The
assembly process is done in an open space with available power source. All the
tools required are prepared along together with the quad copter hardware.
Basically the most important tool is a screwdriver with interchangeable head
shape. This is to all securing screws of different shapes and sizes. Secondly a
solder iron and its iron lead are used to secure certain cables with compatible
connectors.
The first installation
process involves putting the frame together. The frame must be assembled
accordingly to allow strategic placement of the electronic hardware.
The
base of the frame is assembled while having the aluminium pillars arrange with
the same colour side by side. This is to determine the front and the back side
of the quad copter. Most of the parts are secured with screws and it is made
sure that these screws are properly locked in to ensure secure assembly of the
frame.
A frame with long
landing gear is chosen to protect the hardware from damage if a rough landing
were to happen. The aluminium pillars are identified to be long enough to fit
11 inch propellers that are going to be used. This is to avoid unwanted
clashing between the propeller blades and other hardware.
A camera adapter is
also available on the front side of the quad copter. This camera adapter allows
easy and strategic installation of a wireless camera. If not required this
camera adapter can be unattached to the frame rather easily.
Some soldering needs to be done to fix suitable
connectors to the lipo battery cables. These connectors will match the power
harness.
A
power harness unit is installed at the middle of the base and is responsible to
distribute power to all of the quad copter hardware. The power harness will be
connected directly to the 14.8 volt lipo battery will provide parallel
connection to all of the hardware. It is important that the cable and wires are
connected correctly to avoid damage to the hardware, since a large amount of
current flows within this power harness which is about 30A to each motor.
The
electronic speed controllers are attached to each aluminium pillars and the
connected to the power harness. These are strategic locations for the ESC since
there will be a motor on each end of the pillars while also being close to the
APM flight controller board to allow signal wire connections. These ESC are
secured with zip tights to avoid them moving around during flight.
A
power module is also attached to the power harness to provide safe power supply
to the APM flight controller board. Any excess power load onto the board will
fry the APM flight controller therefore this power module is used as protection
to avoid that situation to happen.
The
power harness is covered with different layers of plates and then the APM
flight controller is placed on the top. Plastic screws are used to avoid
conductivity to the electronics on the board. It is critical that the APM controller
board to be placed precisely at the middle of the frame so that the controller
can balance the quad copter properly during flight. The front arrow indicator
is directed towards the yellow aluminium pillars to set them at the front side.
The
brushless motors are secured firmly at each ends of the frame. Its wire cables
are attached directly to the ESC. The yellow wire is the signal wire, red and
black are the live and ground wires. Yellow wire from the motor must match with
the yellow wire on the ESC. However red and black wires can be switched in the
opposite way around if required. This will only effect the rotation direction
of the motor. The correct way of installing the brushless motors are when each
motor rotates in the direction which cancels out each other.
For safety reasons
each motors are fixed to the frame with plastic screws. This allows it to the
motors to break loose from the frame in case of accidents. The result of this is
that the frame can be protected from serious damage during crash scenarios.
The
propeller 11 inch propeller blade is secured on top of the motor according to
its direction of rotation. This is to ensure that air is pushed downwards which
gives lift to the quad copter. Incorrect installation of propellers will result
the quad copter to be stamped towards the ground and will not fly.
Importantly,
the propellers must be locked properly before flight. Any loose installation of
the propellers will cause instant crash to the quad copter since the quad
copter requires all of the propellers to be functioning perfectly for stable
flight.
The
rc module and gps module is placed at the vacant areas of the quadcopter. These
modules are sealed at their places with zip tights. Strategically the gps
module the rc module is attached outside of the frame so signal transmissions
can be received efficiently.
The gps module and the
rc module do not require independent power supply input as they feed power from
the APM flight controller board.
The assembly of the
quad copter is completed by attaching the signal wires from the speed
controllers and the rc module at the correct positions on the APM flight
controller board.
The
final stage of the quad copter development is to connect the APM flight
controller to its software. The software is named APM flight planner. Prior to
use of the quad copter its firmware must be updated first. Then the hardware on
the board such as the accelerometer, gyrometer and its magnetic compass needs
to be calibrated. Finally the input from the rc module is calibrated and setup
for flight modes and fail safe are configurated.
Other than that, each
ESC also needs to be calibrated. This is to allow the speed controller command
correct speeds to the motors with its corresponding signal input. Failing to
calibrate the ESC will cause the motors to spin unevenly.
