Flylight Nynja Build, Manual

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5. Tail Surfaces
5.1 Tensioning the Rear Fuselage
a) Ensure that the front of the vertical fin is not yet fixed to its mount.
b) Check that the rear fuselage is sitting approximately squarely, then tighten the
bolts around the rear fuselage, remembering to use threadlock.
If there is some “set” in the rear fuselage, get a helper to twist it straight
whilst you do the bolts up. This will help when the cables are used to
correct the “set” as detailed below.
c) Ensure the fuselage sets at the right vertical alignment.
This is done by tensioning the turnbuckles on the C cables individually.
Sighting between TU14 forward cabin tube and fin whilst standing
ahead of aircraft will confirm vertical alignment. If turnbuckle tension
required is significantly asymmetric then shortening the length of the D
cable on the opposite side to the turnbuckle that requires the greatest
tension will help. To do this slacken the turnbuckles and undo one end
of the D cable to make the twists, replace and re-tension turnbuckles.
d) Final tension of C cables should be around 5Kg for a 10mm displacement
when cable is pulled at right angles downwards and mid cable length point,
using a travel scale or similar
A and B cables should not be loose but don‟t need great tension.
e) E and F cables should have light to firm tension. Their tension has an influence
over curve in the vertical plane of the fuselage longeron tube
– TU2 and 4‟s.
Asymmetric tension may pull the fin out of vertical. If required adjust tension so
all is straight by winding or unwinding the cable, and reattaching. A helper is
useful to apply pressure to the frame to help reattaching.
f) Finally secure all cables where they cross with a small length of split thin wall
tubing (the pitot tubing can be used) over one cable, and a cable tie.
Figure 91 securing crossing cables