Setting up for a job today, I opened up some wrapped mic cable, fifty-foot lengths of wrapped mic cable, and as I played out the cable, I realized that whomever the (insert pent-up, anger filled, derogatory term here) was who wrapped this cable up- they did not use “over-under” to wrap the cable but made dozens of loops, all in the same direction, which I now had to waste time to fix.
This follows a job just a week ago where I worked with a very tech-savvy kid who just graduated from a University. He was wrapping some cable and I watched him just loop, loop, loop his way through the cable.
I asked him what the heck he was doing.
I’m wrapping cable the right way, he postulated…
Apparently he worked on a “film shoot” and a “senior tech” there instructed him that everything gets wrapped in one direction “so the wires inside don’t get messed up.”
It is clear that there are a lot of misconceptions going on here.
Wrapping a cable repetitively in one direction is wrong.
It doesn’t matter if it is coax (core shield), twisted pair, electrical cable, multicore, triax or fiber. Using the “over under” method saves the cable, and saves time when the cables get pulled back out to use.
I urge all those out there ro read a little bit on the web.
How-To Sound Workshops has a Cable Wrapping 101. (that’s their photography at the top)
Stagecraft has online videos (AVI) on how to wrap cable. (That’s a still from their video on the right) and this is how most pros I see wrap cable- though there are definitely different ways to achieve the same goal.
The Internet Sound Institute has a nice section on this as well.
The multi-core image is from Answers.com which has a nice page on coaxial cable.
It is also called “flip-coiling” due to the nature of flipping thc cable back and forth while coiling it up.
Even Wikipedia has an (unusually short!) entry on “Over Under.”
It says, in part, “Over/under cable coiling refers to a method of storing cables that preserves the capacitance and common-mode rejection ratio built in by the manufacturer with a twist in the cable, and the shielding that encases the twisted pairs within. It also keeps knots to a minimum, allows the cable to lie flat when uncoiled, and makes running the cables easier and faster.”
What it doesn’t say is that constantly twisting a multi-core cable in the same direction forces the outermost wires to travel further than the inner wires, which I have personally known to break over time from the stress. This was in camera CCU cable with 16 different shielded wires inside one fat cable.
Unfortunately, Wikipedia also incorrectly states: “Straight coiling or the practice of coiling a cable in the same direction coil after coil, has the same result as coiling cable on a spool.” This may be where some of the confusion comes from.
If you coil cable repeatedly in the same direction, coil after coil, it does not have the same result as what you find on a factory-made spool. (This is why you must always check several sources and compare information when reading information on the web). A factory spool is made as the wire comes out of a machine, and the spool spins to gather the wire. The wire on the spool has no twist, left or right. The only way to recreate that zero-twist spooling is to use a spool. There are many out there specifically made for video our audio cables- mostly audio snakes, but several companies will make custom-make them for whatever you need. This is the only way to zero-twist wrap your cable because it feeds end-in and is pulled around.
While you can actually do this by hand, it is much more labor-intensive than holding the cable in one hand and wrapping it around and around with the other. Even if you lay it on the ground (as you must do with long multicore or triax) and wrap the cable around in the same direction, you are putting a twist on it. So you must make sure you twist in one direction for one loop, and then twist in the other direction for the next loop.
Not also that this applies to twisted pair cable. That’s ethernet and telephone cable.
I’ve never seen an IT (computer) person do “over-under” but over twisting (or untwisting) the twisted pairs in ethernet cable is bad.
Since ethernet cable is being used more and more in our IT-centric industry (where video is just data to be pushed around) it behooves us to wrap ethernet cable properly.
Even simple coax can be more complex than you can imagine.
It can have any number of layers of core, insulator, and shield.
When working with someone else on set, ask if they know “Over-Under” cable wrapping.
If they don’t… then teach them.