Installation – X45H Helicopter engine
Please read through the section on
Safety
as there are many
areas to consider that may differ from those pertaining to
other forms of helicopter power plant.
Helicopters have a special form of vibration due to
assymetrical gyrations of the rotor head. We recommend
using a locking compound on any critical screws likely to
loosen in service. Use only blue type as the green type can
be impossible to loosen later. If you need to return your unit
for service, please remove clutch and fan assembly and any
mountings.
The unit is designed to operate with the output shaft uppermost. A side and plan view can be
downloaded from
www.Xicoyturbines.com
. Use the link to check for other sizes of mounting and views to
suit specific airframes as they become available.
NOTE.
To accommodate the housing expanding with temperature, the top bearing next to the fan is
allowed to slide against a strong internal load spring. Please note therefore that on installation, you need
to ensure there is no downward pressure on the output shaft which could overcome the spring and
cause the gears to bind which causes noise and excessive and rapid gear wear.
Use the standard clutch.
Retain and use the clutch supplied for the piston engine for the airframe. It
enables the engine to start and run to idle without powering the rotors. It also provides a valuable
slipping point in event of rotor being overloaded or forcibly stopped in a crash, or the helicopter being
blown over by strong gust of wind.
Keep gearbox cool.
The gearbox unit
must
be cooled in operation. Being connected to a gas turbine
producing up to 100kw of heat energy per second, it will otherwise quickly overheat in use. In operation
the fan drive will absorb some 500w which the engine can manage easily. If you planned to use a small
electric fan for the same purpose you will have to find an equivalent 500w of power to run it.
Use the standard fan.
The standard fan included with glow engine helicopters is suitable if used with
supplied shroud which can be trimmed to clear any areas of contact and direct the cooling flow
downwards onto the centre of the exhaust and gearbox. With an effective cooling setup the gearbox
temperature should seldom exceed 50C in operation, though may climb to 80C or more when engine is
stopped due to heat soak from the hot 2
nd
stage.
You can see if the fan is effective enough if the exhaust begins to turn a darker brown shade. Aim to
keep at least 6mm of shroud clearance to any hot surface. Consider the possibility that the fan shroud
may need to be fitted 1
st
, before the fan and clutch assembly.
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