Helicopter Model - GRAUPNER MC-20 HoTT Programming Manual

Dual Rate / Expo
Confi gurable 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 Copy / Erase
Suppress codes Suppress models
Base setup model Helicopter type
Ser vo adjustment Stick mode
Control adjust Dual Rate / Expo
Channel 1 cur ve
Switch display
Open this menu option with a tap on the center
key of the right touch pad.
Roll 100%
––– ––– 0%
Pitch ax ––– 100% ––– 0%
Tail rot ––– 100% ––– 0%
DUAL EXPO
SEL 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 fl ight-
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« menu or separately for throttle
and pitch in the »Helicopter mixer« menu, see text
beginning page 176 and 312.
Similar to control travel settings in the »Control
adjust« menu, Dual Rate operates directly on the
respective 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
124 Detail program description - Dual Rate / Expo | Helicopters
to between 0 and 125 % of normal full travel.
Expo, on the other hand, enables fi ner-grained
control of the model for values larger than 0 %
around the center position of the primary control
function (roll, pitch-axis, tail rotor), without forfeiting
full movement at the end-points of joystick 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 characteristics.
SET
Rotary-output servos, now generally commonplace,
offer another application. This is because the actual
control surface movement is not linear: as the
rotational 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-proportionally with increasing joystick 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
coupling functions.
For both Dual Rate and Expo functions, switch
assignment 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
vertical line follows the movement of the respective
joystick, so you can clearly see the dependency of
the curve value on the transmitter control.
Flight phase-dependent Dual Rate and Expo
settings
If fl ight 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
scenario, you can operate the corresponding switch
to switch between fl ight phases.
Basic procedure
1. Switch to the desired fl ight 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 center SET key of the right touch pad. The
corresponding input fi eld is shown highlighted.
4. Use the selection keys of the right touch pad to set
the desired value.
5. Tap the center SET key of the right touch pad to
complete the entry.
6. A simultaneous tap on 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,
assign a switch in the column labeled with the
switch symbol (as described in the section "Assigning
transmitter controls, switches and control switches"
on page 56).
or keys of the