User manual

70
Digital trim
Digital trim
Functional description and description of C1 cut-off
Digital trim with visible and audible indicators
Both sticks are equipped for digital trimming. When
you give the trim lever a brief push (one „click“),
the neutral position of the associated stick channel
changes by one increment. If you hold the trim lever
in one direction, the trim value changes continuously
in the corresponding direction with increasing speed.
These changes can be made „audible“ by way of dif-
ferent frequency tones. This makes finding the mid-
point during flight easy, without looking at the screen.
When the midpoint is overrun, a brief pause will be
inserted.
Current trim values are automatically stored when a
model memory change is made. Furthermore, digi-
tal trim exercises flight phase specific control within
a memory location (except for throttle/brake flaps
trim) – the socalled „C1“ (channel 1) control function.
These default settings can be altered to “global” in the
»Stick mode« menu, which is available as standard
on the
mc-20 HoTT transmitter only, see pages
114 and 116.
This C1 trim includes yet another special function for
winged aircraft and helicopter models, it allows the
carburetor‘s idle setting to easily be found for a com-
bustion motor.
Since the trim functions described in these instruc-
tions are only effective in the direction „Motor off“,
the presentation in the screen of your transmitter
may only change with respect to individual throttle or
Pitch-min positioning of the C1 stick in the „forward“
or „back“ direction, such as throttle/pitch „left stick“ or
„right stick“.
The illustrations in these instructions are always
based on „Throttle/Pitch right“ for both types of mod-
els and „Throttle back“ for winged aircraft and heli-
copters.
1. Winged models
C1 trimming has a special cut-off trim function intend-
ed especially for combustion motors. This cut-off trim
function is configured as follows: First put the motor
into a safe idle speed.
Now if you push C1 trim in a single motion toward its
„Motor cut-off“ direction until it is in its furthest travel
position then an additional end-position marker will
remain in the display. When the motor is restarted you
can again immediately set the last idle speed with a
single movement in the direction of „more gas“.
stp
flt
Current trim position
M
Trim at motor OFF position
Last idle position
Idle direction
Ch 1 trim lever
This cut-off trim will be deactivated when “None” is
entered on the “Motor at C1” line of the »Model type«
menu, see page 104.
Notice:
Since this trim function is only effective in the “Motor
off” direction, the display illustrated above will change
appropriately if the C1 stick’s control direction for
minimum throttle is changed from “back” to “front” (on
which the above illustration is based) in the “Motor at
C1” line of the “Basic Settings” menu.
2. Helicopter models
In addition to the „Cut-off trim“ function described
below in „Winged aircraft models“, C1 trimming also
has another characteristic which is made possible
by combining it with a so-called „Throttle limit“ func-
tion see page 127. As long as the throttle limit con-
trol – as standard the right-hand proportional rotary
control Lv2 on the right-hand side of the transmit-
ter – remains in the „rear“ half of its travel path, i. e. in
the startup range, C1 trimming acts on the throttle
servo as idle trim and the indication for idle trim is vis-
ible in the screen‘s display:
stop
flt
M
Current trim position
Trim at motor OFF position
Last idle position
Throttle limit control
However, in contrast to winged aircraft models, the
position indicator ( ) will be hidden and any preset
idle position will be deleted when the throttle limit
control is in the „front-side“ half of its travel path.
Stp
Flt
M
Throttle limit control
Notice for helicopters:
C1 trimming affects only the throttle servo, not the
pitch servo. Notice also that the helicopter throttle
servo must be connected to receiver output 6, see
receiver layout on page 75!