LONG servo extensions tech

[Crash]

I have a project coming up where every servo (6-8 servos, depends if I decide to add flaps or program flaperons) will have no less than a 3-4ft lead and possibly up to 5-6ft for the aileron servos. Other than going up on wire size from the standard 22 gauge to 20 or possibly 18, do I need to increase the voltage? I planned on using a castle 10A BEC to power the receiver and servos, but I don't think it has the ability to select between 5 or 6 volts. Do I need to look into other BEC options that can handle the amp load (all digital servos) that can output 6 volts to counter the expected voltage drop across the servo extensions? I planned on desoldering the leads off each servo and soldering the new extensions straight to the board to eliminate connections and any "bottle necks" going from 18-20 gauge extensions to the 22-24 gauge found on most servos. What about adding capacitors to the extensions close to the servos, would that be more efficient than just throwing more voltage at it or should I do both for optimal performance (6V and capacitors on the servo end)?

[SENTRY]

Are you able to test on the bench w/ a meter for V drops? That would be the quick way to know if there will be an issue. But you'd need to be able to test that w/ the motor running as well, since it will likely be pulling v as well in flight.

[Jahunt]

Just installed the CC BEC this weekend and it is voltage programmable, with the purchase of an optional cable. I think default is 5.1 volts, but programmable up to 9v.

[volto]

Wow, are you building a 20' wingspan plane? Sounds interesting!

[Crash]

Not that big lol, just brainstorming some ideas for an upscale of this plane I built earlier this year

http://fpvlab.com/forums/showthread....ild-and-flight

Probably looking at no bigger than 144" span

[Crash]

I will be building a newer version of the original design at the same scale before going bigger, but some of the same tech applies to that one as well.

Jahunt,

Thanks for the info, I will look for that program cable

[IBCrazy]

22AWG is plenty. Voltage drop on a 5 ft run is minimal. That's a 10 foot circuit path (remember V drop must account for both directions) so the impedance would be about 0.2 Ohms. Even if your servo draws 2 Amps, you will have 4.6volts at the servo.

If you go to 8 foot runs use 20 or 18AWG.

-Alex