balance settings are functioning properly. I understand why they dont, ut most of us are technically competent, and able to perform our own troubleshooting if we have the procedure. I even have a labscope I could view the waveform
o, I ust am not sure what points to monitor from. But that's it. With a 5/32 2% thoriated I was able to get fusion on that corner with no preheat.

Wrenchtamer....

I think you need to go back and read your thread. We did give you answers. In fact I gave you some settings to test. You never got back to us or contacted us back directly about this. I gave you settings to try on frequency and balance control.

IF you had told us anything about being able to test certain aspects, Mike could have told you what to test. MOST people are NOT technically competent. If you have a scope and need to know where to test the unit, then I'd say you fall into that category.

I did recommend you check the videos so you could see one welding correctly....You apparently abandoned the thread. You posted no further information or pictures or questions. You can tell a lot from pictures.

We have helped you with confirmed operator error issues as well. So its hard for us to know what level you are at in your welding when these things are basic and our manual states them online.

I have been and will continue be glad to help you but your post isn't fair nor accurate about the nature of things.

So people can see what I am talking about I am posting a link to your posts about it here:
http://www.everlastgenerators.com/fo...-question.html

http://www.everlastgenerators.com/fo...-pm-256-a.html

http://www.everlastgenerators.com/fo...-aluminum.html

ok. First of all my post was not intended to be a shot at customer service and I have done nothing but comment positively up to this point. That reply was just a tiny bit nasty and I do not want to go tit for tat with you because I want to keep things amicable and professional. your knee jerk reaction to what was supposed to be guidance for a fellow user seems a little uncalled for. I have nothing but rave about the performance of this machine and the staff over there since day one. I am not claiming to be the worlds greatest tig welder but I can do the job, I understand a/c balance and frequency ad the effect they have on the arc. I would also understad if you said to me : hey Brian, set this dial here and this dial here with this diameter tungsten and it should not melt. I never until this morning even suggested that I did not get what I was paying for. It was early and because the information was solicited by another user I simply mentioned that some pinpoint evaluation procedures wold be nice. the thinly veiled shot at my competence as a welder is acknowledged and accepted. I may as well be rubbing two sticks together for all you know. It hurts me up a little bit that you were so quick to respond when you thought I had taken a shot at you. In truth I probably was a little butt hurt because I felt like my situation was ignored for whatever reason. I thought my posts were clear on the problem I was encountering and I just wanted some guidance from someone who knew first hand what the machine was capable of. I have defended this machine and this company against everyone who thinks red and blue are the only real units out there. I'm out of time here but the bottom line is this. I love the machine and the customer service has been excellent. I called tech support but I know you may be flooded and that's probably the reason I didnt get a call back. I prostrate myself for having offended thee and wish to go back in time... back to a time before I made that post this morning... Back to a time when my welder wasnt mad at me... I really dont need my welder mad at me.

Okay,
Even though I gave you basic settings to start at, you never posted pictures or gave a full description of what you were trying to do, or what joint type you were trying to weld in. You say corner joint: inside? outside? T type? etc. Joint prep? Single pass?
Lets break your essential beef down:

You want exact settings that can tell you where something should operate:
Lets consider the variables involved:

1) Tungsten size, type and Manufacturer. Manufacturers of tungstens though supposedly uniform in make are anything but that. I have found great difference in brands and even in packages of the same manufacturer

2) You have infinite settings between the controls. There is a UNLIMITED possible number of settings that will work.

3) Skill level. No matter what setting is given, if the skill isn't there it won't work period.

4) Stickout. How far does you tungsten stick into the join?

5) Arc Length, related to stickout, normally kept as close as possible. This controls you arc cone diameter and the "spread" of heat.

6) Torch manipulation. If the torch isn't worked between the two pieces of metal, and evenly spreading the heat between the two pieces, knitting the puddle together, it'll take more heat to get the job done.

7) Amount of oxidation. Heavy oxidation requires more input to break up the oxidation and a bigger electrode.

8) Gas flow rate. How much gas is flowing? This affects the heating up of the tungsten to a point and the oxidation removal.

9) Gas type...A major factor when welding TIG. A little helium can increase penetration and weldability of some aluminum. Argon is still fine, but a small percent of helium less than 20-25 percent can make a difference.

10) Tungsten point shape to begin with.

There are other factors, but in my mind, this is what usually affects what settings are used the most. I am sure I missed some. It is hard to give hard and fast settings based off the unlimited possible conditions you face. I am not there and cannot possibly give you anything but the broadest guidelines. Experience and one on one training is the only thing that can help get you where you need to be. Tungsten melting can result in wrong AC balance for sure, but if your polarity is set wrong as your plasma torch was, it won't work right when you adjust your AC balance. Long arcs can also overheat the tungsten by spiking up the voltage.(this goes back to corner stickout)

I don't want you to thick I knee jerked my response to you. I thought it out carefully. The point is, people are fooled into thinking there is a magic setting that can make them a good welder or make something work better for them. When, in fact, skill and technique are the #1 and #2 determining factors.

