User manual

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Program description - Dual Rate / Expo | Helicopter models
Dual Rate / Expo
Configurable control characteristics for roll, pitch-axis and tail rotor
This option is available as standard on
both transmitter types.
Use the selection keys of the left or right
four-way button to scroll to the »Dual
Rate / Expo« menu option in the Multi-function menu:
Servo adjustment
Stick mode.
Channel 1 curve
Switch display
Control adjust.
Dual Rate / Expo
Open this menu option with a tap on the center SET
key of the right four-way button:
100%
100%
100%
Roll
Nick
Tail
DUAL
–––
–––
–––
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.
It is possible to set up an individual curve for control
function 1 (throttle / collective pitch) using a maximum
of six separately programmable points. This is carried
out in the »Channel 1 curve« menu, which is avail-
able on the
mc-16 HoTT and the mc-20 HoTT
transmitter as standard; see the section starting on
page 141. It can also be set up for throttle and col-
lective pitch separately in the »Helicopter mixer”
menu, which is available on both transmitters; see the
sections starting on pages 188 and 322.
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
center 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
coup ling 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 set-
tings
If flight phases are set up in the »Phase settings«,
page 156, and »Phase assignment« menus, page
158, 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 flight phases.
Basic procedure
1. Switch to the desired flight phase then use the
 selection keys of the left or right four-way but-
ton to select the desired line: “Roll”, “Pitch ax” or
“Tail rot”.
2. Use the  selection keys of the left or right four-
way button to select the right column or the as-yet
invisible column for Expo values, see page 31.
3. Tap the center SET key of the right four-way but-
ton. The corresponding input field is shown high-
lighted.
4. Use the selection keys of the right four-way button
to set the desired value.
5. Tap the center SET key of the right four-way but-
ton to complete the entry.
6. A simultaneous tap on the  or  keys of
the right four-way button (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 “Physical
control, switch and control switch assignments” on
page 68):
mc
 
16 20