ORIGINAL: Scoubidou
Hello Kevin,
You have already told me that your engine can turn an APC 17x6 at 9000RPM (51mph speed). At 3/4 throttle, your plane would fly at 38.25 mph speed .
From your picture, the rudder deflection seems to be around 40 degres from the center?
If we put those number in servo calc software we have:
Rudder
Average control surface chord (cm) 23
Average control surface length (cm) 36
Optional: Maximum available servo torque (oz-in) 155
Maximum deflection of servo arm from center (degrees) 42
Maximum deflection of control surface from center (degrees) 40
Maximum required torque at maximum airspeed (oz-in) 155
That rudder is so huge that we would need 2 servos in parallele to maintain 45 degres deflection at full speed. Amazing!
I think your servo is not enough strong to maintain its position at 3/4 throttle.[8D]
Scou
Scou,
How are you coming up with the average rudder control surface cord length of 23 cm?
My rudder measures 35 1/2cm tall at the hinge line
18cm at the bottom cord, back of hinge line
10cm at the top cord, back of hinge line
I think that gives me a average cord of around 14cm
Need to remember the rudder area forward of the hinge line is not loading in the same direction as the rear.
What do you think??
Kevin