Mounting the APM, config with 9XR and bench testing

APM mounted 270 degrees off Skywalker X5 axis
I installed the APM into my Skywalker X5 a few days ago. There was a little 'faffing' around getting it all to fit the rear bay of the X5, but in the end it seems to fit well. I have it mounted to the airframe on a small plywood board, the APM is stuck to the board using the 'anti-vibration' sticky foam pads.

So this morning I took some time to go through the initial setup of the APM, I found it quite straight forward, although I feel the documentation is still a little 'light on'.

First step was to hook the Rx into the APM. Usually I have throttle on Ch1, elevator Ch2 and Aileron Ch3. However APM needs throttle to be on Ch3 so I had to do a switch around, no big deal but I couldn't find anywhere on the APM Wiki that actually tells the user to do that. Is it common to have throttle on Ch3 and it's just me that is doing it all 'arse about'?

Initial Setup
The latest version of Mission Planner has nice little 'initial setup wizard', once I had my Rx talking to/through the APM I clicked on that button and ran through all 16 steps. I had to calibrate the accelerometer, the compass, the radio, set the flight modes, let it know what extra sensors where installed and more. You'll see a photo of my 9XR and the settings I have for it below, I hope it saves you some time.

The radio calibration proved to be the toughest to get just right ....

Flight Modes
Next I went through and tested the flight modes. For the first test I thought that I'd use manual, stabilise and FBWA modes. If all goes well with them I'll go to mode 'RTL' and then to 'Auto'. Manual mode worked just fine, all inputs were as they have been for the last few weeks. The 'stabilise' mode however was giving me some 'curley' results. The manual inputs (when in this mode) were just fine however the actual stabilisation was completely off ..........