13.5. Checking / Adjusting The Main Rotor; Calibrating Servos = Setting The Centre And Maximum Travels - Multiplex Royal SX 9 Instructions Manual

13.5. Checking / adjusting the main rotor

!
Always secure the model before you adjust servo
direction, centre and travels, to avoid any danger or
damage if the model responds unexpectedly.
13.5.1. Checking / changing the direction of rota-
tion of the rotor head servos
It is important to check the direction of rotation of the
servos (and reverse them if necessary) before making
adjustments to the centre position and travel.
!
Electric helicopters: disconnect the motor!
Set the coll. pitch stick approximately to centre.
Then switch the receiving system ON.
!
Start with the collective pitch function!
If the swashplate responds correctly when you move
the collective pitch stick, and the rotor head servos
are connected correctly (HEAD f/b, ri, le), the directions
of travel for roll and pitch must also be correct.
Checking:
Move the collective pitch stick in the direction of
maximum pitch (climb): the swashplate should now
move up the rotor mast, but remain exactly horizontal.
This is the procedure for altering the direction of
rotation:
a. Open the main menu ¤Servo
(press button K).
b. Open the Calibration menu (Calibrate) and se-
lect Servo.
c. Select line á and open Parameter:
¤Calibr.HEAD f/b
¨Exit
0
á
Now you can reverse the direction of servo rotation
using the REV/CLR button. The effect of the change is
immediately visible in the graph (the curve reverses),
and can also be observed on the model.

Tip:
If you move the collective pitch stick slightly from
the neutral position before pressing the REV/CLR
button, the servo will jump to the new position
when you reverse it. This is an easy way to check
that you have selected the "right" servo.
d. When the direction of rotation is correct, press the
3-D digi-adjuster or the ENTER button to confirm
your choice, then quit the menu via Exit, and se-
lect the next servo you wish to adjust.
!
Note: please don't start adjusting servo travels
until the directions of rotation are correct!
Please don't start adjusting servo travels and centre
positions until you have corrected the direction of rota-
tion for all the servos. If you subsequently reverse the
servo, you will need to carry out the calibration pro-
cess all over again.
13.5.2. Calibrating servos
= setting the centre and maximum travels
In the menu ¤Servo.Calibrate ( 11.7.) you can
adjust the travels (P1 and P5), the centre positions
(P3) and the intermediate points (P2 and P4) for all
servos in such a way that the servos take up the cor-
rect idle position, move evenly across their range of
travel, and reach the appropriate end-points.
!
If you wish your models to fly accurately, precise
servo calibration is a fundamental requirement!
!
The travel you set at this point cannot be ex-
ceeded (travel limit).
!
Always set the largest travel which the servo will
be required to carry out.
Example: when the ailerons are raised for glide path
control, the ailerons deflect up by 20 mm. For
AILERON control only 12 mm deflection is required. If
the ailerons are used as camber-changing flaps, the
required travel is just 3 mm. At the calibration stage
point P1 (and P5) must be adjusted so that the aileron
travel is 20 mm.
This is the procedure for adjusting servo centre:
a. Open the main menu ¤Servo
(press button K).
b. Open the Calibration menu (Calibrate), and se-
lect the servo.
c. Select the line P3 and open Parameter:
¤Calibr.HEAD f/b
¨Exit
0
á
P1 -100%
P2 ---
P3
0
P4 ---
P5 100%
!
Note: first carry out a hardware "calibration"!
Now press button F. This generates the "true" cen-
tre, without the influence of the trim or mixer inputs on
the servo.
If the servo is not in the desired centre position at this
stage, it is essential to correct the control surface po-
sition mechanically (by re-positioning the output arm
on the servo, or otherwise adjusting the linkage).
Wherever possible, the fine-tuning for Point 3 of servo
calibration should not exceed ±15%.
d. "Allocating" Centre using button F:
Now press button F. This passes the Centre value, 0%,
to all servos with the same basic function (or mixed func-
tion).
This enables you to set the centre for the current servo
regardless of the stick position.
Important: moving the stick, or pressing button F
again, erases the allocation!
Manual
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