Teardown video of a Chinese TIG machine

[Zizzle]

Putting this is a separate post since the last one was already long.

Speculation alert, I don't know this to be true, just spit-balling here. This stuff is interesting to me. I'd be happy for info from the horses mouth. But as you can see they are actively hostile to me so I'm not holding my breath here.

Here's the thing - I don't think Everlast really does much engineering on their welders. They just rebadge stuff that is already being made over in China. Maybe add some control circuitry but I'm talking mainly about the inverter stage. Sure they may have their own factory, but the engineers in China are just using existing designs. China has very different ideas about Intellectual Properly. Its not really considered ripping someone off if you use their design. But in general the Chinese designs are evolving and improving.

For example the traditional Chinese 200 amp inverter design is the 3-tier layout that you see in the Everlast 205 Superultra (and probably others):





You can still buy these style machines, even individual boards or kits from China.

Now the newer generation for the same 200 amp capacity is a single board design:



Much more compact and nicer design. Much less wiring is needed. Still don't like the daughter board being largely unsupported in something that vibrates.

Notice how they offer different capacities. I believe they populate different IGBTs and different number or capacity of rectification diodes.

And course there are all sorts of build quality variables depending on where you buy it. Like mechanically supporting the heatsinks so they don't fatigue the board at the joints. High temperature capacitors. Covering the daughter board or not. Main transformer type.



The differentiation is in the build quality and the packaging.

http://www.alibaba.com/trade/search?...Text=zx7+board

In the Everlast welder I saw with this board, I do believe they got 1.5/3 on that front. 105C caps. No cover on the daughter board. Some heatsink support. But flimsy and only between the 2.

See pics here: http://weldingweb.com/vbb/showthread.php...dification-DIY

So I my guess is over time the everlast range will get better as the newer Chinese designs get picked up.

[rick9345]

Opinions vary.
It is an election year.

[7A749]

And the plot thickens........

[rick9345]

Old age= more Hertzs or is that hurts. I am confused.

[7A749]

I'm sticking with Hurts.....

[C. Livingstone]

Yeah,

I saw Zizzle trying to suggest that the HTP 221 was comparable in price to the Everlast 210EXT.

An HTP 221 with "dual-voltage" is nearly twice the price of the 210EXT.

Of course, the HTP doesn't have a choice of wave forms.

So, even at nearly twice the price, the HTP isn't in the same class, even though it is undoubtedly a high-quality European product.



"But the fact remains that we are no longer talking sub $1000 welders. 210 EXT is $1800. Upgrade to a CK torch, flex hose, decent foot pedal and you in the same price range as a HTP 221. That makes the direct comparisons even more valid."

[Zizzle]

Fair point. I bought the 220V only version on-sale and prices have gone up since, so I haven't taken that into account.

Maybe the Lincoln 200 Square wave would be a better comparison.

[C. Livingstone]

Yeah,

And the 210EXT was priced at only $1649, I believe it was, on Amazon, with free shipping, until just recently.

Yeah, maybe the new Lincoln is more comparable. But it still doesn't have the wave forms that the 210EXT does.

Honestly, compared to the 210EXT panel layout/schematic, I don't think I'd like the HTP or the Lincoln.

I'm not a TIG expert or guru. But let me tell, the 210EXT is almost flawless, in my opinion. I mean, I did modify the power switch by adding a two-pole switch on the front, for better ergonomics, though.

[Zizzle]

Great, have you got any pics of how you did your mods? Not worried about voiding the warranty?

Did you upgrade your torch or pedal?

What waveforms do you use and why?

[Oscar]

And no AC/DC tig near the HTP 221s price point has independent amplitude control. BOOM!!! (drops the mic)

Man, 2016 is off to a good start here at welding web!!!!

[C. Livingstone]

Yeah,

I did upload a video to my YouTube Channel of that little mod, which is really a review of the 210EXT itself, when I first got it, about 6 months ago. Feel free to go there, you'll see the insides of a 210EXT almost firsthand. The title is called, Everlast 210EXT: Review, Rationale, 1st Project.

I wasn't worried about anything related to the warranty, except for during the first 30 days, which I articulate how Everlast certainly honored that well for me.

