Horizontal Stabiliser - GRAUPNER NH90 Bedienungsanleitung

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NH90
Press the rear ball-link fitted to the prepared CFRP pushrod onto the front linkage ball on the
bellcrank, and connect the front end of the pushrod to the tail rotor servo output arm. The
pushrod should now run unsupported through the tail boom, without touching or rubbing on
anything at any point; when the servo is at centre, the linkage point on the bellcrank arm should
be vertically below the bellcrank pivot axis.
Fix a linkage ball to the outermost hole in the tail rotor control lever using an M2 x 8 screw and
M2 nut. Check that the nut does not foul the tail rotor housing at either end-point of the tail rotor
control system; round off the edges if necessary.
Cut down the M2.5 x 200 mm threaded rod to produce an overall length of around 200 mm
when the threaded coupler is soldered on and the ball-links fitted. When the tail rotor servo is at
centre and the bellcrank positioned as stated above, adjust the length of the pushrod so that the
tail rotor control lever is parallel to the tail rotor housing when the pushrod is installed as
described below.
Connect the pushrod to the bellcrank and the tail rotor, with the threaded coupler end at the
bellcrank. At the top, where the pushrod runs through the tail rotor bulkhead, check that the tail
rotor can be actuated over its full travel without the pushrod fouling at any point; adjust the
opening in the bulkhead if necessary.

1.7 Horizontal stabiliser

Cut out the ABS horizontal stabiliser shells and sand the edges smooth and flat so that the
shells fit together snugly. Cut the stabiliser spar components (A25) from 10 x 8 mm balsa strip
and glue them in the bottom shell using Stabilit express. In the root face of the bottom shell
(which will later rest against the fuselage side) drill 3 mm Ø holes close to the leading and
trailing edges of the panel. Apply Stabilit express to the stabiliser spar and glue the top shell in
place. Tape it to the bottom shell and glue the edges together by running thin cyano through the
3 mm holes and allowing the adhesive to flow along the joint, rotating the assembly repeatedly
through 360°. When the glue has cured remove the tape and sand the outside of the joint line
smooth using fine abrasive paper. Now cut the hole for the strut in the top surface, taking care
not to drill through the underside of the panel!
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