[Fig.20]
Trim the airbrake support strips 17 to fit on the sides of the
airbrake bottom sections and attach them with a little 5-
minute epoxy. Now trim the airbrake bottom sections to fit
in the slot in such a way that the top edge of the unit is about
1.5 mm below the wing skin. This is done by sanding back
the underside of the airbrake support strips.
Glue the bottom airbrake section in the wing using 5-
minute epoxy.
Trim the airbrake well surround strips 18 to fit, glue them
in place using a little 5-minute epoxy and remove the
parcel tape from the wing while the glue is still soft. Allow
the epoxy to set hard, then sand back the surround strips
flush with the wing skin.
The airbrake pushrods are made from the remainder of
the elevator and rudder pushrod material. Solder a clevis
onto one end of each rod.
Now assemble and install the linkage and the Contest
airbrake actuating arm following the instructions supplied
with the brakes. Leave the top blade off at first, as this gives
better access to the mechanism. Install the pushrod from
the airbrake end, cut it to length and connect it to the
airbrake unit. Check that the linkage works correctly and
freely, and make any adjustments required. Remove a
little foam in the area of the servo output arm to clear the
clevis, and solder the clevis to the pushrod. Check that the
servo and the airbrake are in the centre position when you
do this. Connect the clevis to the third hole from the inside
of the servo output arm and cut off excess output arm
material.
Tip: a good alternative is to fit a threaded coupler at one end
of each pushrod at the airbrake end, as this allows you to
make fine adjustments at any time from within the airbrake
box. To do this you just have to remove the top brake blade.
Install the airbrake servo, connect it and fit a plain servo
frame cover (no pushrod fairing). Install the airbrake
blades.
Attaching the airbrake capstrip
Trim the airbrake capstrip 19 to fit in the opening, sand it
about 0.5 mm narrower all round and attach it to the
retracted airbrake using a little 5-minute epoxy or double-
sided adhesive tape. Check that the system works correctly
and adjust if necessary. Sand the airbrake capstrip flush
with the wing surface with the brake retracted. Work very
gently here and take great care not to strain the mechanism
or the blades, otherwise you could distort the airbrake and
cause it to malfunction.
If your model is the uncovered version you now have to
decide whether to paint the wings or apply iron-on film.
Film: just sand the wing surfaces smooth overall.
Leave the trailing edge about 1 - 1.5 mm thick. On no
account round off the trailing edge, as a thicker square-
edged trailing edge is almost as efficient as a razor-sharp
one, but much more durable in everyday flying - especially
if you cover the wing with film.
Paint: the alternative method of finishing your Alpina 4001
ELEKTRO is to apply glass cloth and resin and then paint
the surfaces (see later for more details). This is the only
route to take if you are aiming at top performance and an
outstanding finish.
Sand the wing surfaces clean and even, aiming to smooth
out and maintain the airfoil section as accurately as
possible. Use a sanding block at least 30 cm long, and
preferably 50 cm long. Make sure that the sanding block
is perfectly straight and stick the abrasive paper to it using
double-sided tape. The best type of abrasive "paper" in our
experience is the abrasive band designed for use with
band sanders. It is slightly more expensive than the usual
type, but lasts much longer. Sand in long strokes, using
light but even pressure, and use a figure-of-eight motion.
This completes the basic assembly procedure.
Installing the radio control system
Installing the servos and control linkages in the fuselage
If you have not already done so, this is the time to install
the elevator and rudder servos.
Solder a clevis 40 securely to the rudder end of the rudder
pushrod 80. At the servo end solder a threaded coupler 41
and fit a locknut 45 and clevis 40.
Solder a threaded coupler 41 to the servo end of the
elevator pushrod and fit a locknut 45 and clevis 40.
Connect the clevises in such a way that full servo travel
can be exploited.
The snake outers for the elevator and rudder pushrods are
located at the servo end using pieces of the channeled
strip 17, which are glued to the fuselage.
Installing the wing-mounted servos and linkages
Install the servos in the servo frames, cut the threaded
pushrods 42 to length if necessary and screw the clevises
40 on the ends. Lock the clevises at the servo end with a
drop of cyano glue, and lock the other clevises with the
M2.5 locknuts 45, so that you can make adjustments as
required.
If your model features airbrakes, install the airbrake
servos and connect the pushrods.
If your radio control system is unable to supply the airbrake
signal to two separate outputs, you may have to install one
airbrake servo with the output arm pointing at the bottom
wing skin. In this case install the servo at the appropriate
depth in the wing and secure it carefully.
It is a good idea to carry out basic adjustments to the radio
control system at this early stage. Please note: the full
travel of the servos should always be exploited!
Attach the servo frame covers 71 and 72 using the screws
73.
Electrical connection, wing / fuselage
The Alpina 4001 ELEKTRO has four or six wing-mounted
servos which have to be connected to the receiver. They
are connected at the fuselage / wing transition using grey
5-pin MPX plugs and sockets; the wings and the fuselage
are designed for these connectors as standard. All the
wing-mounted servo cables should be fitted with
separation filters as shown in the diagram. Cable sets
including all the parts required together with detailed
instructions are available under the following Order
Numbers:
If connecting:
4 servos
Cable Set 2, MPX Order No. 8 5256
6 servos
Cable Set 1, MPX Order No. 8 5255 in
addition
21