Dynasty 350 DX: Variable Polarity

[KB Fabrications]

Sooooooooo, I have had this machine for a few months now and have been ****ing around with the settings on AC to see what all the hype was regarding the variable polarity feature. I have decided that I really like the VP capability but I would also like to stress that by no means is it necessary to successfully tig weld aluminum. I think Miller actually dropped the ball BIG TIME by doing away with the Dynasty 300. They may have something else in store but as it sits, there is a huge gap in their inverter tig lineup between the D200DX and the D350DX.

For those not in the know, the Dynasty 350 has 50 more amps and a few more bells and whistles. The real improvement was supposed to be on the AC side where you could independently set the amperage values for each half of the electrode positive and electrode negative cycles. The values can, according to Miller, be set to "provide enough cleaning while putting more amperage into the part". It is also supposed to give better penetration and faster travel speed. Tungsten life is also supposed to be better using more EN amperage.

This is a tool holder I made for my lathe this afternoon. I used the VP feature on the 350 to make these welds. The settings were as follows:

Machine set at 250 amps
EN Amperage = 268
EP Amperage = 143
Balance = 75
Frequency = 120
3/32" blue tungsten using a gas lense and #7 cup

The material was 1/4" 6061 and the filler was 1/16" 5356. The ratio of EN to EP was 2 to 1. What you do is set your EN amperage to 200 and your EP amperage to 100. Then, set the welding amps to whatever you want and it will maintain that 2 to 1 ratio. The 2 to 1 ratio is also just a recommended starting point. You can basically set the thing to any ratio you want for any given welding task. The balance setting will also have an effect on the "average" that the welding amps end up at.

The first thing noticable was that the puddle formation on the 1/4" material was almost instantaneous. It took maybe 3 seconds before I was ready to add filler and then it was just "get after it". The etched cleaning zone was also substantially smaller than it would have been on the 300 with the same settings, sans polarity adjustment. The really remarkable effect was the lack of tungsten degradation. I welded 6 two inch long beads and the tungsten looked like I had just sharpened it. That would never have been the case if I were using the 300DX or a conventional machine. I pretty much had the pedal maxed, or slightly less, for this project.

The pics are as follows:

1. The toolholder I was making. there are 3 two inch long welds on the top and the bottom.

2. Weld close-up. The wet in at the toes on these settings was awesome.

3. Another close-up of a different weld at a different angle.

4. Tungsten close-up after the 6 welds.

5. Same as #4.



I have more work and testing to do but my preliminary results are super positive. If you have any questions, I will do my best to try and answer them.

[trstek]

Nice work Kb, thanks for the technical info.

Tom

[Engloid]

I think Miller actually dropped the ball BIG TIME by doing away with the Dynasty 300. They may have something else in store but as it sits, there is a huge gap in their inverter tig lineup between the D200DX and the D350DX.

I agree 100%. Now, there really is no "top end" machine, in a class for the hobby/garage welder. THey either go with a 200amp machine, that will struggle for power at times, or step up to a machine that runs up near $8000, which is simply not reasonable for them to purchase.

For those not in the know, the Dynasty 350 has 50 more amps and a few more bells and whistles.

It's about like Ford adding tire pressure sensors on the new Mustang, and bumping the price by $2000. The gain is far from worth the cost. In fact, I have found it to be more hassle to monkey with the settings than to just make the weld and be done with it.

The real improvement was supposed to be on the AC side where you could independently set the amperage values for each half of the electrode positive and electrode negative cycles. The values can, according to Miller, be set to "provide enough cleaning while putting more amperage into the part". It is also supposed to give better penetration and faster travel speed.

THe problem with this is that an unskilled welder will not even understand the settings, much less know how much penetration they are getting. A skilled welder will be able to get the necessary penetration with a lesser machine, anyway. We did it with the Syncrowaves, which weren't even a true squarewave machine.

Faster travel speeds? Faster than what? Faster than a slower operator on another machine?

