10.
q
Now that all stiffeners and doublers are positioned correctly, permanently attach each
one to the keel by soaking all of the joints touching the keel with thin CA. Thin CA will
soak underneath the stiffeners and doublers and form a strong bond. Continue applying
thin CA until it no longer soaks into the joints. Watch out for glue drips, and avoid holding
your head above the glue while it hardens.
11.
q
In the following steps you will mark and drill pilot holes for the servo mounting screws.
Insert all four servos into the servo bays as shown in Fig. 5-2. The sides of the servo
cases should not touch the sides of the servo bays. If they do, vibration may damage the
servos over time. Also allow at least 1/8" (3mm) gap between the servos so that they do
not vibrate against each other. Insert a sharp pencil through the rubber grommet on each
servo mounting arm, and mark the position of each servo mounting screw on the keel.
Hint:
To determine the correct drill size for the pilot holes, drill a practice hole in a piece of
scrap keel stiffener material with a small diameter drill bit (about .050" or 1.3mm) and
an electric hand drill. The diameter of the drill bit should be about half of the diameter
of the servo mounting screws. Carefully screw in a mounting screw into the scrap
material. If the test hole is the correct size, it will be difficult to turn the screw into the
hole the first time, but the wood will not split. If the hole is too large, the screw will go in
easily, but may not grip the wood and will probably pull out. Experiment with different
drill bit sizes until you find the right one.
Construction Manual
Crutch
5-4
LITE MACHINES
Servo
mounting
screws
Left/right cyclic
servo
Fore/aft cyclic servo
Note: Servo wires
are shown clipped
for drawing clarity
- do not cut your
servo wire!
Tail rotor servo
Mounting screw
Rubber grommet
Metal eyelet
Keel
Throttle servo
Keel
Servo
Figure 5-3.