GRAUPNER mx-16 ifs, Programming Manual

Page: 62 / 132

62 Program description: transmitter control settings – model helicopter
Meaning and application of “throttle limit”
I8
+
100% 100%
88% 111%
SYM
+ +
+ +
+ +
ASY
lim
SEL
100% 100%
gyr
t r v
e m p t y
c t r l 6
c t r l 7
As mentioned previously under “Throttle”, the power
output of the engine or motor of a model helicopter is
not controlled directly using the throttle (Ch 1) stick – in
contrast to fi xed-wing model aircraft. Instead it is control-
led indirectly by the throttle curve settings which you set
up in the »
heli mixer « menu. Alternatively the throttle
is controlled by the speed controller if the unit you are
using is a governor or regulator.
Note:
Naturally it is possible to set up different throttle curves
to suit different stages of fl ight using fl ight phase pro-
gramming.
However, this certainly means that a helicopter’s motor
never gets anywhere near its idle speed during “normal”
fl ying, so it is impossible to start or stop the motor easily
unless some other means is used. This applies whether
a speed governor or a conventional throttle control
system is in use.
The “Throttle limiter” function solves this problem in an
elegant manner: a separate transmitter control – as
standard this is the rotary proportional control CTRL 7
at top left of the transmitter – is employed to limit the
setting of the throttle servo or the speed controller to any
speed you like, which means that you can throttle right
back to the idle position for starting the motor. In the
other case, the throttle servo can only follow the throttle
Throttle limit function
“Lim” input
“Throttle”
+
100% 100%
88% 111%
100% 100%
SYM
3
+ +
+ +
+ +
ASY SEL
I5
thr
gyr
t r v
e m p t y
c t r l 6
In principle all transmitter controls (rotary proportional
knob, INC / DEC buttons) and switches present on the
transmitter can be assigned to the individual inputs
within the Helicopter program.
However, please note that some inputs available in the
“Transmitter control settings” menu are already pre-de-
fi ned for helicopter-specifi c functions, and for this reason
cannot be used without restriction.
For example, the receiver sequence printed on page 41
shows that the throttle servo (or the speed controller of
an electric-powered model helicopter) must be con-
nected to receiver output “6”, i. e. control channel “6” is
reserved for motor speed control.
However, in contrast to a fi xed-wing aircraft, the throttle
servo or speed controller is not directly controlled by the
throttle stick or any other transmitter control, but via a
complex mixer system – see »
heli mixer « menu, start-
ing on page 78. The “throttle limit function” (described
on the next page) also has an infl uence on this mixer
system.
Assigning a transmitter control or switch in the “Throt-
tle” line, or its supplementary control signal, would only
unnecessarily “confuse” this complex mixer system.
For this reason the “Throttle” input MUST always
be left “empty” when you are programming a model
helicopter.
„Gyro“
+
100% 100%
88% 111%
100% 100%
SYM
3
+ +
+ +
+ +
ASY SEL
I5
thr
gyr
t r v
e m p t y
c t r l 6
If the gyro you are using features infi nitely variable gain
control, then you can pre-set the static gyro effect by
setting an “offset” within the range ±125%, separately for
each fl ight phase, in the “Gyro” line of the »
heli mixer «
menu – see the section starting on page 78.
Once you have entered these pre-defi ned – static – gain
settings (if need be set separately for each fl ight phase
in the »
heli mixer « menu), you can use a transmitter
control such as one of the two INC / DEC buttons (CTRL
5 or 6) to vary gyro gain around the set “offset point”;
all you have to do is assign that transmitter control in
the “Gyro” line of this menu: in the centre position of
the transmitter control this corresponds to the setting
selected in the »
heli mixer « menu (see page 78). If
the transmitter control is moved from this centre point
in the direction of full travel, gyro gain is increased;
towards the opposite end-point it is reduced. This is
a fast, simple method of fi ne-tuning gyro gain when
the model is in fl ight – perhaps to suit varying weather
conditions – or alternatively to fi nd the optimum setting.
In software terms you can also limit the gain range to
both sides by restricting the transmitter control travel.
However, please be sure to read the set-up notes
provided with your gyro before carrying out these
adjustments, as you could render your helicopter
uncontrollable if you make a mistake.