Copper Wire Degrades?

[ahr43]

Is copper wire degradation over time or over temperature an issue with RC?

Recently stripping some unused copper wire in my stash coming upon evidence of corrosion or oxidation-e.g., 'black wire'.

Is it time to purge the 13Ga super-flex in the stash and replace it with all new wire? Some of the stash wire is 15+ years old. Is there signal leakage or higher resistance unseen in old copper wire used for RC applications?

How about re-wiring older RCs with new wire for improved performance? Worth the hassle?

What is the future of copper wire in RC? Is there a better option on the horizon for the future? An application worth waiting for before beginning to refresh all the copper in the RC car stable?

F.O. (fibre-optics) comes to mind as a transmission medium. Think that will ever happen at the niche level of RC electronics? If nothing else, F.O. over copper would save a bunch of connectivity weight, esp. seeing 10Ga and 8Ga wire seeing increasing use. That wire adds a lot of weight and also levers the ESC unnecessarily requiring more substantial mounting methods.

Recently put a bucket load of wire on the wish list. Like to get you guys' thoughts before hitting the buy button.

Cheers and Regards. 'AC'

 

[Mrgoodwrench35]

From what I've seen, copper wire only degrades if it collects moisture or other contaminants. I don't believe age alone causes an issue.

If your questioning the performance of your wire, do resistance and voltage drop tests to see if there is some sort of performance loss. For the gauges typically used in RC, the resistance per foot should be less than .01 ohms. The voltage dropped per foot should be less than a tenth of a volt.

Its usually easy to tell if there's a problem with the wires. If excessive resistance or voltage loss is present, excessive heat will be generated.

Is fiber optic cable capable of carrying high current loads? That's a subject I don't know much about.

I believe silver core wire is a better conductor but also more expensive and I don't believe you gain much at the current flow of most RC systems.

 

[Greywolf74]

Its generally not going to be an issue with the RC in terms of conductivity unless the oxidation is so old that it has compromised the internal wiring inside the "corrosion sheath". Generally it takes multiple decades for that to happen without being exposed to certain chemicals or maybe extreme conditions. This is because once the outside layer of oxidation forms it dramatically decreases the rate at which the wire can corrode. The main thing you have to worry about here is making sure you clean the ends of the wire with some sort of acid free compound designed to clean copper oxidation specifically. That way you make sure your solder adheres properly to the wire. You dont have to worry about signal degradation or higher resistances.

As for rewiring an old RC, Id say you dont necessarily have to unless the wire is extremely compromised or just looks terrible. Again just clean any ends before re-soldering anything.

The two main wire types used for high current applications are CCA (Copper Clad Aluminum) and OFC (Oxygen Free Copper). CCA is aluminum wire that has been coated with a thin layer of copper and therefore looks like copper wire. The copper on the outside may corrode but the aluminum core wont. That being said if oxidation eats its way through the thin copper layer the CCA will lose a bit of its ability to conduct electricity. The whole reason they add copper around the aluminum is because aluminum by itself isnt as good of a conductor as copper.

OFC is pure copper wire that has had most of the oxygen removed from the copper. Since oxygen is one of the main factors in oxidation the absence of it drastically inhibits the wires ability to corrode. OFC while not "corrosion proof" is pretty resistant to corrosion and is the best thing you could use for RC wiring at least thats available and affordable today.

Fiber optic cable does not carry electricity. It uses light to transmit data in a digital format by pulsing the light on and off just like a computer logic gate works except the logic gates operates on electricity instead of light but the digital on/off format is the same. Fiber optic cable can carry energy but not electricity. What I mean by that is, its possible to use a transceiver to convert electricity to optical light signals and then another transceiver on the other end can convert the light signal back to electricity. BTW, Fiber Optic cable itself is made up on materials that are insulators and therefore a poor choice to try and transmit electrical current through it.

Hope this helps

 

[nino]

Fiber could onlt be used for signal, making everything more expensive and infinitely more complicated to DIY, with practically no benefit. Bandwidth is not a problem in RC.

For power wires, I don't think I've ever seen oxidised wiring when it comes to RC... If anything, I'd scrape away the oxidation on the ends that I intend to solder and that's it.

 

[Jerold]

Technically you can transmit power via optical cable, but it's a expensive and limited in power.

Unless you want gold plated conductor (that don't oxidize) copper is the best material. Copper is also more conductive than gold too.

Copper can oxidize (corrode) over time. It's depends mostly on the environment. If the cable is sealed off from the air (oxygen) it's unlikely to corrode and the corrosion is likely on the end only.

You can clean off the copper oxide with vinegar and salt (acidic), the dunk in a baking soda bath (basic) to neutralize it. But the reality is, it's just a 1/2" of wire so don't waste your time. Just cut off the offending piece, strip the insulation and see what it looks like inside. If you keep finding the inside corroded as well, then that cable probably isn't your best friend and just buy some new stuff.

 

[tudordewolf]

Sounds like you should spot-check a few samples of wire halfway along their length and assess the overall health of the batch. The storage space might be too humid or in a container prone to collecting moisture.

Room-temperature superconductors sure would be fun to see in RC, (or real life...) it's exciting to think what they could do for the motors!
Or a speed-run car with a liquid helium tank to cool the motor windings