Otherwise, I had an earlier DC TIG welder, so I had/have extra torches, etc. What I'm primarily using now, is the new CK SteadyGrip torch hand amptrol device. But I've got a SSC pedal, as well. There's another video at my YouTube Channel on the SteadyGrip, as I seem to be the first one with an Everlast welder to use one, besides the vendor.

I got the 210EXT as an upgrade to my DC unit, which is a GiantTech CAT250D TIG/STICK/Plasma Combo. I've had it over 5 years, and it is still a brilliant unit, especially for $549. I was just removing a TIG torch holder on it yesterday, which caused me to remove the cover, and I further noticed how well the two HF start modules and contact gaps for the TIG and Plasma are contained in clear enclosures, I suppose to protect them from particles and to also contain frequency interference. I mean, even that Lotos-style Mofset inverter CAT250D is far superior internally, that I can tell, from that hideous example of an AC/DC TIG welder that you apparently paid three times more for. I mean, you seem to be way-overgeneralizing about the current or average quality of Chinese output, which is quite good, in my limited experience. And Everlast is certainly above average in that respect, and maybe even on the cutting edge, so to speak, especially now, with their units being nearly all digitally controlled.

So, in answer to your fourth question, and even though I'm still new to aluminum TIG welding, I'm liking the typical Modified Square Wave for general purposes. But along an edge of aluminum sheet, I'm liking the Triangular Wave the best. But, I'm just a newbie with aluminum.

[soutthpaw]

Zizzle, I can't follow the audio on the videos so I have to go on what I've read here in the past. The 140 you referred to in the other thread looks very well designed. I don't see the rats nest of wires you repeatedly complain about. Actually I think that's one of the best machines to come from Everlast. I'm not an electronics engineer so you probably have more knowledge than me in that area. I just don't see some of the things you claim are bad to be so. Putting the adhesive on the outside of each connector seems like a good idea to me. Just a bit of redundancy measures against failure. I've seen comments here complaining about everything on one board that you claim is superior. It certainly makes the replacement boards more expensive. But what I would ask, is how many failures due to soldered high current connections for example? Just about every failure i've seen posted is a board component failure, fried IBGT or capacitor etc. Maybe the Chinese are in the "if it ain't broke don't fix it" method of design I don't see a problem with tried and true designs even if they are old if they lead to more reliable and affordable products. We are talking China after all.
The AHP took a few years of tweaking to make what appears to be a reliable product that performs well for the price. Definitely, buy a major brand if you need the latest and greatest design. I'm the first to tell someone that is using a machine in a professional capacity to go with a brand that has local support.

I think the Everlast product line is too large. It confuses customers. I've talked to a few people already that are confused by the differences between similar products. In addition, I think it takes away from individual product development/improvement. But I guess the approach works for Everlast.

Not going to defend Everlast, or argue with you, just sharing my perspective. Here are some pics of the 210ext I took for you. In my layperson view, I like the AHP design better than this Everlast. It seems like a modular design, the 2 boards in the lower part of the first pic are the same. I'm guessing these are common components needed in many welders, guessing I can probably find the same board in other Everlast products. I'm sure stuff like this keeps costs down and improved production efficiency.




Sent from mobile. Not responsible for Typos

[soutthpaw]

And no AC/DC tig near the HTP 221s price point has independent amplitude control. BOOM!!! (drops the mic)

Man, 2016 is off to a good start here at welding web!!!!

210ext has advanced AC pulse on pulse as well as high speed AC pulse, advanced square, soft square and triangle waveform...BAM!

(Just having fun with ya) HTP is a great machine

[Louie1961]

Is it just me or does the new design of the Everlast 210 EXT look nearly identical to the 2009 Chicom unit the OP was featuring in his video? I mean right down to the excessive solder on the right hand circuit board. Same coils, same transformers, its uncanny. I wonder what part of the design of the 210EXT is new??

[mwr]

I wonder what part of the design of the 210EXT is new??

The green part.

[C. Livingstone]

It's a conspiracy, I tell you!

Haven't you ever noticed how the Everlast Plasma unit internals look like the HTP TIG unit internals?

