The heart of the Voltage 500 is the flight controller. This is where you
attach a USB cable for tuning with a PC.
Having the battery strapped beneath the quadcopter allows for a range of
possible battery sizes.
What is the purpose of that USB port
on the flight controller? If you go to the
Helimax website, you can download
the Voltage 3D app by clicking on the
software download tab. You will need to
get your own mini USB cable (I think
most of us have at least one floating
around), and then you can plug your
flight controller into your PC and access
some settings via the app.
The app lets you set your receiver type
(a necessity if you are using anything
other than S.Bus), and it allows you to
verify control functions and directions. It
will show you what flight mode you are
in, permit you to adjust gain settings, and
damper gain on the aileron/elevator and
There is a warning about the
importance of removing the propellers
before you try to adjust any settings. This
should be a normal practice anytime you
work on a quadcopter when the battery
is plugged in.
My setup was straightforward. I
assigned Channel 5 to a three-position
switch for my flight modes. Position 1
is unarmed, Position 2 is 3D Mode, and
Position 3 is Stability Mode. As per the
manual, I also assigned Stability Mode
to a separate momentary switch—my
You can plug the flight controller
into your PC without having to attach
a flight battery, but if you want to
verify controls, you have to hook up the
battery because it powers your receiver.
(Remember to remove those propellers!)
With the app loaded, I verified that
everything was moving the right way, and
that my mode switch was selecting the
expected flight modes. The instruction
manual contains typical dual-rate
and exponential settings for a Futaba
transmitter, but these settings can easily
be used with other brands. I followed
the throttle curve settings in the manual.
This helps reduce transition time when
the motors are reversed.
The switches can be customized to
your preferences. It is possible to remove
the “off” from your flight modes so that
you don’t accidentally disarm your
motors in flight. I also set my failsafe so
that the controls would be neutralized
and the flight mode set to the off
position to disable the motors.
The Voltage comes with suitably set
gains, but at the urging of other pilots
who have flown the quadcopter, I set
my aileron/elevator gain to 70; aileron/
elevator damper gain to 65; and rudder
gain to 150. Fly the Voltage with stock
settings first and adjust to your taste.
The Voltage has a cool safety
feature that won’t let you spool up the
propellers if you accidentally hit the
throttle stick. After securing the flight
battery to the bottom of the aircraft
using 3M Dual Lock, the Helimax
Voltage was in its disarmed state, which
the ESC LEDs illustrated by flashing on
and off. This could clearly be seen on the
ground beneath the aircraft.
I set my flight-mode switch to 3D
Mode, and the motors were still not
armed and the ESCs continued to flash.
To arm the motors, you have to bring the
throttle stick up to mid-stick, and the
propellers will start to spool up.
After they got up to speed, I gave it
slight negative throttle stick to ensure
that the motors were indeed up to
speed and that they were reversing on
command. At this point, the ESC LEDs
also stopped flashing and remained on,
indicating that the aircraft was live.
The controls for the Voltage are much
like those on a helicopter. If you divide
your throttle stick into two sides, with
mid-stick to high-stick being positive and
mid-stick to low-stick being negative, you
would essentially have a 3-D heli setup.
To fly the Voltage upright, mid-stick
becomes zero throttle, while mid- to
high-stick becomes 0% to 100% throttle.
Mid-stick to low-throttle becomes the
mirror of that when you are flying upside
This is how the 3D Mode operates
on the Voltage, and although the stick
movement is the same for Stability
Mode, this mode won’t let you rotate
the aircraft beyond 45°. The Voltage will
level itself when the right stick is set to
center (let go!). Even if you are upside
down, and do nothing other than let go
of the sticks and flip into Stability Mode,
the Voltage will right itself and stay level
until you grab the controls again.
The Voltage won’t hold its position.
There’s no GPS to weigh down the
aircraft, so beware of drift when bailing
out and be sure to get on the controls
again when you are level.
65 Model Aviation MAY 2016