Spoolmatic Gun on a Thermal Arc?

[djd775]

For the resident welding machine experts: can I hook a Miller Spoolmatic spool gun up to my Thermal Arc Fabricator 252i?

I could swear I've seen reference to this issue on the forum before....but despite lots of searching, I can't find it back.

Here is the wiring diagram for my welder's 10-pin accessory socket:


And the pinout from the Spoolmatic manual:


To the best of my knowledge, it seems like this should work...I don't know enough about possible differences in resistance values, motor amperage values, etc....but the voltages and trigger configurations seem to line up well. Am I missing something, or can this be done?

Also, I've been wondering if it's possible to power a larger push-pull cabinet from this power source (such as a Cobramatic, etc). It seems like I could use the contact closure in the 10pin accessory socket to energize the weld power circuit, supply an external 115V power to the feeder and be good to go. Does this seem reasonable? I've been looking around for more info and availability on the Tweco torque assist guns that I've seen mentioned on this forum, but can't seem to find much.

In essence, my current spoolgun is becoming insufficient, so I'm weighing options for replacement. It would be great to get away from the 1lb spools and up to full size 12" spools, but cost is definitely a consideration in the short term.

[guajilloweld03]

Which Miller spoolmatic ?

[djd775]

I'm thinking a newer one...30A or 30A pro?


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[guajilloweld03]

Not an expert, but yes it would work as long as they have same 10 pin connectors.

[djd775]

Not an expert, but yes it would work as long as they have same 10 pin connectors.

I'm not too worried about the actual plug configuration - I'm sure I could re-wire a new gun to a 10-pin plug as long as the equipment is compatible. Wiring up a 10-pin plug with correct pin locations onto a spoolmatic gun shouldn't be too complicated. I believe miller uses a 14 pin plug?


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[storeman]

If you don't already own the gun, why not get a Tweco that is designed for it?

[mrmikey]

I thought the 30A was 30V and I see on the schematic the 252 has 24 to the drive? but I could be full of it. Someone who knows more will be along before long I'm sure...Mike

[djd775]

If you don't already own the gun, why not get a Tweco that is designed for it?

I currently have the Tweco spool gun, but I'm having more problems with it lately and was hoping to find something a little more industrial.


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[djd775]

I thought the 30A was 30V and I see on the schematic the 252 has 24 to the drive? but I could be full of it. Someone who knows more will be along before long I'm sure...Mike

You could be right, I don't know for sure. I was assuming the 30A was 24v but I don't know where I came up with that assumption now. I thought Miller generally used 24v accessories for some reason.


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[7A749]

The 30A runs off 24 VDC which is generally supplied by a weld control, or from the panel of a Millermatic 252.

I believe the motor is rated up to 36ish volts. I saw this earlier but I've been busy all day. You can run it, but I believe you will have to use a relay for trigger closure since it's not energized.

I would normally say just use a PSA2 transformer sold by Miller, which is a 115 to 24 VAC transformer with a relay. You could do a quick and dirty connection using one of those transformers and run it off wall power, then run the trigger activation wires from the internal relay to the welder. Then, your WC 24 connects to the PSA control, and the spoolgun to the WC 24.

I did a post on it awhile back. I dunno where it is tho.

Getting a PSA and doing the wall power thing is going to be the easiest way without opening up your machine. You can buy them used for about $120. Just cut the factory plug off and strip back the wires. There's an easy to follow diagram on the inside of the unit, or newer ones have it on the outside.

Someone else might have a better idea tho.

IMHO of course

[djd775]

The 30A runs off 24 VDC which is generally supplied by a weld control, or from the panel of a Millermatic 252.

I believe the motor is rated up to 36ish volts. I saw this earlier but I've been busy all day. You can run it, but I believe you will have to use a relay for trigger closure since it's not energized.

I would normally say just use a PSA2 transformer sold by Miller, which is a 115 to 24 VAC transformer with a relay. You could do a quick and dirty connection using one of those transformers and run it off wall power, then run the trigger activation wires from the internal relay to the welder. Then, your WC 24 connects to the PSA control, and the spoolgun to the WC 24.

