Rand-Kar 917 2006, Assembly Manual

Page: 54 / 72

ASSEMBLY MANUAL XAIR April, 04, 2006 MANUEL DE MONTAGE XAIRF 2 Juin 2006 Page 54 / 72
H/ FINAL TUNING OF CONTROLS CONTROL AND SUR-
FACES
This stage is all too often neglected. Yet, these adjustments make all the difference between an aircraft
that gives smooth, coherent response, and a cantankerous, even dangerous beast.
1) The elevator:
Make sure the pivot bolts are not too tight against the washers.
Elevator trim tab: first of all, check it responds in the right direction! Push the trim lever forward:
the tab should move up (so as to push the elevator down, for a nose down response).
Second, adjust the cables so that the trim tab is in line with the elevator when the handle is
vertical. The trim cables must be tight, but don’t go to excess; number of turns wrapped on the pul-
ley: three. Do not apply any lubricant: here, the more friction, the better! You also need a small
screw to stop the cable from slipping.
2) The ailerons:
-Get two straight tubes or rulers, about 2m (6ft) long. Two helpers will make things easier.
-The turnbuckles must be adjusted so that:
The aileron tips are flush with the two rulers held tight against the leading
edge and trailing edge, lying parallel to the keel, level with the inboard, wider ends of
the ailerons.
(Caution: if you place the rulers elsewhere along the wing, aileron angle will be set differently due to
wing twist).
Both sticks in vertical position.
NOTE: It is not a good idea to have too much tightened cables; a reasonable amount of play is prefer-
able, so that the ailerons are not too « stiff », due to excessive friction.
When you are satisfied, do not forget to safety the turnbuckles.
Also check that the sticks do not bind on the pitch axis: the bolts must be free.
3)The flaps:
Adjusting the flaps is made by screwing or unscrewing the rod end at the tip of the flap fork command.
The undersurface of the flap must be in line with the undersurface of the wing.
4) Rudder tab (N°146)
it corrects engine torque effects. Mount it after the first trial flights if necessary.
5) The rudder:
First of all, and once again, because this bears repeating, make sure that:
THE RUDDER CABLES ARE CROSSED!!
The cables will be under slight tension when the rudder is centered; slack in all other positions is nor-
mal.
When the pedals are lined up, the rudder should be in line with the longitudinal axis of the aircraft:
the easiest way to get this is to clamp the rudder between two cleats and set the adjustable links so
that:
- the nose wheel is in line with the longitudinal axis
- the pedals are lined up
- the cables are slightly taut
Watch out those pulleys! The pulleys at the after end of the keel must be installed so that they cannot
move off of their bearings: the red mark must be visible from outside, (only this way will the bearing
keep the pulley in place).
6) Lubrication:
The ideal lubricant is a silicone spray (if unavailable, you can use a WD-40 equivalent, but it is not
so clean); apply to all points likely to create unwanted friction: control tube washers and pivots, elevator
and rudder hinges, aileron and pedal bearings, all pivot bolts of sticks and parallelogram, as well as the
fork main axle during assembly.
In short, to obtain smooth, precise controls, you need: barely taut cables, barely tight bolts, and
regular lubrication.
H4