Wrong axis being stabilized

I’m putting together an X8 with a pixhawk 2 using a FRSky radio and I’m running into a unique issue. I have the manual controls all setup right so the proper control surfaces move, but when I go to FBWA the wrong axis is getting stabilized. Example, I roll the bird and I get both elevens deflecting up or down like it’s stabilizing the pitch axis. I did the accelerometer calibration correctly and the flight ball moves correctly so I’m completely stumped. Any help would be greatly appreciated.

Try going through the steps in this guide carefully:
http://ardupilot.org/plane/docs/guide-elevon-plane.html

Yep I’ve gone through it several times.

Are you saying that:

  1. The manual inputs control the surfaces correctly for pitch/roll,
  2. The sensor directions, as seen by the pitch and roll of the HUD’s artificial horizon when you pitch/roll the vehicle, are correct, and
  3. When in FBWA mode, the surfaces move incorrectly? (ie that rolling the vehicle causes a pitch response on the surfaces, and vice-versa.)

This shouldn’t be possible. (Which you may already know.)

If you haven’t found the problem, could you upload logs and video demonstrating the problem? It would be great to have a short video demonstrating all 3 of the above, and the corresponding dataflash log and tlog. (Note that you’ll probably need to arm the plane to begin logging, and might want to disable arming checks to do the test/video indoors)