In short, I agree with you 100%. Miller made poor decisions having to do with the 300 and 350 machines. I can only hope that they realize the mistake and make appropriate changes in next years' offerings. The company I work for will be buying more machines soon, and I simply don't feel strongly about the options Miller has provided this year.

[KB Fabrications]

In short, I agree with you 100%. Miller made poor decisions having to do with the 300 and 350 machines. I can only hope that they realize the mistake and make appropriate changes in next years' offerings. The company I work for will be buying more machines soon, and I simply don't feel strongly about the options Miller has provided this year.

Believe me, you and I are on the same page 100% about this. Everything you said about operator skill is spot on. If the truth be known, I wish now that I had just kept my 300, and the extra cash it took to get this machine. Don't get me wrong, I like the 350. I understand how to use it and there are some small things that make it fun to use when welding alumunim. With that said, those features (like I said originally) are absolutely not needed to successfully tig weld aluminum. My only intent here was to try and explain the VP feature as I understand it.

[SundownIII]

Wow. I feel vindicated.

A while back I started a thread about how I thought Miller had created a huge gap in the product line with the Dynasty 300 being replaced with the Dynasty 350 and nothing between 200 and 350A.

Now KB and Engloid, two of the best tig welders around, and true professionals in their trade, have both come out and expressed belief that Miller has, in fact, made a marketing fubar. We can only hope that Miller's market research dept. may read these boards.

Miller has always been extremely good at "covering the marketplace". If one looks at the MIG lineup, they're well covered all the way from the 140A hobbiest units to the large industrial equipment. Same thing for SMAW.

In the transformer TIG arena we have the Syncrowave 200, 250 (actually a 300A unit), and the 350. The only problem here is that they are power hogs and lack many features available on the newer inverter based machines.

The Dynasty 200, while a great machine for what it is, is a little light in HP and duty cycle, for those former Sync 250 owners to move to inverter machines. The Dynasty 350, while a great machine, is priced out of reach for many and has "bells and whistles" which will never be used by most.

It would seem that there would be a huge customer base (former Sync 250 and Dynasty 200 owners) who would be prime prospects for a Dynasty 250/275 which had the features of the 200 and a little more power.

Anyone from Miller listening?

Just my .02.

PS Thanks KB for your evaluation of the Dynasty 350. Very informative and well written (as always). If anyone can take advantage of all the "bells and whistles", it will be you.

[Engloid]

I really think that a slip up like this is all Lincoln needs to pull a lot of customers away from Miller. If Lincoln now steps up their customer support, they will find it easier to take away those customers...and keep them.

Perhaps Miller will recognize this and put out something to fill that gap ASAP...even if it means a mid-year addition to their lineup. ..or bringing back the Dynasty 300.

[JMH]

I've been a member for awhile now but just lurk the forum, I couldn't resist responding to this though. I also think that Miller has made a mistake by leaving such a gap between the 200 and 350. I'm in the market for another machine, and buying another 350 is too much. The 200 is a tad shy on amps. I think Miller should come out with a 275. I personally think a 275 would be an awesome machine. Not to big, not to small.

just my 2 cents- Jeff

[joebass]

The only thing Lincoln has to compete is a 200 amp AC/DC inverter and it is not as nice as the Dynastys. I have welded with all but the new VP ones. I owned the Lincoln and sold it after a few months to get the 300DX. If I wanted to replace my 300 the only alternative is a Thermal or VP 350.

[Propulsion]

Good write up, nice pics.

[BBchevy396]

I have a TA 300TSW, and would put it up against a 300 Dynasty any day. It surely fills the gap left by Miller.

I was badgering the Lincoln rep not long ago, about why they left a 300 class inverter out of their lineup, being the Invertec V350, is such a solid performer. (I have one). Add AC to it,.....and whamo,..... a winner.

His response, was a "new" 300 class Lincoln AC/DC inverter tig, has been in R&D for some time, and should be on the market for next spring.

We'll see.