Great Planes Ultra Sport 40 Kit - GPMA0410 - Manual (Page 15)

3. Clean the torque rods and bearing tubes with SAND "FLATS" ON LE AND TE
alcohol.
4. Find the two grooved, tapered balsa center
trailing edge pieces. Lay them on the plan, mark and cut
them off to match the plan for length and angle at the
centerline.
1. Study the wing plan near the wing centerline.
Note that the center portion of the LE and TE must be
sanded flat.
centerline, and approximately 3/32" into the TE at the
centerline. (The flats will end up approximately 4-1/2"
wide at the LE, and 2" wide at the TE). 5. Trial fit the torque rods into the center TE pieces.
Determine from the plan where to cut the clearance
notches, which will permit the torque rod horns to travel
freely. Also cut small clearance notches in the wing TE.
Note: The torque rod horns must exit the TOP of the
wing!
2. Sand approximately 5/32" into the LE at the
6. Slide the plastic bearings toward the threaded
end of the torque rods, then use a toothpick to apply a
small amount of petroleum jelly to the ends of the plastic
tubes (to help prevent glue from getting inside and
locking up the torque rods).
7. Use 5-minute epoxy or CA to glue the plastic
bearing tubes into the grooves in the center TE pieces.
Wipe off any excess glue and allow it to harden.
FIBERGLASS THE CENTER SECTION
NOTE: Because of the high stresses in the center
of this wing, fiberglass reinforcement is
REQUIRED. Please do not omit this important
section!
NOTE: If you have previous experience with
applying fiberglass, feel free to use your favorite
method, providing that it results in a strong bond
between the glass cloth and the wood. If this is your
first time, we offer the following suggested method,
which is the fastest and easiest we have seen.
1. Make location marks for the fiberglass rein-
forcement cloth, 1-1/2" each way from the wing center-
line.
8. Trial fit the trailing edge/torque rod assemblies
onto the wing trailing edge. Sand the center trailing edge
pieces slightly where they join, for a good fit. Glue these
pieces in place with epoxy. HINT: Use masking tape to
hold these pieces to the wing TE. to aid in correct posi-
tioning.
2. Trial fit the 3" wide fiberglass cloth in place.
You can use a scissors or a paper punch to cut holes in the
glass cloth for the aileron torque rod horns.
3. Wrap small pieces of masking tape around the
threaded portion of the aileron torque rods to protect
them from the spray adhesive in the next step.
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