Thanks for replying. all outputs are + or - 100%. This is a new model. We're using a FrSky X8R receiver. I'm not sure what you mean by binding protocol. We connected the receiver to the PX4 using the SBUS port/protocol.
What we find strange is that all of the prior channels (throttle, rudder, roll/ailerons) work fine (i.e. are detected OK by the QGroundControl calibration) for the calibration steps but when we get to elevator, the "full up" is detected fine but the "full down" isn't.
Any thoughts about how to diagnose this? The QGroundControl calibration seems to be mandatory, but, I don't see anywhere in the software where we can do a manual calibration....
If it matters we're using TAER configuration.