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Step 2: Wing Servos & Servo-Wire Extensions
:
In this step you will be installing the wing-servos onto the wing-servo access covers and placing the
wing and elevator servo-extension cables in the wings and fuselage respectively.
Hardwood Mounting Blocks
:
Locate the four hardwood servo-mounting blocks. In two of the
blocks, cut a notch ~ 1/4” x 1/4” to accommodate the servo wire. A
1/4” rat-tail file works well for this job. Round the edges of the cut
to prevent abrading or cutting the servo wire. Make sure the cut is
oriented such that the servo screws will go in the block’s cross-grain.
Prepare the wing-servo Access Covers
:
On both
wing servo covers, measure the width of the opening-notch
and mark the center of the opening. You will be aligning the servo
arm with this mark. Marking both sides will make it easier to align the
servo. The servo-cover only goes on one way. Please observe that
the notches face toward the wing tips; therefore, the servo-arms in
each wing panel face in opposite directions; i.e.; toward the wing tip.
Mount Servo to Hardwood Blocks:
Place the wood servo blocks against the servo mounting tabs as
shown left. Place 2 - 3 pieces of 20 pound paper beneath the servo
to raise it slightly off the surface . While holding the blocks against
the servo mark the mounting holes with a pencil or a punch. Predrill
the blocks with a 1/16” drill bit and mount the servo to the blocks
using the servo manufacturer’s supplied screws.
Now is a good time to mechanically center the servo arms.
Connect the servo to the receiver’s aileron port and turn on your re-
ceiver and transmitter. With the aileron controls (stick, trim, sub-
trims, centering) set to neutral, mechanically mount the servo arm on
the servo shaft, such that it is perpendicular or square with the cover
surface. Repeat this process for both wing servos.
Epoxy Servo Blocks to Cover Plate:
Remove the paper spacer from under the servo and place a
piece of wax paper between the servo, the blocks and the cover plate
to prevent epoxy from getting on the servo. Realign the servo and
mark its position. Mix the two-part, 30-minute epoxy and apply to the
block, reposition the servo on the cover and clamp. Set aside and
repeat process on the other wing servo. Remove wax-paper when
cured. Install the Servo-block safety screw, after curing.
Install Servo Extension Cables:
Locate the servo extension cable-hole on the top of the wing
near the root rib. In not already cut out, cut an “X” in the covering over
the hole. Hold the wing vertically, with the tip down and feed the 18”
extension wire through the wing and into the servo box. Dress the
cable through the hole and tape-off both ends so that you do not lose
the wire. Be sure to note the “sex” of the connectors so it will mate
with the servo connector. (The Female cable-end goes into the servo
box.) You may use the string-pulls in the wing to assist in getting the
extension through the wing, either works.
