7.2.6 Checking and adjusting the tail rotor
7.2.6.1 Checking / changing the direction of servo rotation for the tail rotor
The direction of servo travel must be checked and changed (if required) before
centre and travel are set.
Move the rudder stick to the left, and observe the response of the tail rotor. Does
the pitch angle of the blades change in the correct direction? Otherwise, reverse
the tail rotor servo as described on page 147.
7.2.6.2 TAIL ROTOR mixer
The TAIL ROTOR mixer of the PROFI TX conceals the function "static tail rotor
compensation", which is also sometimes referred to as REVO-MIX (revolution
mixer). The TAIL ROTOR mixer is always displayed in the Mixer main menu when
you create a model based on the model templates HELImech. or HELIccpm.
When a helicopter transitions from hovering to a climb or descent, the torque which
the tail rotor has to compensate for becomes larger or smaller, with the result that
the model yaws in one direction. Once set up correctly, the TAIL ROTOR mixer
compensates for these torque fluctuations, and prevents the model yawing. It also
eases the task of the gyro system, so that you can set a high sensitivity value and
thereby obtain very good tail rotor stabilisation.
For this, the following parameters are required in the TAIL ROTOR menu:
Offset
To compensate for the torque at 0° collective pitch (main rotor), a small tail rotor
pitch angle (= Offset) is required. The value can be set separately in each flight
phase. This will be necessary if you use different system speeds in the various
flight phases.
In the flight phase AUTOROT (auto-rotation) the Offset parameter can be changed
so that no tail rotor pitch is present at all. This is particularly important if your model
helicopter features a driven tail rotor.