In this tutorial I will show you how to build an FPV mini quad (aka racing drone) from scratch. I have chosen some of the most affordable parts that have good performance, and I will also show you how to assemble this quadcopter and configure it for your first flight.
Table of Contents
- Selecting Parts
- Tools and Accessories
- Steps to build this Quadcopter
- Setting up Betaflight
- Pre-built Kit Recommendation
Can Beginners Build an FPV Mini Quad?
I am not against buying a pre-built kit off the shelf as your first racing drone, but if you did, you wouldn’t know how anything works. There is a lot of value in building a quadcopter, you get to know exactly how everything fits together, and how to repair your drone.
So you can and should build a quadcopter even if you were just starting out. It might takes hours even days to finish your first build, but the result is extremely rewarding.
Before we move on, please make sure you’ve read this tutorial to get a basic understanding of mini quad:
You should be able to build your first FPV quadcopter (racing drone) by following this step by step tutorial. The aim here is to get you started building and flying with a well performed mini quad with little budget.
Mini Quad Parts List
It’s a good idea to select parts at reasonable prices for a beginner quad, but just remember that cheap parts are not going to perform as good as expensive parts (most of the times).
So is it worth it using premium parts on your first racing quad? Probably NOT, because it takes time to master the skills to fly your quad to the full potential. It makes sense to start with something cheaper, so even if you break something it won’t stink as much.
You can build this racing quad for as cheap as $180! And yet it provides some of the cutting edge technology and features:
- Durable frame, perfect for beginners who crash a lot
- F4 flight controller – allows you to run fast looptime and full Betaflight features simultaneously
- OSD for real-time voltage/current reporting, you can even change Betaflight settings through the OSD menu including PID and rates
- DShot compatible ESC’s allows smooth and reliable performance
I also provided some more suggestions in case you want to upgrade in the future. Of course you can also mix the parts from different price categories, it’s all up to you.
For more options, check out the Almost Complete Mini Quad Parts List
I’ve highlighted all the components I am using in this build log.
|Frame||Martian II Anni. Edition ($20)||Martian II 220mm ($26)||Alien ($98)|
|Flight Controller||Omnibus F4 AIO ($25)||Matek F405 ($40)||–|
|ESC||RacerStar RS30A V2 ($52)||Betaflight 35A ESC BLHeli_32 ($76)||–|
|Motor||RacerStar BR2306 2400KV ($36)||Sunnsky R2305 ($80)||T-Motor F40 III ($100)|
|Propeller||Kingkong 5040×3 ($1)||DAL Cyclone T5045C ($3)||–|
|RX||Frsky XSR ($17)||–||Frsky R-XSR ($25)|
|FPV Camera||HS1177 ($20)||Runcam Swift 2 ($40)||Runcam Eagle 2 Pro ($50)|
|VTX||Eachine VTX03 ($10)||Matek VTX HV ($30)||–|
|FPV Antenna||n/a||Foxeer Thor ($8)||Lumenier AXII MMCX ($20)|
|Misc Parts||XT60 Pigtail ($1.5)||–||–|
|Low ESC Capacitor ($1.5)||–||–|
|— Total Cost —||$184.4||$309.4||$445.4|
I’ve chosen the Martian II for its affordability and durability. The Anniversary Edition has 215mm wheelbase size, which is slightly smaller than the 220mm normal version.
The spacial version doesn’t come with the iconic red PDB, but because the FC I am using has integrated PDB so I don’t really need it anyway.
The Martian II is a very reliable and good value mini quad frame, it’s roomy and easy to build. You cannot go wrong with it as your first mini quad.
FC – Flight Controller
I personally love the simplicity of “AIO” flight controllers, and I am using these on all my new builds. “AIO” (All in one) basically means combining FC, PDB and BEC into one single board, that minimizes the amount of wiring and soldering in our builds.
I have chosen the Omnibus F4 AIO FC because it’s cheap, and it’s an F4 board which allows you to run all the latest features in Betaflight and has enough processing power for fast looptime at the same time. I also like the pin layout which makes wiring easier.
One negative about this flight controller is the insufficient power filtering. But the easy fix is to add a low ESR capacitor at the power input, which I will show you in the build log.
Racerstar 2205 motor has been a popular choice for many budget builds in 2016 and 2017. But I have instead chosen its upgraded version, the Racerstar 2306S 2400KV, because of the extra power, and they are about the same price, so why not? :)
These are definitely NOT the best motors, but they are so cheap it’s hard to say no :)
I really cannot recommend 4-in-1 ESC’s for someone’s first build. Yes, they are easier to work with, but if you burn out one ESC then you are screwed (you will have to replace the whole module).
It’s safer to use standalone ESC’s, price difference is minimal anyway with the Racerstar 30A V2. These are cheap and allows you to run DShot600, that’s all we need.
Your choice of radio receiver (RX) depends on what radio transmitter (TX) you use. For an Frsky Taranis user, either the XSR or R-XSR is going to be an excellent choice.
