GRAUPNER mx-16 ifs, Programming Manual

Page: 90 / 132

90 Program description: free mixers
Mixer Effect
N.N.*
¼
2 Servo pair 2 + 5 responds with aileron
function
N.N.*
¼
5 Servo pair 2 + 5 responds with fl ap
function
N.N.*
¼
6 Servo pair 6 + 7 responds with fl ap
function
N.N.*
¼
7 Servo pair 6 + 7 responds with aileron
function
Model helicopters: •
Depending on the type of helicopter, up to four ser-
vos may be employed for collective pitch control;
these will be connected to receiver outputs 1, 2, 3
and 5. The
mx
-16iFS software links them together to
provide the functions collective pitch, roll and pitch-
axis.
It is
not advisable to mix one of the transmitter con-
trols into these occupied channels using the free mix-
ers available outside the »
heli mixer « menu, as you
may inadvertently generate some extremely complex
and unwanted inter-actions. One of the few excep-
tions to this rule is “Collective pitch trim via a sepa-
rate transmitter control”; see example 2 on page 93.
Important note:
When dealing with the inter-action of multiple mixers
on one control channel, it is essential to remember that
the mixed travels of the individual mixers are cumulative
when multiple stick commands are made simultaneous-
ly, and there is then a danger that the servo concerned
may strike its mechanical end-stops. If you encounter
this problem, simply reduce the servo travel in the
» servo set. « menu, and / or reduce the mixer values.
Mixer ratios and mixer neutral point
Now that we have explained the wide-ranging nature of
the mixer functions, we can move on to the method of
programming linear and non-linear mixer curves.
For each of the three available mixers the mixer curves
are programmed on a second page of the screen
display. Select the number of the mixer you wish to
adjust, and move to the
symbol at bottom right of
the screen using the rotary cylinder. A brief press on the
rotary cylinder or
ENTER now takes you to the graphic
page.
Setting up linear mixer values
In the next section we will describe a typical practical
application, by defi ning a linear mixer curve intended to
solve the following problem:
We have a powered model with two fl ap servos connect-
ed to receiver outputs 6
and 7, which were programmed
as “… 2fl ” in the “Aileron / Flap” line of the » base sett. «
menu. These control surfaces are to be employed as
landing fl aps, i. e. when the associated transmitter
control is operated, they defl ect down only. However, this
fl ap movement requires an elevator trim correction to
counteract the resultant pitch trim change.
In the »
contr set. « menu, assign the rotary proportional
control CTRL 7 to input 6. The control assigned to input
6 now controls the two servos connected to receiver
outputs 6 and 7 in the standard way, operating as simple
wing fl aps.
“Typ(e)” column (including the trim)
If you wish, and if you are using one of the primary con-
trol functions 1 … 4 (sticks), you can set the trim value
of the digital trim lever to affect the mixer input. Use the
rotary cylinder to select “tr” in the highlighted fi eld for the
mixer you are programming.
The effect of the
Ch 1 trim lever on the mixer output var-
ies according to the function which has been assigned
to it in the »
base sett. « menu (pages 46 and 50) in the
“motor on C1” column for fi xed-wing models.
Additional special features of free mixers
If you set up a mixer whose input is the same as its
output, e. g. “c1
¼
c1”, exotic results can be obtained
in conjunction with the option of switching a free mixer
on and off. You will fi nd one typical example of this on
pages 102 … 104.
Before we come to setting mixer ratios, we have to
consider what happens if a mixer input is allowed to act
on the pre-set coupling of aileron servos, fl ap servos or
collective pitch servos:
Fixed-wing models: •
Depending on the number of wing servos set in the
“Aileron / Flap” line of the »
base sett. « menu, receiv-
er outputs 2 and 5 are reserved for the aileron ser-
vos, and outputs 6 and 7 for the two fl ap servos, as
special mixers are assigned to these functions.
If mixer outputs are programmed to this type of cou-
pled function, you have to consider their effect on the
associated pair of wing fl aps, according to the con-
trol channel:
* N.N. = Nomen Nominandum (name to be stated)