GRAUPNER mx-16 ifs, Programming Manual

Page: 80 / 132

80 Program description: helicopter mixers – model helicopter
ch1
¼
thro (Throttle curve)
3
0%
0%
0%
input
output
point
ch1 thro
normal
Helicopter with glow or electric motor with
STANDARD SPEED CONTROLLER
This display refers only to the control curve of the throttle
servo or speed controller .
The method of setting up a throttle curve for a model
helicopter fi tted with a speed
governor or regulator is
discussed later.
The throttle curve can be defi ned using up to fi ve points,
in a similar way to the collective pitch curve (see previous
page).
In all cases the control curve must be set up in such •
a way that the throttle is fully open, or the speed
controller of an electric helicopter is at full power, at
the end-point of the throttle / collective pitch stick,
(exception: auto-rotation – see page 86).
The hover point is normally located at the centre of
•
the stick travel, and the throttle setting should be
adjusted relative to the collective pitch curve in such
a way that the correct system rotational speed is
obtained at this point.
At the minimum position of the throttle / collective
•
pitch stick the throttle curve should initially be set up
so that the (glow) motor runs at a distinctly higher
speed compared to the idle setting, with the clutch
reliably engaged.
In all fl ight phases the motor (glow or electric) is
started and stopped using the throttle limiter (see
below).
If you are used to a different radio control system which
uses two separate fl ight phases for this – “with idle-up”
and “without idle-up” – please note that the throttle limiter
renders this complication superfl uous, as the increased
system rotational speed below the hover point in the
mx
-
16iFS program is more fl exible, and can be fi ne-tuned
more accurately, than the “idle-up” system used with
earlier
mc
radio control systems.
Ensure that the throttle limiter is closed before you start
the glow motor, i. e. the throttle can only be adjusted
within its idle range using the idle trim. Be sure to read
the safety notes on page 85 which refer to this. If the idle
is set too high when you switch the transmitter on, you
will see and hear a clear warning!
STARLET
#02
5:36h
Stop
Flug
«normal »
K78 IFS
0:00
0:00
9.6 V normal
t h ro t t l e
t o o
h i g h !
The following three diagrams show typical 3-point throttle
curves for different fl ight phases, such as hover, aerobat-
ics and 3-D fl ying.
Typical throttle curves for different fl ight phases:
+100% +100% +100%
-100% -100% -100%
Output Output Output
2 3 4 5 1 2 3 4 5 1 2 3 4 5 1
Control travel Control travel Control travel
Hover Aerobatics 3D
Notes on using the “Throttle limit” function:
We strongly recommend that you make use of the •
throttle limit function (» contr set. « menu, page 62).
When you use this function the throttle servo is com-
pletely disconnected from the throttle / collective pitch
stick when the proportional throttle limit control is at
its left-hand end-point; the motor runs at idle and only
responds to the Ch 1 trim. This feature enables you
to start the motor from within any fl ight phase.
Once the motor is running, turn the throttle limiter
•
slowly to the opposite end-point, so that full control
of the throttle servo is returned to the throttle / col-
lective pitch stick. It is important that the throttle limit-
er should not restrict the throttle servo at its top end-
point; you can avoid this by setting the control travel
to +125% in the “lim” line of the »
contr set. « menu.
Since electric motors by their nature require no idle •
setting, the only important point when setting up an
electric-powered model helicopter is that the adjust-
ment range of the throttle limiter should be set signif-
icantly higher and lower than the adjustment range
of the speed controller, which is usually from -100%
to +100%. It may therefore be necessary to set the
“Travel” value of the throttle limiter to an appropriate
point in the “Lim” line of the »
contr set. « menu. How-
ever, the throttle curve itself has to be fi ne-tuned with
the helicopter in fl ight, just like a glow-powered ma-
chine.
Releasing the full throttle range, and imposing the
•
throttle limiter again, trips the switching threshold of
the control switch “C3” (i. e. in either direction); this
switch can be used for automatically starting and
stopping the stopwatch to record the fl ight time, or
some similar purpose; see page 33.