The Procedure For Calibrating A Servo; Menu Assignment - Multiplex Royal SX 9 Instructions Manual

The numbers 1 ... 5 below the diagram (X-axis) cor-
respond to the servo calibration points P1 ... P5.
Parameter REV/TRM:
The first parameter REV/TRM has two functions:
a. Servo reverse (REV) alters the direction of rotation
of the servo.
To reverse the servo simply select the parameter
value and press the REV/CLR button:

the curve is "reversed"

the prefix changes
(only if the value for á is not 0%).
b. Servo trim (TRM) shifts all points on the servo curve
in parallel.
Servo trim is used in order to compensate for dis-
crepancies from the correct neutral point of any
one control surface. This may occur, for example,
if you are using servos which do not feature ade-
quate temperature compensation, and are there-
fore subject to fluctuating neutral points.
The set trim value acts as an offset on all calibration
points P1 to P5, and produces a parallel shift of the
curve, although the shape of the curve remains
unchanged. The effect is the same as the standard
trim procedure.
!
Note:
Use TRM only for temporary corrections!
The servo trim TRM should only be used to correct
trim deviations which occur when you are operating
the model, and not when setting up a new model.
In the latter case it is always better to adjust the
mechanical servo linkage.
Parameter P1 ... P5:
You can solve many problems by making adjustments
to the servo calibration points (Parameter P1 ... P5).
In detail these are:
 Establishing the maximum working range of the servo:
The values (servo travels) set at this point are never
exceeded (Protection from mechanical servo stalling,
Limit).
 Setting symmetrical control surface travels.
 Matching the travels of multiple servos to each other:
This prevents individual servos placing other ser-
vos under stress when two (or more) servos are
connected to the same control surface.
 Compensating for mechanical differences in the
control surface linkage:
For example, if the individual control surfaces of a
multi-flap wing do not move exactly synchronously,
you can correct this by adjusting the intermediate
points P2 and P4.
Careful and accurate calibration is particularly impor-
tant with servos to which a mixer has been assigned.
!
Note:
First adjust the mechanical linkage as accurately
as possible, and only then fine-tune the system
using the Calibrate menu.
Servo calibration should only be used for fine-tuning.
Careful and thorough mechanical adjustment is
strongly recommended. Never reduce the maximum
servo travels (P1 and P5) by more than about 10 -
20%, otherwise you will forfeit servo resolution, and
any play in the servo gearbox will be amplified unnec-
essarily.
17.1.2.

The procedure for calibrating a servo

a. Servos controlled by basic functions
(e.g. Aileron, Elevator, Rudder, L. gear, ...):
First check that the servo rotates in the correct di-
rection ("sense") relative to the control movement.
If necessary, change the direction in the Parameter
REV/TRM. If you later reverse the servo, you will
need to re-calibrate it.
b. Servos controlled by mixers
(e.g. AILERON+, DELTA+, V-TAIL+, ...):
In the case of servos to which a mixer has been
assigned, the direction of servo rotation is initially
irrelevant, as the correct direction for the control
surface deflection can be set within the mixer itself.
c. Select a calibration point (P1 to P5) and activate
the value (percentage figure highlighted). Now
press the digi-adjuster allocation button <F>.
The servo (or servos, if multiple servos are con-
trolled by the same function or mixer) automatically
takes up the position corresponding to the per-
centage figure at the selected calibration point.
With one hand you can now easily and con-
veniently measure and check the control surface
deflection (ruler, calliper), while the other hand re-
mains free to change the value using the UP /
DOWN buttons ▲ / ▼ or one of the two 3-D digi-
adjusters.
d. When the deflection is correct, press the digi-adjuster
allocation button <F> again, and the servo (or ser-
vos) takes up the position corresponding to the po-
sition of the associated transmitter control.
The number of servo calibration points (min. 2, max.
5 points) varies according to the selected setting
when you initially assigned the servos ( 17.2.).

Tip: Vertical line for orientation!
The vertical dotted line shows the current position of
the associated transmitter control, and is an aid to ori-
entation. If you activate a value using the digi-adjuster
allocation button <F>, the vertical line jumps to the
corresponding point and remains there until you press
the allocation button again, or move the associated
transmitter control.

Menu Assignment

17.2.
Like the MULTIPLEX radio control series PROFImc
3000 and 4000, the ROYAL SX offers the facility to
define the receiver output sequence without restric-
tion. Compared with radio control systems with a fixed
receiver output sequence, this feature offers the ad-
vantage that, for example, the signal for a second ai-
leron servo (generally present at the higher channels,
e.g. channel 5) can be transferred to any channel you
like, and this can make it possible to use a small four-
channel receiver.
Manual
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