3
tailplane horns. The rods are guided with pieces of white plastic tubing, mounted on the outer
side of the tailboom.
Use one pair of the tubes about 130 mm long in the wing leading edge region and another 3
pairs ca. 20 mm long, located evenly along the boom. Another piece of tubing in the stab TE
region is necessary to guide the rudder rod. We recommend just to tape the tubes to the
boom. Easy, secure.
The pushrod is attached to the servo arm with piano wire Z-bend, while the moving surface
horn is attached with L-bend. All is made of 0,8 mm piano wire. The rod is connected with the
wire with piece of shrinking tape. Use clean soldering iron tip to shrink the tape. Set up both
servo arm and movable surface into neutral positions before. You have few seconds to fine
tune the length if necessary, before the tube gets stiff. When satisfied, secure with drop of thin
CA.
At worst, cut off the tubing with sharp knife and start again.
This solution is very reliable and lightweight.
The L-bend on the rudder can be secured with ca. 3 mm of plastic tubing, pressed with pliers
and secured with CA drop. The L-bend of the stab cannot move out, as it is close to the
fuselage side. However, if the leg is ca 8 mm long, there is next to impossible to get loose.
The L-bend allows for easy detaching the stab, what is very good for the transport reason.
Be very careful when apply thin CA close to the rod/tubing. A drop inside can totally destroy
your effort. We recommend to drop CA on piece of paper and to apply with toothpick.
Ailerons and brakes
The pushrod is made of Z-bent (servo side) 0,8 mm piano wire and metallic tip, plus plastic
fork (horn side).
We prefer 2 mm aluminium rod, with threads on both ends, shown on the web. The
disadvantage is that tools to make M2 threads must be used.
Moving surfaces deflections
We suppose to program three flight modes: normal, thermal, speed.
Normal: Flaps (ailerons and brakes) – neutral position, flush with the central part of the wing.
It is ca. 2 deg down in respect to the front wing part.
Thermal: Flaps (ailerons and brakes) ca 6 deg
Speed: Flaps (ailerons and brakes) flat bottom airfoil
The flaps movement must be compensated with elevator, in the same sense: flaps down,
elevator down and vice versa.
Note: Make a cardboard templates with tip angles 178 and 174 deg to adjust the flaps
deflection.
Typical movements of the control surfaces:
Ailerons ca +10/-5
V-tail +/- 8 mm
Fin +/- 20 mm
El/- 5 mm
Butterfly (landing)
Brakes + ca 70 deg
Ailerons – ca 10 mm
Elevator compensation: ca 2 mm, adjust as necessary
Transmitter sticks: according to the pilot habit. Usually, the motor is controlled by a switch.
For the competition type spot landing the brakes (butterfly) must allow for fluent control.
Centre of gravity
The good starting position is ca 70 mm behind the wing leading edge. Usually, the CG is
moved rearwards when you and the model are good friends.