GRAUPNER heim UNI-Mechanik 2000 Mode D'emploi page 75

UNI-Mechanics 2000
3.2 Installing the blade holders
Press the two O-rings 4607.28 into both sides of the rotor head centre piece 4448.26, grease
the blade pivot shaft and slide it through. Centre the shaft, so that it projects by an equal amount
on both sides, then check that the O-rings are still in place. Fit 0.3 mm shim washers (from
4450.56) on the shaft on both sides of the centre piece, followed by the blade holders, noting
that the blade holders must be orientated correctly: the blade pitch arm carrying the mixer lever
must be in front of the blade (see illustration). Thoroughly grease the ball cages and thrust
washers of the thrust bearings 4618.3, fit them on the shaft and tighten the two M5 x 16 socket-
head cap screws.
Check that the blade holders rotate freely, and if necessary tap on the blade holders and the
centre piece with a screwdriver handle to encourage the bearings to seat themselves correctly,
so that they are not under strain. If the blade holders do not move freely because they are
pressing against the centre piece, fit a spacer washer 4450.57 between the thrust washer of
one of the two combination bearings and the blade pivot shaft.
Once you are satisfied that the blade holders rotate freely, apply thread-lock fluid to the M5 x 16
socket-head cap screws, and tighten them fully and permanently. If you had to fit a spacer
washer 4450.57, take care not to over-tighten the socket-head screw, to avoid deforming the
brass washer.
3.3 Assembling the Hiller rotor
(bag U2-10C, U2-10D)
The rocker 4618.27 is assembled and installed as shown in the illustration. The hole in the pivot
rod 4618.28 must line up with the axial bore in the rocker, so that the flybar can be fitted through
it later without jamming or binding. Initially the two rocker shells are held together temporarily
using four M2 x 8 ... 10 screws („borrowed" from other sub-assemblies); eventually they will be
replaced by the longer screws used to retain the rotor brake plate. Secure each of the two
ballraces on the outside by fitting an M2 x 4 screw in the centre piece. Check that the rocker
rotates freely.
Roughen the flybar with abrasive paper at the points where the control bridge 4448.37 will be
clamped. The control bridge is screwed in place, applying thread-lock fluid between the flybar
and the control frame; this prevents any danger of the flybar twisting in the control bridge during
violent aerobatic manoeuvres.
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