Those are all good questions and I can answer all of them. the "beef" was not that I was looking for instructions as to how to successfully fuse a particular joint, but to make sure the balance control functions on the machine are working properly. that is all. Once again you mentioned operator error and once again, I acknowledge it as a possibility. I dont get why you are getting still nasty. I dont think this is getting anywhere but my question was not about the corner joint anyway. I was just looking for some parameters to start from at which the tungsten should not be melting so I could make the determination of machine versus operator error. I was not looking for "a magic setting that would make me a good welder". You had a loyal customer this morning who would buy another welder from you in a heartbeat. I have built a 14 year career in automotive diagnostics on good customer service and I have come behind many who could not resist hurling a volley of insults at the customer upon the hint of disstisfaction. when one of my customers has a problem I take it seriously because I believe in the quality of my work and stand behind it. I know you guys are something of an upstart and I know you have done a lot for your customers. when I have time I will set the machine back up, call tech support and maybe we can sort this thing out. I can answer all of your questions over the phone.

My point is:

Operator error is the cause of 80-90% of our service calls. We take them and work through each from a basic to more advanced approach. When we do get a few units back, still several of them are problems with operator error. I am NOT saying this is your case, never have...but it must be a possibility, especially when a person is inexperienced. AND it is nearly impossible for a beginner or even a seasoned pro coming from another welding discipline to make a determination for themselves whether it is operator error or not. And it is equally hard for a new comer to take an advanced piece of equipment that they are not familiar with and use another advanced piece of equipment to make a determination whether or not it is the machine. It can be done, but it is difficult...

I have not insulted you with a volley of insults. I have only defended the principles by which we have operated in regards to your posts. Yes, I have mentioned inexperience, as a part of the barrier we have working with you or any one for that matter on gaining "common" ground to understanding what is going on and giving us helpful feedback. I cannot see how that is considered insulting, unless there is something at play with you that I don't understand. If there is, please PM me, and I will make things right with you as I am trying to do now.

Its like a new NASCAR race driver, telling the seasoned crew chief there is something wrong with the car....and not being able to give exact feedback. Yes, you can make some educated guesses as a crew chief and listen to the driver, but that is all they are (educated guesses) until you can get someone with experience in behind the wheel and confirm the problem and give some feedback from experience on what the car is doing.

You said this:
I posted in the help forum and they just told me to watc the video at jody's site. I wish somebody in tech support could gie us a definitive step by step test tomake sure the balance settings are functioning properly. I understand why they dont, ut most of us are technically competent, and able to perform our own troubleshooting if we have the procedure. I even have a labscope I could view the waveform
o, I ust am not sure what points to monitor from.

To which I responded that was not accurate and more was done for you and posted the links so people could read all in context.
I then in my next post proceeded to identify exactly WHY it is DIFFICULT to give you a one size fits all diagnosis approach.

As far as insults? Please tell me where I hurled insults at you? I don't intend any insults, but I don't like to see people misinformed about our service on this forum either. We told you MORE than to go to Jody's site. Which you said you only were told to go to Jody's site. That is where the rub began. If I drop the ball or Mike drops the ball on something, then we deserve it, but in this case, we exercised our due diligence in the matter in regards to the post. I never received a call from you directly and if Mike did, then I am not aware of it. And you never followed up with more feedback or questions. What are we to do?

Ok. i appreciate that. I will acknowledge that the original post wasn't entirely accurate as far as your respnses to my requests for help. I think the days of thunder analogy is quite appropriate. I was a little bitchy yesterday morn and perhaps I should not have said what I said in the manner that I did. I failed to consider all angles of what effect that post might have. In my industry, great service is soon forgotten by most, but the memory of poor service is eternal it seems. Like I said, I beieve in your company and want to see you gys flourish. no hard feelings here. That being said, is there a way that you are aware of to connect my scope and monitor the waveforms frequency and balance? I guess that is what I should have asked in the first place. I would think it should be a fairly simple matter, but I thought you fellows might have a specific test procedure for the rare case that you need to examine a suspect or questionable unit. If it would be better for me to just get the machine in order and call mike or yourself then I will do that too.

You can talk directly with Mike. He should be able to walk you through the basics.

However...You can severely hurt yourself if you are not up to speed on the dangers lying inside. That is why we don't put this information out there(one reason anyway, out of several) for ANYBODY to do. Scopes and diagnostic equipment has gotten relatively cheap now, and it is easy for many people to be "tempted" to do something that could come back on us if we just "dispense" this information publicly.

If you want to monitor the waveform with a scope use a 2' long x 1" wide x 1/16" thick piece of steel and lay it on an insulating surface. Connect your ground clamp to one one end and short your torch to the other end. Set the current to 70A. Connect your scope ground to the ground clamp and the scope probe about 1" to 2" from the ground clamp. This is a cheap current shunt and can be used to see the wafeform but is not accurate for current measurement. To increase the signal seen on the scope move the probe closer to the shorted torch, or to decrease the signal move the probe closer to the ground clamp. Its simple and you can measure the frequency and balance easily.