Wire feed on CC?

Date 05-04-2010 19:18

Hello smithcd2208, you are correct about the short-circuiting not working in this scenario. You can as you additionally surmised, spray with this particular set-up in GMAW, providing you have the correct shielding gas and machine settings. As to making code welds with CC, providing you qualify the process you can make code welds with CC as well, it is just generally easier and more forgiving with regard to parameters to make them with the CV mode and in many instances CV is prequalified and doesn't require any additional procedural qualifications. Hope that makes some sense, others will likely clarify this better for you. Best regards, Allan

By smithcd2208 (**)

Date 05-04-2010 19:43

That makes perfect sense to me. I forgot about the fact that any company can submit their own welding procedure and tests to be a qualified welding procedure, so yeah you can make your own "code" welds if you did that. Thanks for reminding me. Did you have any thoughts on using a dedicated TIG machine with pulsing capabilities to do a "pulsed spray"? Most of this is just for fun and to help me better understand the fundamentals of welding and how they relate. With what i knew i just had an idea that if you could do wire feed with flux cored electrodes on constant current, what makes a solid wire any different? With the understanding that a short circuit wouldn't work because the ampergae change isn't sufficient i figured with a high amperage above transition point and high percent argon shielding gas theoretically you could do a spray transfer on constant current. I'm definitely gonna play around with it. It's always nice to know what you can do in a pinch.

By 357max

Date 05-04-2010 22:11

smith; if your cc machine has hot start and arc force/dig/arc control features, set both to maximum values. Set the amperage to 150, adjust the wire feed speed to set the voltage to 17 (use a voltmeter if machine does not have) to 19 volts (depending on shielding gas). You should be in short circuit with these control settings.

By aevald

Date 05-05-2010 00:41

Hello again smithcd2208, I am going to try to include a link from ESAB that has a pretty straightforward approach to CC wire welding. http://www.esabna.com/us/en/newsletters/Using-Cored-Wires-with-Voltage-Sensing-Wire-Feeders.cfm this is a short article that has some good points. As to your question regarding pulsing and using the voltage-sensing feeder with a machine in this mode, I kind of doubt that this would work very well although I don't know for sure and I don't know that I would care to try to find out. I believe that you might damage your feeder because most pulsing modes are putting out seperate levels of current and these might play heck with the voltage sensing aspect of the feeder. I am basing my opinion on the premise that a voltage sensing feeder is varying the wire speed that it puts out due to the voltage differences that are seen as the arc length is changed. A pulsed current would vary the voltage without altering the arc length and likely "confuse" the speed sensing abilities of the feeder. Could be an interesting scenario and possibly an expensive one. As I said though, I don't know what the result would be and I haven't really ever seen any information on this particular topic. Best regards, Allan

By 357max

Date 05-05-2010 02:08

Aevald, w/due respect the following quote from the esab link - on constant current... "If the voltage is too high, turn down the wire feed speed." This is backwards, decreasing the wire feed speed will increase the arc length and the voltage. To decrease the voltage requires the wire feed speed to be increased.

By aevald

Date 05-05-2010 04:17

Hello 357max, that is an interesting statement on ESAB's part, I guess I should have read through that a little better before linking it here. Nice catch on your part. Best regards, Allan

By gndchuck (**)

Date 05-06-2010 01:45

yeah Allan, it will work to an extend, you more than likely won't like what you put down. But then again just depends on if you're trying to hold something together that's not stuctural(sp), (too many drinks), but to hold something that you don't want the ,mmmmmm, safety guy to see, to make, mmmm, work, maybe. But you didn't hear that from me. Sometimes, well depends on what you're doing, we would just because we didn't have enough smaw rods to really do what was asked to do, that we would use a suitcase and do exactly what your asking to do. So NO IT'S NOT PROCEDURE, AND WILL NOT PASS WPS. And that's all I'm going to comment on that.

Chuck Welch

By DaveBoyer (*****)

Date 05-05-2010 00:47

I don't think a TIG pulser wil give good results with a voltage sensing feeder.

Pulsed MIG is a different can of worms. Pulsed TIG changes amperage with the pulses in a drooping volt amper curve. where pulsed MIG changes voltage in a nearly flat volt amper curve.

In pulsed MIG the background voltage is below the spray transition, and the peak is above the spray transition. While there have been pulsed MIG machines for the last 35 years, it is only in about the last 5 that they have become versatile enough to give advantages in a variety of work.

By 357max

Date 05-05-2010 01:54

Dave, inverter pulsed GMAW power sources use a constant current output and pulses between high and low amperage. There are some models that throw in a constant voltage component with the pulsing constant current for arc length and arc cone width control.
The old (40+ years) transformer rectifiers made by Airco & Miller Pulstars used a variable pulse of the primary line frequency of 60 hertz w/either 60 or 120 pulses per second and a constant voltage.

