Model menu
Trim Mix 1 and 2
F X - 4 0
increments) corresponds to a duration of nine seconds. The
default setting is always ‘0’. When you mark one of the
fields ‘there’ or ‘back’, the button fields for the arrows
appear at the right margin.
The servo speed mode can also be defined in the centre
field: the two options are linear and symmetrical modes.
Linear mode is used for controlling the throttle servo and for
switches; this mode is not self-neutralising. The alternative
(symmetrical) mode is self-neutralising, and is therefore the
default setting for all control surfaces.
This screen shot shows the results of programming an
exponential mixer curve for the ‘Butterfly’ option.
• Assigning a trim compensation mixer
Deploying a Butterfly braking system generally causes a
nose-up or nose-down pitch trim change, i.e. a lateral axis
trim correction is required. In the final sub-menu you can
select a suitable elevator travel to compensate for the
unwanted pitch change. The mixer rates and the curve can
be set up and adjusted using the method which should be
familiar by now.
The same technique is also employed for adjusting the tran-
sit speed of the elevator servos.
Finally, please note that the programming options and the
actual appearance of the screen display may vary slightly
according to the model type and wing type you have selected.
18.12 TRIM MIX 1 AND 2
This menu is
used to set up
mixers which
apply to all the
wing control
surfaces and
the elevators,
separately for
particular flight
phases. The
software of the
FX-40 provides
two flight phase
mixers (Trim Mix
1 and 2), but
both mixers are
programmed in
exactly the same way, so this Section only describes the set-
up procedure for the first mixer.
A typical application would be for a model glider, with Trim Mix
1 set up to provide the optimum control surface settings for
the winch launch phase of the flight. These settings would
lower the ailerons and the flaps in order to give the model
maximum possible lift on the winch line. To ensure a stable
pitch attitude on tow, the mixer includes an option for entering
an elevator Offset to provide pitch trim compensation (i.e.
around the lateral axis).
In our example the second mixer (Trim Mix 2) might be used to
set up the optimum control surface settings for the speed
phase of the flight, with ailerons and flaps raised slightly in
order to minimise the aircraft’s drag.
These options are designed to ensure that reliable, reproduci-
ble control surface travels can be recalled again and again
when you select these flight phases. The settings can be cal-
led up using any switch you like.
An Offset can be entered for each of the wing control surfaces
- up to four ailerons and four flaps - in order to fine-tune the
individual wing flap neutral positions. You can also assign one
of the auxiliary transmitter controls for fine-tuning the system.
This allows you to set up a pre-set position for all the control
surfaces prior to fine-tuning in flight. As with all mixers, you
can select ‘Glob’ or ‘Sepa’ mode as desired.
You can also define a trigger switch which activates the set-
tings for the flight phase. At the same time you can determine
whether the function is triggered by a switch (manual mode) or
by a transmitter stick (automatic mode). Naturally, your prefer-
red stick can be selected individually.
It is possible to set the required transit speed individually for
the aileron servos, flap servos and elevator servos, with sepa-
rate settings for the ‘there’ and ‘back’ directions. If you wish,
you can program a delay time for this mixer function, so that
the transition is smooth rather than abrupt.
Start by marking the desired option ‘Trim Mix 1’ or ‘Trim Mix 2’
in the Model menu. The screen display for the ‘Trim Mix 1’
option now looks like this:
75
Tip aileron
(AIL3)
Main
aileron
(AIL)
Spoiler
(FLAP)
Spoiler
(FLAP2)
Brake flaps
(BRFL & BRFL2)
Main
aileron
(AIL2)
Tip
aileron
(AIL3)
V-tail
Ailvator
ELE
ELE
ELE2
ELE2
