Operation Manual

Manual
51
Coll.(pitch)+, Coll.(pitch)-, Offset, Zero point
13.6.3. Basic Offset value
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 set different
system rotational speeds in the various flight phases.
In the flight phase AUTOROT (Auto-rotation) the
Offset 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.
13.6.4. Collective pitch to tail (Revo-Mix)
The Collective pitch Æ tail rotor mixers are set using
the parameters Coll.+ / Coll.-, separately for climb
and descent, and for each flight phase:
Coll.+ Æ correction for climb
Coll.- Æ correction for descent
The exact values can only be established through a
programme of flight testing, as they vary according to
many parameters.
13.6.5. Mixer Zero point
The Zero point is where you set the starting point for
the static tail rotor compensation mixer. The collective
pitch Æ tail rotor mixer takes effect from this collective
pitch angle in the direction of “climb”, using the value
set under Coll.+. In the other direction (descent) the
value set under Coll.- takes effect.
Procedure:
a. Move the collective pitch stick to the position equa-
ting to 0° collective (use a rotor blade gauge if avai-
lable). Note: you should first set up the collective pitch
curve completely.
b. The Collective pitch value (Collect. / last line)
cannot be changed, as it simply shows the current
position of the collective pitch stick, and serves as
an aid when setting-up. This value is set in the
Zero point parameter.
13.6.6. Differential yaw (rudder) travel
The purpose of the Yaw (rudder) differential para-
meter (Rudd.Diff.) is to reduce the tail rotor travel in
one direction. This is necessary if the model behaves
differently when yawing (yaw commands) to left and
right (angular velocity). Since the tail rotor has to
counteract the torque generated by the main rotor,
“Yaw” is usually weaker when the model is required to
turn against the direction of the main rotor.
A separate value can be set for each flight phase.
13.7. Gyro
In the Gyro mixer the optimum gain (sensitivity) can
be set separately for each flight phase.
The Gyro menu is a dynamic menu: if the current
model does not feature a servo which is assigned to
Gyro, this function is not offered in the menu
£Mixer.
The default setting for gyro type in the model tem-
plates HELImech and HELIccpm is Heading. Gyro
gain is controlled using Slider E, and gyro suppression
is OFF (no reduction in gyro effect when yaw com-
mands are given). Servo 6 is assigned to Gyro.
Press button G to open the main menu £Mixer, then
select and open the Gyro menu:
This means that everything is already prepared for
use of a gyro in Heading mode, with gyro gain variable
via slider E.
The following table shows the basic types and charac-
teristics of commonly used gyro systems.
Heading gyro
(heading-lock gyro)
Damping gyro
(normal gyro)
The gyro brakes the rotational
movement of the model
around the axis to be stabi-
lised, and also returns the
model to its original position.
Heading or Damping can be
selected as operating modes
via the gyro gain adjustment
system.
The gyro brakes the rotational
movement of the model around
the axis to be stabilised.
Gain adjustment is variable
within the range
-100% ... +100%:
max.
Damping effect
+100%
-100%
max.
Heading effect
0% (Control)
Gain adjustment is variable
within the range
+0% ... +100%
100% (max
.
0% (OFF)
50%
!
If you set a value of 0° in line 2 of the menu, the
screen displays “Control”, and you can then vary the
gain using the transmitter control which is assigned to
the gyro (default setting: Slider E).