Multiplex alpha 21 Instrucciones De Montaje página 12

2. Superfine glass fibres, Order No. 60 2784, produce a
rock-hard joint.
3. Micro-balloons, Order No. 60 2779/80, convert the resin
into a lightweight filler paste.
4. The special thixotropic agent, Order No. 60 2782, makes
all the adhesives and fillers listed above thixotropic, i.e.
prevents them running off a vertical surface.
The Kit
The kit you have just purchased includes every item you
need to complete the basic airframe, including linkage
hardware, but does not include adhesives.
You can make a significant contribution to the model's
ultimate performance and appearance by building accurately,
carefully and patiently. A badly built model usually flies
badly and is hard to control. An accurately built and well
trimmed model will reward you with high performance,
docile handling and a pleasing appearance, and will give
pleasure to pilot and onlooker alike. Take your time - the
effort is well worth while. These building instructions have
been designed to help you get the best out of the kit, so
please follow the procedures and the sequence of assembly
described as accurately as possible.
MULTIPLEX model kits are subject to constant quality checks
throughout the production process, and we sincerely hope
that you are happy with the contents of your kit. However,
we would ask you to check all the parts before you start
construction, as we cannot exchange components which
you have already worked on. If you find any part is not
acceptable for any reason, we will readily correct or exchange
it once we have examined it. Just send the component to our
Model Department. Please be sure to include a brief
description of the fault.
The alpha21is a rudder/elevator glider which can easily be
converted to a three-axis machine.
The alpha 27 is the ideal model for the week-end flyer who
is keen to move up from rudder/elevator to a three-axis
machine.
... so let's get down to work.
Fuselage
We will start by completing the fuselage, as this is the
reference point for all the other components.
If you have opted for one of the two electric versions, you will
If you are building the glider version you can skip the
following sections (until paragraph 4).
alpha 21
MULTIcont 40/16 BEC MPX speed controller
7/1700 mAh battery
alpha 27
MULTIcont 40/16 BEC MPX speed controller
10/1700 mAh battery
The motor bulkhead is factory-fitted
Your task is to install the motor accurately. If the holes for
motor mounting do not line up exactly with your motor
(manufacturing tolerances), adjust them slightly using a
small round file.
Fit the propeller hub and spinner on the motor to help you
12
align the parts accurately. There should be 1-2 mm clearance
between the spinner and the fuselage. When everything fits
correctly, remove the motor again and apply thickened
epoxy (super-fine glass fibres, MPX # 60 2784) all round the
bulkhead joint. Apply a generous fillet of epoxy on the front
face; on the rear face you will need to be sparing with the
epoxy, otherwise the motor may not fit flush against the
bulkhead.
Fig. 2
Cooling slots
Mark the position of the three cooling air slots on both sides
of the fuselage using a pencil. A template for the slots is
printed in these instructions.
Cut the cooling slots by drilling a series of closely-spaced 3
mm Ø holes, then filing them out carefully to final size.
Fig. 3
Making and installing the battery holder
Assemble the flight battery holder from the wooden parts
62, 63 and 64, and glue the parts together. Glue the block E-
05 to the underside of the battery holder at the front and fit
the screw 66 to reinforce the joint. Sand the block 65 to
follow the curvature of the fuselage, and place the battery
holder temporarily in the fuselage. Ensure that the holder
does not foul or damage the bowden cables, and adjust
their position if necessary. Before finally gluing the battery
holder in position check the model's Centre of Gravity, as
you can move the flight pack forward or aft at this stage to
correct any discrepancy. When everything fits correctly glue
the battery holder to the fuselage, applying thickened
epoxy to both sides at the rear and to the block 65 at the
front. Remember to roughen the inside of the fuselage
beforehand using 80-grit paper.
Fig. 4
The flight pack is held in place as follows: at the rear the
battery engages under the retaining strap and at the front
it is attached using a strip of Velcro (hook-and-loop) tape.
Note that the adhesive on the Velcro tape does not stick very
well to bare wood, so you will need to fix the hook tape to
the plate using cyano.
Towhook support block (glider)
The towhook support block 10 should be epoxied in place
at this early stage while accessibility is still good. Measure
the hook position aft of the extreme point of the nose on
the underside of the fuselage using a tape measure:
Drill a central 2 mm Ø hole at this point and seal it off on the
# 7 2252 outside with a strip of tape. Roughen up the inside of the
# 15 5646 fuselage at the block position using 80-grit abrasive paper.
Glue the towhook block 10 centrally over the hole using
# 21 4131 thickened 5-minute epoxy.
# 7 2252
# 15 5534 Fig. 5
Completing the canopy
The canopy is supplied ready-made, but you may have to
trim it slightly. Remove all rough edges from the steel pin
42 and round off one end. Glue the prepared pin 42 in the
channeled wooden rail 14, then glue the channeled rail
centrally to the canopy using thickened 5-minute epoxy.
for the alpha j21
for the alpha 27
345 mm
385 mm