In this tutorial I will show you how to build a racing drone (aka FPV mini quad) from scratch step by step. It walks you through what components you need, how to assemble the quadcopter, and configure the software for your first flight.
Can Beginners Build an FPV Mini Quad?
There are pre-built drones you can buy off the shelf, but you are not going to learn anything. By building a quadcopter, you know exactly how everything fits together and how to repair it later on.
It’s going to be hard building your first drone, it could take hours, or even days to finish. When you encounter a problem, you might take advice from experienced pilots, or ultimately end up finding your way by trial and error. Either way, the journey is going to be extremely rewarding.
I wrote this tutorial back in 2017, and I have been constantly updating it to cover as much detail as possible, while trying to keep it simple so any beginners can easily follow. My goal is to teach you the steps and basic knowledge of building and setting up a mini quad.
There are a million ways to build a mini quad, different builders might use different steps, tools and techniques. But the goal is the same – building a racing drone that is reliable! And don’t be afraid to do things differently, as long as it works for you.
Learning the Basics
Before we begin, please make sure you’ve read this tutorial to get a basic understanding of mini quad and FPV in general: How to get started with Drone Racing and Mini Quad
if you see an abbreviation and have no idea what it means, you can try looking it up here: Acronyms and technical terms in FPV.
Table of Contents
- Racing Drone Parts List
- Tools and Accessories fpr Building
- Steps to build this Quadcopter
- More DIY Builds
- Pre-built Drone Recommendation
Mini Quad Parts List
For this tutorial, I will be using the following parts in “Primary Options” column. I also listed alternatives.
|Frame||Martian II Speical Edition ($20)||Martian II|
|FC||Kakute F7 AIO|
|ESC||Holybro Tekko32 35A ($64)||RacerStar RS30A V2 ($52)|
|Motor||DYS Sunfun 2207 2400KV ($12)|
|Propeller||HQ 5.1×4.1×3 ($)||DAL Cyclone T5045C ($3)|
|RX||Frsky XSR ($17)||Frsky R-XSR ($25)|
|FPV Camera||Runcam Micro Eagle||Runcam Eagle 2 ($45)|
|VTX||Eachine VTX03 ($10)||Holybro Atlatl V2 ($30)|
|FPV Antenna||Foxeer Lollipop V2||Aomway Cloverleaf|
|Misc Parts||XT60 Pigtail ($1.5)||–|
|IntoFPV Battery Strap||BG Battery Strap|
|Optional||Low ESC Capacitor ($1.5)||–|
|Spare Nylon Standoffs|
If you want to see other mini quad parts that I have tested and recommend, check here: https://oscarliang.com/tag/recommend/
The Martian II frame is a great value frame. I am still flying the one I bought back in 2016, the oldest frame in my fleet. It’s very roomy and easy to build, you can’t go wrong with the Martian II as your first mini quad frame.
By the way, I have a coupon here, FiberRC, you can get the Martian on this page for only $16.8. Expires in June 2019.
FC – Flight Controller
I like the simplicity of “AIO” (All in one) flight controllers, it combines the FC and PDB into one single board, which minimizes the amount of wiring and soldering.
The Kakute F7 AIO FC has been one of the most reliable flight controllers for me. You don’t need to worry about soft mounting because the Gyro is separated from the board by vibration damping foam. It features a powerful F7 processor that allows you to run all the latest features in Betaflight and still has enough processing power to run fast looptime.
The DYS Sunfun 2207 2400KV motor is one of the best value motors I’ve tested. FPV Beginners are going to crash a lot, and motors take the most impact so if you break them it won’t hurt as much.
ESC – Speed Controller
As your first build, I would steer away from 4-in-1 ESC’s. They might be easier to work with, but if you burn out one ESC then you are screwed. It stinks that you have to replace the whole board.
That’s why it’s better to use standalone ESC’s, price difference is minimal anyway. My go-to standalone single ESC’s right now are the Tekko32 35A. They are BLHeli_32 ESC’s, capable of running 48KHz PWM frequency and DShot1200, making them more superior than the older BLHeli_S ESC in terms of performance.
Your choice of radio transmitter determines what receiver (RX) you are going to use. For Frsky Taranis users, both the XSR and R-XSR are excellent choices.
