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xkcd #2810: How to Coil a Cable
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this post was submitted on 02 Aug 2023
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A cable coil will lay flat and neat, and stay orderly indefinitely if two conditions are met:
The coil radius is sufficiently large such that there is little to no tendency to unwind.
There is no twist running the length of the cable.
The solution to 1 is simple: just create loops large enough that no energy is stored in the "big spring".
The solution to 2 is any wrap method which avoids a systematic twist along the cable. If you were an ant walking along the cable, you should find that if you start on the outside surface of the coil, you remain on the outside as you walk the loops.
One method for coiling cables that achieves both goals:
Hold one end of the cable fixed in your off-hand. Let the length of the cable loosely hang such that it may freely rotate. With your dominant hand, slide it down the cable measuring a length which will create a loop large enough that the bend radius doesn't want to spring back open. Here comes the big trick. As you bring your main hand around to create the loop, use your fingertips and thumb to roll the cable in the direction which eases the twist along the cable. Finish the loop, and repeat until done. The coil should lay flat on a table without wanting to unspool wider, or spring up and launch loops into the air (problem and solution 1 and 2 respectively.)
Practice the finger tip movement. It's like tying shoes or whistling. Once you get it, you get it.
Also have one end of the cable loose, and push the tension towards that loose end as you coil, unwinding that excess tangle as you go. Coil the cable in the direction in naturally wants to go after this tension has left and it's no longer fighting you.
I used to shoot live TV in random beaches around the world and this method worked great every time we packed down. We had coil sizes roughly the length of our forearm for super long cables.
I think that's the "quarter turn" method.
In reality, all the methods are the same:
Holy crap this is spot on. I've been doing it for 20 years without thinking but I don't think I could have articulated it in a meaningful way.
Kudos!
This is essentially the over-under method. The idea is that you do a twist in one direction as you make your first loop, then a counter-twist in the other direction, which causes the second loop to sit “under” itself. So your coils follow a pattern of one regular “over” twist, then a reversed “under” twist. So the net result when you uncoil the cable is zero twists, (or at most one twist in the entire length of the cable, if you started and ended the coil with an over twist.)
Professionals use this for coiling, because it helps with cable longevity and running. Your cables never develop the dreaded twists in the first place, because you’ve never introduced more than one twist into them. And in a 50’ run, one twist is negligible and will work itself out as you coil the cable again at the end of the night.
And a figure-8 coil is basically the same thing as over-under, but laid out flat. This is handy for thicker cables that you coil in place. Hubbell Cam feeder cables, for instance. Each cable is as thick as a quarter, and there are up to five of them in a bundle. So it’s incredibly heavy and hard to work with. Instead of dragging the cable to you, you usually have a crew coil it directly onto a cart or into a case. So you’re wheeling the coil around, following the path of the cables, rather than trying to drag the cables to you. But this means you need a way to coil it flat, and a figure-8 solves this. It achieves the same twist-counter twist pattern in a much flatter (but wider) footprint.
The downside to the over-under method is that if one end of the cable gets pulled through the loop, you end up with a series of overhand knots in your cable, spaced evenly across the entire run. That’s why professionals will use velcro cable ties on all of their cables, to ensure the cable ends stay on the correct side of the coil and don’t get pulled through.
Source: I’m an audio technician. In a single shift, I’ll coil anywhere from 500’ to 2500’ of audio cable. Every mic you see on stage probably has either a 25’ or 50’ cable on it, and all of those need to be packed up at the end of the show. On a big gig, I can easily coil half a mile of cable throughout the day. I always joke that the actual show is only 10% of the job. The other 90% is cable management.
Saved for next time I have to wrap a cable or hose or something.
This guy coils.