GRAUPNER mc-32

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Program description - Dual Rate / Expo | Helicopter models
Dual Rate / Expo
Configurable control characteristics for roll, pitch-axis, tail rotor
Use the selection keys of the left or right touch pad to
scroll to the »Dual Rate / Expo« menu option in the
Multi-function menu:
Model select
Servo adjustment
Stick mode
Control adjust
Dual Rate / Expo
Channel 1 curve
Switch display
Copy / Erase
Suppress codes
Suppress models
Base setup model
Helicopter type
Open this menu option with a tap on the centre SET
key of the right touch pad.
0%
0%
0%
Roll
Pitch ax
Tail rot
DUAL
––––––
–––
SEL
–––
–––
–––
100%
100%
100%
EXPO
SEL
The Dual Rate / Expo function permits switching or
controlling of control travels and characteristics for the
control functions roll, pitch-axis, tail rotor, i. e. control
functions 2 … 4; it is switch-driven and flight-phase
independent.
An individual curve characteristic for control
function 1 (motor/collective pitch), featuring
up to 8 separately programmable points, can
be set either in the »Channel 1 curve« (see page
143) menu or separately for throttle and pitch in the
»Helicopter mixer« menu, see text beginning page
190 and 333.
Similar to control travel settings in the »Control ad-
just« menu, Dual Rate operates directly on the re-
spective control function, independent of whether it is
an individual servo or multiple servos connected via
complex mixer and coupling functions.
The control travel for each switch position can be set
to between 0 and 125 % of normal full travel.
Expo, on the other hand, enables finer-grained con-
trol of the model for values larger than 0 % around the
centre position of the primary control function (roll,
pitch-axis, tail rotor), without forfeiting full movement
at the end-points of stick travel. For values less than
0 %, the reverse is true: control increases around
the neutral position and diminishes towards the end-
points. The degree of "progression" can therefore be
set within a total range of -100 % to +100 %, where
0 % equates to the normal, linear control characteris-
tics.
Rotary-output servos, now generally commonplace,
offer another application. This is because the actual
control surface movement is not linear: as the rota-
tional angle of the output disc or lever increases, the
control surface rate of travel over the control linkage
continually decreases – depending on the position of
the linkage point on the output disc. This effect can be
counteracted with Expo values greater than 0 % such
that rotational angle travel increases over-proportion-
ally with increasing stick throw.
The Expo setting also affects the relevant control
function directly, whether this controls a single servo
or multiple servos – via any number of mixer and cou-
pling functions.
For both Dual Rate and Expo functions, switch as-
signment can be set up in any way desired, which
therefore permits the triggering of multiple functions
using one and the same switch. This, in turn, offers
the opportunity to link the triggering of Dual Rate and
Expo functions to a single switch: this offers many
advantages – particularly for very high-speed models.
The graphic screen displays the curve characteristics
directly. Once you select a menu line, the dotted verti-
cal line follows the movement of the respective stick,
so you can clearly see the dependency of the curve
value on the transmitter control.
Flight phase-dependent Dual Rate and Expo
settings
If flight phases are set up in the »Phase settings«
and »Phase assignment« menus and each assigned
a name,e. g. "Normal", the name in question will be
displayed at the bottom left of the display. In this sce-
nario, you can operate the corresponding switch to
switch between flight phases.
Basic procedure
1. Switch to the desired flight phase then use the
 selection keys of the left or right touch pad
to select the desired line: "Roll", "Pitch ax" or
"Tail rot".
2. Use the  selection keys of the left or right
touch pad to change into the column labeled
"EXPO".
3. Tap the centre SET key of the right touch pad. The
corresponding input field is shown highlighted.
4. Use the selection keys of the right touch pad to set
the desired value.
5. Tap the centre SET key of the right touch pad to
complete the entry.
6. A simultaneous tap on the  or  keys of the
right touch pad (CLEAR) will any setting made
back to its respective default value.
Dual Rate function
If a switchover between two variants is desired, as-
sign a switch in the column labeled with the
switch symbol (as described in the section "Assigning
transmitter controls, switches and control switches"
on page 60).