By DaveBoyer (*****)

Date 05-05-2010 02:18

I tried to look up the volt amper curve of the Miller Axcess 300, but the owners manual doesn't show squat with regards to what the volt amper curve of a pulse might look like.

Those old transformer pulse machines were still being sold in the '90s in spite of themselves.

By 357max

Date 05-05-2010 02:31

Check the old Miller Maxtron 450 om. It states that the GTAW toggle switch position was to be used for the GTAW & GMAW-P. 40 years of pulsing gt and gmaw has brought together some great technology

By Lawrence (*****)

Date 05-05-2010 05:16

Maxtron was a strictly CC GMAWP power output.. Axcess is a different thing altogether.. As is everything Miller now sells. All the currently marketed Miller GMAWP power supplies have CC/CV output... This is demonstrated by arc length and current remaining constant when operators change electrode length during welding.

Lincoln salesman says the powerwaves all run CC... But I don't quite believe it. It produces charictaristics of both CC and CV..

We have a spankin new Fronius CMT GMAWP power supply on a truck to be delivered any day... Much looking forward to that can of worms!

Maxtron and ARC Pak were horrible pulsers.... Bill Behnke is the only guy I know that ever had good succsess pulsing one of these things out of position. I spent months with that pendant.. Yuck. Pretty good short circuit and spray though... But heck you could have 3 Deltawelds for the same cost.

By DaveBoyer (*****)

Date 05-05-2010 04:42

With pulse transfer, the volt /amper curve can't drop as sharply as a stick welder, or the arc length wouldn't self correct [with a constant speed feeder].

Thinking more on the subject, I guess the really flat volt/ amper curve is only needed for short circuting, but in CV transformer machines, You have it regardless of metal transfer mode. Even with slope control, it is still a pretty flat curve.

By Cactusthewelder (*****)

Date 05-04-2010 23:31

One thing to remember. A Suitcase Feeder is also called a Voltage Sensing Feeder. In Short this means.... The Feeder is Stupid, It doesn't know whether or not you have CC or CV. You just have to learn to set your machine accordingly. I have a 300D as well as a SA200 as well as my Vantage Machines. I have one of the New Esab 300VS feeders (VS stands for Voltage Sensing) All of the machines will run the Wire one as well as the other. The difference starts to show with the Bigger Wires. Any before anyone says I am Nutts. I will invite anyone to come and try them out. I happen to get plenty of wire samples from the Factory. So.... I have a nice Array to play with.

By joe pirie (***)

Date 05-05-2010 02:40

i've never seen Lincoln nr232innershield wire run on constant current . I believe the newer model ln-25 suitcases have a cc /cv switch

By Cactusthewelder (*****)

Date 05-05-2010 02:46

They do have a CV/CC Switch. But it only works if your machine has CV

By aevald

Date 05-05-2010 04:48

Hello Joe, I believe the LN-25's have had the CC/CV option since their particular model's inception, I'll go out on a limb a bit more to say that they've been around in that capacity for 35+ years, although I'll likely be corrected on the exact time of that. I've also had a bit of a debate with a gentleman on another forum about running various wires on CV or CC with an LN-25, LN-22, 12VS, S32-P, Hobart Hefty CC/CV. Of the grouping that I just listed here the only one that isn't CC/CV is the LN-22, I believe it is CC only, at least that's the way I recall it. I have been running various self-shielded wires on many of these feeders and powering them with various power sources to see just how finicky or not that they will operate. Have used ESAB 8, NR-232, Fabshield 21B, NR 211, they have all been operable with either CC or CV, however the CV tends to be a bit more forgiving concerning parameters and hence a smoother overall arc. Have powered many of them with XMT 304 in CC or CV, and the XMT's voltage sensing selector mode. Have also used an old Lincoln tombstone 250/250 AC/DC CC machine, PowCon 300SS CC machine, Lincoln Weldanpower AC/DC 200 amp portable gas drive CC machine, Lincoln Idealarc DC-600 CC/CV machine. Overall, in most instances the wires can be run on either type of output, but generally the CC output requires a bit more tinkering and fine tuning to get it to run well. Lately I haven't had the time to do much of this and get it documented picture wise so it is a work in process and "someday" I'll finish the compilation and share it here and elsewhere. Best regards, Allan

By 357max

Date 05-05-2010 23:19

The xmt 304 voltage sensing position is constant voltage weld output. Notice when this mode is selected that the secondary contactor is pulled in and the main control potentiometer increases or decreases the voltage value. So, the selector switch on a voltage sensing feeder must be in the cv mode.

