permanently wired facility Question

[R. Exnicios]

Okay fellow Gear heads here is another one for you to ponder.

We are putting together a proposal to permanently wire a facility for fencing and I was wondering what wire people have used and what connectors. We are looking at 6 or 8 strips. The reels and machines will need to be put away at times to use the space for other purposes but the wiring will be integrated into the building. Some of the wires will need to be 300-400 feet long between reels and machines.

Any suggestions would greatly be appreciated.

Cheers

R

[cornflower]

I went to a fencing club that used an overhead reel. It was cool.

[R. Exnicios]

the overhead reel system will not work in this space the ceilings are 30 or 40 feet high. Think Big old Gym/ballroom.

[JEC]

Richard,
It still can work. I seen it at other clubs during my travels. What they do is they run another cable perpendicularly in the middle of the strips as the anchor, and depending upon distance this might need a single anchor from the roof. A similar system is used at the Boston Fencing Center. Your other alternative is like the new strips at Salle Mauro (but with a wider strip), where they have them underneath the wooden floor. I seen a variance of this latter system in San Francisco too.
JEC

[Artisan]

Okay fellow Gear heads here is another one for you to ponder.

We are putting together a proposal to permanently wire a facility for fencing and I was wondering what wire people have used and what connectors. We are looking at 6 or 8 strips. The reels and machines will need to be put away at times to use the space for other purposes but the wiring will be integrated into the building. Some of the wires will need to be 300-400 feet long between reels and machines.

Any suggestions would greatly be appreciated.

Cheers

R

You will probably need to use a heavier gauge wire than the standard floor cord for the 400' runs.

Because the current is DC, the size (diameter) of the wire is a factor at those lengths. Ohm's law: the drop in voltage is related to the product of the current x resistance of the wire. Fatter wire has less resistance. (Thats why audiophiles use "Monster cable" to hook up their speakers). The good news is that scoring boxes use low current, so the drop in voltage at longer lenghts will be less than if say you were running a 12 v light bulb or other highr powered item).

If there is too much resistance in the long runs, then epees may not go on, and foils may not go off.

[MTD]

Yes, wire gauge will be an issue.

I'm looking at this three different ways.

From the perspective of DC electrical behavior, the resistance of the floor cords has to be acceptably low, and that's pretty much the only practical requirement. The voltages are safely low and anything which works in a short cord works in a long cord. The current involved also has nothing to do with length, save to say that it is required that the resistance be acceptably low. While I can get away with using 33' of 24 AWG four-conductor telephone wire to create a floor cord and have one ohm resistance, despite the cost attractiveness of this inexpensive wire for a 333' run, the resistance will be an unacceptable 10 ohms. If I used to find 24 AWG acceptable, I'd have to switch to 14 AWG for the long runs. Start looking at three-conductor extension cord-style wire. Think in terms of getting the wire at an electrical supplier instead of an electronics supplier!

From the perspective of AC electrical behavior, long lines show signal propagation delays and signal degradation, and no matter how low the resistance is, there will be some length of floor cord beyond which the system breaks down. When discussing AC behavior, remember that one needs to speak not only of resistance in the wire, but inductive reactance of the wire, and the reactance of capacitive shunting between the wires. But, for systems which implement rules written with the term "millisecond", this should be a non-issue. In a single millisecond, a signal would propagate around 200 kilometers if it didn't degrade to undetectability first. My only worry is how long it takes to charge up a capacitor formed by running 300' to 400' of parallel wires. I haven't bothered to do the calculations, but am comfortable the capacitance involved will be be tolerably low. (And, if there is any doubt about what is tolerably low, get actual capacitors with capacitances even greater than what the calculations show, deliberately bridge between the lines of a short floor cord, and see if one's favorite boxes even notice anything!)

The third perspective is that of interference. In a perfect world, the floor cords would be shielded and not susceptible to capacitive or inductive connections to other wires (power lines, telephone lines, and even other floor cords). My feeling is that here this is a non-issue, though, because fencing equipment is dealing with low impedances (remember the box is supposed to trigger or not trigger based on rules written with three digit numbers of ohms). Good practice would keep the floor cords from being parallel to power wires for extended runs, though, just to be sure neither the 60 Hz hum nor any noise injected into the power line swamps the scoring box. The chance of the scoring box interpreting any coupled signal as a legitimate touch seems minimal because of the long times involved in legitimate touches and how the reactive coupling drops off at low frequencies, but a box which was not designed robustly could be pushed outside its design limits if enough noise were on the lines.

If I were doing this, I'd think about conducting some actual experiments before sinking any money into this. I'd borrow eight 100' extension cords, connect them to make two 400' floor cords, probably jury-rig connections at both ends involving borrowed épée body cords which I promised to return with screws more snugged than when I borrowed them (we won't mention that they'd be disassembled for a while). I'd deliberately run them alongside routes which I guessed to be the noisiest availaible power circuits, then see if the fencing were anything but ordinary.

[rsy]

I seen it at other clubs during my travels. What they do is they run another cable perpendicularly in the middle of the strips as the anchor, and depending upon distance this might need a single anchor from the roof.JEC

This is what we did at our club spanning a distance of 45 ft. For that short a distance, no anchor to the roof was needed. It works great.

Some of the wires will need to be 300-400 feet long between reels and machines.

If the machines are 300-400 ft off the strip, how are the fencers & directors supposed to see them?

-r

[R. Exnicios]

If the machines are 300-400 ft off the strip, how are the fencers & directors supposed to see them?

