Top Flite Metrick - Manual (Page 12)

directions for the desired control response and can sit
side-by-side with the movement of the output arms not
coming in contact with each other or the fuselage sides,
the servos can be mounted in place using small #2 x 1/2"
wood screws (not supplied). At this point, servo con-
nection with the pushrods is the next stop. First, center
the servos, using the trims on the transmitter. The servo
output arms should fit approximately 90° to the fuselage
sides to deliver equal movement. You will probably have
to drill-out the holes in the servo output arms to about
.076 dia. to accept the 3" threaded one-end studs pro-
vided for servo connection. With a razor blade, cut-off all
but 1/2" of the inner yellow nyrod pushrod that is protrud-
ing into the servo compartment. Thread at least V4" of the
threaded end of the 3" threaded stud into the inner nyrod.
We would suggest "nuetrilizing" the rudder and
stabilator first, with tape. As shown on the plans, make a
"Z"-bend at the servo-end of the stud and cut off the
remainder of the stud. The "Z"-bend can now be pushed
in place through the drilled-out hole in the servo output
arm and the output arm screwed in place on the servo.
Note that the servo plug wires are routed forward,
through the hole in f o r m e r F-5 to the receiver
compartment.
With our METRICK's we chose not to mount the switch in
the typically external manner, but rather left them loose
in the receiver compartment, packed with foam rubber in
the upright position. This requires that the canopy/hatch
be lifted up, the switch activated before and after each
flight. In practice, this proved to be perfectly acceptable
and the fuselage side was spared the need for the cutting
of holes for the switch—use the method that most agrees
with you.
If you are planning on flying your METRICK with 2 chan-
nels, your radio installation is now complete and you can
move on to the PRE-FLIGHT and FLYING sections of these
instructions.
As mentioned earlier in the instructions, if you have
planned to run a third spoiler channel you should now
install this servo. The third, optional, servo installation
shown on the plans for spoiler activation is the system we
used in our prototypes and works quite well. You will
need to fabricate two 3/32" x 1/4" x 1-5/8" ply servo rails
(material not supplied) for mounting this servo beneath
the access hatch, as shown. Use Dubro #181 "Ball-Links"
(not supplied) on each side of the servo output arm for
the loops in the ends of the spoiler chords to slip over. You
can see that as the servo is actuated, by moving the
"throttle" stick or lever on the transmitter, the arm
rotates, thus pulling the individual spoiler chords,
causing the spoilers to be pulled up. As the servo is
returned to its' original setting, the rubber bands in the
spoiler bays pull the spoilers back down flush with the
wing's upper surface. It is most important that the
tension relationships are the same for both spoilers and
that they deploy at the same angles and that they return
flush with the wing panels. Valuable wing efficiency can
be lost with improperly seated and/or deployed spoilers.
Note that the travel of a standard servo is sufficient to
deploy to spoilers to about 50°-70° at full movement. This
amount of travel is more than sufficent to achieve radical
loss of lift. 90° movement of the spoilers in relationship to
the surface of the wing is not needed. Once the servo is
mounted in place to your satisfaction, route the plug
harness wire forward, through former F-6 (you will have
to cut a small, appropriate-sized hole), through the servo
compartment and through former F-5 to the receiver.
Install the wing panels to the fuselage and secure with
two #62 rubber bands between the two eyehooks, as if in
preparation for flight. The two loose, unlooped ends of
the spoiler chords should now be inside of the fuselage,
roughly lined-up with the "Ball-links" on the servo output
arm—the servo should be set at the "low spoiler setting",
in other words spoilers down. At this point, we taped the
spoilers down, flush with the wing, using making tape.
Slip a short length (about 1/4") of 3/32" I.D. brass tubing (not
supplied) over one end of the spoiler chord, wrap the
chord around the "Ball-Link" and slip the end back
through the tubing, creating a loop about 5/16" long. Pull
on the chord until the slightest resistance is felt and crimp
the tubing with a pair of pliers. We applied a small drop of
instant glue to the tubing/chord joint to complete the
connection. Repeat this process with the opposite chord,
remove the tape holding the spoilers in place and test the
action of the spoilers, using the transmitter. Remember
that in order of priority, #1 is to have the spoilers sit flush
with the upper surface of the wing when fully at rest.
Test the action of the entire radio installation to make sure
that it is bind-free and that radio commands from the
transmitter provide the correct surface movement. This
cannot be stressed enough since backward servo instal-
lations are one of the number one reasons for initial
crashes—check it and then check it again!
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