outside of the fuselage in the area of the wing
an stab roots, and also the
inside
surfaces of
the 2 short lengths of 12mm carbon tube that
will be glued into the wing roots for alignment
of the 10mm carbon anti-rotation tube. Also
wax the inside surface of the 30mm fibreglass
wing tube.
Fit the 30mm Ø fibreglass wing tube in the
fuselage, slightly loose between the sides so it
cannot deform it, with the 2 egg-shaped car-
bon/ply reinforcement rings over it. Fit the
12mm carbon tube inside the fuselage for the
stab spar, again slightly loose between the fuselage sides,
also with the 2 carbon/ply reinforcement rings over it. You
can temporarily fit the milled balsa rudder post in the fin to
make sure that the fuselage is not being deformed at the
tail at all.
Do
NOT
glue anything at this stage!
Fit the carbon wing spar and a long, straight, 10mm tube
thru’ the stab spar tube, and eye from the front and back to
make sure that they are both exactly in line, horizontally,
and exactly at 90° to the centreline of the vertical fin. To
check the 90° alignment of stabs to the vertical fin, make
sure that exactly the same amount of tube projects from
both sides of the fuselage, and then measure from the
ends of the tube to the seam on the tip of the vertical fin.
Adjust the holes a little if needed. Don’t worry about wing
and stab incidences at this point, and don’t adjust the
holes for the anti-rotation tube/pins.
Now fit the carbon wing anti-rotation tube, with its rein-
forcement rings, and install the wings on the fuselage. With
a 2nd person to help, make accurate measurements with a
steel tape measure to check that the wings are exactly at
90° to the centerline of the fuselage. Measure from both
wing tips to the top centre of the vertical fin, and adjust the
30mmØ spar hole a little if needed. When correct tack the
fibreglass tube inside the fuselage with 2 very small dots of
5 min. epoxy at each end. Remove wings and check again
that the wing spar is still in line with the long 10mm tube
thru’ the carbon stab tube.
Scuff up one end of the two 6mm carbon anti-rotation pins
and glue them in the carbon tubes in the back of the stabs
with a little 30 min epoxy. When cured install the stabs on
the 10mmØ carbon shaft in the fuselage. Measure accu-
rately between the tips of the stabs and the seam at the centerline of the nose to check for 90°
to the fuselage centreline. Adjust the holes as needed. Finally re-fit the wings and check
between the tips of the stabs and wings. Before gluing anything check everything by eye, also
with a friend to double-check your findings. Your eyes are much more precise than you would
Composite-ARF IMPACT
14
Stab spar tube and
reinforcement
rings
Fin bulkhead and
support plate.