Top Flite TOPA0305 Part 1 User Manual

Page 25

Advertising

FORWARD INNER SKIN

FORWARD OUTER SKIN

-\AFT

SKIN

NOTE GRAIN DIRECTION

Use this photo and the sketch for the next few steps

This photo shows a few weights on top of the wing,

but in actuality we used enough weights to fully
cover the skins.

You can use magazines for

weights too. T-pins in the front ensure that the

skins are securely bonded to the top spar.

Trim the aft wing skin

so it fits the wing.

The

TE should be straight and true and contact the

stopper portion of the jig tabs on ribs W14 and W3.
The front of the sheet should

end in the center of

the top spar. The ends should extend past W2 and
W14 equally.

4. Use your favorite method

to glue the aft

wing skin to the wing. We recommend using
aliphatic resin because it gives you plenty of time to
align the skin and position your weights or T-pins.

Hold the wing skin in position with magazines or

weights made from plastic bags filled with lead shot
or

BBs. If you choose to use T-pins to hold the skin

to the wing, lightly mark lines on the top of the
wing skin indicating the location of the ribs

underneath.

Do not disturb the wing until the

glue fully cures.

5. Remove the T-pins from the bottom spar.

The weights on the aft sheeting will hold your
wing flat.

6. Trim the forward outer wing skin so it fits

the wing. The aft edge of the skin should contact
the aft skin (in the center of the spar) and the front
edge of the skin should extend past the leading

edge of the wing by approximately 1/4". The root
end of the sheet should accurately align with the

glue joint between W4 and W4-A and the tip of the

sheet should extend past W14 by about 1/16.

Note: The grain direction of the forward outer skin
runs parallel to the leading edge of the wing.

7. Wet the top of the forward outer skin with a

50/50

mix of alcohol and water

so it will bend

easier. Glue it to the wing using weights or T-pins

to hold it down.

8. If you haven't already done

so, glue two

more 3 / 3 2

x 3 x 30" balsa sheets together for the

forward inner skin. From that sheet, cut a piece
that fits between ribs W2 and W4 and glue on a
third piece cut from leftover 3/32" balsa to fill up the

rest of the space. Note that the grain direction is
parallel to the leading edge between ribs W2 and
W4. Trim the sheet to fit the wing. Glue it in
position.

9. After the glue on all the sheeting is dry,

remove the T-pins you can reach and lift the wing
off your building board.

10. Clean the glue blobs and wood chips

off

your workbench

so they won't leave dents in your

beautiful wing sheeting. Turn the wing over and

carefully cut the jig tabs off the ribs.

11.

Reinforce all glue joints that don't look

strong. It is particularly important that the joint
between the spar web and both spars are securely
glued.

12. Position the left wing plan on your building

board and cover it with wax paper. Return to step 1
on page 22, and repeat the steps to build the left
wing panel.

FINISH THE OUTER WING PANELS

Start with the

right

wing panel

your progress

matches the photos.

Glue a die-cut 3/32" balsa sub-rib W2A to

rib W 2 where shown on the plan. The

s u b

rib

provides additional gluing area when the sheeting
is installled. Use the W2A that does not have a
notch cut in it for the flap spar.

Glue the die-cut 3/32" balsa flap ribs W2A

and W8A and aileron ribs W9A and W14A to the
wing where shown on the plan. Note that W8A and
W9A are perpendicular to the aileron spar W17.

Advertising