8.
q
Insert and remove the servo again as a final check. If the stiffeners are not positioned
properly, break them free, sand them clean, and repeat the previous step. In some
cases, it may also be necessary to shave the sharp edges of the stiffeners slightly to
prevent the servo wires from chafing against the stiffeners once the servos are mounted.
9.
q
Check the fit of your servos in the front servo bay. Much like the rear servo bay, the front
servo bay must be wide enough to accommodate the servos, but small enough to
prevent the servo mounting screws from splitting the wood. Hitec HS-81 servos should fit
without any further modification. For smaller servos, you may need to add two 1-7/16 “
(37mm) servo doublers made of 1/8" x 1/4" spruce as shown in Fig. 5-1 and the bottom
half of Fig. 5-2. Position the doublers using a procedure similar to that for locating the
lower keel stiffeners. Tape the doublers to the keel, check the servo fit, readjust the
doublers and tack-glue the doublers to the keel.
Construction Manual
Crutch
LITE MACHINES
5-3
Hitec HS-81/ Futaba 3101 servos
Align stiffeners with
bottom edge of servo bay
Airtronics 94501 servos
Add servo doublers
for smaller servos
= Drill holes in crutch
for servo mounting
screws
Raise lower keel stiffener
for smaller servos
Figure 5-2.
