Building a Racing Drone

Miramichi Valley High School Students take us through the process of building a racing drone. Could they be preparing for an upcoming Brilliant Labs Drone Racing League? Be sure to check back in late February to find out!

Materials List:

For this build you will need several items, a computer with internet access is a must. We ordered an all-inclusive kit from amazon similar to the one here although it should be noted that we paid significantly less that the one in the link, and these parts could be bought for under $250 if you are willing to shop around and order these parts individually.

Here is what comes in the kit:

  • 1 x Upper Board

  • 1 x Bottom Board

  • 1 x Board for Fixing the Camera

  • 1 x PR301 Li-ion Polymer Balance Charger

  • 1 x HobbyWing 5V 3A UBEC

  • 1 x BB Bong 1-8S Battery Indicator

  • 1 x 12V 1.5A Power Adapter

  • 4 x HobbyWing XRotor 15A Brushless ESC

  • 1 x 3S 11.1V 1300mAH T-Plug Li-Po Battery

  • 1 x CC3D Flight Controller

  • 1 x Male T-Plug Adapter Cable (100mm)

  • 1 x USB cable (black)

  • 1 x Heat Shrink Tubing (black 100CM)

  • 5 x Double-Sided Foam Tape(25mm*40mm)

  • 20x Nylon Zip Ties( white 150mm*2mm)

  • 4 x Skid Landing Damping Sponge Tube

  • 12x Banana Plug Female Bullet Connector (2mm)

  • 12x Banana Plug Male Bullet Connector (2mm)

  • 16x Screw

  • 1 x Allen Wrench (K2.0)

  • 1 x Strap for Binding the Battery (black 2*20cm)

  • Velcro Tape(10*2.5cm) x1(pair)

  • Quadcopter Arm (red x2 & white x2)

  • 6040 CW/CCW Propeller (greenx2 & yellowx2)

  • EMAX CW/CCM Motor(black bullet x2 & white bullet x2)

In addition to these parts we also bought (Reccomended):

  • Fly Sky i6 controller

  • 2.4Ghz FPV camera

  • FPV monitor

The software program that we are using is called LibrePilot and can be downloaded for free here.

Initial assembly

Once everything comes in you can begin the assembly. Start by assembling the frame; the frame consists of 2 fibreglass plates and 4 arms that are sandwiched between them. First take an arm, orient it so that the legs are facing the work surface and it’s resting on the larger of the 2 plates. Repeat this 4 times and once you are done take the FPV camera mounting plate and set it in the grooves; then screw the top plate to the arms.

The frame should look something like this

Motor attachment:

Now you will attach the motors; the black nut Emax motors will go on the top left arm if the quad is facing away from you, as well as the bottom right. The silver nut Emax motors will go on the top right and bottom left arms when the quad is facing away from you. It’s important to pay close Attention to which motor is where because once we start the configuration process the board is calibrated based on motor position, and will send power to the ESC’s (Electronic speed controller) which will deliver the power to the opposite wire and can short your motors or the ESC.

Attaching the Battery Leads:

To attach the battery lead wires to the PDB (Power Distribution Board/ the frame; it has integrated circuitry), the soldering points are marked with a big plus and minus symbol (it should be located at the back of the drone). Red goes with positive and black goes with negative. Once the wires have been attached, take the UBEC’s (universal battery eliminator circuit) red and black leads, and solder them directly on top of the battery wires. The port plug-in on the other end of the UBEC can be plugged in to port 6 on the CC3D flight controller.

Battery leads soldered and UBEC leads soldered on top of them

ESC attachment and wiring:

Now attach the ESC’s to the frame; you can use zip ties. First, place an ESC on the underside of an arm, and insert it into the slot. (Make sure the orientation is correct; the 3 black wires should be facing the motors and you should be able to see the yellow lettering on the ESC’s). Solder the positive and negative leads to their corresponding spots on the PDB. Attach it with the provided zip ties and repeat this step for the remaining 3 arms.

This is what the underside of the drone should look like with the ESC’s and motors wired

Once this is done you are now ready to connect the ESC cables to the board. On the CC3D Revo (the board included in the kit) the pins are located on the side of the board and numbered 1 through 6; you will only use the first 4 as well as port 6 for the power. Take the 3 pin connector cable from the ESC in the top left corner of the frame if the drone is facing away from you and plug it into the first 3 pin set (Labeled 1). Note the colour of the wires (Red for positive, black for negative and white for control) and line them up with the markings on the board. (+, - or GND, etc…)

ESC control wires plugged into ports 1-4, UBEC plugged into port 6

Heat up a soldering iron; then solder the 2mm bullet connectors to the side of the ESC’s and motors. To connect the motors to the ESCs you match the center wire with the other center wire, right with right and left with left (This orientation is based on the yellow text on the ESC’s facing upwards if the drone is on its back). On the motors with the black nut (CCW) reverse the right and the left wire, but keep the center with the center. Neatly tuck the wire in a fashion that it does not interfere with the rotation of the blades. Use zip ties the hold the ESCs in place. We are now ready to connect the board to the computer and begin calibrating and initial setup.

Flight Controller setup:

This video will show you how to setup your quad copter using LibrePilot.

Connecting the receiver to the main board:

Find the plug with 8 connectors. One end will have 3 wires and the other five will have 1. Plug it into the main board and into the receivers 6 first rows of plugs as shown. Insure they are all in the right way, as it will not work if they are not.

The wiring should look like this when the bind key is inserted

Transmitter Setup:

Once the drone is configured, all that’s left to do is to connect a transmitter. This is done by taking the bind key and plugging it into the spot that says B/VCC. Then plug the battery into the drone. Turn on the transmitter; to put it directly into bind mode, depress the bind switch as you turn it on. The built-in LCD screen on the transmitter will display a RX bar on it once it connects; once you see this the transmitter and receiver are bound to each other. Reconnect your drone to LibrePilot and select the transmitter setup wizard; if you follow the on screen prompts it should work. Once this is complete LibrePilot automatically sets the motors to always be disarmed; in other words, they won’t spin as a safety feature. You can fix this by going into the configuration tab and configuring an arm command; we found the easiest one is the Yaw Right option.


Once the transmitter is setup the drone is ready for its first test flight. A note of caution; this is NOT a consumer drone, therefore it has very limited stabilization and requires continuous pilot input to keep it around the same area. Don’t be discouraged if it doesn’t work the first flight, here’s our first test flight:

Our problem was the ESC wires; we had positive connected to negative and vice versa. Once we flipped the wires it worked just as you see in the later parts of the video. Good luck and good racing!

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