Carf-Models Composite-ARF Yak-55 SP Instruction Manual page 34

Composite-ARF Yak-55 SP (2.6m span)
on the upper plywood plate behind the firewall. The ignition
battery for the motor can be fitted in the same area, and of
course both should be protected with foam sleeves, and
fixed securely with cable-ties. Please make sure that all the
Nicad batteries are fixed very securely in the plane, as the
forces on these heavy items during high 'G' manoeuvres is
extremely high.
NB: Please double-check the manual for your R/C system
if the use of 5-cell NiCads is recommended, or not.
Dual NiCad and Powerbox installation
We recommend using two 5-cell 1800 - 2400 mAH NiCad
packs when fitting the Powerbox 40/24 or Powerbox
Competition systems, as shown.
The PowerBox power control unit is designed especially for
large models and provides dual battery inputs with hi-amp
connectors, multiple outputs for 6 channels/24 servos (no
'Y' leads needed), automatic voltage regulation and stabili-
ty, built-in servo amplifiers for those long servo cables, as
well as dual visual LED battery displays. It comes complete
with hi-current connectors and is fitted with anti-suppres-
sion chokes on all channels.
The Powerbox can be screwed to the milled plywood bulk-
head supplied in the kit, which is glued behind the rudder
servo mounting plate as shown. The receiver is installed on
the same plate, on a foam pad and secured with 2 rubber
bands.
With the R/C installation described here and this motor and
tuned-pipe/mini-pipe set-up, you will not need any addition-
al ballast in the nose to obtain the correct 'Centre of Gravity'
for pattern flying. For the Shulman 2000 scheme shown in
these instructions the 2 Rx batteries (2000 mAH) were
secured with cable-ties to plywood plates glued to the cock-
pit floor immediately in front of/under the wing spar tube.
We also highly recommend the high-quality PowerBox
powerswitches for the dual batteries, and we also use one
of these in the ignition circuits of all our planes. Remember
the high current that 8 digital high power servos can draw
during 3D and Freestyle manoeuvres when making your
decision on R/C equipment.
If fitting the switches into the outside surface of the fuse-
lage, as shown on page 16, please reinforce the area inside
the fuselage with a small patch of 3mm thick plywood to
reduce vibration transmissions to the switches. The switch-
es come with paper templates, making it easy to cut the
slots in the fuselage accurately. We fitted the 2 Receiver
switches on the left side, and the single Ignition switch on
techsupport@composite-arf.com
(above) Rx and Powerbox plate.
(below) The Powerbox 40/24
Professional is highly recommend-
ed for control of dual batteries and
8 high power servos in the Yak-55.
(above) Powerswitches are used
for both the dual Rx NiCads & the
single Ignition Nicad, fitted into the
fuselage sides.
(below) Depending on the Fuel
tank you choose, you might need
to make extra notches for the
cable-ties in the edge of the Fuel
tank base plate as shown here.
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