Choosing Servo Size for RC Airplanes?

by Edward Lopuski
(Boyertown,PA, USA)

How do I find out which size servo I need for a particular RC plane?

I have some 40 size planes, 60 size and a 1/4 scale Extra 300L.Is there a computer program that I can use?

Matt's Reply: What particular airplanes?

Hi Edward,

What particular airplane are you referring to?

The manual or instructions usually tell you what servos they recommend.

It really depends on the size of the airplane and how you plan to fly it.

For example, if you have an Edge 540 that you plan to fly extreme 3-D then you will want servos with much more torque than if you were planning to fly basic non 3-D maneuvers with the same airplane.

Also, if you flying precision aerobatics were you want every move to be perfect, you would probably want to invest in more expensive digital servos which are much more precise. But digital servos are not really necessary for the average sport flyer.

I don't know of any computer software to size servos. The RC airplane manufacturer will recommend the size of the servo based on torque requirements of the control surface which again depends on the size of the plane and how it will be flown.

I hope this helps. If you can let us the the specific airplane in question we may be able to help you find the recommended servos.

Comments for
Choosing Servo Size for RC Airplanes?

Average Rating

Click here to add your own comments

Rating

Proper Servos
by: Anonymous

If there is no particular formula for finding the correct servo to attain the proper torque be it for 3D or whatever. How do the manufactures know what will work properly? Plus what do they base their reasoning on?

Rating

many things to consider
by: Matt

There may not be a formula that tells you exactly what servo to use, but there are many criteria that are taken into consideration.

First you have to determine how much torque you will need. If use a servo that can't handle the torque you will probably be stripping the gears in the servo, or the servo just won't perform properly.

You also have to take into consideration how accurate the servo needs to be. If you're flying precision aerobatics in competition, you'll want a servo that centers and performs the most accurate. This is where the speed comes into play also.

Then of course, you have to consider the weight and size of the servos depending on the particular airplane you are using.

The manufacturers and airplane designers also have the luxury spending the money to test different servos during the design process to find the most economical servo that will do the job.

Some times they even skimp a little too much, that's you will see people upgrade some RTF and BNF to better servos.

Hope this helps...

Click here to add your own comments

Join in and write your own page! It's easy to do. How?
Simply click here to return to RC Airplane Radio