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Cord


Although you wouldn't think it string is relatively easy to make. At its simplest they are but two parallel fibers twisted together into a single ply cylinder or cord. A crude bowstring can be made from such a simple, single-ply cord. Its main body will nold together surprisingly well, but at the nocks it quickly frays and weakens. Another problem is that if single-ply cordage is not kept permanently twisted, it tends to untwist into its original useless disconnected fibers. To make durable, practical cordage we need to prevent the untwisting and this is an almost natural process. If we twist up a cylinder of fibers and continue twisting until the cord begins to kink, then let go the cord will instantly wrap around itself creating a two ply cord, now having neutral twist. Some of the original twist will be used up in the process but enough will remain to supply necessary friction within each ply. A stable durable practical cord results.

This principle is therefor applied in the making of all traditional and modern day string making, although there are many techniques for making cordage. Most are difficult to master through text and illustrations alone. But they are all based on twisted-fibers-will-make-themselves-into-cordage principles. Once you twist the fibers tightly all you have to do is get out of the way and string happens.

Single Ply Cord
a cylinder of parallel fibers twisted tightly enough to function as cordage.
 
Simple Ply
a single ply cord used as the primary building block of reverse-twist cordage. It can be thin or thick, an entire ply, or one of many in a simple parallel ply.
 
Simple Parallel Ply
many small, simple plies, the sole purpose being to give uniformity; they are used in parallel lines as if a simple ply.
 
Primary Ply
one ply in a simple cord, when this simple cord is one ply in a complex cord.
 
Complex Cord
where each ply is itself a finished simple cord

Also crafting a superior bowstring requires more than simply selecting the strongest fibers. It matters very much how the fibers are assembled. Finer fibbers have more surface area, therefore more points of contact, therefore greater internal friction. When given a choice, select or shred fiber as thinly as possible without damaging the fiber. Smooth-surfaced fibers slip past each other more easily, and therefore must be twisted tighter. This weakens the finished cord. Short fibbers must be twisted tighter than longer fibers, also weakening the finished cord. (Excess twisting also shortens the length of the string. This means a longer string is needed, which increases mass.) Excess twisting makes a string more coilspring-like, causing a bowstring to stretch and absorb energy as it slams home after release. Energy absorbed by an elastic string is unavailable to the arrow, thereby reducing its poundage and speed.

Offered by Brian.

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