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Thread: Vertical wire feed

  1. #1
    Join Date
    Mar 2001
    Location
    Nottingham, England
    Posts
    15,198

    Default Vertical wire feed

    Well I'm pi$$ed off with this Camarc 200 amp MIG welder. I have had it about 5 years now and in the first year it spent more time back at base than working. I wouldn't mind but I specified a good welder and was prepared to pay for a decent one.

    The problem is the burn back, when you start off it has this tendency to burn back too quick and stick the wire to the tip and mess up a length of wire that has to be cleared out when it kinks, a real waste of time.
    If you screw the burn back pot up to stop this on normal welding you finish up with 2" sticking out, a quick blat to clean up and it stuck the bastich wire to the tip again.

    I do a lot of quite precise welding if there is such a term on motor shafts without hitting seal track and other bearing surfaces etc.
    I get thru about 6 or 7 30 # reels of 1mm wire a year to give an idea of use.

    Last week on one job it snagged three times, that's 12 odd foot of wire scrap, no big deal, but about 20 minutes sorting the tangles out, big deal.
    So a hunt round the back shed and I unearthed this big 3 phase 250 amp Butler MIG welder with remote wire feed, threw a few bit of wire on it and a new gas line and it works fine, very controllable with course and fine setting and a BIG choke ? knob.

    Two questions from the welders out there, what's the choke knob for? seems to work better lower than higher ? and if I hang the wire feed vertical from the rafters so the torch is hanging down will the gas flow downhill ?

    .
    .

    Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.




  2. #2
    Join Date
    Jan 2003
    Location
    Temple, Tx
    Posts
    1,050

    Default

    John-
    I am not an expert welder, but I can tell you what a choke does electrically. The choke is like a flywheel for current. It tries to keep the current constant by adjusting the voltage. A lot of choke will slow the increase of current when you start, but once you are going, it will help maintain the current at a constant level.

  3. #3
    Join Date
    May 2005
    Location
    UK
    Posts
    1,572

    Default

    Quote Originally Posted by John Stevenson
    Two questions from the welders out there, what's the choke knob for? seems to work better lower than higher ?
    .
    My MIG set just has three sockets for the supply to the remote feeder, for different sizes of choke. I was told to 'choose the one that works best for you'

    I've nicked this quote from

    http://www.welding-advisers.com/Mig-welding-tips.html

    Variable Inductance
    Inductance control regulates the time rate of current change in response to changes in the circuit. Adding some more inductance may prove beneficial in developing a more stable arc initiation.

    One of the Mig-welding-tips that can have practical influence is the following. In Short Circuit Transfer Mode inductance limits the pinch effect, which will be applied more gradually, by controlling the rate of current rise in time. Higher inductance will decrease the number of short-circuits per second. The weld pool will become more fluid, resulting in smoother, flatter weld bead. Too much inductance however will negatively affect arc initiation.

    In Spray Transfer Mode, more inductance will only affect arc starts, which will result softer. No influence will be detected once the arc is running.
    Choke = Inductance

    Tim

  4. #4

    Default

    The gas in under a slight pressure in the hose, so it should flow just as well.

    Since it has a higher density than both nitrogen and oxygen, it'll probably flow better.

    Roger

  5. #5
    Join Date
    Oct 2004
    Location
    Prestatyn, North-Wales
    Posts
    6,002

    Default

    Is easy to become complacent .

    all my tips in the past have ended their life with the wire being welded in the hole .....had a lot of welding out of them before the blockage ...just thought it was one of those things.........and thats how they end their life...............and was like that for many years ...

    until recently ........

    well i just kept getting better at welding ...and hadn't noticed that i hadn't ruined a tip for many months ...........

    it's then that the problems began ...........i was getting burn back after burn back ...but no tip blockage ...........

    what had happened was i actually managed to wear out a tip for the first time ever without it getting blocked ...and the large size of the hole inside was causing the problems ...
    put a new tip on ....and it was like new again ..no burn back when starting up etc ..

    hope this helps.

    other things you can do is

    get lubricator kit for wire

    eventually the wire drive roller can become clogged with the plating off the wire....you end up putting more pressure on the rollers ...which sends the wire spiraling up the liner .

    all the best......markj

  6. #6
    Join Date
    Mar 2007
    Location
    Midland, Mi
    Posts
    851

    Default

    ...And check the earth/work lead on the problamatic welder. I fought similar problems for a long time on a 4-5 year old Miller 251. In the end I found the clamp had begun to arc and the lug crimped on the end of the lead had begun to burn through the sheet metal clamp. I found it after I grabbed the lead after some long problamatic welding and burned the hell out of my hand.

    Other things to check which didn't help me much, but are recomended, check the tension on the wire spool. Check/replace the liner. Check the drive rollers, and as mentioned above, a clip on lubricator/cleaner pad in the welder...

  7. #7
    Join Date
    Dec 2003
    Location
    Regina and Assiniboia, Saskatchewan
    Posts
    5,950

    Default

    Lots of shops have their feeders mounted overhead on a swinging/sliding gantry. The gas will run downhill just fine.
    Burnback...a few other things...too small of wire at too high of voltage, as was mentioned...wornout tips, too little stickout, nozzle too short...allowing spatter to spray back and weld wire to the nozzle.
    Some welders do this a lot when welding overhead. You have to turn up the wire speed.
    Russ
    I have tools I don't even know I own...

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