Building an FPV racing drone Part 3

If you’ve come this far, this means you’re almost done with building your FPV drone.

A quick anecdote before we get started. While doing my initial flight test I burned an ESC. I’ve also decided to pull the power for the FPV transmitter straight from the battery rather than the ESC as I feel this might be the culprit for my ESC burning.

O simply go back to your wiring and create another splice to pull power for the transmitter.

WP_20150104_007 WP_20150104_005

You might have notice that I’ve added some gears. This is optional. However, it makes take offs and landings a bit more stable.

I’ve uploaded the landing gear assembly to Thingiverse here:

You can print your own. It uses a 3mm aluminum pipe and 2mm screws to hold it in place (M2x12mm Bolt) use a bit of Loctite to prevent wiggling.


These are the same screws that are used to hold your motors in place.



Looks like you’re ready to almost fly now. We’ll have to verify a few things prior to flying.


1-Calibrating ESC

2-Calibrating flight controller

3-Calibrating Receiver controls


You can start by downloading OpenPilot GCS here:

Once you get this installed you’ll notice a usb port on your flight controller time to plug this guy in. At this point make sure you have your props off the quad as this can cause major problems.

You’ll soon be needing the battery to power the ESC’s so make sure you have it charged and ready to go nearby.

Once you launch Openpilot GCS connect your usb and start the “Vehicle Setup Wizard”


Here you’ll first be updating the firmware on your cc3d board so simply go through that process.

-Next, you’ll be talking about choosing and calibrating your ESC’s. Here make sure you choose PWM as the input signal configuration

-Quadcopter as vehicle type.

-Quadcopter X has the quad type

-and 490MHZ for the type of ESC. (rapid ESC)

Next get your battery ready you’ll be calibrating the ESC’ simply follow the steps on screen and go through all the steps.



Last you’ll move on to the Receiver configuration. This is important. Make sure you have the battery plugged in while doing this.


One interesting thing is to make sure you have your controller in Acro mode NOT helicopter mode. Simply follow the prompts on screen to calibrate.



One thing to take not of is my Flight mode switch didn’t register during calibration so I simply used another switch on the controller for this purpose. I went with a 2-state switch but since I plan on using a single flight mode for now it should be fine.



After this It make sense to reduce the aggressiveness of some of the stability parameters.

Here are a few screenshots from how my settings look. I suggest starting with the less aggressive and going up from there.

gcs_stabilzation gcs_stabilzation_basic gcs_throttle gcs_idle_throttle


Pre – flight check:

  • Make sure all your props are turning the proper way. So you need to have the proper prop on the proper engine. This is a bit confusing but once I had the proper configuration I simply wrote with a sharpie on my ESC and props in case I need to remove them. (which I actually did)
  • Make sure you got your arm setting correct on your transmitter.
  • Make sure all cables and ESC’s are mounted properly and nothing is going to get in the way of the turning props.



And here is a video of the maiden flight. Be sure to time this flight to understand the endurance of your quad.

Trouble shooting?

Drop your question in the comments area.

Happy Flying!



Building a FPV racing drone Part 2

Once you have all your parts in order you can start your assembly

Start you assembly by putting together the ESC’s I noticed that the 12A hobbyking BEC I’m using are not Simon K flashed so I’ll go into the details of that further but not letting it stop my right now.  I later witched these out with Afro 12A ESC’s that can be found.

First we need to create the power distribution circuit.


If you’re not using a power board get your soldering iron ready as were going to be using it a lot.
Simply put the power flows through the ESC’s to the Flight controller to the receiver

Start by Soldering some 16AWG wire to your Xt60 battery connector. I had a bit of trouble finding good sized heat shrink wrap to put around  the  connection points.


Second you need to cut the 16AWG   wire to form 2 different branches so you can distribute the power to each ESC.


I did this by branching out the positive side and the negative side to two smaller branches.
Once the ESC’s are sorted out we can move across to connecting them to the motors.
This is a bit of a tedious process as you want to cut the lengths of the motor control wires and the motor wires such that there is minimal slack between the esc and the motor.

Below you can see this after the soldering. Take note to remove the power cables from all but one ESC going to the flight controller. The cable color coding is as below. So cut the Brown and red from all esc signal cables but one prior to plugging in. This is explained in the cc3d wiki
ESC signal wires:
Brown – Red – Orange
Neg – POS – Signal


Before we zip tie everything down I’ll make sure to check that everything is working. Remember to cross the wires of 2 opposing ESC to give counter rotation to the props on opposing ends. This will save you some time future debugging hours.

Also ideally you would like the arrow on your CC3D board facing the front of the quad but again this is not necessary as you can tune this later in through the openpilot software. JUST REMEMBER THIS BEFORE YOU FLY. (more details on CC3D board here

At this point you can go ahead and download GCS here :

Simply step through the Aircraft setupwizard. This will make you update your CC3D firmware , calibrate your ESC’s and make sure all you motors are oriented correctly and spinning the right way.

You can now go ahead and plug in your receiver. I removed the casing from mine to make it smaller and easier to mount. I chose to mount it on top of my CC3D board with the dual sided foam tape.

As a transmitter I got the  Turnigy 9x reciever priced at 50$ at hobby king this is a steal. This also comes with a 9 channel receiver.
Here are a few pictures of the setup. I have the FPV transmitter mounted in the back along with the receiver antenna.  I’m thinking this might cause some interference but we’ll see.


At this point we’re almost ready to fly. You’re probably thinking “well , were is my camera?”
This is one step before that. We’ll be needing to calibrate the transmitter and the quad before we’ll be mounting our camera.

I’ll be going over pre flight and final FPV pre checks in the Final and calibration and 3rd post : )