GRAUPNER mx-24s Programming Manual Download

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exactly in the centre of the stick travel. Roughly at the
mid-point of the collective pitch stick the model should
lift off the ground and hover at the rotational speed
you wish to use. If this is not the case, correct the set-
ting as follows:

1. The model does not lift off until the collective

pitch stick is above the centre point.

a) Rotational speed too low

Remedy: increase the va-
lue for the throttle ser-
vo parameter at the centre
point of the stick travel in
the “

Channel 1

throttle

”

mixer.

Important:
Please persevere with this adjustment procedure un-
til the model hovers at the correct rotational speed at
the centre point of the throttle / collective pitch stick.
All the other model settings depend upon the correct
setting of this parameter!

The standard set-up

The remainder of the standard adjustment procedure
is completed on the basis of the fundamental set-up
which you have just carried out, i. e. we assume that
the model hovers in normal fl ight at the centre point
of the throttle / collective pitch stick with the correct
rotational speed. This means that your model helicop-
ter is capable of hovering and also fl ying circuits in all
phases whilst maintaining a

constant

system rotatio-

nal speed.

The climb setting

The combination of throttle hover setting, collective
pitch setting for the hover and the maximum collective
pitch setting (“Coll. pitch high”) now provides you with
a simple method of achieving constant system rotatio-
nal speed from the hover right to maximum climb.

Start by placing the model in an extended vertical
climb, holding the collective pitch stick at its end-point:
motor speed should not alter compared with the ho-
ver setting.

If motor speed falls off in the climb, when the throttle
is already fully open and no further power increase is
possible (this assumes that the motor is correctly ad-
justed), then you should reduce maximum blade pitch
angle at full defl ection of the collective pitch stick, i. e.
in the “collective pitch high” position. Conversely, if
motor speed rises during the vertical climb, you need
to increase the pitch angle. This is effected by selec-
ting the point “H” (high) and changing the reference
point value using the rotary control.

OUTPUT

–

Control travel

Hover point

b) Rotational speed too high

Remedy: increase the bla-
de pitch value for collecti-
ve pitch at the stick centre
setting; this is carried out
in the “

Collective pitch cur-

” menu.

2. The model lifts off below the centre point

a) Rotational speed too high

Remedy: reduce the thrott-
le opening in the “

Channel

throttle

” mixer at the

stick centre point.

b) Rotational speed too low

Remedy: reduce the bla-
de pitch value for collecti-
ve pitch at the stick centre
setting; this is carried out
in the “

Collective pitch cur-

” menu.

OUTPUT

–

Control travel

Hover point

OUTPUT

–

Control travel

Hover point

OUTPUT

–

Control travel

Hover point

130

Program description:

Mixers

The basic set-up procedure

Although the

-24s transmitter provides a broad

range of adjustment for the collective pitch curve and
throttle curve, it is essential that you fi rst adjust all the
mechanical linkages in the model in accordance with
the information supplied by the helicopter manufactu-
rer, i. e. all the system linkages should already be ap-
proximately correct in mechanical terms. If you are
not sure of this, an experienced helicopter pilot will be
glad to help you with this basic set-up.

The throttle linkage must be adjusted in such a way
that the throttle is just at the “fully open” position at
the full-throttle setting. When the throttle limiter is at
the idle setting, the C1 trim lever should just be able
to close the throttle completely, without the servo stri-
king its mechanical end-stop.

Take your time, and carry out these adjustments very
carefully by correcting the mechanical linkages and /
or changing the linkage point on the servo output arm
or the throttle lever. Only when you are confi dent that
all is well should you start optimising and fi ne-tuning
the throttle servo using the transmitter’s electronic fa-
cilities.

With the basic set-up completed, the motor should be
started in accordance with the operating instructions
supplied with it. Adjust the idle setting using the trim
lever of the throttle / collective pitch stick. The idle po-
sition which you set is indicated in the transmitter’s
basic screen display by a horizontal bar at the display
of the C1 trim lever’s position. Refer to page 34 of this
manual for a full explanation of the digital trims.

Caution:
Read all you can about motors and helicopters,
so that you are aware of the inherent dangers
and the cautionary measures required before you
attempt to start the motor for the fi rst time!

The following procedure assumes that you wish to set
up your helicopter “normally”, i. e. with the hover point