Advertisement
Horizontal Stabilisers and Rudder
Parts Required:
Stabs, elevators and rudder
•
Stab parts bag
•
Elevator servo (JR NX8921 or similar)
•
Alloy Servo Arm (SWB, Secraft, Hanger 9 etc) 1.5
•
Tools Required:
Dremel tool
•
X-Acto hobby knife
•
Philips head screw driver
•
Pliers
•
The horizontal stabilisers are pretty much completed for you at the
factory. The dual elevator control horns are pre fitted, and the stab
tube is already set up and ready to go! You will need to trim the 4mm
alloy hinge tube to the correct length, and install your choice of servo.
Fitting the hinge tube is quite simple, and shouldn t take too long. The
SU-31 elevator differs from some CARF models, the hinge pin can
not slide right through, the outside of the elevator does not have an
exit hole. The alloy hinge pin is supplied over length and will need to
be trimmed to suit the SU-31, this also allows you a bit of latitude,
incase you make an error. Using a pair of pliers flatten about 10mm at
the end of the alloy hinge pin, then bend this section over 90°. Drill a
small hole in the flat section for the retaining screw to pass through.
Trial fit the hinge pin and trim to suit, using a small screw locate the
hinge pin into the elevator halve as per the picture. Please keep in
mind these alloy pins are a consumable item, they will wear and will
occasionally need to be replaced, check them as part of your routine
maintenance program, replace when necessary.
In the parts bag supplied you will find 2.9mm x 13mm pan head sheet
metal screw to mount your servos. It s important that you do not use
the mounting screws supplied with your servo. The mounting rib that
is pre installed in the stabiliser has the mounting holes pre drilled for
you and the standard servo mount screws are unsuitable. Some
brands of servos use mounting eyelets that are too small for the
2.9mm screws. You will need to change these if necessary. Use JR
standard servo eyelets.
A servo arm exit slot has been pre milled at the factory. This is only a
preliminary slot, you may need to enlarge the area required to suit
your servo and servo arm. This process is quite straight forward, but
make sure you measure twice and cut once! Mount your servo using
the 2.9mm sheet metal screws provided. The output shaft of the servo
goes toward the stab tube. Pass the servo lead through the pre drilled
hole in the rib before dropping the servo in place. You will need to
assemble the components that make up the push rod. It may be nec-
essary to trim the 3mm threaded rod and brass tube. The brass tube
slides over the threaded rod to add strength. The brass tube should
not be loose, a snug fit is required.
Alternatively you may want to use an aftermarket turnbuckle, such as
those provided by SWB, Secraft or Hanger 9. A turnbuckle length of
60mm is required. A suitable ball link may also be used in place of the
alloy clevis.
Sukhoi SU 31—2.75m/2.6m
Page|12
Advertisement
