that using community soccer or football fields in the off
season with permission works well.
Place the quad on a level surface and plug in the
battery. I ultimately secured my battery with a strip of
Velcro™on top of the deck to make it easy to get to for
testing, and secured the deck down with some Velcro
straps for good measure.
Getting in the Air
Once the quad is powered up, power on the
transmitter and take several steps back from the vehicle.
Check that the trim settings are centered on the LCD
screen. With the throttle all the way down, move the yaw
stick all the way to the right. This will cause the LEDs on the
top of the flight controller to change their flashing pattern.
This indicates that the quad is armed. Gently advance the
throttle and make sure all the motors are spinning up. We
are now ready to take off!
Orient yourself with the quad, facing the same right
and left direction. You should be facing the rear green
motor mount. Slowly push the throttle up until the airframe
just begins to lift off the grass. If it is trying to drift in one
direction, you can counteract with small control inputs.
Continue to increase the throttle until you have successfully
cleared the ground.
Making continuous small adjustments, try to hover. This
is a skill that will take some time to develop, but is essential
to being a good pilot. You can try to go forward,
backward, left, and right, but only make very small
movements on your first voyage.
Finally, gently reduce the throttle until the quad begins
to descend. Hopefully, you will make a gentle touchdown
with a minimum of side-to-side movement when you land
(lateral velocity in the aerospace lingo). Disarm the quad by
placing the throttle at the bottom and holding the yaw
stick to the left. You just completed your first flight!
Learning to fly can be a difficult process, but patience
and persistence are the only way to succeed. There are a
plethora of videos online offering tips that are good to
watch during your lunch hour. I’ve also posted a video
showing the flight of the quad with no further
modifications made ( https://youtu.be/l YqCfuLYOS8).
Once you are comfortable with basic hovering and
flight, you can begin to learn how to use the yaw control
and get a feel for flying in different orientations. Just be
sure to keep safety first and stay below the 400 foot
operational ceiling!
Closing Thoughts
During the first few flights, I noticed a design flaw that
was easily corrected. The wire landing legs we made for the
quad were weak and bent easily. While this could provide
some shock absorbing capability, I didn’t want to be
continually reforming the landing gear. I debated the best
replacement, playing with metal and acrylic options. For
now, the easiest to implement solution has been to use
Wiffle balls zip tied to the motor support arms. There is a
little bit of compliance in this and it is easy to repair.
As an added bonus, I found a pack that contained red
and white Wiffle balls that can be used to help mark
orientation. I also found that balancing the propellers
helped reduce vibration, but is probably not strictly
necessary until we try to collect video from the quad.
The final product of the last few months of our labor
looks pretty good (Figure 11), and is in the air with plenty
of power to spare!
Next month, we add some telemetry and GPS systems
to our quad, at which point you will be capable of flight
planning and logging. SV
Figure 11. After a few months of work, the final product
looks very nice and makes a cool addition to anyone’s UAV
fleet — small to large!
SERVO 08.2016 13
