With the firewall already installed, the tail ring (above left) is attached to the motor to final check the fit to the fuselage and hold it in place while gluing. Success!
weave of the cloth, thoroughly wetting it. The strips of cloth are then placed around the perimeter of the mounting structures (on both sides) to “corner” the glue joints, greatly increasing the gluing area and load distribution on the fuselage sides. At this point, the major construction item remaining is locating and securing the mo- tor Li-Pos and the ESC. As the motor Li-Pos will comprise close to 25% of the weight of the plane ready to fly, a small shift in their location can have a substantial impact on the c.g. Now is the time when I finish up some of the “fiddly” bits to make it easier to get the Li-Pos in the best location. The pre-assembled tail wheel mechanism is easy to install. An approximately 3⁄16-inch diameter hole is drilled on the centerline of the fuselage bottom, about 1 inch in front of the rudder hingeline, into a balsa wood block (already installed by RC-Composit). The tail wheel assembly is glued into place, being careful to avoid getting glue on bear- ing points. The tail wheel is controlled by means of a 0.020-inch (0.5 mm) tiller arm that connects to the rudder. To connect the
With the firewall and tail ring removed, the proper thrust alignment (above right) has been achieved.
tiller to the rudder, I used a ½-inch long piece of yellow nyrod (any similar plastic tube or hardwood dowel can be used) cross- drilled (for the tiller) close to one end. The nyrod is glued into a 1⁄8-inch hole drilled into the bottom of the rudder, approximately 2 inches from the hingeline.
Attaching the tiller to the tailwheel is ac- complished by “pinching” the tiller between the coils of the spring of the tail wheel, and then wrapping the coils with a bit of Kevlar thread (and then a drop of thin CyA). The in- cluded pictures should greatly clarify the pri- or descriptions. While not quite as aestheti- cally slick as some of the commercial units, this assembly is very light and provides a substantial measure of shock isolation be- tween the tailwheel and rudder servo. With all the servos and linkages previous- ly installed, installing the receiver and radio Li-Pos are a quick process. The rudder servo tray provided by RC-Composit has a variety of slots and holes precut to serve the purpose of lightening the tray and facilitate a num- ber of mounting options for the receiver and radio Li-Pos.
The JR 921 receiver was mounted with a hook and loop strap to the right front corner of the rudder servo tray. Three inch long 22 AWG extensions for each aileron servo proved to be just long enough to reach the leads from the aileron servos. A 3⁄8-inch diam- eter sharpened brass tube was used to drill holes in the vertical balsa reinforcement for- mers, allowing the passage of the elevator servo leads and the wire for the satellite re- mote of the JR 921 receiver. The second satel- lite remote was installed below the main re- ceiver, close to the bottom of the fuselage. The pair of Tech Aero Flex Regs (ad- justable voltage regulators) were held to- gether with servo tape, and then servo taped to the bottom side of the left front corner of the rudder servo tray. The pair of Thunder Power 2S1P480 Prolite Li-Pos were held to- gether with servo tape, and then mounted on the left front corner of the rudder servo tray with a hook and loop strap (that addi- tionally provided added support for the Flex Regs). Very compact and tidy installation with minimal wiring length and connectors for low weight and good efficiency.
A tiller arm connects the tail wheel to the rudder and provides a degree of isolation to the rudder servo from shocks from the tail wheel (above, at left). Tiller arm is pinched between coils of the tail wheel spring (at left) and secured with several wraps of Kevlar® thread. With elevator and aileron servos mounted within the wings and stabs, the remainder of the radio equipment (above) is installed on a single tray at the aft end of the canopy opening.
FLYING MODELS 33
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