Flight Parameters

Tailrotor Expert provides the following parameters:

Acceleration adjusts the overall acceleration and deceleration for the tail rotor. Powerful tail rotors work best with the default value of 55. For pod-and-boom-type models use a range of values from 35-60. For larger helis or heavy scale helis, use values between 25-40.

P Gain sets the gain for the proportional part of the control loop (direct output to the tail servo, banked).

I Gain sets the heading hold gain for the tail rotor (banked).

I Limit sets the heading hold range for the tail rotor (banked).

I Discharge sets the heading hold discharge time (5=normal mode) for the tail rotor (banked).

Attention If you make changes to these parameters, always change both by the same amount. This gives the best results by experience.

Stop Gain A and B directly influence the stop behavior for both directions. Increase for crisper stops. Values set too high will lead to oscillation at the time of the stop. For weak tail rotors or large scale helis, set this value to zero (banked).

D Gain adds some extra punch to the tail. The range of values is between ...-... (banked).


Tail Optimize provides the following parameters:

Torque Compensation Collective adds tail input when the collective stick is moved, to unload the tail gyro in situations where high changes in torque occur. To fine tune, do vertical climb outs and watch the tail: increase, if the tail does't hold, decrease if the compensation is too high (banked).

Torque Compensation Cyclic adds tail input when the elevator and aileron sticks are moved, to unload the tail gyro in situations where high changes in torque occur. To fine tune, do elevator or aileron flips and watch the tail: if the tail does not hold properly, increase. If the tail over-compensates, decrease (banked).

Zero Collective tells VBar the point of the least torque. Move the collective stick to 0° collective position and select 'Set Zero Collective'.

Side A and B shows optimizer values. The default of 30 is suitable for powerful tail rotors. You may enter these values manually.

Optimizer activates the built-in optimizer feature for the tail rotor. This will improve the stop behaviour of the tail automatically, for both directions (within the laws of physics, depending on blade length, chord, profile, and rpm). Do pirouettes into both directions with hard stops and with controlled stops. Turn off the optimizer once you are content with the result, to prevent it from changing the behaviour all the time. The values will show in Sida A and Side B. Low values indicate a powerful tail, high values indicate a weak tail. The direction with the torque will be different from the direction against the torque, of course.

Setup Parameters

Allows to set the limits and to revers the servo independently from the setup wizard. You can also choose the tail servo type here. Limits at abou 100 indicate a good throw-force-speed ratio. Move the servo link in or out to get closer to 100 if necessary. If the values differ immoderately, move the servo arm one notch arount it's actual center position and try again, to get less different values for the limits. 

Trim will be done by the trim flight feature (you can also do it manually using the trim flight panel). A list of tail servos can be found in the printed manual, in the PDF file of it, or here. If you do not fine your servo type therein, please check the manual for the servo or the web site of the manufacturer.


Warning Always pay attention to the Device- and Setup-Manuals provided with VBar Control, and the safety related topics therein.

Note This App needs only to be installed during setup. It is not necessary for the operation of the model.