Vertical Fin And Rudder - Carf-Models Ultra Lightning Instruction Manual

Vertical Fin and Rudder

The vertical fin is 99% completed at the factory, and just
needs the rudder servo and linkage fitting. The Rudder is
elastic-hinged and cut loose for you. The carbon spar tube
is shipped fitted into the tube in the fin (for protection and
fit checking), but it must be glued into the fibreglass tube in
the fuselage - not glued into the vertical fin. The front of
the fin is secured to the fuselage with the large M6 knurled
plastic nut (supplied), onto the threaded aluminium dowel
that is already installed in the fin.
With the wings and stabs finished and bolted into position
on the fuselage, fit the carbon tube spar into the fuselage,
with the bottom flush with the end of the fuselage tube,
and mark the part that will be glued in (about 60 - 65mm
long). Lightly scuff both the inside of the fibreglass fuse-
lage tube and the outside of the carbon spar tube that will
be glued together, and clean the dust off with alcohol for a
good bond. Apply plenty of clear wax to just the upper part
of the carbon tube that will be exposed, to prevent it get-
ting glued into the fin, and also the bottom surface of the
fin around the tube area.
Fit the tube into the fin. It should be a very tight fit, and the
wax you applied will help here. Apply 24hr. epoxy resin and
milled fibre mixture (or Aeropoxy/Hysol) into the tube in the
fuselage and on the exposed part of the carbon tube. Fit
the fin and tube in position. Tighten the plastic nut onto the
aluminium dowel at the front. Make sure excess glue does
not seep out and glue the fin to the fuselage! Some tape
on the bottom of the tube in the fuselage stops excess
glue dripping onto the top of the Stab. Check that the fin is
exactly vertical by eye, using a large 90 degree square, and
also by measuring from the tip of the fin to the ends of the
horizontal stabiliser. Tape firmly in place until the glue has
cured (see photo below/right).
Fit the rudder servo (JR8511/8611) into the plywood servo
mount, with the output shaft towards the front end of the
servo, and screw into place with the 2.9Ø x 13mm sheet-
metal screws provided (photo P39). Cut a small slot in the
side of the fin in line with your servo output arm, and
enlarge to suit the linkage later. Fit your metal servo arm
(1" SWB arm, with outer hole cut off, and re-drill the 3rd
hole out from the centre 3mm Ø for the clevise pin) and
make up the linkage using the supplied M3 aluminium cle-
vise, pin and E-clip at the servo end, and an M3 ball-link,
and M3 x 20mm bolt and locknut to secure the ball-link between the dual phenolic horns (P40).
Adjust the linkage to exact length and then fit the 3mm I.D. brass tube over the threaded rod to
stiffen it. The plain M3 nuts at each end of the linkage lock the tube into position, and prevent
(above) Overview showing the
plastic nut at the front and servo
cable with spiral-wrap protection.
(below) Plastic fairing shown
glued over the rudder linkage.
(above) The carbon tube spar
must be glued fully into the fuse-
lage tube, shown above.
(below) Fin taped in place while
gluing the carbon tube into the
fibreglass tube in the fuselage
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