3D Hobby Shop YAK55, Assembly Manual, Page: 10 / 46

Elevator Servo Installation
Elevator servos on your Yak mount inside the horizontal stabilizers. The openings are sized for 'standard'
servo cases such as used on the Hitec HS-7955TG servo. If it is necessary to slightly enlarge the
opening for your larger servos, we find that the best technique is to use a coarse file. Only remove a
small amount of wood as required to fit servos of your choice while keeping the “filing” to a minimum.
This airframe has been tested with servos up to the size of a Futaba BLS157 with excellent performance.
The elevator servos must be installed using a long screwdriver or ball driver to access the mounting
screws. The servo arm must be inserted and tightened properly before flight. The use of thread locking
compound or lock washers is always recommended on all surface control hardware to prevent loosening
in flight. The Photos below illustrate elevator servo mounting and hardware installation. Do not forget to
use some type of lock on all your servo wire to extension plugs.
Center the servos, and slide your servo arms onto the servo output splines. Rotate the servos and arms
as necessary to access all fasteners to lock the arms in-place. Use thread locking compound if indicated
by the servo-arm manufacturer. We also use a dab of silicone adhesive on the servo arm screw to lock it
in place against vibration.
Assemble the elevator pushrod as shown. The elevator pushrods are the shorter of the included
pushrods. The longer ones are for the ailerons. Note that the pushrods have one left-hand thread and
one right-hand thread, so that you can adjust their length after they are installed.
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