Top Flite J-3 Piper Cub - Manual (Page 11)

Remove the 1/4" die-cut F-21 fin supports from their sheet.
Note that these fit in place in the notches provided on each
side of F-9, back to the trailing edges of the fin. Bevel the
inside edge of each F-21 to fit flush with the fin and glue in
place. Allow to dry.
15. Note that notches have been provided in all formers from
F-4 (PLY) thru F-9. These are to support the three 3/16"
dia. stringer dowels. The two side dowels are to blend
smoothly with F-21 at the tail. The center dowel is to blend
with the roof line as shown on the top view of the plans and
at the tail it "carries thru" the fin shape at R-1. Sand and
trim the dowels as required. Fit them in place, relieving any
former that might force them out of true. Glue dowels in
place and secure with tape until dry. Remove the 1/4" scrap
filler from the stabilizer slot.
Using a sanding block and medium paper, sand the F-19, F-21
and the stringer dowels to the cross-section shapes shown on
the plans.
16. Trim F-22 (PLY) tailwheel mount to fit inside of the tail-
wheel bracket. As shown on the plans, epoxy a wedge of
1/4" balsa to F-22 (PLY), sand to shape and epoxy to the
bottom of the fuselage at the tailpost. When dry, mount the
tailwheel bracket to the F-22 (PLY) base with the No. 2
screws provided. Do not overtighten screws. Bend the tail-
wheel wire to the shape shown WITHOUT the "L" bend at
the top. Insert the wire into the nylon bracket and then
bend the 90° "L" bend that goes into the rudder. Drill a
pilot hole in the rudder for the small length of brass tube
provided and epoxy this tube in place. Make a slot below
the tubing to clear the tailwheel wire in the rudder. Remove
the tailwheel assembly from the fuselage.
17. Sand entire fuselage to final shape. Take this time to inspect
joints, double-glue as needed. Do any filling that might be
required. The shaped blocks ahead of the cabin carry thru
the leading edge shape of the wing. It is advised that these be
rough-carved to shape and final sanded only when the wing
panels are mounted to the fuselage.
18. If you are planning to install a top observation window over
the cabin (window material not supplied), take the measure-
ments for its size and location from the plans and cut it out
of the 1/4" cabin sheet. Our prototypes used .020" butyrate
for this detail.
LANDING GEAR
Note that the landing gear wires have been essentially pre-bent to
shape. It may be necessary to slightly correct some of these
bends during assembly with pliers or a vise. Take the time to be
sure that these wires fit well with one another. Before assembly,
clean off the wires with a degreasing agent, such as alcohol, ace-
tone, etc. A good technique is to sand these wires with No. 400
sandpaper around the areas that are to be soldered before assem-
bly.
1. Turn the fuselage over on it's back and position the front L.G.
wire (1/8" dia.) into the forward landing gear block. Be sure
it is centered from side to side. Position the rear landing gear
wire — also 1/8" dia. — into the rear L.G. block. Using the
plans for reference, fit the rear wire to the forward one at the
axles and temporarily hold in place with a small piece of tape.
Now fit the LOWER 3/32" diameter cross-brace wire in place
and correct as needed for proper fit. Carefully wrap the
three wires together at each axle as shown, with soft copper
wire. Solder these joints.
2. With the landing gear still in place on the fuselage, fit the
two 3/32" dia. top joining wires in place as shown. Wrap the
joints carefully with wire and apply just enough solder to each
of the four joints to keep the wires from shifting. Carefully
remove the landing gear assembly from the fuselage and com-
plete the soldering of these joints.
3. Fit the top cross-brace wire in place, directly over the lower
wire. They should line-up when viewing from the side. Wrap
the two joints required with soft wire and solder.
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