8
The final work on the outboard wing panels is to trim the servo well covers to fit and attach them.
Using a soft pencil, draw extended lines on the wing panel to indicate the outline of the servo well.
Place the well cover on the wing with the servo output arm in the centre of the bulged fairing. Mark the
position of the pencil lines on the well cover in this position. Cut along the lines using a pair of
scissors, then carry out any final trimming required using abrasive paper on a block, as shown.
When the well covers are a really snug fit, they can be taped to the wing panels.
Installing the servos in the wing centre section
Sand the inside of the servo wells thoroughly to obtain a good “key” for the adhesive, as described for
the outboard aileron servos.
Cut and file out a 20 mm Ø hole exactly central between the two holes for the wing retaining screws;
the servo extension leads are passed through this hole.
The servos have to be prepared prior to gluing them in the wing, as shown in the pictures.
Use a pair of pliers to expand the heat-shrink sleeves slightly so that they fit over the servos. Remove
the servo output arm before fitting the sleeve. Shrink the sleeve round the servo, allow it to cool down,
then cut the material away round the output shaft; ensure that the output arm does not foul the sleeve
at any point.
Set the servos to centre from the transmitter, then fit the output arms and tighten the retaining screws.
Sand the heat-shrink sleeves before gluing the servos in place.
The slots for the pushrods must again be drilled and filed to shape to clear the camber-changing flap
linkages, as described for the ailerons.
Screw the horns into the flaps as far as they will go, as described for the aileron horns.
The servo leads must now be extended before the servos are glued in the wing. Connect an extension
lead, Order No. 3935.18, to each servo, and secure the connection permanently using a drop of cyano
or a heat-shrink sleeve.
The two flap servos can now be epoxied in the wing as shown.
Once again it is very important to ensure that the servo output arms are exactly in line with the flap
horns.
The next step is to make up the pushrods from the servos to the camber-changing flaps. Screw the
M2.5 pushrod into one clevis, and connect the clevis to the flap horn. Connect the second clevis to the
servo output arm and mark the correct length of the pushrod. Cut the pushrod to length, and screw the
clevis onto the cut end. Secure the clevises with a drop of cyano or thread-lock fluid.
Cut and trim the servo well covers to fit accurately, as described for the aileron servos, and tape them
to the wing centre section.
A further two extension leads, Order No. 3935.75, now have to be drawn through the wing centre
section in order to extend the aileron servo leads.
Glue the extension lead sockets in the facing ribs using cyano. Run all four extension leads out of the
hole in the middle of the wing centre section as shown, wrapped in foam to avoid abrasion damage.
Installing the tail servos in the fuselage
The next step is to glue the servo plate for the two tail servos in the fuselage together with an
aluminium tube (guide sleeve for the tail retaining screw).
Be sure to roughen the joint surfaces of the fuselage beforehand, as already described.
30 mm
Guide sleeve for V-tail retaining screw
Cut the aluminium tube to the length shown in the photo. The position of the servo plate is dictated by
the position of the tail retaining screw.
