:bigplane: I found a picture of a so called "Indoor Racer"

:wub: I think it needs more power. I wish I had a video of this one in flight.

http://2.bp.blogspot.com/_6n6m2YCvlTg/SWN4...acer-796162.jpg

:dontknow: Does something like that really fly??

Be very wary of bloggers... <_<

R is the root chord
T is the tip chord
S is the sweep, measured at the leading edge.

The initial balance point is a distance D measured back from the leading edge of the wing at the centerline of the aircraft. This is a safe place to balance a monoplane RC model for a first test flight of an original design. Of course, if the model is a kit or plans-based airplane, use the balance point recommended by the designer.

Here is the equation for D, using an asterisk to indicate multiplication:

D = ((R*R + R*T + T*T)/(6*(R+T))) + (S*(R + 2*T)/(3*(R+T)))

I find it easier to do the calculation in three steps:

Q = (R*R + R*T + T*T)/(6*(R+T))
P = (R+2*T)/(3*(R+T))
D = Q + S*P

For wings with no leading-edge sweep, S = 0. This means that you don’t have to calculate P because it gets multiplied by zero and doesn’t matter. So Q is your answer. For all flying wings, multiply D by 0.9.

Working out where the initial balance point is becomes a mere matter of plugging in the numbers that you get measuring the wing into the formulas.

Here are some worked-out examples:

Rectangular Wing:
R = 6, T = 6, S = 0
Q = (36 + 36 + 36)/(6 * (6 + 6)) = 108/72 = 1.5
If R, T, and S are in inches, then this wing would be balanced 1.5 inches behind the leading edge. If R, T, and S are in centimeters, then this wing would be balanced 1.5 centimeters behind the leading edge. The formula will work with any units of length, so long as the units are the same for the three measurements.

But the bottom line is
If you can't balance it, It won't fly.

Let's see---

Engine bigger than plane! :yickes:

NO! :no:

Maybe they balanced it with that BIG muffler. :D