Signal wire that can withstand abuse - Page 1
Forum section: electronics / projects

author: plexus
author_rank: Contributor
timestamp: December 08, 2021, 07:22:53 pm
content: I have been tasked with finding a replacement cable for a footpedal. The issue is that the footpedal get's heavily used by the users of it - they have to move it around with their feet during procedures. The pedal has 3 foot switches, out to a cable and terminates in a multi-pin. The issue is that the cable always breaks somewhere in the length. I have tried other small signal cables but they all end up malfunctioning due to the abuse the pedal encounters. There is no opportunity to have the pedal treated better because it's within the context of the workflow of the company.Do you know of a cable or cable-type that is designed for high wear and tear, bending and movement? The exisitng cable has 4 conductors. It only needs to carry low power DC. I have being using regular-type cable I can get from Digikey. Cable length is not critical, around 2-3 meters.

author: mzzj
author_rank: Super Contributor
timestamp: December 08, 2021, 07:31:22 pm
content: Maybe high-flex robotics cable.

author: Terry Bites
author_rank: Super Contributor
timestamp: December 08, 2021, 07:58:36 pm
content: Olflex Silicone is pretty tough. Tip, put cores in parallel to mitigate against single conductor failures.Put a sacrificial sleeve on top. Let them mash that up first. I have put silicone sleeving over expandable braided sleeving and it lasted a while..... but thats O.R. staff for you.

author: elekorsi
author_rank: Regular Contributor
timestamp: December 08, 2021, 08:47:58 pm
content: PUR cables can whistand a lot of mechanical abuse...But the only long term solution will be if you put it into proper metal conduit + cable glands, for example like these:http://www.teaflex.com/en/Products/MetallicSystem/CoveredMetalconduits-Fittings-Accessories/SteelCoveredwithsteelbraid/SVT-MetalConduitgalvanisedcarbonsteelbraidedhttps://www.flexicon.uk.com/product/fsb-system/We use those in heavy industries, such as steel mills and quarries. Those conduits and glands are quite expensive, but really worth their money.

author: ogden
author_rank: Super Contributor
timestamp: December 08, 2021, 08:53:28 pm
content: Pick high flex cable, put it in the heavy duty sleeve. Something like this (quick search):https://www.cabletiesandmore.com/kevlar-braided-sleeving

author: Benta
author_rank: Super Contributor
timestamp: December 08, 2021, 08:53:52 pm
content: Why is it a secret how many conductors you need?

author: plexus
author_rank: Contributor
timestamp: December 08, 2021, 09:21:06 pm
content: Quote from: Benta on December 08, 2021, 08:53:52 pmBecause you didn't read the whole post

author: Benta
author_rank: Super Contributor
timestamp: December 08, 2021, 10:21:55 pm
content: Bad emoji selection, bro. Won't bring you friends.

author: Someone
author_rank: Super Contributor
timestamp: December 08, 2021, 10:48:09 pm
content: "flex", motion, or handling rated cables usually come with a high strand count to be n-way redundant. So you'd be looking at something likeBelden 7111WSBelden 8407Canare L-4E6S

author: plexus
author_rank: Contributor
timestamp: December 08, 2021, 10:50:31 pm
content: Quote from: Benta on December 08, 2021, 10:21:55 pmNeither will not reading a post and and asking sarcastic questions about what you missed. Lessons to be learned by all!Thanks to everyone else that has replied! Some good answers. Considering the applications and what I have seen so far from your ideas and pointers so products, I think a custom cable solution with silicone conductors with a robust outer sleeve may be the way to go. I'll keep looking, though, for a pre-made solution too.

author: thm_w
author_rank: Super Contributor
timestamp: December 08, 2021, 11:14:30 pm
content: Quote from: Benta on December 08, 2021, 08:53:52 pm"The exisitng cable has 4 conductors."

author: ConKbot
author_rank: Super Contributor
timestamp: December 08, 2021, 11:20:02 pm
content: Robust, but still commonly available (at least in the US substitute with local flavor of choice if not US), would be switching it to SOOW cable. Some 18-16awg 4 conductor shouldn't be absurdly large, but still quite robust with the rubber jacket. Fine stranding, EPDM rubber insulators, chlorinated polyethylene(CPE) jacket, Oil, water, outdoor rated. Going beyond that, I would definitely start looking at continuous flex rated polyurethane jacketed cables, and even more resistant than that would start including stuff with actual armor.Crane pendant cable may also be available in small enough quantities, and is pretty rugged. Available with either internal reinforcement, or external steel cables to support the weight of the pendant, or in this case, you could terminate the steel cables to the connector body, or pedal.

author: WattsThat
author_rank: Frequent Contributor
timestamp: December 09, 2021, 01:24:04 am
content: It is curious that the conductors break somewhere other than at the terminations, that would imply that the gauge of the wire is too small and it’s being stretched to the point of failure. Do you know what the gauge and stranding data of the failed cable is? It’s always good to have a starting point reference...A practical note on silicone insulation: While very flexible, the material has poor cut and tear withstand, that softness and flex comes with a price.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: December 09, 2021, 08:11:26 am
content: Use highly flexible cable with lots of thin strands.Cables with rubber insulation are also more durable then PVC.Silicone is not very strong.For extra protection you can also feed it through a garden hose.

author: richard.cs
author_rank: Super Contributor
timestamp: December 09, 2021, 09:44:54 am
content: Quote from: WattsThat on December 09, 2021, 01:24:04 amThis is a good point - midway breaks are usually stretch-related. In which case a cable with a steel tensile core like those used for overhead suspension would be good. Or field telephone wire but that might not be finely stranded enough for the flexing. Something with soft and stretchy insulation like silicone might be bad if the failures are stretch related.How abusive is this environment? Is this a TIG pedal in a welding shop or something?Quote from: WattsThat on December 09, 2021, 01:24:04 amYes, this would be good, or even a part number / datasheet for what you currently use.

author: wraper
author_rank: Unknown
timestamp: December 09, 2021, 10:08:24 am
content: Braided cables resist such sorts of abuse pretty well, since braid takes the tensile forces instead of the cable inside. I suggest buying a decent braided USB phone cable of the required length and cutting the connectors off.