HEX BEAM, Step 5: The Support Cords

http://www.leoshoemaker.com/files/HEXBeam_by_K4KIO.pdf

HEX BEAM

Step 5: The Support Cords

Support cords from the center post to the ends of the spreaders along with two other cords between  the ends  and the middle  of  the two front spreaders establish and hold the shape of the hexagonal beam. When installed properly, very little tension is on the wires as these cords do the physical work.

Measure six radial cords 128 inches including the hooks. You can choose to use knots instead of crimps.

Measure one perimeter cord 128 inches to be used between the two front spreaders because they tend to be pulled apart by the wires and need this counter pull provided by a cord. Add another short cord about 90 inches between the same two spreaders located in toward the center. Don't use hooks on this short cord; use a cable tie on each end to wrap around the spreaders.

Here is how the support cords are connected to the end of the spreaders. Just hook down into the end and then secure the hook with a large cable tie. Measure out 7 cords of Kevlar/Dacron with little "S" hooks on the end. The cords should be 128 inches long, including the hooks. The Kevlar is very strong and will not stretch and the Dacron covering provides resistance to UV radiation. Use the crimps instead of knots. You will need an intermediate cord between the two front spreaders. Make this cord 90 inches long but don't use hooks; instead put a cable tie on each end that will be used to wrap around the spreader at about the 15 M band. You can use plain Dacron instead of Kevlar but it stretches more and you need to pull it a bit before measuring. Also, using knots instead of the crimps is fine.

Here is how the cords are arranged on the spreaders viewing from above.

When measuring the cords, remember that the cords, although relatively stretch-free, will stretch a couple inches under tension. So pull on them when measuring and before crimping them to end up with 128 inchesincluding hooks, when stretched.

There is about 7 pounds of force on the cords when installed on the beam

Here is how the support cords are connected to the end of the spreaders. Just hook down into the end and then secure the hook with a large cable tie. Note how the wire is anchored to the P clip with  a small  cable  tie.  This  should  be  done  on the  back  four spreaders and for 20 meters only, as the last step after all adjustments of wires and clamps have been completed.

Anchoring the wire in this manner will add stability to the overall structure in windy conditions. Plus it will keep the wires from "sawing" through the P clip.

http://www.leoshoemaker.com/files/HEXBeam_by_K4KIO.pdf