9

LENS

The flight controller will have ports for the four

motor controllers, and you will need to refer to

the helpful diagram, provided by the Betaflight

control software, to identify which motor should be

connected to which one. The SBUS/IBUS/PCM port

will also need connecting to the receiver, which you

will need to cable-tie securely to the frame with its

antenna out of reach of the rotors.

ASSEMBLY OF A COMMERCIAL

MULTIROTOR FRAME SHOULD BE

A STRAIGHTFORWARD CASE OF

SCREWING IT TOGETHER

M3 screws, washers, and stand-offs, for example,
and cable ties, foam tape, and heat-shrink sleeving.
If your flight controller doesn’t have them fitted, then
you may also need to find some 0.1” pitch PCB pins.
In our case, we had neglected to buy the stand-offs,
so we had to make a quick trip to Thingiverse for a
model of one to 3D-print.
You will also need to source battery connectors,
and we suggest the ubiquitous XT60 variety, and
suitable silicone-insulated wire to carry your battery
current. Some Velcro battery straps to hold the
battery to the frame will also be useful, though at a
pinch you could use cable ties for the same task.
Assembly of a commercial multirotor frame should
be a straightforward case of screwing it together, but
you may wish to mount the motors on the end of the
arms and attach the speed controllers to them, such
that you attach the arm to the frame as a complete
pre-assembled unit. Remember that alternate rotors
will need to rotate in opposite directions, so take care
to wire your motor controllers appropriately, with
two of the wires reversed on two of the arms. In
most cases, the controller will have large solder pads
for the motor wires; you will need to solder these
connections, as well as solder their power wires to
the power distribution board. When you are done,
place a piece of foam tape onto the underside of the
speed controller, and attach the whole to the arm with
a cable tie. The foam tape will provide the required
cushioning during the vibration of flight.
A pitfall lies in the positioning of the flight controller
relative to the frame, it contains the machine’s
direction sensor, so in a sense its front and back
define the front and back of the finished craft. On
the controller PCB will be an arrow, which must
be aligned with the front of the frame. We first
assembled our build with the controller at 90 degrees
to the frame, and spent a while confused because the
machine tried to fly sideways.

Below

Go slowly at first, as

drone controls can

take some getting

used to