Multiplex DG - 300 Bauanleitung Seite 30

Cut the sealing strips 25 as shown in the drawing, glue them in place,
and sand the edges llush. As mentioned in connection
with the
elevator, take care to leave the hinge pivot edge sharp and dead
straight. Check that the ailerons are an accurale fit t0 the wing.
When fitting the leading edge strip to the aileron, the panel must be
weighted down on a perfectly llat board, with its front edge projecting
slightly, to avoid the risk 0f distortion.
The following section describes two methods of operating the ailerons:
first, the conventional
method using servos m0unted in the fuselage in
conjunction
with bowden cables and bellcranks, and secondly, servos
mounted directly in the wings.
Ailelon bellcranks
Drill a 3 m.m.0 hole in the bellcrank
support 34 where marked.
Assemble the'super-flat"
bellcrank 35 as shown in the drawing, and
screw it to the bellcrank support. The bellcrank should be free-
moving, but free also of lost motion. ll necessary,
this can be achieved
by rubbing one ol the two llanged bushes on grade 400 wet-and-dry
paper to relieve it slightly. Carefully adjust the tightness 0l the screw,
then secure the nut on the reverse side of the suoport with s-minute
ep0xy.
Belore the bellcrank
is installed
in the wing, a little foam must be
removed in the region of the bellcrank well, as shown in the drawing.
Do lhis carelully.
to avoid weakening the wing.
Pass a steel rod 18 into the bowden cable outer from the wing root,
and slide it as lar as the bellcrank.
Pull the rod out ol the well slightly
and roughen up the end. Thread a metal quicklink onto the end, and
bend the final 2 m.m. over at 90'. Slide the quicklink
right to the end,
and solder it securely to the rod. Connect the quicklink to the
bellcrank,
and fit the bellcrank support into the wing (please note the
connection point shown on the plan). Check that the bellcrank rotates
smoothly.
Slide the wing-mounted
bowden cable outer as far as possible
towards the bellcrank, without the quicklink striking the bowden cable
outer at full movement.
The bowden cable outer must not be pulled back more than necessary
(no more than 10 m.m. from the quicklink at lull movement), in order
to avoid the steel rod bowing. The bellcrank and the linkage must not
come into contact with the foam core at any point.
The bowden cable outer is normally free t0 move within the wing. lf
this should not be the case, twist a small round needle lile into the tube
lrom the wing root. Now rotate the outer carefully one way and then
the other until it is released from the wing skin. D0 not use force under
any circumstances.
The bowden cable outer can now be shifted as
required. Be careful not to pull it out too lar, as it is very dilficult to slide
it back into the wing over a considerable distance.
Set the bellcrank to the neutral position, and mark the position 0f the
threaded pushrod 24 on the wing. The threaded pushrod must be at
90'to the leading edge of the aileron.
The pushrod guide 46 is fitted
centrally between the bellcrank well and the trailing edge 0f the wing.
Mark the position of the guide 46 on the wing with a pencil (using the
pushrod guide as a template), and cut the slot with a sharp balsa knife.
Check that the guide fits snugly. lt is not glued in place until the wing
has been finished with film or painl. This sequence is the easiest
method, and ensures a neat appearance.
Cut a tunnel through the foam to the bellcrank using a pointed needle
lile.
Screw a quicklink 20 onto the threaded rod 24, and bend the pushrod
to the shape shown in the drawing. Connect the threaded pushrod to
the bellcrank,
and check that the rod is central in the guide when the
bellcrank is at neutral; reform il necessary.
The bellcrank support 34 can now be glued into the wing with
s-minute epoxy, checking that it is located sufficiently deep in the
wing, and that the crank itselt is not glued.
Hold the aileron against the wing, with an equal gap at either end, and
mark the Dosition 0f the aileron horn 14.
File a slot in the aileron lor the horn, and hollow out a little loam. Glue
the horn in place with plenty 0f s-minute epoxy, alter masking olf the
area round the slot with tape, to keep resin otf the surface. The positi0n
ol the horns 14 must be identical on both ailerons, so that equal
movement
is obtained on both sides.
Temporarily
fix the ailerons to the wings with strips 0l tape and pin 0r
tape them at neutral. Press the pushrod guides into the wings and set
the bellcranks
at neutral. Mark the point on the threaded pushrod
where it crosses the horn, and bend the rod at righfangles at that
point. Cut the excess down to a length of 10 m.m. and connect the rod
to the aileron horn.
The entire mechanism
can now be checked for efficiency. The
movement 0f the aileron should be about 40" up and about 20'
down, and the aileron must not jam or rub at any point. Make any
adjustments
that are necessary.
The bellcrank well is sealed off with the cover 36. Take care that the
grain 01 the wood runs spanwise,
and that the glued joint is really
sound. When the glue is dry, sand the cover back flush wilh the wing
skin.
Mounting the aileron servos in tie wings
Here we can only provide a few general guidelines,
as the methods
required t0 mount the servos vary markedly from type t0 type.
You also have to decide whether the servo well cover is t0 be
removable
or glued in place. Bemovable
covers severely weaken the
wing, and spanwise reinforcements
have t0 be incorporated t0 com-
pensate for this. We recommend litting spruce strips 0f appropriate
cr0ss-secl0n.
In practice the ideal solution is to cover the servo with a lixed panel. lt
is very rare lor a servo to fail, and il this should occur the panel can
easily be cut out and a new one litted. The procedure is much simpler,
and does not weaken the wing substantially.
Installing the servo extension
lead is a very simple iob, as the bowden
cable outer is not lixed in the wing. Pull the bowden cable outer out of
the servo well slightly, cut off the lead at an angle, and glue it into the
outer with a drop ol instant glue. The outer is then carefully drawn out
of the wing root, pulling the lead through the wing with it.
ll servos are installed in the wings, we strongly advise the use of
separati0n filters, fitted just after the wing root rib, fitted in accordance
with the manufactureas recommendations.
(Multiolex extension lead
set with separation filter, order No. I 5138).
The c0nnection between aileron and servo consists of an M2 threaded
rod with outboard quicklink 20, to provide a means of adjustment.
The
threaded pushrod is formed and the pushrod guide is installed exactly
as described for the installation ol the bellcrank.
Check that the servo
output arm is not obstructed
in its arc.
Winglips
Because ol the special shape of the DG 300's wingtips they are
assembled in two parts as shown in the drawing. First the rear part of
the tip is cut from the wingtip strip 33; glue it in place, and sand it to
meet the front part. Cut lhe lront section to length, glue it in place, and
carve the entire tip to profile, prior to rounding it olf.
lf lou wish to have stronger wingtips, we recommend that they be
carved from obechi. However, this does involve much more work, and
a great deal ol skill and experience
(the obechi strip is not included in
the kit). 0n the other hand balsa offers the advantage that it can easily
be replaced il damaged.
Airblakcs
The DG 300 is tactory-equipped
with doublebladed
super airbrakes.
However, they do need t0 be linked up and fitted with their blades. Cut
the steel pushrod 19 in half, bend the final 2 m.m. of one end at 90',
thread a metal quicklink onto the rod, and solder it soundly.
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