Graupner Hendheld RC 2.4 GHz No. of channels: 8 33116 Data Sheet

Product codes
33116
Page of 200
104 Program description: Dual Rate / Expo – model helicopter
D/R Expo
Switchable control characteristics for roll, pitch-axis and tail rotor
100%
100%
100%
0%
0%
0%
DUAL EXPO
–––
–––
–––
roll
nick
tail
The Dual Rate / Expo function provides a means of 
switching to reduced control travels, and influencing the 
travel characteristics, for the roll, pitch-axis and tail rotor 
servos (control functions 2 … 4).
A separate curve for control function 1 (motor / collective 
pitch) can be set individually for throttle, collective pitch 
and tail rotor in the “
Helicopter mixers” menu. These 
curves feature up to five separately programmable 
points; see the sections starting on page 114 and 189.
Dual Rate works in a similar way to transmitter control 
travel adjustment in the “
Transmitter control settings” 
menu, i. e. it affects the corresponding stick function, re-
gardless of whether that function controls a single servo 
or multiple servos via any number of complex mixer and 
coupling functions.
For each switch position the servo travels can be set to 
any value within the range 0 to 125% of full travel.
Expo works in a different way. If you set a value greater 
than 0%, exponential provides fine control of the model 
around the centre position of the primary control func-
tions (roll, pitch-axis and tail rotor), without forfeiting full 
travel at the end-points of stick movement. If you set 
a value lower than 0%, travel is increased around the 
neutral position, and diminishes towards the extremes of 
travel. The degree of “progression” can be set within the 
range -100% to +100%, where 0% equates to normal, 
linear control characteristics.
Another application for exponential is to improve the 
linearity of rotary-output servos, which are the standard 
nowadays. With a rotary servo the movement of the 
control surface is inevitably non-linear, as the linear 
movement of the output disc or lever diminishes pro-
gressively as the angular movement increases, i. e. the 
rate of travel of the control surface declines steadily 
towards the extremes, dependent upon the position of 
the linkage point on the output disc or lever. 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 disproportionately as stick 
travel increases.
Like Dual Rates, the Expo setting applies directly to the 
corresponding stick function, regardless of whether that 
function controls a single servo or multiple servos via 
any number of complex mixer and coupling functions.
The Dual Rate and Expo functions can also be switched 
on and off together if you assign a switch to the func-
tion. The result of this is that Dual Rates and Expo can 
be controlled simultaneously using a single switch, and 
this can be advantageous - especially with high-speed 
models.
Flight phase dependent Dual-Rate and Expo set-
tings
If you have assigned a switch and - if you wish - a more 
appropriate name to one of the phases 2, 3 or Auto-ro-
tation in the “
Base settings” menu (see page 87), then 
this appears at bottom left, e. g. “normal”. If necessary, 
operate the associated switch in order to switch between 
the flight phases.
The basic set-up procedure
Switch to the desired flight phase, and then select 
1. 
the desired line “Roll”, “Nick” or “Tail” using the arrow 
buttons  of the left or right-hand touch-key.
If necessary, use the 
2. 

 buttons of the left or right-
hand touch key to select the desired column.
Briefly press the central 
3. 
SET
 button of the right-hand 
touch-key: the corresponding input field is now high-
lighted (black background).
Set the desired value using the arrow buttons of the 
4. 
right-hand touch-key.
Touch the central 
5. 
SET
 button of the right-hand touch-
key to conclude the input process.
Simultaneously press the 
6. 

 or  buttons of the 
right-hand touch key (
CLEAR) to reset any changed 
settings to the default values.
Dual Rate function
If you wish to switch between two possible D/R settings, 
use the  button of the left or right-hand touch-key to 
move to the right-hand column, marked at the bottom 
edge of the screen with the switch symbol 
, briefly 
touch the central 
SET
 button … 
100%
0%
roll
DUAL EXPO
–––
push  desired  switch
into  position  ON
… and assign a physical switch as described in the sec-
tion “Assigning switches and control switches” on page 
57. The assigned switch appears on the screen together 
with a switch symbol which indicates the direction of 
operation of the switch.
Select the left-hand column, marked DUAL at the bottom