Cobramatic push-pull guns?

A cobramatic push pull feeder with gun sells for around $3500 new (US$)

Used ones even 15-20 years old sell for around $1000 (US$)

Yes parts are still available for every model.

MK Products still makes them.

You can run it from a CV power source (a 250 amp MIG or larger) or a CC power source (a TIG/STICK machine 200 amps or larger).

Even if you can't use it immediately you can likely resell it for more money.

On Thu, 18 Nov 2004 18:35:42 GMT, Ernie Leimkuhler vaguely proposed a theory ......and in reply I say!:

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Thanks for the reply. Funny. Your name sprang to mind as I posted! Can't think _why_.

Looks like the _worst_ I can do here is buy a $200 steel box!

Holy Canola!

Thanks Ernie. I was looking through the ads for stuff like the LN25, and I saw they were easy Aud$750-1000

I was amazed at the amount of stuff on the Web about them, showing them to be very active still. I had never heard of them. (blush!)

Yes. I actually asked my Father to trot around and put $50 on it. because the guy had another phone call even as I was talking to him. I was willing to pretty much risk that $50, as I started to see what I was looking at. Thanks for the info.

A question. I do not have a 250A MIG. I have a 220A (Migomag. Hardly known but very heavy duty and I am happy ). I am pretty sure it will not have the right connections for the wire feeder. Can I fix that, or is the welder simply not suitable? I have found the connection diag for the Cobramatic on the Web, but what is it about the welder that will not suit? Any idea?

***************************************************** Dogs are better than people.

People are better than dogs for only one purpose. And then it's only half of ofthe people. And _then_ most of them are only ordinary anyway. And then they have a headache.........

On Thu, 18 Nov 2004 18:35:42 GMT, Ernie Leimkuhler vaguely proposed a theory ......and in reply I say!:

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Sorry. I suppose the real question is: "What does the welder _need_ to drive the unit?", rather than asking you whnat my obscure beastie does not have...

***************************************************** Dogs are better than people.

People are better than dogs for only one purpose. And then it's only half of ofthe people. And _then_ most of them are only ordinary anyway. And then they have a headache.........

They are specialized machines. You only normally see them in production shops doing a lot of aluminum fab, like boat yards and trailer manufacturers.

They are prohibitively expensive for smaller fab shops. Smaller shops make do with spoolguns.

You can likely jerry-rig it into your MIG. Mainly it needs to be able to trigger the contactor controller in the MIG power source. You hook up a heavy jumper cable for the welding current from inside the MIG near the wire feeder to the cobra cabinet.

The gas goes directly from the flowgauge to the cobra cabinet. You can run steel in a cobra but it will wear out the very expensive teflon liner.

It needs power and contactor control.

How do you know if the liner is worn? If it is worn, where can I get a replacement?

On Fri, 19 Nov 2004 00:52:51 GMT, Ernie Leimkuhler vaguely proposed a theory ......and in reply I say!:

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Thanks Ernie. I shall start delving.

The gun on this thing is a mean-looking muvver. Handles 1/16th" (1.6mm) wire, I believe.

That's the irony. If I get this thing working it's the cheapest wire feeder I have ever found. And it's push-pull if I need it!

It _looks_ in "as new" condition. It may of course be busted inside there somewhere.

Ya pays yer munny....

That's what I wanted to hear! .

Great! Another "adventure" to make my wife happy that I am not attending to "core business"

Ok. Yep. I need to see what all of those pins do.... I have delved into my MIG a couple of times, so I know of possible ways to control the beast.

Cable came with it. Gas line and all. But it will need adaptation.

Thanks for the warning about the liner. I may see if I can get a normal steel liner for it, for most work.

Thanks Ernie. At least I don't feel that I have bought another white elephant.

***************************************************** Dogs are better than people.

People are better than dogs for only one purpose. And then it's only half of ofthe people. And _then_ most of them are only ordinary anyway. And then they have a headache.........

Rager source for replacement. So how do I know if the liner is worn and I need a replacement?

