Fin and Rudder
The vertical fin and elastic-
hinged rudder is laminated
from a lightweight fibreglass
and foam sandwich, cured
under vacuum, and painted in
the molds in a single colour. It
has been fitted to your fuselage
at the factory, to check align-
ment, but small directional ad-
justments can be made when
gluing in the 2 joiner rods and
installing the retaining bolt at
the front. Note that the rear
tube for the fin spar/joiner is
offset to the (pilots) left side to
allow clearance for the stab
linkage on the centreline.
The 2 joiners (Ø 7mm x 90mm) must be perma-
nently glued into the fuselage,
not
into the fin, inside
the 2 tubes that are bonded to the rear bulkheads.
Apply 2 coats of clear wax to the root of the fin and
the top of the fuselage, in case you get some glue on
there in the next steps. Prepare the 2 joiner rods by
lightly sanding the end 35mm length of the front rod,
and 25mm length of the rear rod - which will be glued
into the fuselage. Lightly sand the inside of the tubes
in the fuselage. Wax the remaining length of the
rods, and push them into the Fin, leaving just the
correct lengths projecting. If they are a bit too loose
in the fin tubes, you can spray a coat of ‘clear’ or
paint a thin coat of laminating epoxy on the rods.
Apply a
little
thick mixture of slow epoxy and micro-
balloons inside the fuselage tubes and on the joiner
rods, and fit the fin into position. With the wings and
stabs fitted, view carefully from the back, and
measure from the wing tips - to ensure that the
fin is vertical and straight - and then tape se-
curely in position until the glue has cured.
Some tissue or rag laid in the bottom of the
fuselage under the fin joiners catches any glue
that seeps out.
When fully cured, remove the fin and wipe off
the wax with Ronsonol, or equivalent. The fin
is secured to the fuselage for flight with a M4
x 25 bolt at the front, that screws into an M4 T-nut that has been factory-fitted into the fin base al-
ready. The hole has been drilled in the fuselage for the bolt, but can be adjusted if necessary. Cut
a small reinforcing plate of 3mm plywood, approx. 20 x 30mm, and drill a 4mm hole in the centre
Fox Composites Co., Ltd.
19
(above) Fin is secured with 2 x Ø 7mm joiner rods, which
must be glued into the fuselage, and an M4 bolt at the front.
Back joiner has 25mm glued into the fuselage, and front has
35mm. Rear joiner is offset to give clearance for stab linkage.
(above) Linkage is parallel to fin base.
Hole for horn is 10mm back from rudder
L.E and approx. 10mm up from root. Drill
right thru’ rudder and tap M3 thread.
(below) Mini-servo installed in milled
6mm ply mount, and glued into Fin.
