Everything About Throttle - Multiplex COCKPIX SX Manuel D'utilisation

A brief press on the 3-D digi-adjustor opens the
parameter; you can now set the desired value.
A further brief press stops the value flashing.
You can now move to another point on the collec-
tive pitch curve using the 3-D digi-adjustor, or
leave this menu via EXIT.
The advantage of this procedure:
We assume that your model's motor is already
running, and you wish to increase the blade set-
ting for collective pitch maximum. In this case you
can select point 5 on the collective pitch curve
without having to move the collective pitch stick to
the maximum position.

16.6. Everything about throttle

The diagram below shows how throttle is affected by
the throttle limiter, the throttle curve and the collective
pitch stick. Section 16.6.1. explains these terms in de-
tail.
Throttle curve for helicopters
Throttle
Zone not reachable
(blocked by throttle limit)
P2
P1
Real throttle curve
Fig. 16.6.1.
16.6.1. The meaning of Limiter, Curve, Minimum,
Trim, DTC and Throttle Cut
... Throttle Limiter (THR-LIMIT)
The throttle limiter limits the maximum possible throttle
value. For normal flying the limiter is left at maximum.
This means that any throttle value dictated by the col-
lective pitch stick in accordance with the throttle curve
arrives at the throttle channel.
Once the motor has been started, the throttle limiter is
moved slowly to increase the speed of the main rotor
"manually".
... Throttle Curve
The throttle curve of the C
and determines how much throttle is assigned to the
individual settings of the collective pitch stick.
The aim is constant rotor speed, i.e. the greater the
collective pitch, the higher the throttle setting.
Programmed
throttle curve
P5
P4
P3
Collective stick
THR-LIMIT
SX has five points,
OCKPIT
Operating Instructions
... Throttle Minimum and Throttle Trim (idle)
THRMIN (Throttle Minimum) is used to set the motor's
idle speed.
If you set the throttle limiter to minimum, you can adjust
the idle characteristics of a glow motor using the trim to
suit the operating situation (ambient temperature, hu-
midity). The trim button adjacent to the stick is used for
this. The stick is the one which you have selected (via
STICK MODE) for controlling COLLECTIVE PITCH.
... DTC ?
DTC stands for Direct Throttle Control. If DTC is
switched on (SNAP/DTC switch in the ON position), the
throttle channel can be controlled directly using the
right-hand slider on the transmitter; this works indepen-
dently of the collective pitch stick.
DTC is useful for starting a glow motor and for adjust-
ing the carburettor.
... Throttle Cut (THR-CUT = Emergency motor OFF)
If you hold this button pressed in, the throttle channel is
held in the position which you have preset with the
travel adjustment for servo 5. This enables you to "cut"
a glow motor by setting this value to "carburettor fully
closed" ( Fig. 16.6.2.).
!
Caution - electric helicopters: you must remem-
ber that the throttle channel immediately returns to the
last used throttle value when you release the THR-CUT
button. This could cause the main rotor to start spin-
ning again.
16.6.2. Setting up the throttle servo for a glow
motor
First set the direction of rotation for the throttle servo in
the SERVO REV menu, then set the end-points (carbu-
rettor closed / full-throttle) in the SERVO TRAVEL
menu.
This is the procedure:
a. Direction of rotation
Move the DTC switch to ON (direct throttle) and
set the right-hand slider to centre. The throttle
servo is now at half-throttle.
Now press the TH-CUT button (Throttle Cut =
emergency motor off). The carburettor should now
close (motor stopped).
If this is not the case, you must reverse the direc-
tion of rotation for servo 5.
(Brief instructions, servo reversing
b. Motor OFF
Hold the TH-CUT button pressed in, and set the
travel for servo 5 in the SERVO TRAVEL menu so
that the carburettor is fully closed, but the servo is
not mechanically obstructed (stalled).
b. Full throttle
Move the right-hand slider to the full-throttle posi-
tion. Set the travel for servo 5 in the SERVO
TRAVEL menu so that the carburettor is fully
open, without the servo being mechanically ob-
structed (stalled).
Page 65
16.4.1.)