I've installed a Walkera plastic gimbal to my FC40 but having a bit of trouble with the tilt in naza. In Servo Travel Limit, I've set the max and min but not exactly sure what the center setting does? Someone posted this but not exactly sure what he means: On my installation the “Center” setting on the Gimbal screen had no effect. But I was able to set the gimbal’s center position by returning to the calibration screen, recalibrating, and then moving the cursor one unit (or as needed) in the required direction before clicking “Finish” Also, can someone explain what the Automatic Gain Control setting is? My camera does tilt from horizontal to straight down, but it's difficult to gauge any position in between.