For each flight mode setting, there will be different
Revo-mixing amounts. For forward flight the settings
will be lower than hovering due to the aerodynamic
forces effecting the helicopter. Here is a starting point
for revo values:
Tail Rotor Setup
Pilot
Problem: Not enough
pitch in tail rotor to
match torque setting of
engine.
Action: Increase pitch
by shortening the
rudder pushrod.
1
Nose rotates
left at hover.
Pilot
2
Nose rotates
right at hover.
Problem: Too much
pitch in tail rotor to
match torque setting of
engine.
Action: Decrease pitch
by lengthening the
rudder pushrod.
What separates airplane radio equipment from the
helicopter version is in the control of the individual
curves discussed earlier and in the Revo-mixing.
Take a moment to consider the helicopter
hovering
in front of you.
Once the tail rudder pushrod is adjusted
correctly so the tail does not rotate ( don't consider
wind now ) the revolution mixing can be adjusted.
Revolution Mixing
The revolution mixing function allows the helicopter
to climb or descend without the tail rotating. There is
a high & low setting on the helicopter radio.
The values shown will vary depending on engine,
blade pitch and fuel but provide a starting point for
the beginner.
These values correspond to the total travel for the tail
rotor pitch. To adjust the high setting, hold the
helicopter at hover and increase the throttle so the
helicopter climbs steadily. Notice the direction the
nose rotates:
High Stick Setting: 40
Low Stick Setting: 20
Normal Flight
Mode
left
increase revo value to
increase tail pitch.
right
decrease revo value to
decrease tail pitch.
Nose rotates
High
&
Low
To adjust the low setting, start from a high hover and
decrease the throttle to descend, notice which direc-
tion the helicopter rotates.
40
Gyro Gain Adjustment
The gyro assists in holding the tail rotor, actually
compensating for changes in wind direction or quick
movements.
First check that the gyro is installed correctly
by watching the rudder servo. While holding the
rotor head move the rudder stick to the right and
observe the direction the servo arm moves. Now
quickly rotate the nose to the left, the servo horn
should move in the same direction. If the rudder
servo horn moves in the opposite direction reverse the
gyro direction.
Generally the starting setting for the gyro gain is
60%, keep increasing the gain setting until the tail
starts oscillating back and forth, then reduce the
setting slightly.
Problem: Tail rotor makes sudden uncontrolled
rotations.
Solution: The gyro direction is possibly set in the
wrong direction.
