4 Rigging Coupler Assemblies (R/C link, Rigging Coupler
& Lock Nut)
4 Copper Swage Tubes
2 1200mm (47") lengths of nylon coated steel pull cables
In addition, you will also need your rudder servo and output arm.
A pull-pull rudder control system is all about geometry. Ideally the
distance between the opposing pull-pull control horn connections
at the rudder is the same distance between the pull-pull
connections on either side of the servo output arm. If these two
separate connection distances vary too much, excess strain can
be placed on the servo or the rudder at extreme movements. This
information is useful if you should decide to make your own
custom rudder servo output arm, as we did.
The Edge 540T was designed with control horn mounting locations
that approximates the mean aerodynamic cord of rudder itself.
The rudder was built with thick hardwood control horn mounts at
its leading edge, on both sides. These mounts can usually be seen
if you hold the rudder at an oblique angle to the light.
For
reference, the photo below shows the outlined mounting pad
location.
1) The rudder must first be hinged to the vertical fin, using the
hinging instructions provided earlier.
2) The rudder servo is now mounted into the large center opening
on the plywood tray in the fuselage.
As always, it should be
mounted using the hardware provided with you particular radio
system. We positioned our rudder servo with its output spline
forward. Note that the plywood mounting tray has been built in with
a slight upward angle to better line-up the servo and pull-pull
cables with the two cable exit slots at the rear fin/fuselage fairing.
3) Two of the rigging coupler assemblies are now fitted to one end
of each of the two pull-pull cables. Slide a copper swage tube onto
the cable and thread the cable end through the hole in the rigging
coupler and back through the swage tube, leaving about 1/2" of so
of excess cable. Use a pair of thin nose pliers or a crimping tool
to squeeze the copper swage tube tightly over the cable, locking it
17
servos aft, back with the receiver(s), rudder servo and the airborne
radio system battery pack(s).
There are two servo cut-outs located on each side of the center
mounted rudder servo tray in the fuselage. Locating the throttle
servo into one of these openings is ideal. Since the fuel tank is
already mounted and plumbed on the left side of the fuselage, the
right side servo opening is likely the better choice. The servo can
be mounted into the servo tray opening using the mounting screws
provided with your radio system. The Edge kit also includes a
separate plywood laser-cut throttle servo tray. This can be used if
you wish to mount the throttle servo in different location.
Once you have chosen a location for the throttle servo and have it
mounted, the servo can be connected to the carburetor throttle
arm using either a commercial 2-56 or 4-40 nylon pushrod system
(not included). Note that the kit also includes a single 1.8 x 300mm
metal pushrod and clevis. This can be used, if desired, when
hooking up your throttle linkage. Below is a photo of our own
custom throttle servo set-up, showing a lite-ply mounting tray that
we made to fit between the forward fuselage cross braces, just
ahead of the rudder servo. As you can see, we used the Sullivan
#517 gold/black 4-40 pushrod system. This set-up gave us a
straight shot forward to the carburetor throttle arm.
For throttle pushrods, we suggest the Sullivan Gold-N-Rod #517
Black/Gold 4-40 semi-flexible system, or the Sullivan Gold-N-Rod
#575 Blue/Grey 2mm semi-flexible system or the Sullivan
Precision Rod #580 White/Black 2-56 semi-flexible system. These
are great set-ups for use in the Edge and include 36" of inner and
outer tubing, as well as all the required hardware for hook-up. Just
be sure to support the outer tube every 8" to 10" forward to the
carburetor, using scrap pieces of lite-ply.
Rudder Servo & Pull-Pull Installation:
The rudder servo and the pull-pull connections will be made in the
following steps. You will need the following parts from the kit:
2 Control Horns - 1 Left, 1 Right
8 T2.6 x 16mm Phillips head screws