A strange problem

[Triton]

I need some help diagnosing this interesting problem...

This weekend, I set up the electrics for sabre practice, everything is set up correctly as far as I can tell, but the scoring box starts registering hits for both sides... before anyone has made any contact or even moved.

The box is Eigertek, and we've used it about twice so far. (There was an off-target light problem last time, but it was likely the body cord from one fencer.)

The reels are brand-new Favero millennium reels, with new floor cords.

The fencers are using gear that checked out just fine the last time they used it, and/or new body and mask cords.

Everything is connected properly, power is coming from the outlet and not battery.

As the fencers are standing as still as they can, the box is registering hits for one side or the other, randomly as far as I can tell. They are nowhere near each other, haven't even put the masks on yet.

Probability of both body cords being at fault is low, I think. (Though I do not have a tester, and should probably get one.)

Any ideas?

[Stormbringer]

Presumably, the box is on the correct weapon setting, yes?

TTBOMK, sabre and foil can register valid hits only when when the B-line (smaller prong) of the bodycord comes into contact with the opponent's A-line (lame clip). Epee, on the other hand, requires contact with the fencer's B-line and their own A-line (the two wires that run up to the point of the weapon).

The C-line (larger prong in sabre/foil, the far prong in epee) grounds the weapons from each other in all three, I believe.

Connecting two sabreurs to a box set on epee mode would result in both fencers being able to activate the colored lights by touching their weapons to their own lames/cuffs/masks (thus, bringing their own A and B lines into contact). This would be especially true if there are stray conductive fibers extending from the cuff and/or the insulation on the sabres' guards is chipped, worn, or otherwise damaged.

[Triton]

The box was indeed set for saber, however it might have been interesting to see how it would have responded set to foil or epee.

There were no apparent stray threads or own saber to lame contacts.

The two fencers were even trying their best to stay still while I was trying to figure this out. They did occasionally try to tap themselves for the off-target light, but it was hard to tell if that caused anything as the box was pretty much registering on-target hits for both sides constantly anyway.

My fear is that the box itself might be wonky for some reason, or else I'm missing something so obvious I've overlooked it.

[SJCFU#2]

First a quick review of how the saber circuit is supposed to work:

The signal goes out the C line to the socket, guard and blade, and returns through the B line to the machine (this is the reverse of foil, where the signal goes out the B line and returns through the C line, although it really shouldn't matter much for saber any more since they did away with the captuer years ago). If the signal goes out and doesn't return to the machine then it indicates a break in the circuit and a white light on the machine comes on to indicate a problem (such as a bad body cord).

If any non-insulated portion of the weapon comes into contact with the opponent's target area (which can include their blade if they happen to be holding it so that the guard is in contact with their lame) then a signal returns to the machine via their A line. At this point the machine will check for whip-overs. Assuming that the contact with the lame occurred within 4ms of any contact between the blades (a C-to-C short) or lasted longer than 15 ms after said blade contact (or there is no blade contact whatsoever) then the machine considers it a valid touch and the appropriate colored light comes on. The only way you can get valid touches when everything is set properly is if there is a conductive path between the saber and the opponent's lame. This path can be through a conductive piste if both fencers touch their blades to the piste at the same time while one of them is touching their guard to their lame, but not through air.

Stormbringer's suggestion sounds plausible - touching your saber to your own lame would create an A-to-B short which might register as a touch in epee, especially since an Eigertek would ignore the B-to-C short inherent to saber.

Was everyone hooked up when you first turned on the machine? When you first switch on an Eigertek it will look for shorts. If it detects a B-to-C short on at least one side then it will automatically switch to "foil" (or maybe it has to be both sides - it's been a while since I tried that) - otherwise it will default to "epee". Either way you have to manually switch the machine to "saber" for it to work properly (at which point both blue lights should be on).

[SJCFU#2]

The box was indeed set for saber, however it might have been interesting to see how it would have responded set to foil or epee.

There were no apparent stray threads or own saber to lame contacts.

The two fencers were even trying their best to stay still while I was trying to figure this out. They did occasionally try to tap themselves for the off-target light, but it was hard to tell if that caused anything as the box was pretty much registering on-target hits for both sides constantly anyway.

My fear is that the box itself might be wonky for some reason, or else I'm missing something so obvious I've overlooked it.

If everything is set properly and you're still seeing problems then try isolating the problem by removing various components. Start by unclipping the body cords from the lames (or better yet simply replace the fencers with a couple of working body cords and a couple of sabers. Then eliminate the sabers and body cord by shorting the B and C jacks of the fencer end socket together (most armorers use a short length of wire with a banana plug at each end, however in a pinch you can get by with just a piece of bare wire), then the reels, and finally the floor cords.

If you get to the point where the B and C jacks of the machine are shorted together and you're still seeing problems then you machine is probably wonky and it's time to contact Eigertek. However most of the time when people blame the machine it turns out the problem is actually somewhere else.

[catwood1]

Check the batteries in the box. From what I've heard, as batteries in the eclipse go bad, the box gets funkier and funkier.

[SJCFU#2]

Check the batteries in the box. From what I've heard, as batteries in the eclipse go bad, the box gets funkier and funkier.

The lights on an Eigertek will start flashing if the voltage drops too low (as happens when a battery runs down) , but I wouldn't exactly call it "acting funky" - there is a regular pattern to the lights and no buzzer. Moreover, the OP has already stated that the machine was being powered from an outlet at the time so there were no batteries to run down.

Still, it might not be a bad idea to try another power supply (or maybe even a fresh 9-volt battery, just in case there are problems with the local power distribution system - I've heard of venues where the local AC was so "dirty" that it would cause machines to reset at random).

[Triton]

Both fencers were hooked up before I switched on the box. I did make sure to put it on Saber.

Dirty AC? That's a new one to me, but given the way our school gym is wired I wouldn't discount that entirely.

I'll do some more experiments to see what else I can determine about the situation. I'm an amateur armorer at best, so I don't have all the tools or expertise I need do get too complicated, but I should be able to test a few of the variables.

Thanks for the advice so far!