XSR and R-XSR have the same features and range, but the R-XSR is smaller and lighter. Size is really not an issue for the roomy Martian frame, so you might want to consider the XSR because it’s slightly cheaper than the R-XSR. Anyway, it really doesn’t matter.
I am using the Eachine TX805 VTX in this build, simply because it’s cheap and has got all the features I ever need in a VTX! It has SmartAudio, selectable power levels range from 25mW to 800mW, MMCX connector, and a built-in Mic.
The Runcam Eagle 2 is simply the best “All-Around” FPV ever made, excellent performance in both day and low light. They also make a smaller version, the Micro Eagle. But yes, the Martian only takes full size cameras, but you can get this adapter so you can mount a micro camera just like a full size camera.
There are cheaper FPV cameras, but being able to see well in your FPV goggles makes a huge difference in your confidence and how well you can fly.
Most racing drone propellers these days are made of Polycarbonate plastic, which means they last much longer! My personal favourite props for this build are the DAL Cyclone 5045×3, and HQ 5.1×4.1×3. Get whichever prop you can find.
Other Equipment for Flying
You will also need to have the following accessories in order to fly a quadcopter. If you don’t already have these, take a look at my shopping guides to get some ideas what to buy.
Some 4S 1300mAh or 1500mAh LiPo Batteries. There are quite a lot to learn about LiPo in this Buyer’s Guide, because if you don’t handle them carefully they can be dangerous. See this post for our LiPo Recommendations.
Tools and Supplies for Building Drone
These are the basic tools for building a drone.
You might already have some of these tools lying around in the toolbox. If not, you should get them, these tools will come in handy for repairing and building your next quadcopter.
- Soldering Iron and solder
- 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 ties
- 3M Double sided tape (Buy from Amazon)
- Multi-meter (Buy from Amazon)
- Ummagrip battery pad
Steps to Building a Racing Drone
Here are the steps, click the link will take you to that part of the article.
- Frame Preparation and Assembly
- Installing Motors
- Wiring Diagram and Dry Fit
- Installing ESC
- Installing FC
- Testing Motors and ESC Setup
- Setup Receiver
- Connecting FPV Camera and VTX
- Installing Buzzer
- Using 3D Printed Parts
- Mounting Receiver Antennas
- ESC Protectors
- Top Plate and Battery Mounting
- Racing Drone Build Finished!
- Setting up Betaflight
- How to Tune Mini Quad
- Learning How to Fly a Racing Drone
1. Frame Preparation and Assembly
Prepare the frame by
- First, sand down sharp edges on carbon fibre peices (sharp edges can cut wires and battery strap in crashes, chamferred edges also prevents delamniation)
- Then wash all carbon fibre parts in soap water to remove any carbon dust remained (carbon fibre is conductive), then dry with towel
Assemble the frame by installing the arms, bottom plates, long aluminium standoffs and nylon standoffs for the FC.
2. Installing Motors
You can now mount the motors to the arms.
It’s recommended to use loctite (thread lock) on motor screws. That’s because motors make vibrations 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 if your motor screws are too long.
There is no need to use washers.
3. Wiring Diagram and Dry Fit
Think about how you are going to connect all the components, draw the plan on a piece of paper. If you are using the components I recommended, here is a wiring diagram you can follow.
You can then try to “dry fit” all the components in the frame – install them in the frame without actually connecting or soldering anything. This allows you to visualize how and where everything should be mounted, and spot any potential issues with space and mounting.
You can also see roughly how long the wires have to be. For example, check if the FPV camera cable is long enough to reach the “Video Input” solder pad on the flight controller.
You get the idea…
4. Installing ESC
You are about to do some soldering, if you are new to it, please see my tutorial on How to Solder for Beginners.
From the “dry fit”, we know where we will be mounting the ESC on the arms, and how long the motor wires have to be. So you can cut motor wires to length (leaving a tiny bit of stack), strip the wires (around 2mm) and tin the ends.
Before installing the ESC, put electrical tape on the arm for insulation. Remember, carbon fibre is conductive, and the Tekko32 ESC doesn’t come with heatshrink. If your ESC have heatshrink then you don’t need the electrical tape.