I did a post on it awhile back. I dunno where it is tho.

Getting a PSA and doing the wall power thing is going to be the easiest way without opening up your machine. You can buy them used for about $120. Just cut the factory plug off and strip back the wires. There's an easy to follow diagram on the inside of the unit, or newer ones have it on the outside.

Someone else might have a better idea tho.

IMHO of course

Thank you sir. As long as I know there's a way to run it, I'll probably look into getting a 30A from my lws. I can deal with the details as I find the right parts. I assume I'm on the right track in thinking the 30A is my best bet for a high quality spool gun?


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[soutthpaw]

I discussed this recently with Steve about connecting my 30A to my TA LM300 which had 14 and 17 pin outputs. Just use a WC24 from Miller should do it. You could probably go with something similar

[7A749]

The 30A is probably one of the best guns on the market IMHO.

As long as you have the WC 24 you can make it run off just about any machine with a remote. The PSA 2 transformer will provide 24 VAC and a relay for contact closure for non energized contact closure systems. You just wanna make sure you do not feed power into a non energized trigger closure or you'll create problems you don't want. I know the way I described above is pretty hack, but it'll get the job done and you won't have to do anything to your welder to make it work.

[djd775]

OK great, thanks guys. I have an email out to my LWS for pricing on a 30A and a 30A Pro. Anyone have good knowledge of the differences between the standard 30A and the 'PRO' 30A guns? Would it be worth the extra coin? I see there's an XR-A feeder and 25' pistol-style gun for sale locally too, may have to see where prices go on this.

[djd775]

SOLUTION FOUND:

Just thought I'd update this in case anyone else is looking for a similar answer, as I have made some headway. Big thanks to everyone for your help/input.

My LWS was good enough to order me a Spoolmatic 30A, send it home with me and tell me "if it works for you, I'll bill it out, otherwise just bring it back". I spent a few hours pulling the plugs apart on the old Tweco spool gun and on the new 30A to verify pin-outs, resistance values, etc. Everything seemed to line up perfectly except that the Tweco had a resistor between pins J and H - 4.7k ohm, while these pins on the 30A are open circuit. I took a bit of a risk and plugged it into my TA Fabricator 252i...remote wirespeed worked, but the drive motor didn't run...in fact, when the 30A trigger was pulled, the solenoid and feed motor for the built-in mig function (wire drive system inside the welder cabinet) were both energized...not ideal.

A bit of experimentation and some more research, I tracked down an actual adapter plug from Tweco that is essentially a pass-through for all pins on the amp plug, with a 4.7k ohm resistor across H & J pins (referred to by TA as a 'peripheral program resistor'). LWS quoted almost $400 and minimum 2 weeks wait time....didn't sound very appealing.

I thought about taking the resistor from the Tweco gun (which is in fact soldered directly into the back end of the amp connector) and putting it into the 30A but didn't want to limit the future use of the 30A in any way (compatibility with a Millermatic welder, etc.).

Decided I'd break into the welder cabinet, found the wires for the H & J pins, and soldered in the program resistor...also wired in a switch to allow me to switch in the 4.7k ohm program resistor, or switch it off to return H & J to open circuit condition, in case I ever need to. Worked perfectly...30A feeds wire, the correct gas solenoid in the welder is energized, and the output contactor is energized.

I've been using the 30A occasionally for a couple months now, and everything seems to work great. Only issue is the WFS needs to be calibrated, it is feeding the wire faster than the display by a factor of 1.4. I know I calibrated the Tweco when I first bought the machine, but can't remember where I found the calibration procedure. Also, would be nice if I could get the internal gas valve int the 30A to lock 'open' so I could use the 4T (latch) function, as my welder has an internal gas solenoid for the spoolgun and pre-/post-flow timers.

I know this probably won't help that many people, but I have received tons of great advice from this forum, so I wanted to post in case anyone could make use of the information. Thanks everyone who makes this site so informative.

Picture of the back side of the switch...the resistor is soldered inline with the one blue wire (under the double layer of heat-shrink)...front of switch is accessible from inside the wire drive cabinet: