ORIGINAL: Clancy Arnold
I used your calculation method and substituted the numbers for my CL Scale Taube:
Weight 10Lb 2 Oz. (10.1), Speed 37 MPH (7.5 Sec laps on 65 Ft lines.)
Answer was 14 .24 Lbs line pull. When flying the Taube it does not feel like there is even that much pull on the lines.
The calculation is for the force that is required to keep an object flying at a constant radius. If the object is
a rock, all the force must be supplied by 'pulling' on the object with the line(s).
If the object is a powered aircraft, then some of the force can be supplied by aerodynamic forces produced
by the aircraft itself - lift of the various surfaces and thrust can be used to supply some of that force. Even the
drag of the lines is trying to pull the model into the circle, so that is another bit of force that actually helps the
pilot and is therefore not felt by him. Calculations probably can't be easily done but small variations in the
surfaces can. It should be possible to trim the roll and yaw to supply ALL of the force, such that you feel
no pull at the handle, but you would have to be ready to run when some gust suddenly flings the model into the circle.