User manual

101Program description - Base setup models | Helicopter models
flight-phase switches.
Corresponding parameter settings for …
• pitch servos
• throttle servo
• tail rotor servo
• swashplate rotation, if available
• gyro setting
… are made in the »Helicopter mixer« menu,
page 188.
Cut off
Within the framework of autorotation settings for the
mc-16 HoTT and mc-20 HoTT transmitter’s heli-
copter program, there are parameters for an emer-
gency “cut off” of the throttle servo or motor actuator,
refer to the programming proposal on page 323.
However, this option is not available if an idle position
is specified in the “Throttle position AR” line of the
»Helicopter mixer« menu instead of an (emergency)
OFF position; for example, to avoid restarting the mo-
tor after every landing during autorotation practice.
This option can be used on the
mc-16 HoTT and
mc-20 HoTT transmitters as an emergency OFF
function as well as an alternative “cut-off trim”, see
“digital trims” on page 70.
Depending on the “forw./rear” choice made for the
“Pitch min” line of the »Helicopter type« menu, this
“cut off” option can be coupled to a switch for thrott-
ling down a speed controller or a carburetor servo to
the motor OFF (or idle) position.
This cut-off (or idle) position is specified in the left
column’s field, above the SEL column label, and its
value is to be established through trial and error.
However, the speed controller or throttle servo only
moves to the selected position when two conditions
are fulfilled: a switch is operated, and a particular ser-
vo position or switching threshold is exceeded. This is
done by setting the desired servo position (threshold
value) into the middle column field, directly over the
column label STO, then selecting the appropriate ON/
OFF switch function in the right column.
• If the percentage value specified for the middle
column is greater than the current servo posi-
tion, i. e. the current servo position lies below the
threshold, the switchover will occur as soon as the
switch is put into its ON position.
• If the percentage value specified for the middle
column is less than the current servo position, i. e.
the current servo position is above the threshold,
the speed controller will initially reduce motor
speed or close the carburetor’s throttle servo only
to the extent dictated by the value in the left col-
umn as soon as the servo’s position once under-
runs the threshold (max. +150 %) after the switch
is changed over to its ON position.
The speed controller or throttle servo will remain in
this cut-off position only until the selected switch is
again changed over followed by a one-time throttle
servo or speed controller movement beyond the
preset threshold with the throttle/brake stick con-
trol.
The factory setting for the left column is -100 % for
the throttle servo “cut-off” position and a threshold of
+150 % servo position setting in the middle column:
Base setup model
DSC Output PPM10
Autorotation
–––
Auto.C1 Pos.
–66%
9
cut off
SEL
–––
+150%
STO
–100%
Programming procedure
To change the throttle servo’s preset “cut-off” posi-
tion, tap on the center SET key of the right four-way
button. The current setting will be displayed in inverse
video. Now use the selection keys of the left or right
four-way button to set a value at which the motor is
reliably “off”. If a combustion motor is involved, be
sure the throttle servo does not perform mechanical
runout, e. g. -125 %:
Base setup model
DSC Output PPM10
Autorotation
–––
Auto.C1 Pos.
–66%
9
cut off
SEL
–––
+150%
STO
–125%
The – upper – preset value in the middle column
ensures the motor can be stopped, throughout the
maximum possible positioning range of the servo or
speed controller, alone by the switch to be assigned
in the right column.
However, if you prefer to set a lower switching thresh-
old, i. e. the point below which the throttle servo or
speed controller moves to the motor OFF position
when the switch is closed, then use the throttle / col-
lective pitch stick and – if in use – the throttle limiter
(by default the right-hand side-mounted proportional
rotary control) to move the throttle servo to your pre-
ferred position, and then press the central SET button
of the right-hand four-way button:
Base setup model
DSC Output PPM10
Autorotation
–––
Auto.C1 Pos.
–66%
9
cut off
SEL
–––
+100%
STO
–125%
Finally, use the column at the right to specify a switch
with which you can cut off the motor directly (emer-
gency) or which will be activated by the threshold.