User's Manual

167
Programming example: model helicopter
and assign a fl ight phase switch for fl ight phase 2, which
is already assigned the name “Hover”, but this simple
programming example deliberately excludes such refi ne-
ments.
You have now completed the basic settings at the
transmitter, i. e. the procedure which you will need to use
time and again when setting up a new model. The actual
helicopter-specifi c set-up is carried out primarily in the …
“Heli mixers” menu (pages 94 … 105).
ch1
ch1
ptch
thro
tail
normal
gyro
0%
inp8 0%
In the very fi rst line you will see the “Collective pitch”
function, and a brief press on the central
SET button of
the right-hand touch-key takes you to the appropriate
sub-menu. At this point you will see a graphic represen-
tation of the collective pitch curve. This is initially defi ned
by only three reference points, and in most cases this is
quite adequate.
Tip:
Always try to manage with these three reference points
initially, as additional points just complicate matters,
and extra complexity is just what you don’t need at the
moment.
The reference point for hovering should generally be the
mechanical centre-point of the collective pitch stick, as
this position feels completely natural to most pilots. You
can, of course, set up the curve to locate the hover at a
different point, but you should not be tempted to do this
unless you know exactly what you are doing. Start by
setting the collective pitch stick to centre. Assuming that
you previously adjusted the servos in accordance with
the manufacturer’s instructions, the servo output arms
will now (usually) be at right-angles to the servo case.
If you have not already done so, adjust the mechani-
cal linkages to the rotor head so that all the blades are
set to a collective pitch angle of 4° to 5° positive for the
hover. All known helicopters will fl y at this setting.
Now push the collective pitch stick fully forward to the
maximum collective pitch point (the full-length vertical
line indicates the current position of the stick). Adjust
Point 5 on the collective pitch curve using the arrow but-
tons of the right-hand touch-key, with the aim of obtain-
ing a maximum collective pitch setting of around 9° at
the main rotor blades. This point should be at a value of
around +50%.
Note:
A rotor blade set-up gauge, e. g. the Graupner item,
Order No. 61, is very useful when setting up blade pitch
angles, as you can read off the angles directly.
Now pull the collective pitch stick right back to the
collective pitch minimum position. Set the blade pitch
angle for Point 1 to 0 to -4°, depending on your piloting
ability. This produces a graph line with a slight angle at
the hover point, forming what is known as the collective
pitch curve. It might look approximately like this:
input
output
point
5
–100%
–80%
–80%
ptch
normal
If you now switch to the auto-rotation phase - you will
see the name of the fl ight phase “Autorot” at bottom left
on the screen - the “old” collective pitch curve will re-ap-
pear. In this phase you should set the same values as in
the normal phase, with the following exception: increase
the pitch angle at Point 5 (collective pitch maximum) by
about 2°. This gives slightly more pitch for fl aring the
model when practising “autos” at a later (!) date.
Once you have set up the collective pitch curve, oper-
ate the auto-rotation switch again, then briefl y touch the
central
ESC button of the left-hand touch-key to return
to the helicopter mixer menu select point. Now we move
on to the “Ch1 ¼ thro” line, where you can set up the
throttle curve.
The fi rst step here is to enter the idle trim range by
adjusting the throttle curve. Move the collective pitch
stick to the minimum position, and set Point 1 to a value
of around -65%.
input
output
point
5
–100%
–65%
–65%
c1
normal
thro
With the throttle limiter closed and the idle trim fully
open, pull the collective pitch stick to the “fully back”
position and move it slightly to and fro: the throttle servo
should not respond to this movement. This arrangement
gives you a seamless transition from idle trim to the
throttle curve. You will probably need to make further ad-
justments to the throttle curve, but this process must be
carried out later as part of the fl ight-testing procedure.
If you now switch temporarily from this graph to the