Great Planes F4 Phantom - GPMA0440 - Manual (Page 12)

1. Cut four of the 1/8" x 3/8" x 29-7/8" basswood spars to
Retract Gear
4. Skip to step 5 if you are not installing retracts. If
you chose to install retracts, use 30-minute epoxy to glue
the die-cut 1/8" plywood rib doublers R-4R to the die-cut
1/8" balsa ribs R-4 and the die-cut 1/8" plywood rib
doublers R-5R to the die-cut 1/8" balsa ribs R-5. Be
sure to make a right and left of each rib assembly.
18" long sub spars. From the remaining 1/8" x 3/8" x 29-7/8"
basswood spars cut four, 10" long sub spars. Save the
leftover spar material for use later.
1-1/2"
2. Sand a 1-1/2" long taper on one end of each 10" and
18" long sub spar.
5. Skip this step if installing retracts. Use 30-minute
epoxy to glue the die-cut 1/8" ply rib doublers R-3F to the
die-cut 1/8" balsa ribs R-3 and the die-cut 1/8" ply rib
doublers R-5F to the die-cut 1/8" balsa ribs R-5. Be sure
to make a right and left of each rib assembly.
6. Cut notches in the balsa ribs to match the notches in
the plywood rib doublers. If installing the fixed landing gear,
also cut the notch at the TE of R-3.
7. Use 30-minute epoxy to glue the die-cut 1/8" balsa
ribs R-1 together.
3/8" 3/8"
3/16" 3/16"
3. Make four main spars by gluing a 29-7/8", 18" and
10" sub spar together with medium or thick CA. Make sure
the sides and square ends are flush.
Note: Be sure the spars are flat and straight.
8. Make the center TE plates by using 30-minute epoxy
to glue a shaped 3/16" balsa center plate between a
shaped 3/8" and 1/2" balsa top and bottom center plate.
Make sure to align the ends and the long straight edge.
This will produce a notch at the front for the aileron torque
rods. Make two center TE plates.
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