Here is the basics for the tail weight...
Input:
Rotor offset (meters)
Diameter of Rotor (meters)
Wind speed ( meters/sec)
Tail tip weight (kg)
Length of tail (meters)
Calculations:
Rotor thrust = Diameter of Rotor^2 x windspeed^2/24
Tail moment = Tail tip weight x Length of tail
Rotor moment = Rotor thrust x Rotor offset
Tail mount angle = sin-1(Rotor moment/Tail moment)
To find tail weight at a given tail mount angle:
Tail moment = Rotor moment/ ( sin(angle in degrees)
Tail weight = Tail moment/ Length of tail
Good to go!
Have Fun
Windstuff Ed