Prepare The Wing For The Top Sheeting - Top Flite Douglas DC-3 User Manual

14. Mount your aileron servos to the hatches with
5/16" x 3/4" x 7/8" servo mounting blocks. Bevel the aft
block (and a bit of the servo mount if needed) so it will
not interfere with the top wing sheeting.
15. Remember we told you not to glue the bottom
sheeting to the servo rails or the ribs on both sides of
the servo compartment so it would be easier to cut the
openings for the hatch covers? Now you can remove
your hatch covers and glue the sheeting to the rails and
ribs. After the glue dries, temporarily fasten your hatch
covers to the wing with the #2 x 3/8" flat head screws.

PREPARE THE WING FOR THE TOP SHEETING

1. Cut along the lines you marked on the center W1
rib and remove that section of balsa to accommodate
the fuel tanks.
2. Glue leftover 1/16" plywood fuel compartment
floor reinforcement strips to the bottom sheeting as
shown on the plan. You can see the strips in one of the
following photos.
3. Make two fuel tank hooks by bending both 1/16" x
4" wires as shown in the sketch located on the wing plan.
4. Use 30-minute epoxy (and mix in some milled glass
fibers if you have any) to glue the fuel tank hooks to the
fuel compartment floor and the ribs as shown.
5. Glue a piece of leftover 1/4" x 3/8" balsa to the top
center section spar between ribs W4 and W3. Sand the
balsa piece to match the shape of the top of the wing.
6. Glue the die-cut 3/32" balsa TE ribs W3F, W3AF and
W5F to the center TE spar and outer TE spars over the
flaps. Use a straightedge to make sure the ribs align. Cut
1/8" off the front of the W3F that glues to the ply brace.
7. Reinforce any glue joints you missed or that don't
look strong.
8. Sand the top of the wing to accommodate the top
sheeting. Sand the aileron hinge blocks even with the
ribs and the outer TE spar and sand the TE spar, top
spar and LE even with the ribs.
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9. Connect your servo extension cords and
Y-connectors to the servos and route them through the
wing. We temporarily set the fuel tanks in the fuel tank
compartment to see how all the wires would be routed
over, around and past them. Secure all the connections
with vinyl tape or heat shrink tubing and label the wires
so you will know where to plug them into your receiver. If
you have to take your servos out of the wing in the
future, tie a piece of string to the connector and pull the
cord out of the wing leaving the string in the wing. When
it is time to route the servo cord back through the wing,
pull it back through with the string. You may make paper
tubes which you could install in the wing to help guide
your servo cords. If you're installing retracts, route your
air lines too. We suggest you connect both "up" lines to
each other with a T-fitting and both "down" lines together
with another T-fitting. Plug the remaining "up" and
"down" fittings on your air valve.
10. Route your fuel lines through the holes in the ribs.
Each fuel line should be approximately 20" long so you
can work with them for now. You'll trim them to a more
reasonable length later.
11. Use the holes in the wing bolt plate as a guide to
make the holes in the bottom sheeting for the wing bolts,
using a 1/4" brass tube sharpened at one end or a 1/4" drill.