Tail Boom - GRAUPNER heim Starlet 50 Mode D'emploi

Starlet 50

7. Tail boom

(bag SR-0)
7.1 Assembling the tail boom braces
(bag SR-1)
Press the strut end-pieces 1292.11 into both ends of the aluminium tail boom braces 4445.8 as
far as they will go, and set the eyes parallel to each other. Drill a 1.5 mm Ø pilot-hole through
each brace and into each end-piece, and fit 2.2 x 6.5 mm self-tapping screws to secure them.
Apply bearing retainer fluid to the M3 x 25 grubscrews and screw them into the two canopy
stand-off pillars 4445.12 as far as they will go. Allow the fluid to cure completely.
7.2 Preparing the mechanics for mounting the tail boom
Screw the tail boom flange 1292.5 to the bearing holder 4448.14 on the mechanics using two
M3 x 16 socket-head cap screws. Press the M3 x 12 socket-head cap screw and M3 nut into
the tail boom clamp, and tighten the screw fully to cut the threads. Loosen the screw again to
the point where the tail boom can be pushed into place later.
7.3 Preparing the tail boom
(bag SR-2)
Note that the tail boom is curved at the front end; the purpose of the curvature is to raise the tail
boom towards the tail. This increases tail rotor ground clearance, but - importantly - also
ensures that the tail rotor drive shaft runs in a gentle curve, and thereby runs smoothly, without
vibrating.
Push the two shaft bearings 1292.10A into the tail boom 4445.9 using a length of beech dowel
or similar. The front bearing should be located 200 mm from the front end of the boom, and the
rear bearing 300 mm from the rear end. The spherical recess in both bearings should face
forward. Now place the guide ring 4451.7 in the front end of the tail boom, with the conical
opening facing the rear, and set it at a depth of exactly 27 mm. When the tail drive system is
connected, the union sleeve is guided accurately onto the coupling yoke by means of the guide
ring.
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