Bungee/Pully system instead of floor cords and reels?
My club is thinking about setting up some bungee/pully system, and I've seen them before but I'm not entirely sure I see how they work. I tried following the wire back to the box but I couldn't keep track of it on the system I saw in Augusta, GA. I was just wondering if anyone could point me to a diagram of a typical pulley system, and/or explain it to me. If that doesn't happen I suppose I could just wait but so far when asking my coach about it I haven't quite been able to picture where the live wires go.
You know that the bungee runs between two anchor points, one at each end of the strip, through a pulley, right? So each wire runs from the box to the anchor point, though a second pulley attached to the bungee cord.
Somebody posted this on rec.sport.fencing about a million years ago:
***** = bungee cord
.... = cable
O = big (3-4 inch) pulley
o = small (1-2 inch) pulley
\ and / = anchor points for big pulleys (to wall or floor)
[] = scoring machine
f1 = fencer 1
f2 = fencer 2
With appropriate plugs/sockets at the ends of the cables. The cables also need to be anchored next to the scoring machine so as not to stress the plugs or the machine sockets and to keep the machine from being tugged around if it's not secured. You'll need 14 meters of bungee cord and two 8-9 meter lengths of thin, flexible 3-conductor cable.
Why sabre? Because you don't take heads with the point.
Does anyone know if Triplette's bungee system matches this diagram, with the two sets of pulleys?
Simple, clear purpose and principles give rise to complex, intelligent behavior. Complex rules and regulations give rise to simple, stupid behavior. - Dee Hock
That diagram is the "floor mount" version essentially the same. The Triplette system is the same, they just have all the part and nice light blocks as well as mount plates for the floor version.
We have one of these at our club, and we are getting a second as they are cheap and fairly durable, but there are a few things to be aware of.
1. The wires are under a lot of stress. For the ceiling mount versions if someone lets it go from mid-strip it can do a fair amount of damage, as in taking chunks out of a sheetrock wall!
2. Unless everyone has a well fitted lame it can eliminate/alter some target area for foil as it pulls lose lames up fairly high in the back leaving some of the sides and lower back exposed. It also tends to make a nice pillowy bulge in a less than very tight lame that is great for catching a long and deep flick to the back.
3. On the PBT system you will need some soldering skills to assemble it correctly. Also you will need to get a bolt and nut or a cam lock to put in the wire to position it where you want it to hang if you have a very high ceiling.
Having said all of that we are very happy with ours and have put off buying the extra floor reels that we were going to get in favor of putting in another bungy system.
Last edited by CvilleFencer; 03-25-2004 at 01:08 PM.
Just another lost soul saved by the (hit) First Church of EPEE!
Many overhead reel/bungy system designs have one very important difference to watch out for when you're fencing on them -- your opponent can increase or loosen tension on *your* side of the wire to the box. This means that if your end of the wire has an intermittent break that only occurs under tension, then your opponent can (knowingly or unknowingly) affect a test of your weapon/side. Tension related intermittent breaks have been fairly common on the overhead systems I've seen. They often fail intermittently under tension to the puzzlement of the fencers before failing completely.
So when you test your weapon when connected to an overhead reel system, make sure your side is under tension. [And when your opponent tests, perhaps cut them some slack :-) ]
Many overhead reel/bungy system designs have one very important difference to watch out for when you're fencing on them -- your opponent can increase or loosen tension on *your* side of the wire to the box. This means that if your end of the wire has an intermittent break that only occurs under tension, then your opponent can (knowingly or unknowingly) affect a test of your weapon/side. Tension related intermittent breaks have been fairly common on the overhead systems I've seen. ]
Thats why ours has a non-stretchable cord along with the conductive cable that takes up the tension. both pass through the same sheave.
If you are making your own bungee reels, there is some thing you might want to consider.
1. Get a small bungee cord diameter
When I first built s bungee reel I made the mistake of getting too big a bungee cord. That will do major damage on the hook at your jacket. You usually want a thin bungee cord as that will often be sufficient to get the reel to move back and forth
2. Don't skimp on the wire
When assembling a bungee cord system the wire is the most important thing, just make sure the wire is flexible and strong. The best stuff is the reel replacement wire. If you can't get that get the extension cords. They are susually pretty flexible albeit a bit heavier
3. Make sure you take the stress off the connections.
The is actually pretty important. Stress on the wire is the single most prevelant cause of on/off targets. Use a knot to take the stress off.
Other than that you can assemble a reel system pretty cheaply with stuff from the home depot
When assembling a bungee cord system the wire is the most important thing, just make sure the wire is flexible and strong. The best stuff is the reel replacement wire. If you can't get that get the extension cords. They are susually pretty flexible albeit a bit heavier
These are very good suggestion, but there is also one other very important consideration. Remember you are replacing both the reel and the floor cord. Unless you get extra long reel cord or have an extra short strip or you don't have the base behind the strip you are going to have a problem.
You will want extra long cable. Some will say the farther down the strip you go the bungee system will shorten the distance. Have you had to fencers explode at each other (We won't mention the weapon) and travel some distance. The same bungee is attached to both.
We just set up 3 strips at our club using reeless overhead systems. The idea of using sailing blocks was considered, but spending $30+/block for a pulley that is rated to 2,000 lbs seemed a little too extravagent. The local harware store carried some light plastic 3" blocks that cost $5.00 each and they work very well.
We also didn't use a central pulley to hold up the shock cord for fear that a kink might jam it. Because we have the height, we strung a plastic coated 3/16" wire across the middle of the room perpendicular to the strips about 15' high and just ran the shock cords over it. The overhead wire also supports the center strip's "floor cords" run back to the wall mounted scoring machine.
Lastly, one of the sockets on the cord was damaged when someone accidentlally let it go while unhooking and it snapped back to the pulley and whipped into the wall ($35 to replace the cracked socket). To prevent this we attached a "stop" on the cords about 6 ft from the end so that the socket cannot snap back to the pulley.
Lastly, one of the sockets on the cord was damaged when someone accidentlally let it go while unhooking and it snapped back to the pulley and whipped into the wall ($35 to replace the cracked socket). To prevent this we attached a "stop" on the cords about 6 ft from the end so that the socket cannot snap back to the pulley.
-r
What did you use for a Stop? BFK? (A type of Knot whose name I will not expand upon) or did you find a mechanical stop that screwed on? We have a floor system at our club, and I think they're in need of somthing like that, to avoid bruised ankle syndrome.
Pepster- I have used that BFK on a floor cord, but never intentionally.
The stop we used was a 1" plastic ball with a hole through the middle with one side of the hole "countersunk". The cord is threaded through the hole with the countersunk end facing away from the pulley. You then tie an overhand knot and pull the ball over it and the knot disappears into the countersunk space. Home Depot carries the little doohickies in the aisle with the cords, wires and pulleys.
Originally Posted by mfp 
