Intermittent Grounding

Discussion in 'Armory - Q&A' started by nikkip12, Feb 5, 2019.

  1. nikkip12

    nikkip12 Rookie

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    I just rewired a German epee and I am testing it before putting in the tip. I plugged the weapon into a test box and stuck a metal screwdriver down the barrel to test if it is conducting properly. When the screwdriver is perfectly down the middle of the barrel, I get a green light as desired. But if the screwdriver touches the sides of the barrel at all, I get a red light (grounding(?)). I then took a german tip and an epee spring and compressed them in the barrel without tip screws. 80% of the time I would get the green light as desired, but the other 20% I would get at least a flickering, dimmish red light. Did I somehow crush the wire when rewiring this or is it a simpler problem? Thank you.
     
  2. ktinoue3

    ktinoue3 Podium

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    Are you touching the top of the tip with your finger and gripping the blade with you hand when you you depress the tip? You are most likely grounding B-C that way. It should be fine. If the wire insulation was damaged it most likely would be grounding all the time not when you just depress the tip. Try finishing assembling the weapon and trigger it on the floor. There shouldn't be a red light.
     
  3. nikkip12

    nikkip12 Rookie

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    Thank you! I will finish assembling it tomorrow! I hope it works!
     
  4. neevel

    neevel Armorer

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    For the first case, if the screwdriver is touching the B-line contact of the wire and the barrel (C-line), you should expect to get the red LED lighting. In the second case, you are seeing your body conducting between the top of the tip (A and B) to the blade (C). LED test boxes will often show a dim light for resistances in the 100k- or mega- ohm range.
     
  5. nikkip12

    nikkip12 Rookie

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    Update: I finished assembling the blade and tested again. 95% of the time the test box light goes green as desired but about 5% it goes red and green at the same time.. grounding? I tried tightening both the barrel and the grip, and am going to use the weapon in a tournament this weekend since its working almost all of the time, but is there something I'm missing? I really don't think it's worth rewiring but I'd really like to know what, if anything, is wrong with it...
     
  6. K O'N

    K O'N Podium

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    Get a meter. Test boxes will give you a lot of high-ohm false positives. Very often when you see a flickering or dim red light you have a "ground" that's something like 100k ohms. That's nothing, forget it. But really, get a meter and throw the test box away.
     
  7. neevel

    neevel Armorer

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    Try wearing a glove on one or both hand when holding the weapon to test it. If the red light does not occur then, it was conductivity through your skin causing the B-C short and is nothing to worry about. LED test boxes are good for doing weight and shim checks and gross continuity checks, but of more limited value when troubleshooting anything else.
     

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