whale2

Regarding necessary torque for control surfaces - here are some approximations: http://www.mnbigbirds.com/Servo%20Torque%20Caculator.htm

Combined flaps and ailerons do exists (flaperons) but AN-140 does not utilize them :) And on take-off elevator usually produces negative lift force to raise nose wheel and increase wing angle of attack. Using of separated elevator for banking is not effective as force arm is much less then arm of ailerons.

Flaps increase lift for cost of increasing drag, most important thing that they are lowering stall speed making possible to take off at slower speeds and do landing approach at slower speed. Elevator works as a single surface, there is no need to separate it into left and right. Ailerons movement is mirrored, either mechanically or electronically, so it uses only one receiver channel. Otherwise you will have to have very unusual handling on controller - two sticks for two ailerons. Are you talking about telemetry? If not, generic RC receiver only provides outputs and not require any input.

Roughly speaking lift force is directed perpendicular to wing surface, while gravity force is directed always straight to the ground. When aircraft is banked, vertical projection of lift force is lower. It's very easy to imagine if plane is rolled by 90 degrees - no lift force at all. High roll angle accompanied by lack of airspeed could lead to stall. Like here from 2:20 -- It depends on current airspeed, control surface area and angle of attack. To get some approximations you can play with some numbers here: http://www.grc.nasa....lane/foil3.html Flaps indeed should not deploy very fast, but ailerons, rudder and elevator should be controlled in real time. I think almost every production servo will do, as no exceptional characteristics are required, only make it flyable. You will also need good brushless motors and speed controllers. Comparably weighed models have 1-2 KW of power. 6 channel receiver/transmitter is a minimum - you have to control ailerons rudder elevator flaps landing gear engine RPM Also, if controlling each aileron with own motor, some synchronization should be implemented, so when stick is in the middle, both ailerons are aligned with wing surfaces. Youtube link not displaying properly. Try this: http://goo.gl/6Cl97 (From 2:20)

No, this type of things should be given more attention. Roll bit too far and you will stall. I was talking about servos used in RC model aircraft like this: http://www.hobbyking.com/hobbyking/store/__9549__Turnigy_TG9e_9g_1_5kg_0_10sec_Eco_Micro_Servo.html I can think of two option for controlling an aircraft - use production non-Lego servos or re-implement such a servo using micro-motor, some potentiometer installed on control surface shaft and control board from production servo. Nevertheless, how are you going to control the plane?

Sure it is smallest. I just trying to say that gearing it down will make very large lag between control input and aircraft response. It will take more than 3 seconds to move aileron from 45 degrees up to 45 degrees down. So if plane is banking right and you move a stick to left, the plane will respond in 3 seconds or more. This makes the plane very hard, if ever possible, to control.

My two cents - micro-motors are very slow. Being geared down to 1:8 it will be very-very slow. Typical servo used in RC models are 2-3 times faster (80-90 RPM vs 35 RPM) and have ten times more torque. I believe torque, developed by micro-motor could be considered enough for mild and slow flight, but response time when using geared down micro-motor will be very big so it will be very hard to control aircraft. Also RC servos have feedback circuit with potentiometer on output shaft (and microprocessor, one task of which is to keep requested angle on control surface), which, in turn, leads to question - how are you going to control the aircraft if it is supposed to lift off the ground?