[Spiritus]

Hi!

The manual claims the AC is independently set.
This can't be true?
I have mailed everlast about this. No response.

Page 19 point 21:
The unit features two pulse modes. The standard mode is available in AC and DC modes.
The Advanced AC mode, works only in AC.
Pulse is used to control heat input on metals by pulsing amperage between a high and low amp value.

Best regards

[cj737]

Not exactly the same thing as Miller and HTP represent as “independent AC”. Sounds more like simply “advanced pulse”.

Miller allows the selection of a different waveform on either side of the wave, plus the amperage for either side. HTP allows selection of the amperage either side of the wave, but no waveform changes.

[LtBadd]

From the manual p19 point 21

The Advanced AC pulse pulses between AC and DC– polarity to control heat input on thin aluminum. In advanced mode, AC is assigned the welding amps stage of the pulse, and DC– is assigned the pulse amps stage of the pulse.
Both the standard and Advanced pulse modes have the same features of pulse time on, pulse frequency and pulse amps. Other than changing the polarity in Advanced AC pulse mode, the two pulses are similar in adjustment.

Why do you not believe it performs this function?

On the Dynasty you change the amperage for the EN and EP side of the AC waveform, different then the Everlast

[VA-Sawyer]

The Advanced AC mode does switch between DC and AC on a pulse type basis. The DC time is EN and allows more heat into the puddle. The AC time gives you cleaning action. This mode can really increase penetration on thick aluminum. Jody covered this in the video where he compares AC waveforms using a Miller Dynasty for the first 3 tests, and an Everlast for the last one.

I think the independent thing Everlast is talking about, is the fact that pulse settings you input for DC welding are not affected by pulse settings you make for AC welding.

[Spiritus]

Mixed AC/DC is one part AC(DC+ alternating with DC-) at least one cycle, and one part DC+ or DC-(not alternating). And then it starts over. AC(DC+ and DC-) followed by DC+ or DC-.
On the Aland machine the everlast255ext uses DC- for the last cycle.
Everlast calls it Advanced AC Pulse.

Independent AC is DC+ alternating with DC- where you can set the current(AMP) individually on the DC+ and DC-. Like DC+ 250A and DC- 115A.
Most machines doesn't have independent AC. Their current is equal on DC+ and DC-, alternating(AC). Like DC+ 250A and DC- 250A. You can't set the current independently.

@VA-Sawyer
That is an interesting video. I would like to see one just like that, also including independent AC.

@LtBadd
I guess I would have thought that if it had independent AC, they would clearly say so. Some manuals, maybe more often the Chinese brands, isn't very good. The seller don't know what they are selling or doesn't care.
I hope I am wrong.

@cj737
That's what I'm also guessing. It's just another bad manual.
Hope it's not though.

Thank you all for answering. 

[VA-Sawyer]

You are correct, Independent AC amperage is the ability to set the current for each half of the AC cycle. It is an additional (advanced) control to Balance, which allows setting the time length of each half of the AC cycle.
My 255EXT does NOT have Independent AC amperage. It is my understanding that the Dynasty can do it, if you buy the upgrade card.
Mike Zankanato (spelling?) has done more with Independent AC than anyone I know of. It sounds like he is using it in a manner a bit different than Miller expected. He talks about it with Jody in one of the videos. I believe he also talks about it on a podcast.
My current welding skills are still short, of where I think they need to be to take advantage of Independent AC current. Still, I wish that my 255EXT had it to play with.

[Spiritus]

@VA-Sawyer
I also thought that was interesting. The video with the bike builder.

There are some Chinese brands with independent AC but the specifications isn't that good.

I will probably go for the Stel 221 with independent ac. They are above the Chinese in quality and also price.
They have a awful manual though. They say they are working on it. For now one can read the htp manual instead.

If disregarding the independent ac, Walter might be a good quality machine.
They have mixed AC/DC and gental low amperage. It's one phase though with a demand for a large fuse.
The manual is almost ok and you get no answer when you mail them.
If I remember correctly they are outside of Europe so there will be a waste of customs.

Thank you Sawyer!

[Oscar]

You won't be disappointed with the 221. I have the "American version", known as the HTP Invertig 221, and it has quite the (good) reputation! Not the same as having a 300A+ machine, but that is about to change soon with the Invertig 400 AC/DC!

[Spiritus]

@Oscar

It's a lot of money. When I decide I will try to get a refurbished one. I think.
I justifies the high price with some savings I can make. One of them is an air to air heat exchanger. They start at 2500 euro and I can probably build it for half. Maybe a third.
The thinner aluminum the better I think.
How is the htp at say a 0.004 to 0.02 parts of an inch.
Is that realistic with the htp?

Thank you!

[Oscar]

0.004"? You're gonna have a heck of a time if you're never tried to weld something that thin before! That's like aluminum foil territory. If you have to ask, then you won't be able to, LOL. Even 0.020" thick material will drive you up the wall unless you have the perfect settings and perfect hand control. The machine will hardly come into play, it will be 99% operator skill.

[LtBadd]

When welding the really thin stuff, it's all about the fixturing

[Spiritus]

Sorry, I was going for 0.5mm to 1mm.
That's should be 0.02 to 0.04". Hope that's right.
I devided mm/25.4.
0.02 is still very thin.
May 4 amp be to much?
Isn't also the quality of the arc very important at low amps?
I understand that it takes practise, but I mean if the machine is too "clumsy" it can't be done.
Can it be done with a htp you think?

Thank you!

[LtBadd]

Can it be done with a htp you think?

Thank you!

I don't own a HTP, but I'm sure it can be done

[Oscar]

It can be done with a $500 TIG welder if the operater has enough skill, so yes it is within the capabilities of the Invertig 221.

[cj737]

You'll have a hell of a time even establishing an arc at 4 amps, let alone stabilizing it as a new Welder. Certainly can be done, but I don't think a $500 welder would do it, though I am dead certain an HTP or Dynasty, or many other models would.

A little pre-flow helps immensely in establishing the arc at very low amps. A smaller tungsten too, ground to a long needle point. Some chill block backers would be my approach. And prayers. Lots of prayers