Well, using the throttle channel I get around 25-30 degrees travel, I mixed with rudder to get almost 90 degrees, but it now returns to the Halfway point instead of either up or down.

Looking at the screen on th tx, throttle only gives an output of 0-100, but rudder outputs between -100 & 100, which explains the extra swing... so if I can work out how to multiply the output it should be better... I'll report back