Test box red light faint blink before green light on

Discussion in 'Armory - Q&A' started by WeaponCheck, Mar 10, 2018.

  1. WeaponCheck

    WeaponCheck Rookie

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    I am using Absolute test box to check Epee weapons. If I press tip slowly, I noticed that red light faintly blinks before green turns on. It only happens to some weapons. I am wondering what may cause red light blinks. It seems that the weapon is functioning but I am not sure if it has some potential issue in the competition. FWIW, I use the same body cord.
     
  2. SJCFU#2

    SJCFU#2 Podium

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    It's possible you are creating a short between the tip and the blade through your own body, especially if all you are seeing is a dim glow from the red light (your body's resistance could probable be measured in megaohms, but even that will sometimes allow enough current to get through to get a slight glow out of an LED).

    If the intermittent red light is brighter than a dim glow than it sounds like you have an intermittent short somewhere in the weapon. Possibilities include (but are not limited to) a bent contact spring momentarily coming in contact with something else, or a nick in the insulation of the wire. First, you may want to try taking apart and cleaning the tip, replace the contact spring if anything looks out of place (how much effort do you want to spend on a $0.40 spring?) and test, first without the weight spring in place, then with it in place, to see if you can recreate the short. Hopefully that is enough, because if it runs deeper than that you may eventually need to rewire but you might as well try everything else first.
     
  3. Purple Fencer

    Purple Fencer Podium

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    You can also use something like the floor to push the tip down to eliminate the resistance from your hand.
     
  4. St.Meow

    St.Meow Made the Cut

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    I'm guaranteeing these guys are right and it's because you're pressing down with your thumb while holding the blade with your fingers. The contact spring is touching one of the contacts but not the other, so all 9V are being pushed through your hand to the barrel/blade. When you fully depress it, it shunts the A and B lines together, so the majority of the current is going between those rather than through your hand. If you press it against something like your foot or use a test weight, the problem should disappear.
     
  5. Purple Fencer

    Purple Fencer Podium

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    When I'm assembling a weapon, it hangs with the point low enough to the ground that I can hit it with my foot from beneath.

    It's only when I push the point in with my hand and bend the blade back I forth to check for intermittent contact that I get the faint shorting tone.

    I used to worry about it until Matt Porter explained what was going on.
     
  6. WeaponCheck

    WeaponCheck Rookie

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    Thanks for everyone. Yes, I used my thumb to press the tip while holding the blade in the palm. St. Meow's reply also explained why the symptom disappeared after I disassembled and reassembled the tip which might make the contact spring to touch both contacts at the same time. Will do more tests and report back.
     
  7. Purple Fencer

    Purple Fencer Podium

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    That's not what he said, tho. He mentioned the contact spring only touching one of the contacts.

    The spring touching both is how it's supposed to work.

    Go to
    to see a cutaway I did showing how the parts work.

    Also go to
    and check out from about 5:50 to 9:30 for something that may help you avoid the issue of the spring only hitting one contact.
     
  8. St.Meow

    St.Meow Made the Cut

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    What I was saying was the reason it stops is because the red light is current going from the B line to the C line. So if your contacts are uneven and your epee is wired in such a way that the B line is the contact being hit first, you'll get that faint red light. If your A line is being contacted first (180 degree rotation if the contacts are even but the spring is not) then you will not get a faint light as your standard LED box typically has A and C at the same voltage (+9V or 0V, depending if the B has the positive or negative). So the issue can vanish if it's just the spring or contacts being uneven and he rotated it around or wired the socket backwards.
     
  9. WeaponCheck

    WeaponCheck Rookie

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    Everyone is correct. I put two fingers of the same hand on two connectors of test box. I can see very faint light on LED. When using the palm holding the blade, It might create better conductivity since larger contact surface.

    Question for Purple Fencer: do you think I can fix uneven contacts with punch + hammer like what you did in the video? I understand that I may have to replace contact spring after that. BTW, I will go through all your videos once I have time. :)

    St.Meow, you are right. I did rotate the tip after removing tip screws. If contact points have uneven surface but contact spring is even, rotating the tip should not make a difference. If both have uneven surface, rotating the tip may compensate the unevenness. :) If only contact spring has uneven surface, rotating tip does make a difference.

    In general, should I worry about this issue? Does it affect performance in competition?
     
  10. Purple Fencer

    Purple Fencer Podium

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    The punch/hammer combo is used on the contact pins in the wire cup....it has nothing to do with the contact spring in the tip, although you may have to readjust the spring.

    The original issue no....you're not touching the tip with your hand while you fence.

    The possible uneven contacts? Yes....if you don't level them, you will not get a reliable circuit closure wen the tip is depressed.
     
  11. neevel

    neevel Armorer

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    One nice feature of the FWF epee point setter is that it has a little nib at the end (sized to fit into the volcano rim of an Uhlmann/Allstar wire) that will level the contacts as you set the point.
     
  12. jkormann

    jkormann Podium

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    A hole-punch does this as well. I have both, depending on the wire.
     
  13. Purple Fencer

    Purple Fencer Podium

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    A 3/32 flathead punch has doe this for me for years.
     

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