What's new
What's new

Miller Pipe Pro 304 - A Turd!

Pete Deal

Stainless
Joined
Apr 10, 2007
Location
Morgantown, WV
A while back I bought a Miller Pipe Pro 304 welder. Didn't know a lot about it other than it had a Kubota diesel engine in it and it didn't have many hours. This welder turns out to be basically an engine driven XMT 304 which is a multi-process inverter welder and I think the XMT 304 has a pretty good reputation. When I got my welder the generator worked but it wouldn't weld. I found a repair manual online, very rare for a Miller as far as I know, and did manage to get it welding.

Fast forward a year or so and the welder craps out again. I have 4-5 different Miller welders and generally like them a lot. The more I look at this thing and the schematic and how it's all wired I just can't believe what a piece of crap it is. Every engine driven welder I've ever seen lives outside. This thing leaks rain water like crazy. Lots of big holes for mice to get in, which I plugged with screen but..., The PC boards don't look at this point like they ought to work after 7-8 years in this environment. And there was not even any attempt by Miller at weatherproofing the wiring as is typical in a car. Anyway, I know I really can't complain because I didn't buy it new. I guess my point is that the concept an inverter welder outside seems like a really bad idea.

I'm not one to patch up a turd and try to pass it on to some other unsuspecting person so I think I may rip the guts out of it and buy a generator head to stick on the very nice Kubota D1005 engine. The voltage regulator for the generator does work but it looks about as bad as the rest of the boards in the inverter box so isn't likely to last either.
 
One good thing about them is that if you have 220 power you can plug it in and not use the engine. The bad thing it it has no autolink like a real xmt304 so you are stuck with the 220v. That is the way my buddies is and he was sure mad when he found out it did not autolink. Maybe they fixed that on later models??

Is there a coating you can spray on the boards to weatherproof them a little better?
 
That's the other thing about this welder, it's full of little oddities. The ability to run the welder off external power was an option mine doesn't have. There are also other things that make them not quite exactly XMT 304's- like when welding below say 180 amps or something the engine stays on the low speed.

The boards do have coating on them. I think they call it conformal coating. But it's flaking off. The whole thing seems like a bad idea.
 
The whole thing seems like a bad idea.
It was a good idea, it was implemented badly....very badly.

My friend the pipeline welder had one, it let him down so many times (many hours from home) he traded for a Lincoln.

That led me to think that the concept was sound, a person could simply buy a good, dependable normal 3 phase genset (Kato or Onan)
and mount whatever inverter you want on the same skid, make a large sheetmetal enclosure for the whole thing.
 
It was a good idea, it was implemented badly....very badly.

My friend the pipeline welder had one, it let him down so many times (many hours from home) he traded for a Lincoln.

That led me to think that the concept was sound, a person could simply buy a good, dependable normal 3 phase genset (Kato or Onan)
and mount whatever inverter you want on the same skid, make a large sheetmetal enclosure for the whole thing.

I think the idea of a separate generator and welder is a good one. Especially for me. I don't really need to weld any real distance from power much.

I've been looking for a long time at the Central Georgia Generator web site. They sell pretty decent looking Generator heads. The down side to converting this welder is that it looks like it doesn't have a standard SAE bell housing. So I may have to scrounge for that and maybe a flywheel. We'll see. Probably a looser of a project financially but it would be fun and I think would wind up with a pretty nice 10kw generator.
 
For Generator use and welding above a certain threshold (can't remember what that is) 3600 rpm. For lower welding currents it welds at the low speed which is above 1800 RPM somewhat. If I convert it to a generator only it would be 1800RPM. According to a data sheet I found for the d1005 running at 1800rpm it ought to be good for just under 10kw at 1800rpm.
 
I have a 20kw trailer mounted generator. Wacker G25. I paid about $6k for it during one of the recessions. It has under 2k hours on it. But I haven't seen one that cheap again. New $15k+.

And, at this point it's not about practicality.

Looking at that link. I'm not sure those are diesel generators. From what I have seen in light plants running the D905 engine, one size down, these things can go 20k-30k hours.
 
this does sound like a poorly executed machine. While I have owned many miller machines, they are totally capable of making the occasional dud. Their plasma cutters, for example, have never been a great choice.
I love my XMT 304, and I have a 110/220 Maxstar for site work.
But when I need a generator drive welder, I rent one. A good one is five to ten grand, and I just dont need em often enough to justify having that much machine sit around 345 days a year.
Plus, gas drive anything needs to be run, or it will deteriorate.
 
I have used my XMT304 daily since I bought it a year or two ago. I haven't found anything I don't love using it for. A shitty MIG welder (Lincoln 256 cough, cough) will make you hate welding. A nice one makes you smile every time you use it.

