Dynasty DX 200 & 3/8 6061

[lramberson]

I am just about to make the jump for the Dynasty 200 DX and have two projects sitting in the shop that require a small amount of 3/8" 6061 aluminium fabrication.My question is simple, Can the Dynasty handle the 3/8 with a single pass or multy passes or is this beyond the machine capicity? I have a MM251 with a spoolamatic if i need but I really would like to tig the whole project. I am known to over kill but I cannot afford the Dynasty 300.
A fellow fabricator wanted me to go with the red 205(competor name withheld) claiming more amperage from the same size machine, I just like blue better even though I will be limited with a lower amperage due to single phase. Am I correct in the assumption I am limited to 150 amp on single phase?
Thanks for the help..
Laurence

[Alex]

Laurence,
Just checked the spec sheet on the Dynasty 200. Yeah, 150A @ 60% TIG duty cycle is what Miller claims.

Alex

[jeffscarstrucks]

The Miller is made in the USA, the Lincoln isn,t. The Miller customer service is very customer oriented, fast, and friendly to everyone, Lincoln's is't. They are both good machines but I guess you can tell why I have five Blue units now. I have owed both but experience has directed my spending. You will love your 200dx... Keep us posted. JEFF

[dseman]

Re: Dynasty DX 200 & 3/8 6061

Originally posted by lramberson
Am I correct in the assumption I am limited to 150 amp on single phase?
Thanks for the help..
Laurence

No you are not correct. The machine will run at 200amps on 230vac,1phase w/out a problem.The spec for 150amp just indicates the duty-cycle at that point is 60%. At 200amps, the duty-cycle is 20% for tig.

If by 'single phase' you meant to say 115vac, single-phase input, then 150amps is the max. for tig with that input voltage

-dseman

[lramberson]

220 single phase is my source of power. Any feelings on the capicity of 3/8 6061. I will use the mig if it is too much..
thanks.

[dseman]

Originally posted by lramberson
220 single phase is my source of power. Any feelings on the capicity of 3/8 6061. I will use the mig if it is too much..
thanks.

The 200dx is fine for 3/16 stock, single-pass and argon shielding--though the duty-cycle is only 20% at this limit. If you must do 3/8" once in awhile, you can use a 75/25 He/Ar gas mix which should effectively give you the same heat as a 300 amp supply since He ionizes at a 70% higher arc voltage. Preheat of the base AL would also help, though I don't think it would be necessary if you used the 75/25 He/Ar gas.

If you plan to do this thickness on a regular basis, and it must be tigged, I'd go for the Dynasty 300DX. If the work could be migged instead, then the MM251 with the spool gun would work fine.

-dseman

[HAWK]

iramberson,

dseman is correct. I have done 3/8" 6061T-651 in a single pass with the Dynasty 200DX running a 75%helium/25%argon shielding gas and swirling the torch after each filler addition to adequately wash in the weld bead toes. It is a slow process and be careful not to over-do the machine duty cycle. If you are not careful to let the machine cool, you could blow out the polarity swithing IGBTs or even a power IGBT or some input bridge components.

In this application it is all about input wattage rather than amperage. The helium, as deseman as expounded on, will increase your input wattage as will a 200-300 degree preheat.

[BCarlucci]

dseman and hawk are both right, i've had and seen customers use 75/25 he/ar mixes to get away with that, i know this is repeating what was said but please becareful not to over heat the machine, these are sweet machines and we (as in distributors) don't like ot see them abused (to much). I've also known some customers to use a ar/hydro mix, not sure of the exact mixture, but i'm sure the hydrogen % is very low maybe a 1%. But this is will also give you increased arc heat. It's something to look into.

BC

P.S. - If i'm wrong in the hydrogen let me know, i'm just going off of what 2 of my customers have told me.

