GRAUPNER HoTT MC-16 Series Programming Manual Download

Page: 128 / 332

128 Program description - Control adjust | Helicopter models

Input

Output

Point ?

+50%

normal

Thro

Curve off

Note:
Since throttle trim has no effect if the throttle limiter is
open, its position here is meaningless.

Now – without starting the combustion motor – adjust
the throttle servo, preferably mechanically and, if nec-
essary, also by way of the servo 6 travel adjustment
option in the »Servo adjustment« menu, so that the
carburetor is completely open.
Now close the throttle limiter completely by moving
the side proportional slider all the way to its rear limit.
Use the trim lever of the Throttle/Pitch stick to place
the trim position marker into the motor OFF position
or actuate the “Thr. CutOff” option, see page 101.

Note:
In contrast, when the throttle limiter is closed, the
position of the throttle/collective pitch stick is mean-
ingless. It can therefore remain at the maximum col-
lective pitch position so that, when adjusting carbure-
tor linkages, the throttle limiter alone can be used to
switch between full throttle (throttle limiter open) and
“Motor OFF” (throttle limiter closed).

Now, with the throttle limiter closed, adjust the car-
buretor linkages so that the carburetor is (just) com-
pletely closed. Take extreme care to ensure that the
throttle servo does not become mechanically blocked
in either of its end positions (full throttle/motor OFF).
To complete this basic configuration, the idle trim
adjustment range must now be matched against point
“L” on the throttle curve. Do this by setting Point “L” of
the “C1



Throttle” mixer, in the »Helicopter mixer«

menu, to about +15 to +18 %.

+16%

normal

+16%

Input

Output

Point

Thro

Curve off

To configure a smooth transition from the idle trim
to the throttle curve exactly, the collective pitch stick
should be moved to and fro slightly at its minimum
position with the throttle limiter closed and the idle
trim fully open. The throttle servo must not move as
well! Any further adjustments to the throttle curve
must of course be made later in flight.
The engine or motor is always started with the throttle
limiter completely closed; the trim lever of the throttle
/ collective pitch stick trim only affects the idle range,
and the motor engine is stopped using the “cut-off
trim” function of the digital trims; see page 70.

Notes:
• Take advantage of the »Servo display« to ob-

serve the influence of the throttle limit control. The
»Servo display« screen can be reached from al-
most any menu position with a simultaneous tap
on the



selection keys of the left four-way but-

ton, Bear in mind that servo output 6 controls the
throttle servo on the transmitters

mc-16

HoTT

and

mc-20

HoTT!

• A servo connected to output 8 or 12 can be used,

independently of this, for other purposes by means
of mixers, provided that this servo is decoupled
from the operating element specified by input
function “Lim.” via the »Mix only channel« menu;
see page 216. On the

mc-16

HoTT transmitter

this option can be unlocked at extra cost.

• The throttle restriction set by the throttle limiter is

shown as a horizontal bar in the throttle curve di-
agram on the second display page of the “C1



Throttle” option in the »Helicopter mixer« menu
(see page 191). The output signal for the throt-
tle servo cannot be higher than the level set by the
horizontal bar:

+50%

normal

Throttle limiter position

Input

Output

Point

Thro

Curve off

The above diagram shows precisely this scena-
rio: in the above example, the throttle limit control
is set to about +20 % and thus restricts the move-
ment of the throttle servo to about +20 % of full
travel.

Time delay for the throttle limiter

To safely prevent the carburetor from opening too
rapidly, assign the throttle limiter input “Lim.” to a
time delay that takes effect only in the direction of full
throttle. This applies especially if the throttle limiter is
controlled by a switch rather than, as preset, with the
right-side proportional rotary slider.
To set a delay time, push the throttle limit control to
its forward limit or move the switch into its full-throttle
position then use the selection keys of the left or right
four-way button to select the “– time +” column:

In5

– time +

0.0s

Thro

Gyro

Lim.

0.0s

normal

After a brief tap on the center

SET

key of the right

four-way button, the selection keys of the left or right
four-way button can be used to select the desired
time delay, e. g. 5 seconds: