Sukhoi SU 31—2.75m/2.6m Page|14
The aileron servos need to be attached to the hatch covers on the
bottom of the wing. Plywood mounts are provided for this purpose.
Once assembled these mounts will need to be epoxied onto the servo
hatch. Assemble the mounts and for now, just CA them.
You will need to mark out the placement for the servo mounts on the
hatch covers. Be careful that you have the hatch cover in the correct
orientation. The servo hatch sits on a plywood retainer built into the
wing. This small ledge is about 5mm wide. You will need to mark this
area on the servo hatch as shown. The servo mount is mounted
slightly off centre in an effort to get the servo output shaft as close to
the centre of the servo arm slot as possible. The servo needs to be
installed with the output shaft toward the leading edge of the wing.
Place the servo mount so as your servo arm fits nicely between the
edges of the cut out. When satisfied with its position epoxy in place,
making sure you epoxy the inside corners of the servo mount. Don t
forget to give the surface of the hatch a light sand before applying the
epoxy. Set aside and allow epoxy to set.
Now your servo hatches are complete, and you can now fit them to
the wing. Sit the hatch in place and hold them there with some mask-
ing tape while you pre drill the holes for the hatch retaining screws
Use a small drill bit (1.5-2mm) to drill the holes for the hatch cover
retention screws. Use the 2.9mmx15mm sheet metal screws pro-
vided.
A couple of servo extension leads will be required to have the servo
leads exit the wing root. As these leads will be permanent, it would be
wise to use a safety clip or some heat shrink to prevent the leads from
separating. This is good practice for all extension leads that will re-
main permanently attached.
Assemble the push rods from the components in the parts bag. If necessary trim to length. The servo arm should exit
the hatch at 90° to the hatch. Ensure that both the aileron servos are aligned like this. The push rods for both sides
should be the same length. If you wish to use after market turnbuckles a 60mm or 2.5 item is required. Alternatively a
ball link can be used in place of the alloy clevis.
Attach the servo hatch's to the wing using the 15mm screws provided. The aileron control horns are pre fitted at the
factory and ready to use. These double horns provide excellent strength and the 3mm ball link provided will fit nicely
between the horns. When you have adjusted the push rod to the correct length, fit the push rods between the servo
and control horn. Carefully move the aileron through its full travel to ensure there is no binding.
Ailerons