Carf-Models Composite-ARF Yak-55 SP Instruction Manual page 35

Composite-ARF Yak-55 SP (2.6m span)
the right side. These powerswitches are available as
options from C-ARF, please see our website for current
details.
Composite-ARF advise you to keep all the cables between
the motor ignition battery, ignition switch, and high voltage
ignition unit as far away as possible from the receiver and
R/C system.
Servo extension leads etc.
Please make sure that you use good quality extension
leads, of heavy gauge wire with gold-contact connectors, to
all the servos. Certainly we recommend that all servo leads
and extensions longer than about 30cms (12") are fitted
with ceramic chokes (ferrite rings) to prevent RF noise, at
the receiver end - normally within 100mm (4") of the receiv-
er. Of course, if you are using a 'Powerbox' this unit is
already fitted with all the ceramic chokes etc, and comes
with the required high-quality switches. Also no 'Y' leads
are needed, as the powerbox provides 4 inputs for each
channel.
At C-ARF we hard-wire all our servos with twisted cable
leads of the exact length required and Multiplex 6-pin con-
nectors (see photos). For the 2 aileron servos you can use
1 pin for each wire, and for the elevators you can gently
squeeze pairs of adjacent pins together and use a pair of
pins for each cable. We glue the female connectors into
small plywood plates in the sides of the fuselage for con-
necting the stabs and ailerons when assembling the plane.
Making up the proper extension cables and connectors is
only a little work, if you are proficient with a small soldering-
iron, and makes assembly of the model at the airfield very
quick and easy! Once all wires are soldered to the gold-
plated pins, fit a short length of heat-shrink tube over each
one. Finally protect all the connections from vibrations etc
with a nice blob of glue from a hot-glue gun. Job done.
Motor ignition system
The ignition unit is fixed to the top of the motordome, inside
the cowling area, on a piece of hard foam, and retained
with 3 cable ties. See bottom photo on page 27. At C-ARF
we recommend a 4-cell 1200 - 1400 NiCad for ignition
power, and we use a Powerswitch for the cut-off. The bat-
tery can be installed anywhere to obtain the correct Centre
of Gravity, even on top of the motor dome next to the igni-
tion unit if you wish, but a common choice is on the plywood
plate next to the main landing gear securing bolts.
Add a very small cable tie, or 'safety clip', around the cable
from the motor pick-up to the ignition unit for extra security.
techsupport@composite-arf.com
(above and below) 6-pin MPX con-
nectors are used for extension
leads, with one half mounted in
the fuselage sides.
(above) The MPX connectors are
mounted in the sides of the fuse-
lage in plywood plates, making it
very quick and easy to assemble,
and dis-assemble the model.
(2.6m Extra shown here)
(below) A small cable tie makes
sure that the ignition connectors
cannot come undone in flight!
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