XSR and R-XSR have the same features and range, but the R-XSR is smaller and lighter. Size is really not a big deal for the roomy Martian frame, not to mention the price of XSR has dropped significantly since the release of R-XSR.
I would probably recommend getting the XSR for this build if you want to save money.
I am picking the Eachine VTX03 transmitter because it’s small, affordable, and just works. We can power it with the 5V on our FC.
It comes with a simple dipole antenna so we don’t need to buy an FPV antenna separately, that should be good enough for 500+ meters open field.
I use Runcam Swift 2 and Eagle 2 FPV cameras on nearly all my quads, because of the superior image quality. For budget builders, the cheaper Foxeer HS1177 CCD camera is also a good option.
All these cameras have the same dimension, mounting, and wire connections, so don’t worry which one you are getting, the installation will be the same.
There is no need to have OSD in the camera really, because our FC has built-in Betaflight OSD.
Many recommend the Eachine 1200TVL camera ($13), I personally do not agree because of its terrible WDR and more importantly, the weird shape. It’s going to be a nightmare mounting it in the frame.
I am using Kingkong 5045 Triblade in this build. These are a bit “slow” for me, but they are perfect beginner props. You get them for $1 a set and they just don’t break! I have been using the same set for over 20 LiPo now and they are still going :)
I prefer the DAL Cyclone 5045×3 for faster flying.
What Else Do You Need?
You will also need to have the following accessories in order to fly a quadcopter. I assume you already have them, if not, take a look at my shopping guides to get some ideas what to buy.
- Radio Transmitter (Buyer’s Guide)
- FPV Goggles (Buyer’s Guide)
- LiPo Battery (Buyer’s Guide | Our Recommendation)
- Battery charger (Buyer’s Guide | Our Recommendation)
Tools and Supplies
You might already have some of these tools lying around in the house or in your toolbox. If not, you should get them, these tools will come in handy for repairing and building your next quadcopter :)
- Soldering Iron and solder (Our tutorial on soldering and equipment)
- Hex drivers set (Buy from Amazon)
- A small Phillips head screwdriver (Buy from Amazon)
- A pair of scissors for stripping and cutting wires
- Electrical tape (Buy from Amazon)
- Zip tie
- 3M Double sided tape (Buy from Amazon)
- Multi-meter (Buy from Amazon)
Steps to Building a Racing Drone
Prepare the carbon fibre frame (I prefer to sand off the sharp edges as shown in this tutorial), and assemble the arms, the bottom plates, and the FC standoffs.
Plan your connection diagram. Tin all the solder pads on the FC and ESC’s you are going to use, and skip the ones you don’t use, solder weights a lot, and every gram counts on a mini quad.
Measure how long you want the XT60 pigtail to be (just long enough to stick out of the frame a few CM) and solder it to FC. I had mine at about 9cm. Make sure polarity is correct.
Pro Tip: Avoid soldering XT60 connector directly on the PDB or FC, always use silicon electrical wires in between and strain-relieve the XT60 pigtail on the frame to prevent pulling the solder pads
I also recommend to solder a low ESR capacitor at the power, this will reduce some of the noise from ESC and motors, which could affect your Gyro sensor and FPV video.
Further reading: why adding capacitors to mini quad?
I simply solder the capacitor to the FC power, and secure the cap on the FC with double sided foam tape.
I decided to put the RX under the FC, and use double sided foam tape to fix it on the frame.
Make sure to put transparent heatshrink over the RX if it hasn’t already got some. Or you can just wrap it with electrical tape to avoid direct contact with the CF frame, but remember to expose the LED so you can see the RX status.
Then connect the RX to the FC (SBUS and SmartPort), bind it to your TX, and setup failsafe.
Test it to see if the channels are working correctly in the receiver tab, test SmartPort by checking VFAS, and finally test failsafe.
Now mount the motors to the arms.
Beware that the RacerStar motors come in CW and CCW threads, indicated by the colour of the prop nut. Follow this guide to learn about CW and CCW motor threads.
Pro Tips for Mounting Motors:
- It’s recommended to use loctite on motor screws, because motors make vibration and there is a chance those screws can wiggle free over time
- Make sure motor screws do not touch motor winding – here is how to check your motor screws are too long
- Should I use washers on the screws? No
Mounting the flight controller to the frame. You should “soft-mount” your FC whenever possible, luckily the Omnibus F4 AIO comes with rubber grommets.
Make sure The arrow on the FC is pointing forward.
Feature Reading – Why soft mounting FC is important
Mounting the ESC’s on the arms with double-sided foam tape,
Now trim the ESC wires just long enough to reach the FC, and do not get in the way of the standoffs.
Pro Tip: keeping wires as short as possible can minimize resistance in the system, but you should also leave enough slack so it doesn’t stress the solder joints or the copper pads
Slack in the ESC wires can also maximize the effectiveness of the FC soft mounting. If wires are too tight it will transfer vibration to the FC more easily.
