How to conversion Aliexpress FX-703 glider to twin engine RC plane 4 channels 69 cm wingspan

How to conversion Aliexpress FX-703 glider to twin engine RC plane 4 channels 69 cm wingspan


we have bought a glider in Aliexpress
for a price of about 12 euros the wingspan is 69 centimeters and the wing
area is 0.065 four square meters the center of gravity for the Glide is 3.5
centimeters from the leading edge of the wing which corresponds to the first
third of the wing cord the weight of the original glider is 99 grams the weight
of the glider without the canopy is 72 grams the plane has a hard plastic
canopy plus a soft plastic tip it also has an EVA rubber protector on the belly
to cushion landings in addition the glider mounts some LED lights on the
belly that are light unbias which we have bought a three millimeters diameter
carbon fiber rod in the decathlon store using the rod we have reinforced the
wings and tail the stabilizers have been reinforced with wooden sticks the
ailerons have been cut from the wings on top wooden sticks have been placed to
define the hinge line in addition strips of thick packing tape
have been arranged to fix the hinge on the trailing edge stakes have been
placed to prevent the deformation of the ailerons the tail arrived with a little
deviation so we have placed a small piece of 2.5 millimetres diameter carbon
fiber rod on the trailing edge of the wing and we have anchored the tail to
the rod with a thread this way we corrected the deviation of the tail
anyway we have added a rudder without servo in
case we had to make any corrections in the yaw of the plane the elevator has
been cut from an extruded polystyrene sheet taken from a food tray it has a
width of 2 centimetres and is sewn in four points to the horizontal stabilizer
the elevator has been linked to the servo with a wooden stick of three
millimeters in diameter the motorisation has been carried out with a pair of n60
motors with three inch diameter three blade propellers both motors are wired
in parallel and controlled by an ESC for brushed motors the set provides a
maximum thrust of 100 grams with a two cell battery we can achieve up to 100
and 40 grams using a 3 cell battery but in this case the motors overheat so we
have decided to better use the 2 cell battery the motors have been mounted on
new cells made of wooden sticks it is convenient to separate horizontally the
propellers from the leading edge of the wing to minimize the propeller wing
aerodynamic interference we use servos of 3.7 grams of weight since the angle
of these servos is little we have lengthened the arms by mounting on top
of the original arm the typical ones of the 9 gram servos which are longer the
weight of the first version is 225 grams the thrust to weight ratio is 0.44 and
the wing loading is 3.44 kilograms per square metre in the tests we noticed
that the centre of gravity of the motorized aircraft is in the same
position as in the glider that is 3.5 centimeters from the leading edge of the
wing this means that the thrust of the motor does not create unbalanced moments
on the plane anyway we have lowered the position of the battery a little to make
sure that the thrust line of the motors passes through the centre of gravity we
also noticed that the plane flies well at half power that is it flies with a
thrust equivalent to approximately half of the maximum thrust this indicates
that the aerodynamics of the aircraft led us to operate with the thrust to
weight ratio below 0.3 which implies that we can add more weight without
compromising its ability to fly in addition when operating with low power
we extend the life of the n60 motors master Rafah member of the aero model
ism holy temple be doing today in the final version of the plane a
servo has been added to control the rudder the linking to the rudder is made
by threads so we add the minimum weight to the glider the rudder and the
ailerons have been mixed in the transmitter to do coordinated turns
coordinated turns are used in commercial aviation to prevent the plane from
slipping in the opposite direction to the turn that is to prevent the nose of
the plane from sliding out of the turning path the opposite effect when
too much rudder is applied during a coordinated turn is the skidding of the
tail in the transmitter we have to find the right mixing percentage for the
rudder channel and the aileron channel so that the turning is as smooth as
possible the weight of the final version is 230 grams the thrust to weight ratio
is 0.40 3 and the wing loading is 3.5 kilograms per square meter we see the
final images of the plane and this is all thanks

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