Custom tail-sitter VTOL servo outputs and control

Hi, I’m currently trying to build a custom tail-sitter VTOL with retractable wings. The VTOL has 2 coaxial motors mounted in a duct for thrust.
I’m using the PixHawk 4 mini FC. I want to know how to alter what the servo outputs can do? I’m using mission planner, and I see that there are outputs for Ailerons, Rudders, etc. but I would like to get a servo to control the extending and retracting of the wings.
I would also like the “roll” of the vehicle to be controlled by the motor speeds (similar to a conventional quad-copter) while the aircraft is vertical, but in fixed wing mode I am planning on controlling it with a small weight controlled by a servo which will change the aircraft’s center of gravity. Is there a way to see how the aircraft is controlled, i.e. what components get powered fer certain inputs?

Post photos and a drawing of the layout you have in mind for this, that would be extremely helpful!


First make some quick numbers on the inertia of body & propellers, to
check that your roll control is possible (looks more like yaw btw).
Then check the Pixahawk 4 board manual for the wiring.

For retractables (landing gear…) you can use any aux servo.

DUAV.pdf (200.0 KB)

Hi guys, I’ve attached a drawing with a sketch of the wings over it. I can use the landing gear function in the servo output tabs to control the wings (A), but what function should I use to control the 2 ailerons at the bottom of the aircraft? If I use elevator and rudder they don’t seem to respond as they should. I also am having issues with the motors, as if I select both motors as ‘throttle’ I cant get yaw control to work, and if I use motor1 and motor2 they don’t respond at all

If it doesnt match any existing airframe, you may have to create it