Table of Contents
Advertisement
full tail rotor deflection, the effective gyro gain is as
follows:
"current control position
minus
gyro suppression value".
This means that at 0 % gyro suppression, gyro
gain is constant for tail rotor stick movement; at
50 % suppression, gyro gain is reduced to half
if the assigned transmitter control is moved to
the +50 % position (as shown here); and only at
>150 % suppression is gain reduced to zero with
the slider at this position, well before full tail rotor
deflection.
Exemple:
+50 %
left
centre
Stick deflection tail rotor
•
Linear gyro suppression with reduced control trav-
el, e. g. -50 % to +80 % of full travel.
Gyro gain is infinitely variable within these trans-
mitter control limits. Here too, for purposes of il-
lustration, we plot gyro gain values in relation to
tail rotor deflection for various parameter values of
gyro suppression.
196 Program description - Helicopter mixer
Exemple:
+80 %
Adjusting the gyro sensor
To achieve the maximum possible level of stabilization
for the helicopter with the gyro along the vertical axis,
observe the following:
•
The controls should have as little friction and "play"
as possible.
•
There should be no "spring" in the control linkage.
•
Use a strong and comparably fast servo.
When the gyro sensor detects a model rotation,
the faster its response – a corresponding corrective
change to tail rotor thrust – takes effect, the further the
right
gyro gain adjuster can be moved without causing the
tail of the model to start oscillating, and the better the
model's stability about its vertical axis. If the response
is slower, there is a risk that the model's tail will start
to oscillate even at low gyro gain settings. Here, fur-
ther reductions to gyro gain will need to be made to
eliminate the oscillation.
If the model is flying forward at high speed or hov-
ering in a powerful headwind, the net result of the
stabilizing effect of the vertical fin combined with the
gyro may also lead to an overreaction that once again
manifests itself through tail oscillation. To achieve
optimum gyro stabilization under all conditions, you
can make use of the option to adjust gyro gain from
the transmitter using a transmitter control assigned to
left
centre
right
Stick deflection tail rotor
input "7", in connection with gyro suppression and/or
the two settings on the Gyro NEJ-120 BB.
Further notes on gyros with configurable multilevel
gyro gain (e. g. NEJ-120 BB)
Since you cannot specify the gyro gain from the
transmitter proportionally via the transmitter control,
the gyro's own control 1 must be used to set the
(weaker) gyro gain (e. g. for aerobatics) and control 2
the stronger gyro gain (e. g. for hovered flight). Even
though a proportional control is used for control func-
tion 7, only a switch-over between these two values
takes place and the setting is therefore not propor-
tional.
You should therefore advance control 2 to the point
where the model is on the brink of oscillating when
hovering in calm conditions, and advance control 1 to
the point where the model does not oscillate with its
tail even when flying at maximum speed into a strong
headwind. Depending on the state of the weather
and the flight program planned, you can also switch
over the gyro gain from the transmitter – also with
gyro suppression dependent on tail rotor deflection if
required.
Gyro gain
Important notice:
The value of this option is identical to the offset
value set in the "Gyro" line of the »Control adjust«
menu, page 126. For this reason, any changes
made always affect the other menu directly – and
vice versa.
Most of the latest gyro systems not only feature infi-
nitely variable proportional gyro gain setting, but also
offer a choice of two separate types of gain mode on
the transmitter.
If the gyro in use has at least one of these features
then this alternative offset setting provides an op-
portunity to preset both "normal" gyro gain as well
(Gyro Offset)
Advertisement
Table of Contents
