Tig with pulser?

I've seen a few Miller Synchrowave 250s go in the $2500 range around here ..
GWE

I've got a Thermal arc 185, A/C, D/C inverter based, TIG / stick . it has a pulser, sequencer, digital read out. lift arc, high freq. gas pre flow, post flow adjust Stick- hot start adjust A true advanced squarewave TIG .
I really like it. it was $1650.

I've got a Thermal Arc 185 TSW that has a pulser. Great machine. $1650-ish from IOS. IIRC, you're close to San Francisco...? You're more than welcome to come by and give mine a try.
Peter

A Syncrowave 250 with a pulser and a foot pedal can be had for about $2500. If you get the regulator, torch or cooler options, it will add about $300 I think. It's a thoroughly nice machine.
Bob

I went the used welder route and am curious. Are used welders more prone to failure than they were when they were new? As for the inverter based ones, what is it that can go bad in them besides the capacitors?
i

steamer,
Im looking at the same ones too. Seems like someone said the Miller were better than the Lncoln but I really dont know. If your like me , a used one not trashed wld work fine but they are hard to find. Plus, again , if your like me, just for shop and home use, it wont get used much and wld prob last forever,.
Im gonna stay intouch with posts on the dynasty. I did see one guy post that he really liked his. But heck he cld be a salesman too. Go figure..
Good Luck and let us know what you do.

That makes sense... I looked into my Cybertig a little bit... If the boards fail, I am likely fully screwed. If the power modules like SCRs fail, I hope that I would be able to replace them. Mine seems to be built such that it stays well within the safe operating area for the electronics, so I hope that I will get some life out of it.
i

Note that the problem of stocking semiconductor spares goes way way beyond welders. Consider the lifespan of say a Boeing B-52, now in what, they're 40th year of service? Whenyou think of a product which has decades of service life, then compare that to the rapid change in semiconductor technology. Say a chip was designed that went into some board on a large machine in 1978. The manufacturer would have to had ordered, tested, labeled, and stored enough spare parts from their initial semiconductor run to last FOREVER. How would you feel if you went to ask for a little part for your welder and they said they have it, but it's $2400? How much does it cost to keep parts around?
My point is that chip was designed in technology that is now ancient by modern standards, it would be as if we had to go back to Bronze Age smelting techniques to fix a pulley on a sailboat, just ridiculously impractical. It's conceivably possible to fully specify the function of the chip and then redesign it for another production run later one if needed, but then you run the terrible risk of not getting the design quite right.
I own a Tektronix 2445 oscilloscope, for which many parts are no longer available from Tek. My only solution was to buy and store a complete parts scope. I have been offered $500 for a single *chip* out of my parts scope!
So yes, you have to figure welders with complex integrated circuitry have a finite lifespan, but realistically this will be reflected in their value, and so old broken ones should become available with spares, kind of like if you own a 1930s Packard car.
GWE

Well, I do not knw much about B-52 parts, but I heard thet B-52s have modular construction and a lot of systems undergo upgrades. These planes are projected to last for decades to come. But I know that the military stocks up a lot of old parts, I know that by getting them as surplus.
Onan still has parts for my 26 year old DJE diesel generator. Not as much for Onan CCK generators, the older gasoline gensets.
You do have a good point about obsoletion.
As well as a very low production run.
Me too, 2445A
Seems like too much, I thought that they are worth a lot less.
I agree. You made some good points. I really like my $9.99 welder and they seem to be generally available, so I could get spares if I needed. Mine seems to be built to last (meaning parts operate well below their rated limits and are of good quality), but like you said, everything can fail eventually.
i

You can definitely get the SCR's and the like for it. I've had to replace mine twice. The first time I didn't have the schematic so I didn't know someone had switched wires in the machine. The second time I found the crossed connections and I've not had any problems since. Actually the SCR's are the easy part. The hard part is the high speed fuses that protect the SCR's. Those cost me much more than the SCR's the second time.
Wayne Cook Shamrock, TX

Absolutely. I have a behemoth of a welder, as far as relation of size and weight to output power is concerned. And I like it that way:
1) everything is fully open and if not obvious (to a newbie like me), at least I can trace what is going on.
2) It is overbuilt, which can hopefully add some years to its life.
And cost.
My welder was completely covered by filth. It was so bad. It still is filthy, as some dirt is basically glued to it, but to a lesser extent now. I spent perhaps 20 min vacuuming it.
i

Thanks Wayne, that's interesting. I suppose that replaceemnt boards are not available.
i

Not likely. When I was calling around for manuals I barely got a civil response once I told them what machine I had. Most told me that no parts where available so why was I looking for a manual.
I'm in a little better shape than you are in some ways. The only electronic bit in mine is the SCR controller. The rest is just time delay relays and the like which are standard industrial control products.
Wayne Cook Shamrock, TX

Well I had to check around a little to find the parts. I finally found a industrial electronics company that specialized in high power SCR's and the like (there main line was motor controllers). I think that once I found them the SCR's where something like $40-60 or less for a pair of them. In fact I had trouble getting up enough to make there minimum order and had to order extras. I've got two hanging on the wall in my electronics shop right now just in case.
I probably could of used some from the Surplus Center of the like but they're kind of high on them from what I found and they didn't have the exact match which I wanted.
The fuses on the other hand I had to get at Grainger and I think those where something like $60-70 each.
The manuals for the welder on the other hand cost me more than a lot of it. I think that I had to pay $60 for one and $50 for the other. I also had a much harder time finding them. The welder itself wasn't to hard. But my control drawer is a unusual one for it's age and I had to call a lot of places before I found it and when I got it I wasn't happy. It was just the operators manual instead of the tech manual I was trying to find.
Ok I just drug out the catalog they sent me and the company I got the SCR's through is Galco Industrial Electronics.

Highly recommended. They helped me a lot and even reviewed the application to make sure I got the right part.
Wayne Cook Shamrock, TX

Times must have changed, I spoke to some pleasant ladies who emailed me the manuals.
That's great... I hope that my machine would hold up to actual use...
i

Wayne, SCRs are available on ebay these days for dirt cheap prices. Very many of them are on the amrket from disassembled equipment.
i

Since the Synchrowave is not an inverter, doesn't the pulsar have a limit of only 25 PPS?
Richard

Pulsing is not the same as the frequency of current. Imagine this waveform, with high and low amplitude:
VVVVVVvvVVVVVVvvVVVVVvv
that is, some cycles are with low amplitude and some with high amplitude. The AC period is the width of the letter V, the pulse period is the length of sequence VVVVVvv.
i

Steam,
I just got he word Miller is coming out with a new one after the new yr. I think its an upgrade for the SYNCROWAVE 180 SD but will be a 200 version and will have the pulse..and a few other features. Hooks on both sides and other good ideas.
We'll see i reckcon.
Blueraven