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  1. #1
    Join Date
    Dec 2011
    Posts
    6

    got an old airco tig welder, need some help setting it up

    as the title states, i got an old airco tig/stick welder. The orange box is model 1.8a/ddr, and the grey box on the bottom of the cart is a model hf-15.
    The hf-15 appears to be an arc welder, and the 1.8a/ddr looks like an inverter? The HF 15 has 2 switches, the one on the bottom left hand side is a power switch, but there's one up between the lugs as you can see in the pic below that is not marked. Any idea what that's for?


    Also, the 4 big lugs on the hf-15... the two on the right look fairly cut and dry, one has the ground, the other has the torch. the two on the left have large banana plugs, which i assume get plugged into the front of the big orange unit, the 1.8a/ddr which is pictured below. However, i am not exactly clear which ones to plug it into. The cables are only long enough to plug into the ones on the left of the 1.8a/ddr. What are the other plugs for?


    Also, the torch has a few lines going to it. there is no water pump, but there are hoses which looks like it connects to a faucet. I'll probably hook up a small circulating pump and tank for it. The argon and water lines go through some sort of pedal seen in the first pic below. It apears to be a variable valve or something. There is also another pedal which seems to just be an on/off switch, it doesnt appear to be variable. the picture of that is the second one below. What's the reason for the 2 pedals, and what does each one do, or how should i use them? im only used to the single variable pedal on newer welders.
    gas/water pedal on the ground


    on/off electrical pedal, on the ground in front of the grey box
    http://farm8.staticflickr.com/7034/6...506dd4fa_z.jpg

    Also, the grey box above has some switches and a big contact inside. the welder was shorting out, i traced it down to the ground wire being connected directly to one of the terminals on the contact, which was connected to one of the other leads from the 220v. Not sure why it was like that, but there was a slow burn fuse in line of that circuit. I assume they were trying to get 110v for the coil on the contact, and for the fan in the 1.8a/ddr. That circuit needs work. I bypassed it and the welder does turn on though, so i think it works. below is a picture of the box pictured above when it's open, if anyone has any comments for that. I'm not exactly sure what to do with the knob on the front or the switches, or if i should even keep any of that stuff wired up.
    I assume the post purge knob is to control how the current tapers off after you release the pedal?


    Lastly, there is no regulator for the argon tank. As you can see in the picture of the foot pedal, the connection for the argon has no line coming from it. Any idea what to get here?

    Thanks in advance, and sorry for the long post and big pictures, i figured they were neccesary to read whats on the machine.
    Dan

  2. #2
    Join Date
    Dec 2011
    Posts
    6
    oh, and if anyone has a manual for this thing, i'd love a copy!

  3. #3
    Join Date
    Jun 2007
    Location
    Elsewhere
    Posts
    356
    Post in the Miller forums too, as Miller made many machines for Airco and someone may recognize it.

    http://www.millerwelds.com/resources...ng-Discussions

  4. #4
    Join Date
    Dec 2011
    Posts
    6
    ah, thanks!
    i figured out the switch from a picture online, it's for ac/dc. The switch on the grey box likely bypasses it i assume. The short ended up being the magnetic contact switch coil, trying to find another one around the house right now.

  5. #5
    Join Date
    Dec 2011
    Posts
    6
    so i got the thing working, kinda. However, there was a buzzing/arcing sound coming from the HF-15, so i took a look and i could see some sparking/arcing going on inside through one of the vents. I'm not sure what it is, some idiot welded on the tube to hold the tank right behind the access pannel, and the thing is bolted down to the cart. I'm hoping it's just some crap in there, but i'm guessing it's the transformer. bummer. It will weld though, there is definitely a good arc between the electrode and the grounding clamp when i test it.
    Any ideas?

  6. #6
    Join Date
    Dec 2011
    Posts
    6
    got the access pannel off, and there were 4 blocks with these 4 rusty metal rods in them. it was arcing between the metal rods. is this normal, or shoud i take the rods out and clean them up or something?
    Attached Images Attached Images

  7. #7
    Roger Guest
    Post Purge is shielding gas flow after arc stops.

    Contacts arc and sparking is normal part of the HF (high frequency) arc start system. There is a specified spark gap for proper operation.

