Electric flight and servos

by Lomac
(Yan Yean, Victoria, Australia)

I have just purchased some new gear for my glider. I have bought Hitec HS55 servos as they fit neatly in the wing compartment, but have noticed that the two output torque ratings are at 4.8-6.0v. Does this mean I can only use up to a 6v battery in my glider?
I plan to fly with my DX7 radio and AR500 receiver, flying with a brushless motor and folding prop. I was hoping to use a li-po for the weight advantage but can't find them under 7.4v. I also checked some giant scale servos and noticed they had the same volt rating of 4.8-6.0 which has confused me. I see picture in magazines of small planes with li-pos which must have small servos. How do they do it. Please help confused a Aussie...

Comments for
Electric flight and servos

Click here to add your own comments

Jan 31, 2009
Electric flight and servos
by: Pete

Servos are usually given ratings of 4.8v to 6v because these are the most commonly used separate battery packs (4 cell or 5 cell) for powering rx and servos. But if you're plumbing your rx into the motor circuit, then the motor li-po will power the rx and servos.
ESCs have a built in BEC (Battery Elminating Circuit) that 'syphons off' sufficient power from the li-po for the rx and servos, eliminating the need for a separate rx battery pack.
Check your component specs to make sure you don't exceed the BEC load, but most off-the-shelf ESCs can cope with an average electric plane such as a powered glider.

Click here to add your own comments

Holiday Shopping!

We can recommend...

Browse RC airplanes at Red Rocket Hobby Shop

eBook now available

Beginner's Guide To Flying RC Airplanes

The Beginner's Guide To Flying RC Airplanes is the essential companion if you're thinking about flying rc airplanes, or wondering how it's done.
Step-by-step guidance on all you need to know about getting in to this fun and exhilarating hobby!