MMA holder change

  1. SwissTony Member

    Messages:
    434
    UK, East Sussex
    My thermal arc came with a tweco. On mine, the jaws don't seem to be parallel which means the rod is only pinched one side, if it sticks, the rod can move about in the jaws.
    I will probably do what was suggested above and file the grooves deeper.
     
  2. metalmelt Member

    Messages:
    589
    Location:
    UK
    You dont solder welding cable you crimp the end on, heat shrink is a non starter as it is an insulater.
    Grease should never be used because of the heat of rod holders will melt or ignite it. You clean the threads with a wire brush and remove all the detritus.

    Our Kings are simple, pull the handle down, take a ferrule and measure the length and strip the end of the cable to that length, fit the ferrule and crimp, slide the rod holder handle over the cable and push the ferrule into the top with the V of the crimp aligned with the screws, tighten 8MM studs with an allen key and fit the seal, slide the handle back up and push the locking pin back in.

    No exposed cable.
     
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  3. Memmeddu

    Memmeddu Member

    Messages:
    2,943
    Location:
    Italia Sardegna
    There is special grease for electrical contacts and you don't have to put a big amount , just little bit to prevent the screw to seize up .
    Soldering the wire on a lug terminal instead of crimping (do you have a 50mm² crimper?) Because it's easier.
    Heat shrink tubing to limit corrosion on the joint and keep everything nice and clean .
    I have two styles of holders .
    One uses the ferrule as you said and 2 Allen screws
    The others use a lug terminal as same as ground clamps

    In the case of the ferrule there is no need for soldering but you still can put heat shrink to cover 2 cm of the brass body of the holder and 10 cm of your cable.
    Providing protection from the air and preventing the cable to move sideways in the joint breaking the strands .
     
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  4. metalmelt Member

    Messages:
    589
    Location:
    UK
    I have a 90mm crimper on the truck, small and portable and crimps from 15 - 90mm, our other trucks have crimpers of 50mm and 70mm as this is the most popular cable for us.

    We do use some 90mm cable for long runs and I have the first of these crimpers as the die fitted determines the hydraulic crimp torque.

    Ours have a seal fitted as these are site cables and electrode holders and they stop all dust and debris including water ingress, the problem is also that we often carry grease and we never allow two types to be carried in case someone uses the wrong type, blame our H&S guy for that.

    Our only two points for moisture ingress are the holes where the electrodes fit.
     
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  5. DAPPH

    DAPPH as dyslexik as I'm daft

    Messages:
    2,870
    Location:
    Near to Cross Hands Llanelli SouthWales GB
    Years ago .when I changed my buzz box & leads over to a dinse set up with a commercial cable size plus the black & yellow 600 (?) amp electrode holder I had to turn some brass rod into a tube using my drill press & anneal it to get the ferrule for the electrode holder as nobody seemed to hold them in stock locally & I couldn't find them on eBay .
     
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  6. metalmelt Member

    Messages:
    589
    Location:
    UK
    Thats right, they used to supply the ferrules with the rod holder for the designated maximum size cable which fitted the rod holder, one old guy I worked with many years ago used copper pipe, he slit them lengthways and slid one inside the other until he had approximately the correct inside and outside diameters and used them.

    I did ask one of our welding reps about these when we changed to crimp types and he said we supply you (the company) with so much cable in two sizes that its a gesture by them to supply a bag of ferrules for both 50 and 70MM cable which fit our electrode holders to ensure our continued trade and that welding supply companies were stopping supplying single ferrules due to them having to break a bag open, and its more profitable to supply a bag of 50 ferrules to a company.
     
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  7. Feet 'n Inches

    Feet 'n Inches Out of the rat-race at last

    Messages:
    363
    Location:
    Devon, GB
    Did that recently with the old buzz-box at my Men's Shed. It's working perfectly.
     
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