Elevon_Output Help

Hi Guy’s I just got my APM, and I’m getting ready to set it up. My setup will be on a Zephyr2 wing. For Elevon_Output mode, the instructions say to setup the TX as a standard plane. A standard setup would be ailerons, elevator, rudder and throttle. Is that rudder channel, that my Multiplex Evo 9 will be outputting going to cause any problems?



No, the rudder channel shouldn’t cause you problems, it should have nothing hooked up to it. Here’s a wiring diagram to show you how it’s done:

Note that the yaw controls on the wingtips are optional and most people don’t make them.

Hope this helps!

Rick Burd

Thanks Rick.

I’ve never seen a yaw control system like that on a wing, very clever.

The flaperon setup on your Spectrum is interesting. I know that the mixing is going on in the APM, but don’t you need two aileron outputs from the rx when using a flaperon mix?

I’ll try and set up my TX like yours, and try out a flaperon mix.

Traditionally speaking, flapperons are control surfaces that combine the functionality of flaps and ailerons and therefore are only used on conventional airframes. That said, the “Elevon Mixing” diagram I posted above has a flap-function built into it located on the blue box titled “FUNCTION LIST / FLAP SYSTEM” that gets setup on the Spectrum DX8 transmitter. This moves the control surfaces upward (instead of downward like traditional flaps) in order to provide extra lift at slower speeds while coming in for a landing but this is not something you need to setup yourself, it is optional.

On flying wings the flaps (or what we could call: elevon-flapperons) are located aft the center of gravity (CG) so they move in the opposite direction of conventional flaps that are always on or forward the CG (where they are counter-acted by the tailplane) but flying wings often don’t have a flap button or ‘switch’ because they are the exact same control surfaces as the elevons and the whole thing is controlled by an avionics computer. because of how the Arduplane software calculates landing trajectories, it is often necessary (depending on the airframe being used) to manually trigger (or use a python script to activate) the “flaps” that I built into the Spectrum DX8 transmitter as shown on the Elevon Mixing diagram; all this does is input more up-elevator on the elevons when the drone is landing so the drone can land at slower speeds than it otherwise would using the arduplane software.

Hope this helps!

Rick Burd

Alright, I assigned ailerons to ch1, elevator to ch2, throttle to ch3 and a 3 position switch to ch5. Everything seems to be working correctly with aileron_output. I turned the gain up to 1, but the elevator throws seem to be lacking.

Are you sure the problem is not mechanical? It’s hare to know what’s going on without any photos…a video of your servo movements would be ideal.