Why, oh dear God why?
I was bored. It was late. There was a large roll of ethernet cable available. Also, the birthday of a friend of mine was coming up, and I enjoyed irritating her. So I decided to make her a little present. Having already exercised my skills in using Cat 5 as a basic natural resource by making a primitive basket, I now felt ready to take on a more complex task.
So, how do you do it?
Acquire about 1.5 to 2 metres of Cat 5 cable, without plugs. Using a pocketknife or thelike, cut open the plastic sheathing along its length, leaving about 30 cm uncut. Remove the cut sheathing, which should leave you with a handle and four strands of two twisted wires each. Untwist the wire pairs. This takes time. If possible, coerce innocent but equally bored bystanders into helping you. Once you have untwisted and straightened all eight wires, your whip is done. (Okay, so it's only got eight tails. Bite me.) If you want to be nasty, put a little knot into the ends of each of the wires. You may also want to make a knot into the end of the handle so the whip doesn't slip.
You're done. Go whip your friends and giggle as they squeal and recoil. (Safety warning: the ends of the wires are copper-tipped, which does not go well with people's eyes. Don't aim for the head.)
In my experience, jeans will stop it from stinging unless the whipper really tries. Using it on naked flesh can be painful if enough force is used, and will certainly result in amusingly hard-to-explain red lines. (Where have you been, honey?)
And once that short period of amusement was over?
I labelled it "New Hall Computer Rep Basic Equipment - User Re-Education Tool" and presented it to aforementioned lady on the next occasion we met.
Would you like to super-size that?
I theorise that if instead of using a single length of Cat 5 cable, one could to use 9 about 3-metre-long pieces. Braid their ends together into a handle, and decrease the thickness of the strands step by step, by first removing the plastic shell and twisting all 4 pairs together, then leaving out two of the pairs, then leaving out another pair, and finally tipping the strand with just one single wire. This makes for strands that taper off towards the tips.
-------
XXXXXXXXX
XXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXX-------
XXXXXXXXX
-------
Cable 4 pairs 2 pairs 1 pair 1 wire
This would produce a much bigger and heavier version. Since the whole idea of such a whip is to have all the momentum of its weight concentrated into the tips, making it much heavier also makes it much more capable of doing damage. I haven't tried it. It would probably be able to seriously injure people. So unless you plan on doing just that, stay with the small version, yes?