Making Fancy Cables Part 2: Soft Headphone and Composite Cables

Part 1, Making Fancy Cables: Network Cables!  examined how coloured and patterned nylon braids could be used for cable assembles: ) Those cables are intended for demos/presentations and so on.

Nylon braid is very easy to use because it can expand a lot, and is slippery against the wire so it slides on well too. However, although it looks visually nice, it is not soft. For home use, maybe a softer braiding is preferred.

For a long time I have wondered how to create composite cables without using metal or nylon braid. Composite cables are those where there could be a mix of different conductors for different signals. A good example is an audio and video (A/V) cable. It can contain wires for the left and right channels, but also some coax for the video signal. A/V cables are not used much nowadays, but sometimes I do want to transport low-power DC alongside a coax cable. There are not many off-the-shelf composite cables that contain all that. Another example was a handheld pick-and-place project discussion while back, where it was desired to have a air (pneumatic) tube, but also a couple of electric wires for illumination, all in a single cord.

I explored what cotton braid was available intended for such purposes, and came to the conclusion that it was really hard to find!

In the end it was noticed that some cotton rope is actually made of two or more concentric braids : ) Problem solved!

The procedure is really easy, just tug on the inner braid layer to pull out an inch of it (the photo shows below the cable a fragment of blue rope with the inner braid partially pulled out), and use sticky tape to attach it to the bundle of wires you wish to use. Then at the other end of the cotton rope, tug on the inner braid layer as well, and keep pushing the outer braid down until it starts covering the wires, and keep going.

It is really easy, except that cotton braid cannot be easily expanded, so it only works for a limited thickness of wires. If the wires are thicker, then the cotton braid won’t expand over it.

The diameter of braid that I used was impossible to fit over a cat-5 network cable for instance. But, there was no problem fitting it over RG316 coax (3mm diameter) plus a couple of 10/0.1 wires for power, as shown in the photos. I think it would also work really well for headphone wires, since it is soft.

Here’s a zoomed-in photo:

The cotton braid does look a bit faded, it is not as neat-looking as nylon braid. However, maybe there are sources for obtaining better braid. I'm still searching.

If the ends of the cotton braid need terminating properly, then adhesive-lined heatshrink sleeving can be used. It is great for finishing off connectors especially where there is no existing strain-relief.

Something like the 4:1 shrink ratio sleeving such as TE ATUMTE ATUM is useful, because it can fit around the housing of the connector, but also shrink down to the cable diameter, and glue itself around the cotton braid so it doesn't fray. Another (easier) method to terminate the braid could be to get some typical household glue (e.g. UHU impact adhesive) and let some soak in to the end where it will pass inside the connector shell. The glue should keep the cotton together, and attached to the inner cables.

Thanks for reading!