[dseman]

Originally posted by BCarlucci
dseman and hawk are both right, i've had and seen customers use 75/25 he/ar mixes to get away with that, i know this is repeating what was said but please becareful not to over heat the machine, these are sweet machines and we (as in distributors) don't like ot see them abused (to much). I've also known some customers to use a ar/hydro mix, not sure of the exact mixture, but i'm sure the hydrogen % is very low maybe a 1%. But this is will also give you increased arc heat. It's something to look into.

BC

P.S. - If i'm wrong in the hydrogen let me know, i'm just going off of what 2 of my customers have told me.

BC,
I've heard the same and read some about the use of Hydrogen and Argon blends, though I've not tried them myself. The hydrogen (<5%) changes the gas shield to reducing, which clarifies the weld pool, enhances 'wetting' at the toes, AND constricts the arc for deeper penetration. The arc constriction is what I found interesting. Somewhere a month or so ago I read an article which had photos showing the arc with straight Ar, Ar/He, and Ar/H. The Ar/H blend had the most constricted arc. Hawk has commented a lot on the use of Ar/He, but he's indicated that he needed to use pulsing to constrict the arc back to normal since He tends to increase the pool size. Other than the fact that too much H can lead to hydrogen cracking in the weld, I kinda like the idea of the constricted arc.

Hey HAWK and Andy,
Are you guys up for another lab experiment with a hydrogen blended gas, or have you used it before??

-dseman

[BCarlucci]

dseman,

Thank you for the input on the use of Ar/H mix, at my store we have a Bulk AR and also Bulk H, along with a mixer, because we do our own fills, so i'll see if my operations guy can't mix me up a small bottle of it to try. I'd be interested to see how it works. And maybe andy and hawk could try it or tell us if they used it before.

Thanks again

BC

[lramberson]

Thanks for the input, the 300 is just too much money for my limited budget. The DX 200 will surely fill the bill, I won't be doing to much thick stuff.(sure am glad the 251 is in standby if needed) I have that toolman attitude and bigger is always better(wish I had the Plasma 625)and that will some times get you in trouble..
The space advantage,portability, features & design direct me to the DX 200 could easly get away with the syncrwave 180 or 250 but really like the additional features of the DX 200.. More than one person insisted that I won't require all the bells & whistles but I insist that if they are required once they are paid for & available..(the welder makes the weld not the machine)I believe the machine assists the welder in making a functional weld & increased productivity..
I have been contemplating this decision since completing tig school and will probably never exceed this unit capacity..
Thanks again for your direction and help, I watch this site quite regurarly for tips, just my 3 question to the forum.
An old man following a kids dream, just a little late than I would have liked.

[HAWK]

Originally posted by dseman
BC,
Other than the fact that too much H can lead to hydrogen cracking in the weld, I kinda like the idea of the constricted arc.

Hey HAWK and Andy,
Are you guys up for another lab experiment with a hydrogen blended gas, or have you used it before??

-dseman

dseman,

The H embrittlement is an issue I am still thinking through. I do use the pulsing a lot for anodized and cast materials. However, it is the arc frequency I crank up near 250HZ to constrict the arc when using a high He content. A 90%He/10%Ar also works well.

[dseman]

Originally posted by HAWK
dseman,

The H embrittlement is an issue I am still thinking through. I do use the pulsing a lot for anodized and cast materials. However, it is the arc frequency I crank up near 250HZ to constrict the arc when using a high He content. A 90%He/10%Ar also works well.

HAWK,
I think this thread took a different course when we started talking about Hydrogen. I probably wasn't clear, but all my reading shows that Ar/H2 gases were applied to high Ni/Cr steels where the extra hydrogen didn't cause porosity problems (praxair and linde). I didn't mean that it should be used for Aluminum, which was the original topic of this thread. I found another article in the July 2004 issue (p203) of the Welding Journal where the Ar/H2 and He/H2 gases were used for magnesium welding. You may want to check it out.

-dseman

[HAWK]

dseman,

Thanks,

One of my WE/CWI buddies said Ar/H can be used for welding of certain AL alloys. I am still not clear on the specifics.