GRAUPNER Skalar, Manual

Page: 32 / 59

elektro
Skalar
32
7.6 Connecting the tail boom to the mechanics
Withdraw the tail rotor from the tail boom to the point where the shaft coupling becomes
accessible. Undo the grubscrews in the shaft coupling so that the tail rotor shaft 4451.19 can be
pulled out of the coupling. Now carefully de-grease the shaft, push it into the shaft coupling as
far as it will go and tighten the grubscrews to secure it. This is the procedure: first remove the
grubscrews from the coupling entirely, apply thread-lock fluid, Order No. 952, or bearing retainer
fluid, Order No. 951, to the threaded holes, then fit the grubscrews again and tighten them fully.
If possible, grind a flat in the shaft at the engagement point of the grubscrews on one side, to
optimise the strength of the joint. Fix the tail rotor to the tail rotor gearbox bracket 4475.107
using three 2.9 x 13 mm self-tapping screws. Apply a little grease to the quick-release coupling
and to the front end of the tail rotor shaft.
Fix the struts to the left and right mechanics side frames using the stand-off pillars 4445.12
prepared in Section 7.1.
The complete tail boom assembly can now be pushed into the mounting bracket 1292.5 as far
as it will go, checking carefully that the quick-release coupling engages correctly. Rotate the tail
boom so that the tube curves upwards, with the curve exactly in the vertical plane when viewed
from the tail. Rotate the tail rotor bracket so that the tail rotor shaft is at right-angles to the main
rotor shaft when viewed from the tail. Tighten the M3 x 12 socket-head cap screw in the moun-
ting bracket to clamp the boom in its final position. We recommend that you hold the tail boom
pointing vertically upwards while you tighten the clamping screw.
Adjust the position of the rear tail boom strut bracket 1292.6 so that the upper tail boom struts
4445.8 can be attached to it using an M3 x 30 mm socket-head cap screw and M3 self-locking
nut, as shown in the drawing. Now attache the lower tail boom struts 4475.8 to the support
clamp using another M3 x 30 mm socket-head cap screw, but without tightening this screw.
At the front end the struts are attached to the main frame using 2.9 x 16 mm self-tapping
screws; if there are 2.9 x 13 mm self-tapping screws from earlier installation, they have to be
removed first.
The position of the support bracket is given by the length of the four struts; tighten the clamping
screw in the strut bracket firmly in this position, then drill 1.5 mm Ø holes through the tail rotor
bracket 4475.107 and the tail boom bracket 1292.5 and into the tail boom. Fit 2.2 x 6.5 mm self-
tapping screws in the holes and tighten them to prevent any of the parts shifting or rotating in
flight.
7.7 Stabiliser panels
(bag SKR-3)
Fix the vertical stabiliser to the tail rotor bracket using 2.9 x 13 mm self-tapping screw. Slip both
halfes of the horizontal stabiliser bracket on the tail boom from above and from below, then po-
sition the horizontal stabiliser on top of it and lock it in place by two M3 x 30 mm socket-head