9
In the prototype, the larger of the three air tanks serves the gear
and doors, while the smaller tanks serve brakes and air brake
respectively.
Refer to the general construction tips for an explanation on
gearing up the air systems.
Install three air tanks in the space beneath the forward
component board, with the large tank in the middle. Use several
dots of a silicone based glue such as Zap-a-Gap-a-Goo. Don’t
overdo the glue, however, as you may want to remove the tanks
in the future and the component board will hold the tanks
partially in place in any case.
When the glue is dry, run air system lines to the tanks. In the
prototype, all air and fuel fill lines are run to the rear hatch so
that the cockpit may be left in place while servicing the plane.
Lay out the air system components on the forward component
board and then bolt the board into place with four small wood
screws.
Run air lines to the nose gear and nose door cylinders. A little
patience and good skills with a forceps will be required. Test
each line as you go with a hand pump for leaks. It will also help
to follow a color coding scheme for future line identification and
trouble shooting.
photo 15 – air micro switch to active small nose gear doors
As described in the general notes, the twin doors that flank the
nose gear strut in the prototype are activated by an air micro
switch. Make a small platform of scrap ply and attach the micro
switch with a wire tie or a bracket. Push the switch up against
the bottom of the steering servo when it is in the retracted
position and secure to the top of the retract unit with wire ties
(
photo 15
).
Step 6: Vertical Fin and Rudder
Before attaching the aft section of the fuse, the vertical fin and
horizontal stabilizers need to be attached and the wires run from the
servos. This is because the pipe must be in the aft section when
installed, and access to the wiring is restricted once the pipe is in
place.
In most kits, the hinges are preinstalled in the control surfaces, but
must be glued into the flight surface.
When removing the servo well covers, label appropriately for proper
re-installation.
Trial fit the rudder into the vertical stab. You may need to snip
about 1/8 inch off the bottom hinge as it butts up against the
rear aluminum spar. Trim and sand to achieve the maximum
throw your servo arm will allow.
Attach two aluminum “L” brackets to an 8411 servo or
equivalent. Position the brackets such that the spindle of the
servo faces forward when installed in the servo well. Do not use
the rubber grommets supplied with the servo, but bolt it directly
to the brackets. Use Loctite.
Using a JR Matchmaker or your receiver, power up the rudder
servo and set it at neutral. Attach the control arm at a vertical
position.
Position the servo on the two ply mounting tabs and attach the
“L” bracket with 15mm wood screws.
Run the servo wire out of the bottom of the vertical stab.
Trial fit the phenolic control arm in the slot routed in the rudder
at the factory. You may need to use a small carbide cutter to
enlarge the slot slightly for a good fit. Be careful not to route
through the other side of the control surface. A small piece of