On top of electrical tape, put a strip of double-sided foam tape for sticking the ESC to the arm.
Install the ESC on the arm, tin the solder pads and solder the motor wires on. Don’t worry about wire order and motor direction, we can change it later in the software (BLHeliSuite).
Then solder the power wires and signal wires to the ESC. The Tekko32 ESC’s come with these wires, the power wires are 18AWG (red & black), while the signal and telemetry wires are 24AWG (white & blue). Color doesn’t really matter, it just makes it easier to tell what is what.
I am not soldering the signal ground wires on the ESC, because there isn’t a signal ground pad on the FC. But if you really want, you can solder it to the power ground pad on the FC. In my opinion, it shouldn’t be much a problem without it, because the signal wires are going to be very short.
- Use a good amount of solder flux and solder, and make sure solder joints are shiny and full; if you can see wire strands, it’s a sign that you haven’t applied enough solder; if the solder “sticks” to the tip when you remove it from the joint, then you have to apply more flux
- It’s okay to use high temperature when soldering, the important thing is to make it quick and avoid heating the copper pads for too long (I personally use 450°C or 840°F for motor wires and power)
This is what it looks like when ESC’s are all mounted on.
5. Installing FC
In this build, I decided to mount the radio receiver (RX) under the FC. Because of this, I had to replace the original standoffs (6mm long) with some slightly longer ones (10mm long). You’d have to purchase these 10mm standoffs separately as they are not included in the kit.
If you don’t want to change out the nylon standoffs, you can just mount the RX somewhere else in the frame. There is so much free space!
Install the flight controller on the nylon standoffs, make sure the arrow on the board is pointing forward.
Cut the ESC wires to suitable lengths. Shorter is better as it minimizes resistance in the wire and less likely to pick up interference. But it’s good to leave some slack so it doesn’t stress the solder joints.
Slack in the ESC wires can also maximize the effectiveness of the FC/Gyro soft mounting. If wires are too tight it will transfer more vibration to the FC from the frame.
It’s all about balance :)
Before soldering ESC wires to the FC, I strongly recommend covering the FC with some tape on areas you are not working on, so you don’t accidentally drop solder on the board which could ruin your FC forever.
Tin all the solder pads you are going to use on the FC. Skip the ones you don’t use.
Use solder flux as it helps soldering big wires tremendously! And apply a decent amount of solder at the same time, the solder joint will look shiny, round and solid! Here is an example.
Good work takes time! Don’t rush it.
You can now solder the XT60 pigtail to the FC as well. The wire length really depends on how you are going to mount the XT60 pigtail in the frame. Check mine later in the build log for ideas.
Personally, I normally make sure it’s just long enough to stick out of the frame. My XT60 pigtail is about 8cm to 9cm long.
Watch out for polarity (positive and negative wires).
I also recommend soldering a low ESR capacitor at the power (on the same pads as the XT60). See this post to learn why adding capacitors to mini quad.
In a nutshell, when you have very noisy gyro or FPV video, the capacitor will help “clean up” the noise coming from ESC and motors. Even if your mini quad is “super clean”, when you have a bent prop you will start to get noise from motors, and a capacitor can have you covered in these situations.
You can mount it however you like. I normally just stick it on the bottom plate with some double-sided foam tape, then zip tie it to the standoff.
6. Motor Test and Setup ESC
Time to test our motors, which means we will be plugging in LiPo battery for the first time!
For safety, you should check continuity first to ensure there is no electrical short. You can do this with a multimeter: put it on continuity mode and touch on the positive and negative XT60 connections with the probes.
Here is a quick tutorial on what multimeter you should get, and how to test your drone with it.
If there is a short circuit, the multimeter will start beeping non-stop. If this happens, you need to find out what is causing the short and fix it. One common cause would be excessive solder connecting pads next to each other and so this will need to be removed.
Pro-Tip: sometimes the meter might beep for a split second then stop. That’s because there are capacitors between positive and negative. When you touch the pads with your probes, it charges the caps up so the meter thinks there is a short, but when the caps are charged the beep will stop. That’s normal and nothing to worry about, it should be fine if the meter doesn’t continue to beep.