    The bottom orange box is AC/DC stick welding machine. Top gray HF box is what makes it a good TIG welding machine with foot amp control and high frequency arc starts. You can scratch start TIG welds without HF but HF is required to restart arc as AC welding current changes polarity maintaining welding arc.

    The 2 right female sockets are for DC welding current output.
    The right 3 female sockets are for AC welding current output.
    Welding leads can be plugged into these sockets for stick welding and HF input leads are plugged into sockets for TIG welding. TIG welding leads are attached to output sockets or terminals of the HF unit.

    To the left and a little above axle of the amp setting crank is the bar indicator showing amp setting with AC high and low amp scales above indicator bar and DC amp setting scale below indicator bar. When welding lead or HF input lead is plugged into high amp socket use high amp AC scale for setting or when plugged into low amp socket use low amp AC scale for setting.

    It was common to use water from faucet for water cooled torch. Should be water solenoid for that cooling water so really cold water doesn't cause condensation in torch between welds. If you are using recirculated coolant you should by pass the water solenoid.
    Last edited by Roger; 12-30-2011 at 02:07 AM.

  8. #8
    Join Date
    Dec 2011
    Posts
    6
    Quote Originally Posted by Roger View Post
    Post Purge is shielding gas flow after arc stops.

    Contacts arc and sparking is normal part of the HF (high frequency) arc start system. There is a specified spark gap for proper operation.

    The bottom orange box is AC/DC stick welding machine. Top gray HF box is what makes it a good TIG welding machine with foot amp control and high frequency arc starts. You can scratch start TIG welds without HF but HF is required to restart arc as AC welding current changes polarity maintaining welding arc.

    The 2 right female sockets are for DC welding current output.
    The right 3 female sockets are for AC welding current output.
    Welding leads can be plugged into these sockets for stick welding and HF input leads are plugged into sockets for TIG welding. TIG welding leads are attached to output sockets or terminals of the HF unit.

    To the left and a little above axle of the amp setting crank is the bar indicator showing amp setting with AC high and low amp scales above indicator bar and DC amp setting scale below indicator bar. When welding lead or HF input lead is plugged into high amp socket use high amp AC scale for setting or when plugged into low amp socket use low amp AC scale for setting.

    It was common to use water from facet for water cooled torch. Should be water solenoid for that cooling water so really cold water doesn't cause condensation in torch between welds. If you are using recirculated coolant you should by pass the water solenoid.
    Thanks! a few things i'm confused on.
    1. when i'm welding with dc, i suspect i'd use the dc sockets. when i weld with ac, do i swap the sockets to the ac side on the orange box, or is that only for when i am stick welding without the HF box? There's switches for ac and dc on the HF unit, that's why i ask. im not sure if i just flip the switch, or if i flip the switch and change the sockets.
    2. the torch has 3 tubes coming out of it. 2 go to the foot pedal selenoid, one goes to the HF unit and there's a little block that bolts to the lug for the electrode on the HF unit. I asume that tube has the cable for the electrode inside of it. The way it's set up now, that tube hooked up to the electrode lug is for the water cooling. Is this normal? I thought that one was supposed to be for argon.
    3.There is not a foot amp control, just a foot on/off switch, and another foot switch for the water/argon. Does this mean i'll likely have to scratch start it all the time? Any way to hook up a foot amp control?
    Thanks a ton!

  9. #9
    Roger Guest
    Common for electrode lead to run inside water coolant hose to keep electrode lead cool. This way electrode lead can be smaller, lighter, more flexable and torch can be smaller and lighter. If you loose coolant flow while welding electrode lead can burn up fast. There is also coolant return hose and argon supply hose to torch.

    Is there a gas solenoid and water solenoid? That way gas flow stars with welding current and stops a little after welding current stops to protect tungsten until cool. If no water solenoid leave water on until finished welding and use recirculated water from water cooler. If you get warm water from faucet then use that if you must. You can TIG weld by manually turning on Argon as you just make bad weld easily fixed if gas is off and regrind tungsten. Much harder to replace melted electrode lead.

    No HF then must scratch start and no AC welding on aluminium.

    No remote foot operated or hand operated amp control then only way to compensate for heat build up as you weld is by increasing travel rate and adding filler.

    Have fun trying to make this work. It is probably a good stick welding machine. It might be a usable to OK TIG welder. No remote amp control would be a big missing feature.

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