Wren 44 Gold Helicopter Owners Manual
Page 13
The Align T-Rex 700 is shown overleaf offered up into the airframe to see how and what
modifications are needed. As it turned out, the standard fuel tank with the kit and of good
size so was retained.
The obvious difference is that though the gearbox is largely modelled on the comparable i/c
engine outline the turbine and 2
nd
turbine section is clearly something which has to be
accommodated within the fuselage structure itself. The implications for this are some degree
of cutting around the existing mainframes and some additional structure and in other cases
simply replacing the mainframes in their entirety.
Canopies are generally quite narrow and
so we have made the exhaust width small
with short outlets to enable most to be
eased into position after cutting suitable
apertures to clear. It is important to have
some clearance around the outlets to
prevent the canopy from suffering heat
related damage – at least 5mm all round.
Fuel tanks are often increased in size from the
standard supplied and these larger tanks need
careful positioning and secure mounting,
safely clear of the engine exhaust heat. This
Align T-Rex 700 tank was ok at the standard
630ml and was retained.
Virtually standard practice in heli’ installs is the
use of Velcro type fastening to hold critical
parts such as battery and receiver in position
and turbines are the same.
The turbine installation is virtually
completely vibration free so no need to
go mad on the soft packing.
Clearly visible here is the good clear
space around the hot 2
nd
stage parts,
give them lots of clearance from the
airframe and anything else that doesn’t
like getting hot. Important not to allow the
hot air to collect and stagnate inside the
canopy.
The clutch and fan arrangement is nicely shown here on the “Three Dee” plus the
replacement home-milled carbon side frames used on this conversion.
The modern day predominance of 2.4GHZ systems make long aerial routing a thing of the
past. Aim to keep the receiver well away from the heat though.
