4 replies to this topic

[dj2020]

As I wait for parts on my UAV500 build, I've been browsing through LemaLife, Enthalpy, and Juz's build logs. Is there a difference between simply twisting the ESC servo wires OR should they actually be braided to reduce RF interference?

Also, twisting/braiding the brushless motor wires and battery leads is also recommended to reduce RF interference?

[Kenn Sebesta]

The RF interference is going to come from the magnetic field induced by the current flow. So if you wrap wires together tightly such that the net flow in both directions across a tiny cross-section of space is 0 (all the current that goes in one wire comes out the other) then you will have achieved your desired drop in RF noise.

Which one yields a tighter, more efficient packing factor for noise, I don't know. I suspect that the reason they're braided is because it's easier to ensure that they stay in a tight braid. If you can accomplish the same tightness with a twist, then for all intents and purposes you'll have the same results.

Likewise for the battery wires, except here obviously you don't have the braiding option. But this is fine because a two-wire twist holds together very well.

[dj2020]

Thanks Kenn

[flouSH]

The RF interference is going to come from the magnetic field induced by the current flow. So if you wrap wires together tightly such that the net flow in both directions across a tiny cross-section of space is 0 (all the current that goes in one wire comes out the other) then you will have achieved your desired drop in RF noise.

Which one yields a tighter, more efficient packing factor for noise, I don't know. I suspect that the reason they're braided is because it's easier to ensure that they stay in a tight braid. If you can accomplish the same tightness with a twist, then for all intents and purposes you'll have the same results.

Likewise for the battery wires, except here obviously you don't have the braiding option. But this is fine because a two-wire twist holds together very well.

To sum it up for a stupid newbie:

- Servo cables --> Twist or braid tightly
- Battery cables (+/-) --> Twist
- Motor cables (3 phases) --> What to do here?

THANKS!

[Kenn Sebesta]

- Servo cables --> Twist or braid tightly

It would be interesting to hear from someone who has more experience in these things, but I wonder if you should only twist the + and - wires, leaving out the signal wire. Maybe D-Lite might shed some light on this. However, unless you have massively large servos or if low RF noise is crucial then the already existing flat three-conductor cable should be fine.

- Motor cables (3 phases) --> What to do here?

Braid.