| Cut
ribs W5 to W9 in pairs using the plan drawings. Check
position of main spar slots against the main wing plan to
ensure the accurate positioning of ribs during assembly.
Leave the trailing edge pieces attached at this stage.
Cut
the ply wing braces, checking slot positions and depth of
cuts. Cut main spars, L/E and rear spars and aileron spars
to length, allowing for final trimming.
I
allow 3mm extra width and slot the leading edges 1.5mm top
and bottom to provide support for the wing L/E sheeting.
The leading edge and spars are then steam bent to curve as
per plan prior to assembly. The rear and aileron spars,
due to the cantilever wing shape, are thickest near the
wing panel centre and taper towards both ends. These
should be cut 20mm wide initially and shaped during
assembly.
Cut
12 rectangular vertical grain shear webs 67.5mm x 37mm
from 1.5mm balsa. These will assist as rib spacers and
will be marked to final shape and installed after fitting
the top main spar. Trace wing plan details on 1.5mm bottom
T/E wing sheeting and cut to outline. Do not cut the out
ailerons at this stage. Cut and join 1.5mm centre section
sheeting from T/E to main spar. Note that the top and
bottom T/E centre piece is 1.5mm ply.
Commence
wing assembly with the centre section, as follows: Pin the
bottom centre sheeting over the plan. Trim to length and
glue main centre bottom and rear spars in place. Cut W1
ribs at rear spar and glue the four centre ribs in place.
Attach the main wing brace and top centre spar. Add the
L/E wing brace and leading edge.
Trim
and fit the four T/E pieces of W1 ribs and the two filling
blocks. If you use the centre mounted servo for aileron
control, this should now be fitted. I prefer wing mounted
servos for precise operation and ease of installation. Add
the top sheeting. When this is all set, remove the wing
section from plan and sheet the front bottom from spar to
L/E. Shape the top centre L/E but leave the bottom square
for addition of fuselage fairing.
Add
the remaining two W1 ribs to form an attachment point for
the outer wing panels. Centre section is now complete. Set
up a hinged building boar, one side flat on the bench and
the other angled to give 18mm dihedral at W9 as per plan.
Tape the plastic covered plan in position and locate the
wing centre section over the plan. With this firmly fixed
in position, locate a 1.5mm spacer along the main spar
line and cover with plastic. Glue and pin the bottom main
spar and T/E sheeting in position over the plan. Cut the
ribs to length, keeping the T/E pieces for trimming and
fitting later. Attach the T/E spar. Glue in the ribs,
using the shear webs for location and squaring. Fix the
top spar. Now trim and fit the shear webs.
Add
the front aileron spar. Trim and fit aileron and trailing
edge ribs W2a - W9a remainder of rib T/E pieces, leading
edge, support for aileron horn and 6mm square spruce
aileron servo plate framing (if using wing mounted
servos).
When
all this is set, sheet inboard bottom section forward to
main spar, fit and screw 1.5mm aileron servo plate in
position and sheet between plate and T/E sheeting. Fit U/C
blocks and drill outer ends for torque rods.
Mark
position of aileron cutouts on outside of bottom sheet but
do not cut out until wing sheeting is completed. Trim the
rear spar and T/E to final shape and proceed with top
sheeting and cap strips. Sheet bottom from main spar to
L/E and add cap strips, ensuring that wing panel is
perfectly flat.
Shape
and fit tip block. Reverse the building board and assemble
the other wing panel as above. Now cut out the ailerons
and trim to shape. Hinge in place. Fit aileron horns and
linkages. Dowels and wing bolts will be fitted later.
Check the wing for lateral balance and give the lot a
final sand.
While
on the subject of flying surfaces and flushed with success
at completion of that little project, let's try something
a tad more relaxing before tackling the fuselage. |
HOME
