Top Flite TOPA0140 - Manual (Page 36)

MOUNT THE FIN AND STAB
❏
1. Slightly bevel the edges of the die-cut 1/4"
[6.4mm] balsa fin spacer to match the tapering
angle of the fuse sheeting. Glue the fin spacer to
the stab saddles, accurately aligned over its
location on the plan between the fuse sheeting.
❏
2. Pin, but do not glue, the sheeting to the
fin spacer.
❏
3. Carefully sand the balsa fuse side sheeting
so it is the same shape as the stab saddles. Do
this without sanding the stab saddles (and
inadvertently changing the incidence of the stab).
❏
4. Cut a small piece of sheeting from the top of
the stab to accommodate the leading edge of the
fin. This piece doesn’t have to be perfect. It just
has to allow the stab LE to go through the sheeting
and fit over the center rib. Use a 90-degree
triangle to draw a centerline on the top of the stab.
❏
5. Position the stab on the saddle with the
centerline on top of the stab in the center of the
fuse. Place a weight on top of the stab to hold it
down. View the fuse from the rear and make sure
the stab is level. If necessary, shift the weight or
carefully sand the
high stab saddle until the stab
will rest level.
Hint: Position a 1-3/8" [35mm] balsa block under
both sides of the stab. This way you will be sure
both sides are an equal distance from your
building board and the stab is level.
❏
6. Insert a T-pin through the sheeting and the
stringer in the center of the fuselage behind the
mark you made in the upper firewall former. Tie a
small loop in one end of a 42" [1070mm] length of
string and slip it over the T-pin in the front of
the fuselage.
❏
7. Fold a piece of masking tape over the other
end of the string and draw an arrow on it. Slide the
tape along the string and align the arrow with one
tip of the stab. Swing the string over to the other
stab tip. Shift the stab and slide the tape along the
string until the distance between both ends of the
stab and the front of the fuse is equal. Now your
stab is centered and square with the fuse.
❏
8. If you haven’t already done so, final-sand the
stab before you glue it to the fuse. It’s easier to do
when it’s off the fuse than it is when it is glued
in place!
❏
9. Now that you are sure the stab will align,
glue it to the fuse sheeting and the ply stab saddle
with 30-minute epoxy. Use the pin-and-string
technique to recheck your alignment. Wipe away
excess epoxy before it cures. Do not build up a
fillet between the stab and the fuse. Do not disturb
the fuse until the epoxy is fully cured.
❏
10. Taper the trailing edge of the fin so it will fit
between the sheeting on the fuse. Fit the fin to the
- 36 -