Multiplex Alpina 4001 ELEKTRO Notice De Construction page 20

and wipe off excess epoxy with methylated spirit on a cloth.
Allow the resin to set hard then remove the parcel tape,
unscrew the cover and sand the area flush using a long
sanding block (uncovered version).
Separating the ailerons and camber-changing flaps
To avoid transport damage the control surfaces are supplied
still attached to the wings. Using a fine hacksaw blade (for
a straight, clean cut), saw out the surfaces at right-angles
to the fuselage centreline. At the inboard (fuselage) end
leave a fixed panel about 95 mm long attached to the wing.
The camber-changing flap should be about 850 mm long,
and the aileron 900 mm long. Do not leave a fixed portion
between the aileron and flap. Glue the plywood end lining
pieces to the cut faces of the wing and control surfaces,
remembering to take the thickness of the plywood into
account when cutting the control surfaces to final length.
There should be a gap about 0.5 - 1 mm wide between the
flaps and ailerons.
[Fig. 14]
Installing the wing retainer system
The wings are held against the fuselage using the
MULTIlock system. The wings can be fitted to the fuselage
quickly and easily, but are adequately secure while the
model is in flight.
To disengage the MULTIlock system and dismantle the
model, grip the wing with finger and thumb at the spar
position (i.e. wrap your hand around the root leading edge)
and hold the fuselage against your body. A brief tug at the
wing will release the MULTIlock system, and the wings
can then be slid off in the usual way.
[Fig. 15]
Fix the MULTIlock sockets 47 in the fuselage with a drop
of cyano. The MULTIlock plugs 46 have to be installed in
the wings.
Mask off the fuselage root fairing with wide parcel tape and
apply mould-release wax to the area around the wing
retainer. Push the retainer plug 46 into the fuselage-
mounted socket. Plug in the wing and check that the
retainer can be sunk completely into the wing root.
TIP: If you need to separate the retainer plug from the
fuselage before gluing it in place, the easiest method is
to use a pair of pincers: grip the retainer plug by the
innermost groove and "roll" the pincers along the fuselage
root fairing to disconnect the retainer.
Apply plenty of thickened 5-minute epoxy to the hole in the
wing root, plug the wing in and tape it in place. Remember
to fit the MULTIlock plug before you do this! Allow the resin
to set hard, then release the wing from the fuselage as
described above.
Installing the ring-screws (aileron / flap horns)
The horns are installed as described for the rudder horn,
although in this case it may be necessary to remove a little
of the lining strip below the skin. A small rotary cutter is very
useful here, although it is also possible to use a small
sharp bradawl.
To provide adequate aileron movement the ring-screws
should be shortened by 5 mm. For the camber-changing
flaps use the horns full-length.
[Fig. 15]
20
Installing the film hinges
This model is designed for tape hinges, i.e. the finished
ailerons and camber-changing flaps are attached to the
wing with adhesive tape. One long strip is applied to the
top surface, and a second in the slot on the underside. This
method of attaching control surfaces has proved durable
and efficient in the long-term.
Unfortunately there is a tendency for the strips of tape to
"float" over the course of several months due to unequal
pressure in storage and warming up at the flying field. The
hinge is then no longer efficient, and the resultant "step"
can look unsightly. This problem can be eliminated by
fitting supplementary plastic film hinges. However, they
can only fulfil their purpose if the pivot axis of the hinge is
located exactly at the pivot axis of the control surface.
Fit three film hinges 50 in each control surface - in each
case one should be immediately adjacent to the horn.
Cut a slot for the hinge starting exactly at the point of the
hinge pivot line, cutting into the lining strip at an angle of
about 45° to the top surface. The best tool for this is a thin
diamond-tip grinding wheel mounted in a 12-Volt electric
drill. You can use a junior hacksaw blade to clean up the
slot and adjust it to fit the hinge. If the slot gets too wide and
the hinge is a loose fit, pack it up on the underside with a
strip of thin plywood.
Caution: the film hinges are simply pushed into their
slots; don't glue them!
[Fig. 16]
Installing the (optional) airbrakes
If you intend to fly your Alpina 4001 ELEKTRO
predominantly from the slope we recommend that you
install 370 mm Contest airbrakes, MPX Order No. 72 2646.
The first step is to install the airbrake servo frame in the
underside of the wings.
[Fig. 17]
Installing the airbrake servo frames
Mark the position of the servo frame on the underside of
the wing skin and cut through the skin and the foam core
with a sharp craft knife.
[Fig. 18]
Note that a small section of the airbrake servo box must
be sawn out so that the pushrod can be installed "under
the skin".
[Fig. 19]
Glue the servo frames in the wing as described in the
section "Installing the wing-mounted servo frames".
To install the airbrake units first mask out the appropriate
area on the top wing skin with a strip of wide parcel tape.
Mark the position of the airbrake as accurately as possible
using a narrow-tip waterproof felt-tip pen. Hold the bottom
section of the airbrake on the wing skin, top side down, and
cut out the wing skin (20 x 370 mm) using a sharp balsa
knife. Carefully remove the foam core down to the bottom
skin, leaving a neat slot. This is best done using light
pressure and a gentle sawing motion to achieve a clean
cut.