Trio Avionics EZ Pilot - v 2.3 User Manual
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When the servo is to be connected to an aileron control system that is operated by
cables, the installation kit shown below will be provided. A shorter pushrod is included.
The clamp that is attached to the pushrod will be placed around the cable and securely
tightened.
7.3 Selecting a Site for the Servo
For most aircraft, it’s relatively easy to find a suitable site for locating the crank arm
servo. The length of the pushrod and, to some extent, the angle it makes with the driven
element are user selectable.
The rod end bearing allows some misalignment, usually about 8 degrees, between the
servo pushrod and the plane of rotation of the crank arm. This limit on angular
displacement often determines the minimum pushrod length. Any side-to-side
movement, such as may be caused by elevator action being mixed with the aileron
movement at the stick, must not jam the rod end bearing. A suitable hard point must be
found, or built, for mounting the servo. The mounting place needs to be as accessible as
possible, and there must be a means of linking to the aileron control system.
The mounting place must be strong and rigid – conceivably a lateral force of up to 50
pounds could be encountered. If, for example, you need to mount the servo on the skin
of an airplane, it will likely be necessary to use additional bracing or a doubler to provide
appropriate rigidity. You do not want the push-pull of the servo to fatigue the metal that
holds it.
When mounting the servo, be careful not
to drill mounting holes into a wing spar or
other load bearing member. It may be
best to construct a wooden, composite or
metal mounting plate, place and bond
machine screws so that they will interface
with the case mounting tabs, and then
secure the assembly into place. Once the
assembly is complete, the servo base
Note: A longer aileron crank radius dictates a correspondingly longer radius at the drive end. The
ailerons must travel from aileron stop to aileron stop within the range of movement allowed by
the servo stops which limit crank arm rotation.