Elevon moves in opposite direction when APM changes orient

Hi guys!

I’m a longtime APM:Copter user building up my first flying wing! I’m stuck on a problem that I need some help with.

Currently, when I push pitch forward on my RC control (in Manual of FBWA), the elevons both move down as expected, pushing the plane’s nose down. When I switch into FBWA mode, and I rotate the plane’s nose down, both elevons also move down. I believe this is incorrect, I’d want the elevons to move up above the wing to counter the nose’s rotation.

(I assume orientation is as if you’re sitting in the cockpit, so looking down the nose of the plane).

  • I have a flying wing setup with a APM2.6 board running the latest ArduPlane 3.2.
  • I’m using a FlySky TH9X radio with a D4R-ii receiver in PPM mode.
  • The right elevon is connected to Output CH1
  • The left elevon is connected to Output CH2
  • The motor to CH3.
  • The transmitter has elevon mixing set up, so I can fly in manual mode just fine.

Any ideas guys?

Did you follow these instructions for reversal?
plane.ardupilot.com/wiki/ardupla … evon-mode/
Use reversing in your transmitter to make manual mode work right and then use the arduplane reversal settings for auto mode corrections.

Just FYI, I would use the “new style” mixing in the APM and no mixing in your TX.

After combinatorially searching through all the reversing options I found one that works correctly.

Are you guys suggesting that I use the ELEVON_OUTPUT parameter to generate elevon mixing inside APM and keep my TX unaware of the elevon setup?

Yes. The mixing function is separate from all of the other modes (it works in “manual”) and keeps all of your inputs clean.