-r

The machines are mounted at the ends of each strip (2 for each strip) the reels are on the floor the wires are in the wall. Like outlets, plug reel into outlet with short cord.

The overhead thing will not work, we cannot obstruct the open space. Picture a historic ballroom with high ceilings and lights. Use the space but do not alter the look and feel etc.

I've been experimenting with various network wiring and thermestate wires to see what reistance they have over long distances.

R

[JEC]

Richard,
Are you able to change the floor? If you're able to place a floating floor, then you would be able to place all cables under the new floor. You might also be able to hide reels and connectors for boxes.
JEC

[Pepster]

One type of wiring you might consider is good old standard house electrical wire. It's a nice heaftly wire, and you can snake it through a metal conduit if there's any concern for interference.

I would say you might need to get creative with connectors, but anything with three contacts should work. If you can find a wall plate with a 1/2" stereo jack (Think of a headphone plug's older brother) Then just keep your L/R/Gnd straight with your A/B/C lines across all the connectors. You can pick up the male plugs at Radio Shack or order from any electronics catalog, and make up a short Stereo to Three-prong Adapter cable.

Or, you could keep things simple, and order banana plugs and flat face plates, drill holes, and make your wall connection a standard three-prong.

-Pep

[Mergs]

What's wrong with two pair phone line?

[telkanuru]

What's wrong with two pair phone line?

24 AWG wire would have a fairly high resistiance over a large distance, wouldn't it?

Could someone post pictures/diagrams of the task in question? I find it rather difficult to visualize from the description.

[R. Exnicios]

Could someone post pictures/diagrams of the task in question? I find it rather difficult to visualize from the description.

No picture yet but I'll work on that. Basicly we have an olg ballroom style Gym a little larger than a full size basketball court. We want to run 6 to 8 strips in the space all parrallel to each other. We cannot alter the floor or obstruct the ceiling clearence in any way. The space is used during the day for high school PE and such. righ now we set up strips, machine, floor cords, reels everynight. We want to hard wire the space so all we do is plug in the reels along the outside walls and the machines mounted at the ends of the strips. main machine on one end and repeater lights on the other. each strip woul have 2 sets of lights, one behind you and one infront of you when you are on strip.

the wiring needs to run the circumfrance of the building. So the strip in the center will have to have its wire run completly around the building to the other side.

Thanks for all of the ideas so far. I've been experimenting with all sorts of stuff. so far no great discoveries.

Cheers

[telkanuru]

Oh. Given that scenario, I'd say cat-5 cable would prove more than sufficient, as it is specifically designed to carry low-power signal over distance.

Is it strictly impossible to run the cables up and over the ceiling?

[rsy]

If you can't go up and over, or out and around, how about down and accross?

Is it possible to drill through the baseboard and snake the floor cord wire down to the floor below. It can then be run along the joist or in a plenum, hanging ceiling, etc., directly to the machine and in a similar fashion to the repeater. You then just plug your reels into the connector coming out of the the baseboard and start fencing.

If you could do this there would be no long runs and you would have the added advantage that if the the power supplies are bricks, they can be plugged into outlets installed on the joists below the floor level and the power lines snaked up the wall along with the floor cord to the machines and repeaters for a nice, clean installation. When not in use, all you would see is a plug on the baseboard at the end of each strip and a machine or repeater mounted on the wall with no wires coming out of it.

As an added thought, if you used the Favero flat reels, they could be permantly installed on hinged platforms that fold down on the floor for use and flat up against the wall when stored. I am sure some engineering type could even make them hydraulic. Tssssssss, fencers ready?

-r

[R. Exnicios]

Thanks for the input on the wiring. We are installing Cat 5e wire and using Leviton RJ 45 speed connectors. We tested the wire and connectors and found that we can run about 200' without any resistance problems.

The only problem now is to make sure people don't think the gym is wired for some weird computer network

Thanks for the ideas

R

[glowstix]

Okay fellow Gear heads here is another one for you to ponder.

We are putting together a proposal to permanently wire a facility for fencing and I was wondering what wire people have used and what connectors. We are looking at 6 or 8 strips. The reels and machines will need to be put away at times to use the space for other purposes but the wiring will be integrated into the building. Some of the wires will need to be 300-400 feet long between reels and machines.

Any suggestions would greatly be appreciated.

Cheers

R

yeah, please don't use overhead wires. they suck!!!! i was at a tournament recently and they had those there. someone said that earlier, the reel was let go and hit someone in the face. not worth it.

[EricS]

Thanks for the input on the wiring. We are installing Cat 5e wire and using Leviton RJ 45 speed connectors. We tested the wire and connectors and found that we can run about 200' without any resistance problems.

The only problem now is to make sure people don't think the gym is wired for some weird computer network

Thanks for the ideas

R

You might also want to find a way to secure the reels, otherwise they WILL tear the RJ45 connectors out. I found this out the hard way...

[Pelle]

although an indoor wired facility is much more reliable and less prone to damage, it may simply not be the most practical choice for you if the area is not 100% devoted to fencing. i will give you the layouts of my club tho. Over head reel system with a box with settings and large lights on one side of the piste with another smaller "hit" box at the other side. both boxes are wall mounted with the main one covered by a large metal grate to avoid being hit. the settings can still be adjusted by the fencer as there is room for hands/weapon tips. keep in mind this is permantly wired and is DEVOTED to fencing as any permantly wired area should be. also we are the most advanced fencing club in canada