GRAUPNER MC-22S

64
Program description: Transmitter controls
Dual Rate / Expo
Control characteristics for aileron, elevator and rudder
A i l e r o n 1 0 0 % 0 %
E l e v a t o r 1 0 0 % 0 %
R u d d e r 1 0 0 % 0 %
D U A L E X P 0
S E LS E L
t
The Dual Rate function provides a means of swit-
ching to reduced control travels for aileron, elevator
and rudder (control functions 2 ... 4) in fl ight via an ex-
ternal switch; the D/R values can be set separately for
different fl ight phases. A separate menu (»Channel 1
curve«) is provided for setting up a curve for control
function 1 (throttle / brake). This curve can feature up
to fi ve separately programmable points.
The control travels for each switch position can be set
to any point within the range 0 to 125%, separately
for each direction. Dual Rate works in a similar way to
servo travel adjustment in the »Servo adjustment«
menu, but the Dual Rate function does not affect
the servo directly; instead it affects the correspon-
ding stick function, regardless of whether that func-
tion controls a single servo or multiple servos via any
number of complex mixer and coupling functions.
The exponential control characteristic works in a dif-
ferent way. If you set a value greater than 0%, expo-
nential provides fi ne control of the model around the
centre position of the primary control functions (aile-
ron, elevator and rudder), without forfeiting full travel
at the end-points of the stick arc. If you set a value lo-
wer than 0%, travel is increased around the neutral
position, and diminishes towards the extremes of tra-
vel. The degree of “progression” can be set within the
range -100% to +100%; 0% equates to normal, linear
control characteristics.
A further application for exponential is to improve the
linearity of rotary-output servos, which are the stan-
dard nowadays. The movement of the control surface
is inevitably non-linear with a rotary servo, as the li-
near movement of the output disc or lever diminishes
progressively as the angular movement increases,
i.e. the rate of travel of the control surface is reduced
steadily towards the extremes, dependent upon the
position of the linkage point on the output disc or le-
ver. You can compensate for this effect by setting an
Expo value greater than 0%, with the result that the
angular travel of the output device increases dispro-
portionately as stick travel increases.
Like Dual Rates, the Expo setting applies directly to
the corresponding stick function, regardless of whe-
ther that function controls a single servo or multiple
servos via any number of complex mixer and coupling
functions. The Expo function can also be programmed
asymmetrically, can be switched on and off in fl ight if
a switch is assigned to it, and can also be program-
med separately for different fl ight phases.
Since switches can be assigned to the Dual Rate and
Expo functions with complete freedom, it is also pos-
sible to operate several functions using one and the
same switch. The result of this is that Dual Rates and
Expo can be controlled simultaneously using a sing-
le switch, and this can be advantageous – especially
with very high-speed models.
The graphic screen displays the curve characteristics
directly. When you select the appropriate menu line,
the central vertical line follows the movement of the
stick concerned, so that you can easily observe how
the curve value changes relative to movement of the
transmitter control.
Different Dual Rate and Expo settings in fl ight
phases:
If you wish to try out different fl ight phases in the
»Phase setting« and »Phase assignment« menus,
the assigned fl ight phase name – e.g. «Normal» – is
displayed at bottom left of the screen. Operate the ap-
propriate switch to move between fl ight phases.
Dual Rate function
If you wish to switch between two possible D/R set-
tings, select the
fi eld and assign an external
switch ...
A i l e r o n 1 0 0 % 0 %
E l e v a t o r 1 0 0 % 0 %
R u d d e r 1 0 0 % 0 %
D U A L E X P O
S E L
S E L
M o v e t h e d e s i r e d s w i t c h
t o O N p o s i t i o n
( e x t . s w i t c h : E N T E R )
t
... or one of the control switches G1 ... G4 (or one of
the inverted control switches G1i ... G4i), as descri-
bed in the section entitled “Assigning external and
control switches” on page 30.
If you use one of the “G” switches, the stick position it-
self acts as the switch (see page 27). In this case it is
essential (!) to move to the »Control switch« menu
and assign the control switch to the stick you wish
to use. The switch you have assigned appears in the
screen display together with a switch symbol which
indicates the direction of operation when you move
the switch.
Select the SEL fi eld to change the Dual Rate value,
and use the rotary control in the inverse video fi eld to
set the values for each of the two switch positions se-
parately, e.g. in the “normal” fl ight phase:
A i l e r o n 2 1 2 5 % 0 %
E l e v a t o r 1 0 0 % 0 %
R u d d e r 1 0 0 % 0 %
« N o r m a l » D U A L E X P O
S E LS E L
t
The Dual Rate curve is shown simultaneously in the
graph
(CLEAR = 100%).