That's really too bad about the genset version though.

XMT304/350 plus a 3 phase genset would be a sweet combo. I've been thinking about getting a backup diesel gen for my shop/house and sizing it right for the XMT would be another reason to buy one.
 
I have a 2000 Pipe Pro 304, I quit using it because it started smoking so bad, it was always a good welder however.
Let me know if your interested in putting your motor in it, its been sitting up in my pallet racking for about 4 years but still worked when I put it away.
 
I have a 2000 Pipe Pro 304, I quit using it because it started smoking so bad, it was always a good welder however.
Let me know if your interested in putting your motor in it, its been sitting up in my pallet racking for about 4 years but still worked when I put it away.

I thought the only good part of that welder was the engine....
 
Sorry, didn't see that there were a few more posts.

Portable Welder: I paid $2k for it. If I sold it that's what I'd want for it. Which, I think is too much and with the distance even more so. The D1005 engine is a good one. I have a light plant with a D905, this thing, and a mower with a D1105. Pretty much all the same motor just a little variation in horsepower.

Thermite: The whole thing is a looser for me start to finish. I like diesel generators that run 1800 RPM. They are sort-of naturally nicer to be around even if not "tactically quiet". Also, that's pretty much of an idle and they will run for a long time this way. Too small an engine for a skid steer. I think the best way for me to salvage the thing is making it a project generator. Lots of guys understand souping up cars and trucks and putting thousands into them. Why can't anybody understand souping up a generator?!

We loose power around here a lot, very crappy rural electric service. As a result my wife really loves generators so I can even consider it a honey doo project. Even though I have several generators already.
 
The rest of the story with this post...

Couldn't stand to see a good Kubota engine go to waste so I pulled the welder guts out of it and ordered a Central Georgia Generator 11k generator head and SAE 5 Bell housing/flywheel assy. and converted it into a generator. Stupid project I wouldn't recommend to anyone but it turned out pretty well. Still a few things to do but pretty close.
 

Attachments

  • Left 1000w.JPG
    Left 1000w.JPG
    591.3 KB · Views: 19
  • Right 1000H.JPG
    Right 1000H.JPG
    582.8 KB · Views: 19
  • Put Together 1000H.JPG
    Put Together 1000H.JPG
    620.5 KB · Views: 19
Last edited:
I love most Miller products,well designed and built, that said they missed the boat with the Pipe pro 304. The problem is every manufacturer is on a race to produce the next multi process engine driven welder, first problem you cannot make a welder that is perfect in all process, it may be great in SMAW and so so GTAW , the cost to build such a machine would make it unsaleable due to cost to build. So theres a lot of turds out there. All the main players build some very good machines and some very bad ones as well. I am old and old world, When it comes to engine drives I love our old Miller Big 40's and Lincoln Classics, we have a couple Miller air pacs but I like the old machines better, they run forever and are easy to maintain and repair. I did spring for some new Miller Bobcats EFI and there nice.
Research goes before purchasing,
 
Hurts to hear it's made so poorly for the use case.

I can't remember what it was but I've seen an outdoor high power inverter where the boards were mounted around a hollow tube heatsink with fins pointed inwards. A fan blew air through the center and there were no vents anywhere else.

I do know this approach is complex in terms of not toasting your capacitors and other passively cooled components that benefit from airflow. Extra care has to be taken to get everything appropriately coupled
 
Hurts to hear it's made so poorly for the use case.

I can't remember what it was but I've seen an outdoor high power inverter where the boards were mounted around a hollow tube heatsink with fins pointed inwards. A fan blew air through the center and there were no vents anywhere else.

I do know this approach is complex in terms of not toasting your capacitors and other passively cooled components that benefit from airflow. Extra care has to be taken to get everything appropriately coupled
IIRC its when Miller bought out Powon, and re-designed them. They called it "windtunnel technology", suppose to keep the dirt out of 99% of the machine.
 
IIRC its when Miller bought out Powon, and re-designed them. They called it "windtunnel technology", suppose to keep the dirt out of 99% of the machine.
Well I think they did some of that stuff in this machine but they forgot some real simple stuff-
Also need to keep the rain out
Also need to keep the varmints out

I bought it more for the generator than the welder. The welder part would have been a bonus. It was also a crappy generator. I hate two pole (3600 rpm) generators. And that's what it had. Of course they did that so they could get lots of horsepower (watts) out of a smaller engine.

I'm with Dana Gear, I like Miller stuff too but they really blew it on this one. I do like my new generator though.
 








 
Back
Top