RE: Setting up airplane rudder gyro
I would put it near cg. Just wrap it in foam and secure it well. You will be able to control it from your tx so I would use it on a switch with the following settings.
'Switch on' with rate mode set to 70-80% gain. 'Switch off' gain set at 5% to effectively turn off gyro. In case in flight flutter or wagging is observed. Do not use or let tail lock activate. That is asking for trouble.
To others saying loose the gyro etc.. This will not negate the need to use the rudder but will reduce the violent snaps caused by high P-factor. Some models may need this depending on engine, prop, plane, weight ground angle, gear placement, and several other factors. So before you condemn someone for using a gyro be considerate enough to ask questions.
All of my models are tail draggers and one of them is completely unmanageable on the ground. The scale location of the gear is not a good setup for the model. But I want it to be scale. After a gyro was installed it is a dream to takeoff and land. It requires as much corrective input as my large warbirds even with a gyro but it is much more manageable than before.