On Fri, 19 Nov 2004 09:44:46 GMT, Gunner wro

On Fri, 19 Nov 2004 00:52:51 GMT, Ernie Leimkuhler vaguely proposed a theory ......and in reply I say!:

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Ok. I did a quick look last night.

The Posi Start (slow wire feed for the first arc start) does not work on this machine. It has its controls blanked off. - I am assuming that this was an option that this (ex govt) machine did not have?

Likewise Remote Wire Feed Speed Control is blanked. - I am not sure what this means. It worries me a bit.

The Cobra motor, surprisingly for Oz, is 115V AC. Now this is inconvenient. I am not sure how bad. - My MIG machine uses 240V AC, but what it feeds its _motor_ I am not sure. There is nothing written on the motor to indicate. - It must also feed it something to control its speeds fairly accurately under loads, right? - So my problem is: What controls the wire feed speed on the Cobra? There is a little multi-turn pot on the handle of the gun. If I am real lucky, this will synchronously control both push and pull motors, and all I need is to find a 240-120 trannie and supply power to the machine on the correct pin. Otherwise I can NOT run this very easily from my machine, unless by extreme luck I have a machine that has a

15V motor. - what worries me is the fact that there is a "Remote wire feed speed" control option, as if there was an option to feed a signal back to the main welder to control the speed. This means of course that the main welder has to be able to control the speed. That could be a bummer.

I can start asking the makers, but it's the weekend. Never buy a strange toy on a Friday!

Appreciate any help.

***************************************************** Dogs are better than people.

People are better than dogs for only one purpose. And then it's only half of ofthe people. And _then_ most of them are only ordinary anyway. And then they have a headache.........

Posi-start is not worth the trouble anyway. We leave it turned off on our Cobras.

That means being able to set the wire speed from the cabinet.

Many large CV power sources can output 115 volt AC for motor controls. Should be simple enough to rig up a transformer, and just plug it into the wall.

No the power source just supplies welding power and maybe a 115 volt source to run the feeder

That multi-turn pot controls the speed of both motors.

What you have is a standard Cobra, with no extras.

On Sat, 20 Nov 2004 07:48:16 GMT, Ernie Leimkuhler vaguely proposed a theory ......and in reply I say!:

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Thanks Ernie. And GOOD news as well!

Eeeeuw! "OUR COBRAS eh?" Show-off!

But anyway, fine. I assumed it was an "unwanted extra"

Yes. I was worried that it was some way to send back to the "mother" welder. But your later comments make me feel better.

Given your news, that is what I plan to do. I have a 115V - 240 volt trannie, and I _was_ going to use it for this "in reverse". But it's not a proper isolation trannie, I have discovered. It is a centre-tapped trannie. When used in reverse it will be a bit dangerous, and gives some very suss voltages between the pins at the

115Volt end, under no load (read "if any wire ever came loose etc".)

Ah! Now there's the GOOD news! Thank you.

I mean...I would have thanked you anyway, but it's much better this way!

Unbelievable. I emailed them at some ungodly hour on Friday evening, and had a reply on Saturday! These guys are really on the ball. And I was completely honest with them about my secondhand purchase, my dodgy setup and all. I said I would buy a manual if that would help with setup. The guy responding has _sent_ me a manual, no charge, no postage, and has asked what my welder is, so he can help me set it up with the feeder. As far as it goes, you get _service_ for your money with these guys, anyway.

D'Oh. I wanted the flashy bits!

Really apprecaite the help Ernie.

"Ernie Leimkuhler"

Posi-start is rather useful when running constant current procedures, usually with large dia. wire.

That pot controls the pull motor in the gun, the other motor is a slave motor of low torque to assist in feeding wire and its speed is not controlled.

Remote speed control is used when the setup is mechanized.

On Sat, 20 Nov 2004 18:23:09 -0500, "Phil Kangas" vaguely proposed a theory ......and in reply I say!:

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Thanks for jumping in.

Well, as I said, it's moot for me..

hmmm....OK. So this thing _has_ to run as push-pull. This makes sense given that the motor is 115V 50 Hz AC. Not easy to control the speed of that. I assume the gun motor must be supplied other power that can be controlled?

OK. Again moot .