Contact, hf, pilot arc, hf pilot arc, mechanical pilot arc???

  1. anjum Member

    Messages:
    1,003
    Location:
    London UK
    Can someone explain the differences between the various types of starting and advantages/ disadvantages, please??
    The more I look and ask various retailers the more confused I get. (is it just me??)

    Also a list of which makes and models use which might be useful to potential buyers.

    Clarke


    Hypertherm



    R-Tech



    etc
     
  2. chevy2

    chevy2 Member

    Messages:
    1,599
    Location:
    Herts.
    I have the Eastwood plasma,
    The pilot arc will initially burm away the paint etc but the cutting arc only starts once the contact tip touches the workpiece.
     
  3. scotty41 x

    Messages:
    85
    Location:
    x
    HF uses a high frequency arc to start the arc, like a spark plug on a car, the electrode and nozzle and in a fixed position, the HF arc jumps the gap and the air blows the arc out the nozzle
    pros.
    no moving parts in the torch
    no misfires (torch does not arc)
    cons.
    can intefere with pcs and stepper motors and probably ECU`s

    mechanical or contact start, the nozzle or electrode move by pressing the torch on the work or pulling the trigger, what happens is the electrode shorts to the nozzle inside the torch and this starts the arc, then the air blows the arc out the nozzle.

    pros
    no HF interferance
    cons
    more moving parts, more mis fires.

    Plamsa torches have both positive and negative in the torch, what you are doing when you fire it is making an arc across the 2, when there is a metal within reach of the torch or arc, the arc latches to the metal as its the easiest way to earth, there is a big resistor on the earth that is in the torch thats make the metal more attractive.

    Both HF and Contact Start (pilot arcs) eat consumables, plasma cutting is by no means free, see your front end comsumables as your welding wire or welding rods, they are going to be eaten up as you use the plasma.

    Both will go through paint long as you get your earth clamp on a part that is bare metal.
     
  4. anjum Member

    Messages:
    1,003
    Location:
    London UK
    Thanks for the replies.

    Which of the above pilot arcs can be used for mesh etc?

    What about non-pilot hf and contact systems?

    Is it possible to compile list of plasma cutters and which category they fit into?

    As I said this seems to be a confusing issue for a new buyer.
     
  5. Robotstar5

    Robotstar5 Casanunda Staff Member

    Messages:
    16,539
    Location:
    Birmingham
    Hypertherm have a continuous pilot setting for mesh
     
  6. scotty41 x

    Messages:
    85
    Location:
    x
  7. anjum Member

    Messages:
    1,003
    Location:
    London UK
    Thanks for the info, Slightly less confused now.

    I've bought a Clarke 35n which has turned out to have a problem with the pilot arc.....some days you can't win...
     
  8. scotty41 x

    Messages:
    85
    Location:
    x
    I remember when i had a clarke plasma king 50, same as the 55 now, it used to pulse the pilot flame about 3 times, then you have to release and pull the trigger again and it would do the same, it always cut if the pilot flame found metal so i did not see a problem, if its not eratic its a tip saving mode built in.
     
  9. Robotstar5

    Robotstar5 Casanunda Staff Member

    Messages:
    16,539
    Location:
    Birmingham
    The Hypertherm pilot arc stays on a fair while in free air, they're hoping you will buy lots of their expensive consumables? :laughing:
     
  10. anjum Member

    Messages:
    1,003
    Location:
    London UK
    Thanks. Sounds hopeful then.
    Anyone else with a 35n to confirm Northstars findings. The man at Clarkes seemed to think it was not normal and the manual says 2-3 seconds.

    Tips? I'd be more worried about the relays inside with the Clarke system.
     
  11. anjum Member

    Messages:
    1,003
    Location:
    London UK
    Anyone with a Clarke plasma king 35n?
    Does the pilot arc stay on for a few seconds or pulse as Northstars?
     
  12. RussKo New Member

    Messages:
    2
    Location:
    USA Midwest
    The tip does not have to touch the workpiece with a pilot arc machine.
     
  13. Mr shiney Member

    Messages:
    1,218
    UK northants
    Not on my Eastwood. Press the button, the pilot fires and off it goes.


     
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