Assemble Fuselage - GREAT PLANES Piper j-3 cub Instruction Manual

Assemble Fuselage

1. Test fit Former F2 in place on the left fuse side so that
F2B is in front of F2A. Press it down into its slots and use a
90 degree triangle to keep it perpendicular to the fuse side.
Glue it in place with thin CA.
2. Test fit die-cut 1/8" ply Former F3 (CUB4F11) in place
on the left fuse side and use the die-cut 1/8" ply F3 Angle
Gauge (CUB4F09) to properly slant it backwards. Make
sure to install the former in the proper direction (see plans).
Tack glue it in place with thin CA but do not glue the angle
gauge in place. Note: You may have to sand off part of the
lower tabs on the sides of F3 to permit the edge of F3 to rest
fully down on the fuse side along its full length. If the tab
protrudes through the fuse side it will contact the workbench
before the edge of F3 contacts the fuse side.
3. Position die-cut 1/8" ply Formers F4 (CUB4F10) and
F5 (CUB4F12) in their respective slots on the left fuse side.
Use the die-cut F4 (CUB4F09) and F5 (CUB4W07) angle
gauges to slant them backwards. Tack glue F4 and F5 in
place with thin CA. Do not glue the angle gauges to the fuse
side. Do not apply glue to the joints near the TOP of former
F3, because you will later (step 6) have to spread the fuse
sides to install the wing mounting block.
4. Position the right fuse side in place so all four formers
key into their slots. Tack glue the fuselage side to the
formers. Do not apply glue to the joints near the TOP of
former F3, because you will later (step 6) have to spread the
fuse sides to install the wing mounting block.
5. Slide the 3/32" balsa aft fuse top that you assembled
earlier into place and allow the formers to key into their
notches. Make sure the fuselage is symmetrically lined up with
the top and glue the top to the fuse sides and the formers.
Glue the aft portion of the cabin doubler to the aft fuse top
6. Slide the laminated Wing Mounting Block into the
notch in the cabin side doublers and lock the tab into F3.
Securely glue it in place with epoxy. As you glue the wing
mounting block in place, also securely glue the upper portion
of Former F3 to the fuse sides.
7. Place the die-cut 1/8" ply Lower Tank Floor (LTF)
(CUB4F09) into the bottom notches of former F2. Make sure
the embossed letters are towards the top of the fuselage
since this former helps set the correct right thrust. Glue the
lower tank floor at the rear tabs only.
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