How to Balance an RC Airplane

by the world without servo's | May 9, 2012 | (8) Posted in Tips

Callum. W


All RC planes have a centre of gravity (CG) this is the also known as the balance point. If the plane balances in front of the CG point it is said to be nose heavy, aft of the CG point and it is tail heavy. There is an old saying "a nose heavy plane flies poorly, a tail heavy plane flies once." A tail heavy plane has hyper-sensitive rudder and elevator movements making the plane very hard to control

Instructions

 

Use the ruler to mark the wing where the suggested CG is located. Mark the underside of the wing on a high wing plane and the top of the wing on a low wing plane. The marks should be as close to the fuselage as possible.

Place your fingers on the spots you just marked. Your fingers should be under the wing on a high wing plane. Low wing planes are balanced up-side down so that the bulk of their weight will be below the wing.

Balance planes that have fuel tanks aft of the centre of gravity full of fuel. The plane will become gradually nose heavy as the fuel is burned.

Lift the plane and pay close attention to the nose, if it drops then the plane is nose heavy, if it raises then it is tail heavy. A slightly nose heavy plane will be more stable in the air and easier to fly.

Move equipment like receivers or battery packs forward or aft to try and balance the plane; add weight only as a last resort.

Tips & Warnings

Buy stick on lead weights, they can be cut into ΒΌ ounce sections and have peel and stick adhesive on the back.

Never fly an unbalanced plane, have an experienced RC pilot help you if you can't balance the plane yourself.

 

COMMENTS

jamesamoran on November 30, 2012
What if you dont know where the suggested CG is located. If scratch build sometimes you will know know.
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hardekool on May 18, 2012
Simple explanation to a key factor of flying. If not done correctly it will make or brake a newbie pilot (and plane). Thanks for the info.
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AERODROME on January 6, 2015
easy way to find the balance of any wing - trace one wing half on a stiff piece of cardboard cut out and find the point at which the cardboard balances -- draw a line - measure the line- take 25 percent of that line and mark a X transfer the X to both wings - that is the balance points for good stability -. use up to 33 percent for aerobatic response - tailless flying wings use 15 to 20 percent
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AERODROME on January 6, 2015
additional info - canards are a bit more complex -- the balance point is 55 to 70 percent depending on how large the front wing is--the larger the front wing the more percentage - keep in mind that the center (mac---mean aerodynamic center ) of a wing is also the center of lift -- the balance point is aft of the mac and the nose is heavy but the front wing creates lift and holds the nose up
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How to Balance an RC Airplane