By tazmannusa (**)

Date 05-05-2010 23:32

Been a long time ago but the only wire I found that would run decent in CC was NR-211 flux core .068" or bigger. I tried some of the others and solid gas sheilded with not much luck. aluminum is ok on CC
Tom

By 357max

Date 05-05-2010 21:50

O.035" wire requires about 350 amps to clear the short circuit. If a cc machine is limited to 150 amps by setting that amperage value therein is a problem using the cc machine for short circuit metal transfer. If the cc machine's arc control is set to maximum and the hot start is set to maximum the cc machine should have the additional amperage to clear the short circuit. The hot start only works at arc start therefore clearing the short circuit at "arc start" and arc control's additional amperage at low voltage (less than 19-21 volts) The short circuit transfer produces a very short arc length (arc out) and therefore a very low voltage. The arc control works off a cv foot on the volt amp curve. The shorter the arc length and the lower the voltage below 19 closer to 1 the maximum additional amperage is added.

The "danger" of using a gtaw pulse machine with a volt sensing feeder is the high frequency which may be turned on when the feeder is connected. The hf could possibly over voltage the printed circuit boards on the feeder.

By ssbn727 (*****)

Date 05-05-2010 22:30 Edited 05-06-2010 01:56

Hi 357 Max!

The scenario you painted regarding the use of HF is a very true one as I once experienced the results as a witness when I was sent to service a malfunctioning Miller VS wire feeder (If I remember correctly, it was an S-32 voltage Sensing wire feeder) which according to Miller at the time voided the warranty on the feeder because of the improper use with HF... So you may want to avoid that as 357 Max so eloquently described. ;)

Respectfully,
Henry

By gndchuck (**)

Date 05-06-2010 01:52

Henry,

I did that same thing on a Lincoln machine some years ago for a habitat job, later found out that the particular machine that I was using won't do what we were wanting to do. Live and learn my friend, live and learn. Just hope that the others out there will take what we've learned and prove us wrong. When I first started out there were many much older and wiser than I, (not what I thought at the time), that schooled me, (by means that are not correct nowadays), of how things would be. They like, I now would like to be proven wrong, (like I have, them on 3 occasions in the last 13 years have done). You never know what can really be done until you tell someone that they can't do it.

with the utmost respect,
Charles Welch

By ssbn727 (*****)

Date 05-06-2010 02:20

Hey Chuck!!!

How's it going there buddy??? Hope you're still busy!!! Yeah, that circuit board was toast when I opened that wire feeder up to diagnose & troubleshoot why it wasn't working properly anymore as I was the same person who set the feeder to run with their equipment, and made darn sure to emphasize to the customer not to use the wire feeder with the power source set up with the High frequency on at all... Now one would think that they would have gone out of their way to make sure of this, but sometimes you just cannot always count on your customers to follow your recommendations or your warnings and I'm sure you know what I'm talking about my friend! ;)

The sad part about it was that the reason they didn't avoid what caused the board to fail was the fact that they did not properly go over with a relatively new person the had employed who was working with this set up on a project in the shop... In other words, a classic case of bad decision making, yet they swallowed their pride and ordered a new board and we got the puppy working again by the end of the week... This was one of those happy endings, and I wish there were more of them instead of the more common cases where the customer would deny they did anything wrong, and insist on having the repairs covered under warranty regardless of the fact that they even admitted that their own mistake was the reason why the machine failed - Go figure huh??? Then when you offer to give them the part and labor for practically nothing just so they appreciate the fact that you want to continue providing services to them, they get all hot under the collar screaming how expensive the repair will be and that all I'm doing is taking advantage of their mistake for crying out loud!!!

Yeah buddy! I can go on and on with describing all sorts of calls I made when I was a tech rep for a welding distributor in NYC back in the day, but some of those memories are so messed up that I'd rather not even go and relive them because of the abuse I had to put up with from some of the customer base I had to interact with...

Anywho, It's always good to see you in here, and I hope things are well with you!!! I hope you don't mind me asking you this Chuck, but have you heard anything regarding that rig explosion that occurred a few weeks ago around your neck of the woods??? I figured you're probably someone who might know something about what's going on with that tragedy, and I hope you didn't lose anyone from that incident...

Well, here's to you my friend!!! Good to see you're still around old friend!!! Now don't you go off and work yourself to death ya hear??? ;)

Respectfully,
Henry

By gndchuck (**)

Date 05-06-2010 03:50

Yeah, I was the one responsible for the fried board, after taking recommendations from the rep.. Well you know how I ended up feeling about the situation. But things worked out.

As for the rig that went down, I didn't personally know any of the person involved, but my prayers for for them and their families. One of my cousins, his rig was there 3 days before the accident, but was out of the area went the explosion happened. Have a friend who is one of the ROV pilots on that location, and he's said that he can't divulge any info. Sure that here in a few months that we will know what went on and the events that lead to it. Unfortunately it was more than likely human error. Hope not.

As far a working to death, not this year, only worked a couple of months, slow, slow, slow for diving in the Gulf of Mexico. Right now in Louisiana testing for an underwater welding job for Shell, will be finished up on Friday and heading home to the family for the weekend. Will be finishing up a tree house for the boys.

Regards,
Chuck