I have an Align 450 Pro v2 FBL that used to connected with a Skookum SK720 tuned to close to perfection with extremely low vibes. Now I removed the SK720 and trying to get the APM 2 to work on it. Finally got all the trims, limits, zero pitch center, servo directions, and the APM auto level correction moving to the correct direction today. I've noticed the tail behave very strangely.
When I do not have the Gyro Enable box checked, the tail seems to try to counter the external movement for a split second and return back to the center. When I use the rudder control, the tail servo hardly ever move.
When I have the Gyro Enable box checked, the rudder control works perfectly. The tail also works like in HH mode. To test it, I held the heli in my hand without the main blade and spin the motor up. When I twist the heli, the tail correct the tail perfectly. I twist it more, the rudder move more to counter the movement until I let it twist back to the original position.
According to the wiki and some other write up, that checkbox suppose to be for external Gyro. I think that info is for the older APM. The APM 2 seems to have the Gyro working internally when I have that box checked.
Now the weird part, while it is in HH and countering the external force, if I move the rudder control from my remote, it doesn't matter which direction, it immediately set the rudder back to the center. I even tested it with the main blade on. At first, when I spin it up, the gyro kicked it to counter the movement. As soon as I touch the rudder control, the rudder servo immediately back to the center and let the heli spin wildly. Quite scary to see. Could anyone give me some hint on what I can do to get the tail working?