Am I missing something obvious here?

[old jupiter]

Problem is to weld a bunch of cracks in an aluminum dump-truck body. The guy I reached at the manufacturer said use 4043 wire (I got .035"). Power source is a Millermatic 175, very low hours, S/N LF420467N, Stock no. 907020. To this I've hooked up a Traffimet GPZ-2 200A spoolgun with control box, also very low-time, S/N C2003-268T. If I get it to work, I rented a bottle of 50Ar/50He to give my little MM175 a chance.

So far as I can see (not far enough, evidently) I've hooked it all up correctly. But when I pull the trigger on the spoolgun, the drive-motor in the MM175 spins over, and the spoolgun drive doesn't move. Since this machinery mostly just sits (I used the spoolgun one time only, three years ago, and it worked well then), I tried making and re-making the connections several times to break through any oxidation in the pins/sockets. Turning the WFS control knob on the spoolgun has no effect. Yes, the control box is plugged into 115VAC and lights up.

I just doubt that there is anything wrong with the gear (always dry-stored), and suspect that the dumb operator has forgotten something . . . ???

[SBray]

I'm not familiar with the MM175, or the Traffimet GPZ-2 200A spoolgun with control box, but it sounds like your machine is still not recognizing the spoolgun.

On the MM175, is there a selection switch that you change the position on to operate the spoolgun?

Steve

[tommy2069]

I switch inside the mm175 to switch the power to the spoolgun . we had a 212 miller and a Hobart with the spoolgun hooked up and you have to flip switch to give poer to spoolgun also we had to turn the gas on inside the box. I know the 212 is not what you have but you might have the switch inside the box that you will have to flip to give power to spoolgun.

[aametalmaster]

So you got this one ?

http://www.trafimetusa.com/Products/Mig%20Range/Spool%20Guns/Brochures/Revolution_USA_06_09_02.pdf

[old jupiter]

Bob, that's the control box, though the pictured gun doesn't look quite like mine. I see no switch inside the MM175, just the two electrical leads to switch around to get DCEN or DCEP which is what I'm on. It recognizes the trigger of the spoolgun.

If you look at the photo of the control box, you'll see the start of the cable to 115VAC (the white thing). When you replace the MIG cable/liner/gun, you disconnect the short lead that goes to the 4-pin connector (only 2 are used) on the mm175 that completes the trigger circuit for that gun. You then slide in the big brass connector for the spoolgun cable; it picks up the welding current and the shield gas there, but not wire, of course. This big end of the cable has a short lead somewhat like that on the MIG cable you replaced, but it has a bigger connector with more pins, and it plugs into the control box. From the back of the control box comes the trigger circuit cable with the 4-pin connector that plugs into the front of the MM175. I have pulled each of the pin connectors in turn, and with either one out, triggering the spoolgun has no effect. With everything connected, as I say, triggering the spoolgun activates the wiredrive motor in the MM175, but not the motor in the gun.

As I write this, I'm thinking maybe I'll turn the wirespeed dial on the MM175 fully counter-clockwise, then trigger the spoolgun . . . I would have thought that control would have been taken out of the circuit, but maybe not, and maybe the power for the two wiredrive motors is being shared, to the detriment of the spoolgun . . . shoulda tried it before. As I say, I had this combo working just fine when I welded with it a few years ago, and the MM175 has been in use since then, so I'm sure the problem is just something the dumb old man is doing wrong.

[old jupiter]

(The next morning)

Okay, it works now. As I expected, it was something stupidly simple, and my fault.

When I got up this morning, I went out and tried my notion of last night of dialing the WFS on the welder all the way down. The drive motor in the welder no longer ran when I pulled the spoolgun trigger, but that didn't get the spool gun working.

So, frustrated, I'm sitting looking at the gear, which all is neatly built into a cart that I made for it, my first project using the MM175 when I got it home about nine years ago. Remember I said I had plugged and unplugged the multi-pin electrical connectors from the spoolgun control box to the MM175 several times each to break up any oxidation that might have occurred while the machinery had sat idle? Well, there are three of those connectors, and it occurred to me that I had only done this to two of them. In the photos that Bob linked, above, is one of the control box . . . with a white connector in the front of it. When I bought my Traffimet gun, and fit the control box to my welding cart, that plug (partly for the 115VAC power, but it connects some other circuits) stuck out in the way. So I took the control box apart and relocated that white fitting to the back of the control box, out of the way and out of sight. Well, out of sight and out of mind; I didn't remember that it was a pin-connector. Until this morning. So I pulled out the control box so I could get at that (third) pin-connector and do my little drill of jiggling and disconnecting it several times. That solved the problem. Spool gun works fine now.

Looking at past posts, I see that Cruizer has advised applying some dielectric grease to the pins of these connectors to prevent the oxidation in the first place . . . . (Cruizer, if you happen on to this thread, have you got a preferred product in the form of a contact-etching spray that will remove oxidation from the pins/sockets before I use your dielectric grease?)

I just "knew" it was something stupid that I had missed!! Dang! I'm SIXTY-NINE YEARS OLD; when am I ever going to get smart?????

Thanks for your interest.


(FWIW, on the very slim chance that somebody finds this thread while doing a search for "Traffimet" because they have the same model spoolgun as mine, a model that came with a built-in glitch that I was able to fix, you can read about this by finding my old thread of 1/12/2015 on "Welder Hot-Rodding.")