Pro Tip: make sure no electrical contact is touching the frame, because carbon fibre is conductive, otherwise you could have a short circuit. Consider putting electrical tape on the frame under the component just in case
Now cut the motor wires short, tin the wires and the 3 pads on each ESC, and solder the motor wires on.
Let’s move on to our FPV system.
Connect the VTX and FPV Camera to the flight controller, and test it to make sure you are getting a clear picture on your goggles.
Solder the buzzer on the board. I recycled the wires from our ESC’s :)
We’ve finished the soldering, all the components are now connected! Next I will install the 8 standoffs.
Then mounting the FPV camera in the frame.
And secure the buzzer – you can simply strap it to one of the standoff with a zip-tie, make sure it won’t get chopped by a spinning propeller.
Here I am using a 3D printed beeper holder for the clean look :)
Secure those RX antennas.
A nice trick to protect your antennas is to wrap zip-ties around the front arms pointed back. Then you can use some heatshrink tube to affix them to the zip-ties so they won’t get damaged by the spinning propellers.
Pro Tip: make sure the RX antennas are approximately 90 degree to each other and not obstructed by the frame to ensure the best possible signal
Here is how the quad looks like so far.
Another tip is adding some protection to your ESC’s using plastic cover.
I simply recycled some old props, cut them into rectangular shapes and put them on top of the ESC. This will prevent “prop strike”, where spinning propellers can be bent and hit the ESC in crashes.
You can also use water bottles :)
Finally wrap the plastic cover, ESC and arm in electrical tape, or zip-tie.
The VTX is installed under the top plate with double-sided tape and zip tie.
You can fix the VTX antenna by using the same trick we used on the RX antenna.
Strap the XT60 pigtail to the top plate like it’s shown in the picture, keep the wires away from the spinning props.
We are almost there :)
I am using velcro and a battery strap on top of the frame for mounting the battery, so it doesn’t move around or slide out in crashes. You can also use Kyosho Pad for a similar result (purchase from Amazon).
When mounting battery, make sure the centre of gravity is as close to the centre as possible. To check if you have placed the battery at the right spot, simply grab the middle of the top plate with 2 fingers as shown in the following photo, and the quad should stay level.
Pro Tip: It’s important to have the COG (centre of gravity) right in the middle of the FC. Because if the quad is back heavy for example, the rear motors will have to work harder than the front motors in order to maintain balance, and this will impact flight performance.
Pro Tip: Don’t leave the LiPo battery balance lead hanging around, it can get chopped by propellers. I usually put a rubber band on the battery and hold the balance lead in place.
Finally, attach the propellers – be aware of the different CW and CCW propellers and install them in the correct motors. Otherwise your quad is going to flip over when taking off.
Before plugging in your LiPo battery, do a final check for short circuit.
You do this with a multimeter: put it on continuity mode and touch on the positive and negative connections in the quad with the probes:
- the + and – of the XT60 pigtail,
- positive and negative of all your ESC’s
- signal, positive and negative of your VTX and FPV camera
If there is a short circuit, the multimeter will start beeping non-stop. If this happens, you need to find out where the short is and fix it. This could be in the form of excessive solder connecting pads next to each other and so this will need to be removed.
Now… take some beautiful pictures before it gets covered in dirt and grass :) Don’t forget to share you build on our forum – IntoFPV.com
I am mounting the GoPro Session 5 on my quad using this 3D printed mount.
The quad weighs 350g AUW, without Battery and HD camera.
Setting up Betaflight
To setup Betaflight for your first flight, follow the instructions in this guide “how to setup Betaflight for the first time“.
You will also need to enable Softserial for SmartPort, because F4 can’t take inverted SmartPort signal, and soft serial is the easiest workaround for it (here is the instruction).
In this video I was flying with the DAL Cyclone 5045×3 propellers. It really flies like a dream!
This one is with Kingkong (KK) 5040×3 propellers. I got to say the KK props are considerably less powerful, and they are harder to tune in terms of PID. Personally not a big fan of them, but for practice and crashing they are good options.
Sorry about the video quality, It was a windy and cloudy day, footage looks a bit dark and shaky…
Here is the DVR footage to show you what I was seeing in my FPV Goggles.
It also shows you how much difference it made by adding a low ESR capacitor in this quad. It really does a good job cleaning up most of the noise!
My PID and Rate Profile
You might have your own preference about PID and Rate/Expo, but if you have no idea where to start, you can try my personal preference.
For the Kingkong 5040×3 props
set p_pitch = 46 set i_pitch = 50 set d_pitch = 32 set p_roll = 38 set i_roll = 40 set d_roll = 20 set p_yaw = 65 set i_yaw = 45 set d_yaw = 20 set tpa_rate = 35
For the DAL Cyclone 5045×3 props
set p_pitch = 54 set i_pitch = 50 set d_pitch = 33 set p_roll = 43 set i_roll = 43 set d_roll = 26 set p_yaw = 70 set i_yaw = 45 set d_yaw = 20 set tpa_rate = 30
Here is a screenshot of what I was using in the first flight video.