Installing The Radio Control System - GRAUPNER Starlet 50 Instruction Manual

Starlet 50

2. Installing the radio control system

(bag UM-9)
2.1 Mounting the servos
Attach brass linkage balls to the inside of the pitch-axis servo arm (1), and the output arms of
the roll servos (2) + (3), using M2 x 10 screws, and secure them with M2 nuts on the outside.
Apply thread-lock fluid between screw and ball and also in the nut. The distance from the servo
output shaft axis to the ball centre should be about 18 mm. The first servo to be installed is the
pitch-axis servo, which should be placed in the servo aperture in the right-hand side frame from
the inside, with the output shaft at the top. Secure it with four screws, rubber grommets and
tubular metal spacers (these parts supplied with the servos). Note that the tubular spacers
should be fitted in the rubber grommets from the underside, and the screws fitted from the top.
The servo mounting holes in the mechanics are intentionally offset slightly towards the outside;
this places the rubber grommets under slight tension when the screws are fitted, and this in turn
improves overall control precision.
Install the roll servos in the right and left side frames from the outside, with their output shafts
also at the top (see drawing). Secure each with four screws as already described. Connect the
servos to the receiver in the sequence explained in the RC system instructions, then switch on
the RC system and activate the swashplate mixer at the transmitter (setting: symmetrical three-
point linkage, two roll servos, 1 pitch-axis servo at the rear). Set the collective pitch, pitch-axis
and roll controls to neutral, and fit the output arms on the servos, at right-angles to the rotor
shaft. Fit and tighten the output arm retaining screws.
The tail rotor servo can now be installed in the left-hand side frame from the outside, with the
output shaft again at the top. Fit the retaining screws. The servo output arm should point straight
down, and should be parallel to the main rotor shaft when the collective pitch stick is at centre.
Fix a brass linkage ball to the outside of the throttle servo output arm, and secure it with an M2 x
10 screw, secured with an M2 nut from the rear. Remember to apply thread-lock fluid between
screw and ball and also in the nut. The distance from the output shaft axis to the ball centre
should be about 11 mm. Mount the throttle servo in the left-hand side frame with the output
shaft at the top and the servo output arm facing up.
The servo leads can now be routed through the remaining vacant servo aperture at the front of
the right-hand side frame, and routed forward along the right-hand side of the mechanics to the
receiver. Bundle the wires together in spiral tubing. Please take great care when deploying the
servo leads; eliminate any chance of wires contacting shafts or gears, as the model could easily
crash if the wires chafe and rub through.
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