Set up a Miller CP-200 with two Millermatic 10a feeders?

I recently purchased a Miller CP-200 on an auction sight unseen, came with two Millermatic 10a wire feeders. Was a gamble and I think I am OK. Reading the SN and what I can read online the machine was made in 1974. Is a 230/460 3 phase input unit. It appears that the machine was left set in disuse for some time. When it was used, they welded aluminum as it also came with a very worn out spool gun as well as a regular MIG gun. The regular MIG gun with it is in such bad shape that I don’t see that it can be used, further the feed cable from the feeder to the gun it'self is missing. When I powered up the machine the fan runs nice and quiet, all appears to be working but I have no real way to test it. The trigger on the very worn out MIG gun when closed elicited a click in the wire feeder that I believe was the gas valve opening and the roller gears on the feeder turned without any hesitation and the variable speed feed clearly works. I know I will need to buy a MIG gun, a gas regulator, a ground clamp, and feed rollers for the Millermatic 10 a feeder that came with it before I can weld. Larry Gruner of Weldmart.com says he has what I need to get the machine working. That is going to be an outlay of about $400, a lot more than the $115 I paid for the machine. At $515 not a bargain but I doubt I can buy a Miller MIG cheeper.
I am a hobby welder, welding is my way to be creative and help friends. This machine will likely not get more than 10 hours a year of actual weld time. Just from time to time I wanted a MIG and I had chance to get this machine for what I felt was a good price. I am primarily a stick welder, partly a point of pride, I feel it takes more skill to use a stick welder, also a 6010 on my old Lincoln AC 300/DC 250 Idealarc will burn through any rust and dirt or a 7014 will lay a nice bead on clean metal.

I am thinking since I have two feeders why not mount the two wire feeders side by side on top of it, one set up for stainless and the other for mild steel. I like the convenience of not having to stop and change wire if I want to weld one material or another.

Several questions.
1. Any words of wisdom how to test the machine further before I spend $400 only to find out that the machine does not work?
2. Any experience or advised to share on an old Miller CP-200?
3. Has anyone tried attaching two wire feeders to one machine, granted use only one at a time but would call for an additional outlay of about $300 for the luxury of not having to change wire for the job?
4. What expertise would you offer as far as using a homemade rotary phase converter as opposed to changing the machine to single phase 240? I already have the phase converter for my monster old drill press and a 16X60 Pratt & Whitney lathe.

Far too many words in your post. Stick a cheap roll of Home Desperate wire in it and pull the trigger. Spend a bit more and try flux cored wire. Sparks and some burned up stuff will tell you some part works.

How often do you really swap wire?

I have two feeders on a Miller XMT304- A programmable 60M W/dual shield and a suitcase with .035 hard wire. I just swap the 14 pin plug and the power cable to go from one to the other.

I would buy another old feeder with a good gun for $100 before I shelled out $400 for a welder that's worth $100.

I recently made the switch to inverter MIG and I now fully understand why you can't give away a 3 phase transformer machine.

Good idea but the mig gun w/ the machine is missing too many parts to even try that idea.

Scruffy887 said:

Far too many words in your post. Stick a cheap roll of Home Desperate wire in it and pull the trigger. Spend a bit more and try flux cored wire. Sparks and some burned up stuff will tell you some part works.

Click to expand...

Well today I did have a chance to power up the unit again. When I pulled the trigger on the very worn out mig gun, the voltage on the meter on the front of the machine immediately moved to reflect what was dialed, also I heard a click in the machine which I believe is the contacts closing to energize the gun and I heard a click in the feeder which I believe was the solenoid opening the gas flow. I feel pretty confident it is a working machine. I would enjoy comments from someone if it is a good idea to continue to power it on my home made 25hp Rotary Phase Converter.

Your CP-200 will run just fine on a 25hp rotary. Also works great, and not difficult to convert to single-phase 240, and will run nicely off an ordinary 'range plug'... like kitchen stove or electric clothes dryer. The CP-200 is incredibly robust, conservatively rated, and contains no fancy, proprietary, or unobtainium devices, components, or circuit boards. Easy to clean, maintain, and repair... and it'll weld circles around most anything else you'd put it up against.

Common issues, if you have any, are degraded ground and hot cables (water ingress wicking in, and turning the cable into green powder), dirty contacts on the voltage-varying taps, and dirty/worn/burned contacts on the primary contactor. I pull the covers, park it in the driveway, and wash mine out with a fan-spray nozzle on my pressure washer. Don't blow off the wire markers, and don't ruin the wiring diagram on the inside right hand cover.

Dual feeders is cool, but if you're only doing 10hrs of hot-glue a year, you'll likely wind up with the whip liners being fouled with crud about every time you use it... it doesn't take much sitting around for atmospheric crud, oil, dust, and corrosion to coat the wire, which immediately gets packed up inside the liners, jamming up the feed. I would run just one feeder, and keep the wire spools in my dry-storage compartment (pronounced 'old refrigerator', and load them in only during timeframe where I need them....

And as for worth, I bought my first CP-200 for $75... cleaned it up, converted to 240v single phase. A buddy (who used the CP-200 extensively in commercial fabrication) bought it from me for $750, and it, as well as my present unit, welds circles around the much newer units at my company's shop. Get it going, I'm certain you won't be disappointed, and you'll use it more often than you estimate...

Just thought maybe some would care for an update. I have been working with Larry of Weldmart Online Welding Supplies, Parts, Machines and Welding Repair | Weldmart Online out of Texas. He thought he could get me rollers for the Millermatic 10A feeder but did not really have what I wanted. He did fix me up with a nice new gun. I did buy a roller from him that would have sort of got me going with 0.035 wire but I really wanted 0.030 wire. He did not have rollers for 0.030 wire. My hang up getting the machine working has been finding feeder rollers. I have called multiple welding repair shops in Virginia and out of state, one thought he had some old ones in back warehouse but came up dry. Someone had suggested watch Ebay for some NOS. I have been watching Ebay since I started this thread 3 months ago and still not seen any come along. I did see someone selling a whole Millermatic 10A feeder with a set of 0.030 rollers so I purchased that whole feeder and cannibalized the feeder rollers out of it. Now I have a working unit. It does not weld as hot as I thought it should, I have not taken time to really play with it as much as I would like to. I did pull the shield off and sand / clean the contacts which helped but still not as good as I hoped.
So I paid $115 for the machine
$375 for the new mig gun w/ adapter, a roller, and a few other odds and ends
$17 for some misc hardware,
$15 for postage for something
$50 for a gas regulator
$192 for a set of rollers cannibalized out of a feeder that I bought.
So now I have a working machine, albeit not working quite as good as I hoped though I have confidence I will get it working better soon, for a cost of
$764, Bother I saw one sell on auction working for about $350 just last week.
So I did not get the bargain I hoped for. I think I have a working machine that will sever me well. I might one day decide to try and convert it to 220volt.