Dynasty 200DX questions

[yomax4]

A 200 dynasty should be able to weld over 1/4 if you crank up the Hz. This constricts the arc like a shotgun choke. It creates a smaller heat effected zone giving you more capability and you can run a larger tungsten. The Dynasty is the noisiest AC unit out there. She Screams with high Hz high amp welding. There are a couple brands out there that are much quieter on AC. Anyway. I opt for a cooler only to run a HW20 style torch with gas lens. 1/2 the size of the 17 which is a 150 amp. I want nothing to do with the 26 broom handle torch. Aslo. Bernard sources their cooler. they don't make it although they had the idea and marketed the cooler before many others. I know 4 manufacturers that source the same cooler.

 

[Shield Arc]

These inverter welders just amaze the crap out of me with how much control they have over the puddle!

For me an aluminum fillet is a tough weld to make, and get really good penetration. As yomax4 say the higher the frequency the narrower the arc, and when doing fillet welds I want a very narrow arc or I get a little horse shoe which seems as the arc is not penetrating into the crotch of the joint.

Here are some high lights of my settings for doing aluminum fillets with my Dynasty 300.
Frequency 250.
Semi-sharp point on the tungsten, with really high amps, a very sharp tungsten can melt off the tip.
I use pulse, this will also narrow the arc, I like 85% background, 80% peak time, 200 pulse per second.
When starting the puddle I have to wait until the little horse shoe closes up before adding filler. Otherwise I don't seem to dig right down into the crotch of the joint.

 

[Rob-D]

I've heard that "soft square" might give better penetration. Are you using that wave?

 

[Rob-D]

Although I don't doubt you I'm not sure why the Dynasty should be any louder than any other variable wave/freq. machine. If two waves have the same basic shape and the same frequency at the same power I would think the sound should be pretty much the same db level. I haven't compared waves from different companies on a scope but the only thing I can think of is even/odd order harmonics which comes down to how well a machine filters and contours a wave, you can really cheat on that and cut corners, even show nice waves in your ads. It's only when you start looking at FFTs (Fast Fourier Transforms) and waves under heavy loads that you can see what's really going on with the circuit design.
The other thing is will the machine put out the same wave in 5 years it does when it's new which comes down to a bunch of things like capacitors and how much over spec the circuit is. If an IGBT (Insulated Gate Bipolar Transistor) specs at 50 amps do you use it in your 45 amp circuit or do you go with one that specs at twice that? I think those are the things you can't see in a machine when you only look at the bells and whistles on the front panel and say, "See both machines do the same thing". Miller, Lincoln and a few others build pretty good circuits, they know their rep is built on it, I've been inside those machines, cores, laminates and circuits are all top notch. Do you pay more for it? Well maybe not in the long run.

One thing I did see is how amazing these new TIG machines are at controlling puddles and warpage.

Rob

 

[yomax4]

I'm not sure on the noise level on AC. That is way out of my league. For some reason, For instance the Sanrex built Thermal Arc is half as loud as the Dynasty. Both top of the line units but sound very different. Have you been inside a Sanrex machine.? I'm just curious about this.

 

[Mark @ Everlast]

I'm not sure on the noise level on AC. That is way out of my league. For some reason, For instance the Sanrex built Thermal Arc is half as loud as the Dynasty. Both top of the line units but sound very different. Have you been inside a Sanrex machine.? I'm just curious about this.

I believe it would have to do with the switching of the transistors. How hard or soft it switches, along with the wave form shape would affect the sound.

A true square wave (advanced) would get more penetration. That's why the inverters are capable of more penetration over units with a soft square wave like the synchrowaves.

 

[Rob-D]

I know the TA's are rated well but I haven't had them apart. I'd like to see the two machines next to each other both with the same wave, EN, EP, etc and hear the difference, maybe I could give you a better idea of what's going on. Now that I think of it, it could be how the magnetics are would and the gaps, etc. that each company uses, could you be hearing this I wonder?

Mark:
I'm not sure what you're saying, a true square wave is easy to generate, hence the "mod square wave" inverters that flooded the alternate energy market before "pure sine" inverter technology caught up 8 or 10 years ago.
Switching transients, even 'N' type high side charge pump driven MOSFETs (Metal Oxide Silicon Field Effect Transistors) are a product of rise time, capacitance loading (the Miller Effect, etc.) new MOSFETs are fast and relatively cheap with slew rates in the 100 and 1000's of V/uS. RDSon values are in the mOHMs so I can't see where this would be something even a circuit designer with minimal experience in magnets would have a problem.

The noise difference is probably not saying much just the different approaches to generating the final wave, and there can be many ways to get to that end. I'd say the thing that separates machines is core materials, winding philosophies, winding material purity, temperature tolerances of the winding material used and how overbuilt the circuits are. Some of those things denigrate gradually and may even take a few years to show up full bore, that's one reason why I bias toward machines like Miller and Lincoln. Just me probably, to each his own, and I don't fault anyone's machine choice.

Rob

 

[Mark @ Everlast]

The Dynasty are IGBT driven..as well as many other brands. The way it switches has a lot to do with the noise level of the arc. I've welded with some of the softer switching welders and you'll see that they are quiter in the noise level. But there is a difference in soft switching and a Soft square wave. A soft square is what you'll find that is in the old Miller Synchro waves that have to use a HF overlay...although a soft square in an inverter switches quickly, so no hf is needed, it mimics the older square (soft) technology. You are talking about square wave generators, and sine wave generators...and mixing apples and oranges when it comes to the application of it...The wave designation of square, sine etc only applies to the AC side of the welder when welding aluminum. And I think you may have understood Yomax to mean the noise level of the machine...not sure, but he was referring to the arc noise from the AC... The default square wave generated by Miller, and yes, Everlast, though there are minor differences is the wave that people look for in inverters, because it does offer better penetration...It is louder. The sine, and the modified, soft square wave are designed to imitate older type welders which have an arc that is broader, with a "fatter" feel than the "advanced" more penetrating square wave. Regardless of what you call the wave...old or not...this truer form of square wave is what Miller markets as "advanced"...It's advanced primarily because there is no HF overlay, and secondarily to make you think you are getting more for your money.

I've used both the TA, and the Miller, and side by side, I'd have to give the TA the nod on the arc quality and feel.

 

[Rob-D]

OK, let's clarify some things, first let's define "soft switch".

Rob

 

[Shield Arc]

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