They're the same! They're the same, I tell you! Ha, ha,ha...

[Sandy]

Is there anything technically incorrect in the 1st video, the one linked by yesindeed ?

[EastTex]

You fellers reckon I could build a boat trailer with my Hazard Fraught 90A 120v wire feeder? It's a welder with a circuit board, isn't it?

[Zizzle]

Zizzle, I can't follow the audio on the videos so I have to go on what I've read here in the past. The 140 you referred to in the other thread looks very well designed. I don't see the rats nest of wires you repeatedly complain about. Actually I think that's one of the best machines to come from Everlast. I'm not an electronics engineer so you probably have more knowledge than me in that area. I just don't see some of the things you claim are bad to be so. Putting the adhesive on the outside of each connector seems like a good idea to me. Just a bit of redundancy measures against failure. I've seen comments here complaining about everything on one board that you claim is superior. It certainly makes the replacement boards more expensive. But what I would ask, is how many failures due to soldered high current connections for example? Just about every failure i've seen posted is a board component failure, fried IBGT or capacitor etc.

Maybe I didn't make the point clearly, I think the Everlast 140 is a decent design, no need for a mess of wire like the 3 tier design. Agree with you there. But the 140 is an off the shelve design (except for maybe the front panel circuit). Most small ebay inverters will look the same these days.

Like most of my criticisms, from a EE point of view, the connectors and soldered current carriers unsupported daughter board etc. don't inherently make a machine a non-buy. But you have to ask yourself if these were worthwhile cost saving trade-offs. Like I said before, how much would it cost to use bigger plastic connectors with clips (no need for glue). How much for machine screws and terminals for the current carriers. etc.

Similarly the main problem with them is sometimes what it does to serviceability. Now if the argument is that they aren't serviceable at all, just throw them away if they break, which is the model many Chinese goods use, then fair enough. Just know that is what you are buying - a disposable $1800 welder.

As far as failures do to soldered current carriers - unlikely as you suggest. That is more of a serviceability issue.

But don't discount dry solder joints in other areas. Mechanical vibration can cause invisible cracks in solder joints that raise the resistance or go open circuit. Similarly connectors can move, corrode, get conductive dust in them. The symptom of which could be a failed component no where near the bad connection.

IGBT (or MOSFET) gate drive is critical in an inverter. You want your IGBT to act as close to an ideal switch as you can. Either fully off or fully on. If it's half on then it has to dissipate massive amounts of power -- for every amp it's half conducting it has to dissipate on the order of 300W of heat.

To switch on an IGBT you need to get the gate up to ~15V. But the IGBT has parasitic capacitance. To get it to 15V quickly you need to be able to deliver quite some current to it (~10 - 30 amps depending on the device). Keep in mind your switching it on and off tens of thousands of times per second.

Now suppose you have a dry joint or weak connector. It cannot handle the current to switch your IGBTs quickly enough. They start dissipating more heat and eventually die. You will see a blown IGBT and blame it. But the cause was elsewhere. Now if you have those little white connectors with a little corrosion, this cause may be intermittent. You might not see it while diagnosing, but may reoccur after you wheel it around on a welding cart.

Here is where a good layout can make a reliability difference: eliminate the wiring and cheap little plastic connectors in your gate drive circuits.

The serviceability of single vs multiple boards can go either way depending on the design. The single board 140 would be good to work on. Easy to get to nearly all parts of the circuit and probe while live if needed.

The 210 EXT would depend on which part of the machine you suspect the fault. It would be difficult to get to board that sits below or between the heatsinks. How would you test each diode in the rectified stage? You'd have to pull each one out. But then you'd have to melt some of those massive pads.

Having said that, the EXT does look like an improvement on the control circuit side. No more free standing daughter boards. The wiring has been neatened up to some extent. Still some free standing TO220 devices which people like Dave Jones frown upon. The overall layout and main inverter stage looks largely unchanged like others have noticed. The AC output generation stage looks revised (by Everlast?) - they are using the newer higher rated IGBTs (instead of a bunch of little ones) and look they are even using hardware terminals on their current carriers.

