Basic Idle Setting - GRAUPNER mx-16 ifs Programming Manual

curve, and therefore reach its full-throttle setting, if you
release full servo travel using the throttle limit control.
That is why the "Lim" input is reserved in the Helicopter
program for the "Throttle limiter" function.
For this reason the right-hand positive value in the
"Travel" column must be large enough to ensure that it
does not limit the full-throttle setting available via the
Ch 1 stick when the control is at its maximum posi-
tion. Usually this means a value in the range +100%
to +125%. The left-hand negative value in the "Travel"
column of the input should be set in such a way that the
throttle is closed completely when the digital Ch 1 trim
is used, so that you can reliably stop the motor. For the
same reason you should leave this value of the throttle
limit slider at +100%, at least for the time being.
This variable "limiting" of throttle travel provides a
convenient means of starting and stopping the motor.
However, it also gives an additional level of safety if, for
example, you have to carry your helicopter to the fl ight
line with the motor running: you simply move the control
to its minimum position, and this prevents any accidental
movement of the Ch 1 stick affecting the throttle servo.
If the carburettor is too far open (or the speed controller
not at "stop") when you switch the transmitter on, you
will hear an audible warning, and the screen displays
the message:
th ro ttle
t o o
h ig h !
Important note:
Setting the "Lim" function input to "empty" does not
switch off the Throttle limit function; it just switches
the limiter to "half-throttle".
Tip:
You can call up the »Servo display« menu to check the
infl uence of the throttle limit slider. Move to this menu by
briefl y pressing the rotary cylinder from the basic trans-
mitter display. Bear in mind that servo output 6 controls
mx
the throttle servo on the -16iFS.

Basic idle setting

Start by turning the throttle limiter – by default the
rotary proportional knob CTRL 7 located at top left of
the transmitter – clockwise to its end-point. Move the
throttle / collective pitch stick to the maximum position,
and ensure that a standard throttle curve is active in the
"Channel 1 throttle" sub-menu of the ...
»heli mixer« (page 78)
... menu. If you have already altered the standard
throttle curve which is present when you fi rst initialise a
model memory, then this should be reset to the values
"Point 1 = -100%", "Point 3 = 0%" and "Point 5 = +100%"
– at least temporarily.
ch1 thro
input 0%
0%
output
point 3 0%
normal
Note:
Since the throttle trim lever has no effect when the throt-
tle limiter is open, its position is not relevant at this point.
Now – without starting the glow motor – adjust the
mechanical linkage of the throttle servo so that the
carburettor barrel is fully open; if necessary, carry out
fi ne-tuning using the travel setting for servo 6 in the
»servo set.« menu.
Now close the throttle limiter completely by turning the
rotary proportional knob CTRL 7 anti-clockwise to its
end-point. Use the trim lever of the throttle / collective
pitch stick to move the trim position marker to the motor
OFF position (see illustration in the centre column of the
next page).
Note:
In contrast, when the throttle limiter is closed, the posi-
tion of the throttle / collective pitch stick is not relevant;
it can therefore be left in the maximum collective pitch
position, i. e. the throttle linkage can be adjusted be-
tween full-throttle (throttle limiter open) and "motor OFF"
(throttle limiter closed) using just the throttle limiter.
Now, with the throttle limiter closed, adjust the mechani-
cal throttle linkage so that the carburettor is just fully
closed. However, do check carefully that the throttle
servo is not stalled at either of its extreme end-points
(full-throttle / motor OFF).
To complete this basic set-up you still have to adjust the
idle trim range to coincide with point "1" of the throttle
curve. This is accomplished by setting point "1" of the
"Ch 1 throttle" mixer in the »heli mixer« menu to a
value of about -65 to -70%:
ch1
input
output
point
To check that the setting is exact, i. e. that there is a
seamless transition from idle trim to the throttle curve,
you need to close the throttle limiter and move the
Program description: transmitter control settings – model helicopter
thro
–100%
– 66%
1 – 66%
63