Flap Installation; Join The Wing Halves - GREAT PLANES RV-4 Instruction Manual

Flap Installation

You now have to decide if you want to build the wing with or
without the flap option. If you decide to build it with the flap
you will need two additional standard 40 oz. servos and a
5th channel available on your radio system. The use of flaps
allows the plane to fly markedly slower than without the flap
option. This allows you to fly slower, land slower and take-off
in a much shorter distance. If you have a computer radio
with flap to elevator mixing you can also program the plane
to do very tight loops with flap elevator coupling.
If you are not installing operational flaps proceed with the
next two steps. If you are installing operational flaps proceed
to step 3.
NON-FUNCTIONAL FLAP INSTALLATION
1. Glue the flap leading edge to the wing trailing edge
and the root rib of the flap to the rib W2.
2. Sand the flap to match the contour of the top and
bottom of the wing.
FUNCTIONAL FLAP INSTALLATION
3. Mark the location for the flap hinges on the wing
trailing edge and the leading edge of the flap. The slot for the
hinge needs to be 1/16" from the bottom of the wing. Do not
mark the hinge location on a centerline.
Hinge Slot
4. Cut the slots for the hinges using the same
procedure used for the aileron except the slot needs to be
cut into the wing and the flap at an angle as shown.
5. Trial fit the aileron and flap with the hinges to the wing
making sure that you have at least a 1/16" [1.6mm]
clearance between the control surfaces.
6. Attach the control horn to the bottom of the flap
following the same procedure used for mounting the control
horn to the elevator.
7. This completes the construction of the left wing panel.
The sheeting and servo trays that have not yet been
installed will be completed after the two wing halves are
joined together. Go back and repeat the wing assembly
procedure for the right wing panel.

Join the Wing Halves

1. Locate the die-cut 1/8" [3mm] plywood dihedral brace
(DB) and dihedral brace doubler (DBD). Use 6-minute
epoxy to glue the dihedral brace doubler to the dihedral
brace, centering the doubler on the brace.
20
1/16"