I do notice that they haven't glued all the little white connectors but did glue the hardware on the AC chopper (see the glue near the current sense transformer in the left of the plastic guard in pic 2).

It's interesting that they are still using gate isolation transformers to drive the main H-bridge. I don't keep up with the latest in this area, but my understanding is that there are now integrated devices that care of gate drive and isolation at pretty low cost. Could shrink the main board footprint a bit.

Overall I'm a little disappointed not to see a new design on the inverter side. I think they could have optimized the layout and cut down on the wiring. But I guess economically it makes sense to re-use what they have.

Based on the noises Everlast reps were making previously about the EXTs I was thinking it would be on par with the HTP or Dynasty.

Thanks for posting the pics.

[Zizzle]

Is there anything technically incorrect in the 1st video, the one linked by yesindeed ?

Not really. Only some minor misunderstandings about what some parts do. For example he didn't recognise that the pigtail thing in the bottom left is the HF start output transformer but he did annotate that in the overlay text.

Also the current shunt - that is actually a current sense transformer on the output bus bar.

All his design/build quibbles are spot on in my opinion.

[7A749]

Zizzle, I'm currently repairing an older Miller inverter for a customer and after the full checkout, etc it blew an IGBT and the protection diodes on one side of the board. I identified part of the problem as a mistake I made, but after putting good used components back in it, it just doesn't seem right. OCV is higher than normal and I'm not hearing the "frying bacon" sound these machines always make when the IGBTs are firing. It will power up and I can turn the solid state contactor on, but I've been afraid to put it under load again. OCV was just as high before the first failure and was jumping all over the place..

Everything fired up fine last time tho, and when I put a 100 amp load on it, the module blew. Usually, if you got something wrong, or something you cannot readily test is bad, the modules will blow up the second either the secondaries come online, or when you turn the contactor on, which is how I test them on my load bank.

I've been working on these machines a long time and know them quite well, but the point you brought up about corrosion has me thinking.

There was an unusually high amount of corrosion inside this machine, and I replaced a number of components with heavy pitting and rust/corrosion but it sounds like there may be something more to it. I spent a great deal of time inspecting and testing many suspect parts and power conduction leads. Anything suspect I replaced.

I don't mean to hijack, but I just found it interesting you mentioned that specifically. The blown module came from me accidently swapping two identical bleed off lines to the firing resistors to a varistor module. I'm thinking that's what happened anyways. I triple checked everything, but missed that since they look exactly alike. But now that I'm back at jump street, something just doesn't seem right and I've worked on enough of these machines to know that it shouldn't be doing what it is. Don't really wanna risk another board or module. I'm really thinking the true problem lies deeper than the mistake I made. As thoroughly as I checked it out, a couple ppl worked on it before me and I'm afraid something else may be incorrect and I'm overlooking it. I dunno....

I'll dig deeper and see what I find. Interesting thread for sure.

Any ideas? Just PM me if that works for you, at least if you want to

[soutthpaw]

Good info Zizzle, at least they are making improvements. Also I think the similarities to the original video support my thinking that many parts and component assemblies are mass produced and bought many (in the hundreds) of the Chinese welder factories from a single or a few suppliers. Also explains the similarities in many of the exterior and case designs.

Sent from mobile. Not responsible for Typos

[shovelon]

Is it just me or does the new design of the Everlast 210 EXT look nearly identical to the 2009 Chicom unit the OP was featuring in his video? I mean right down to the excessive solder on the right hand circuit board. Same coils, same transformers, its uncanny. I wonder what part of the design of the 210EXT is new??

I see that too. Good eye.

[C. Livingstone]

Gee,

Do any HTP 221 users actually know what amplitude control is or how to use it? Ha, ha, ha...



http://www.yellowbullet.com/forum/sh...d.php?t=882578

And no AC/DC tig near the HTP 221s price point has independent amplitude control. BOOM!!! (drops the mic)

Man, 2016 is off to a good start here at welding web!!!!

[mwr]

Gee,

Do any HTP 221 users actually know what amplitude control is or how to use it? Ha, ha, ha...

I'm sorry, did the guy who as of six months ago hadn't even welded aluminum in his laundry room/shop just question other peoples' experience or knowledge?