For the first time you plug in the battery, use a smoke stopper. You can build yourself a smoke stopper. This is a great and simple device to avoid magic smoke! You can also just buy one but it’s not as effective as the light bulb version.
You don’t have to use a smoke stopper, it’s just something I would strongly recommend. If you don’t have it, check with a multimeter at the very least.
DO NOT install propellers!
Now you can plug in the battery, go to the Motor tab in Betaflight Configurator, and try to spin up the motors one by one, and verify if the motors are spinning the right direction (instructions).
If it’s spinning the wrong direction, then you’d have to reverse it.
There are two ways to reverse a motor direction.
Firstly, you can swap two of the motor wires around.
Or even more easily, you can reverse motor direction in the software (BLHeliSuite). That’s why I said earlier it doesn’t matter how you connect the motor wires :)
Here are instructions on how to connect your BLHeli_32 ESC’s to BLHeliSuite.
While we are at it, you can also adjust ESC settings to optimize performance. The two settings i always change are PWM frequency (to 48KHz), and Motor timing (to Auto). See this post to learn about BLHeli_32 ESC Settings.
Did something go wrong? Here are some troubleshooting tips.
Motors are not spinning at all? Did you connect the battery? If so, did you hear the ESC beeps as you plug in the battery? Are the ESC signal wire soldered to the correct pads on the flight controller? And And check motor wire soldering.
If one motor still isn’t spinning after checking everything, it’s possible that the ESC or that motor is faulty. You can try swapping this motor with another working one on the same quad, it will help rule out whether it’s the faulty ESC or motor.
If you need assistance, just ask in our forum, https://intofpv.com
7. Receiver Setup
After confirming the motors, ESC and FC are working, we can now move on to soldering the radio receiver to the flight controller.
- Black Wire (GND) goes to GND pad on the FC
- Red Wire (5V) goes to 5V pad on the FC
- White Wire (SBUS) goes to RX4 on the FC
- Yellow Wire (S.Port) goes to TX6 on the FC
With the receiver connected, the next step is to bind it to the Taranis transmitter (instructions).
In the Ports tab in Betaflight configurator, enable “Serial RX” under UART4, and select “SmartPort” under UART6.
Then go to the configuration tab, under “Receiver” section, select “Serial-based receiver”, and choose “SBUS” as the provider.
Once that’s done, you want to confirm the receiver is fully working in the Receiver tab. When you move the transmitter sticks, the bars (channels) should move as well.
If the wrong channels are responding, try a different channel map, it’s normally either “default (AETR)”, or TAER.
You will need to setup at least two switches on the Taranis (instruction) for arming and enabling “lost model beeper”. Again, confirm it’s working in the receiver tab, these should show up as channels AUX1 and AUX2.
Next you want to test if SmartPort is working. You can do this by simplying go to the telemetry page on the Taranis. plug in the LiPo, and the LiPo voltage should be displayed under “VFAS”. If you don’t see “VFAS”, then scroll down and select “Discover new sensors…”.
And finally setup and test failsafe (instruction) on the receiver.
If you have any questions or issues, post in our forum: intoFPV.com
8. Connect FPV Camera and VTX
Let’s move on to our FPV system.
Solder both cables from the VTX and FPV Camera to the flight controller. I am powering the VTX directly from LiPo voltage (BAT), and the camera from 5V. SmartAudio from VTX is connected to TX1.
Pro tip – twisting cables this is a great way to help reduce unwanted RF noise.
Power on the quad with Smoke Stopper, to test make sure you are getting a clear picture on your goggles. Since the VTX is brand new, it could be on any channel. Use the “search feature” on your FPV goggles to find it, or simply scroll through all channels.
Here are instructions on how to setup SmartAudio so you can change VTX settings in Betaflight OSD.
9. Installing Buzzer
Solder the buzzer to the FC: Buzzer positive goes to 5V, Buzzer negative goes to Z-.
To mount the buzzer in the frame, you can use the same trick we used on the capacitor earlier – double-sided foam tape :) Don’t block the hole though!
Stick it to the frame, then wrap around it to a standoff with electrical tape .
10. Using 3D Printed Parts
Most things are open source in the FPV hobby, including 3D printed parts for our quads! You can find lots of useful 3D printed part designs online.
While 3D printed parts are not necessary, they can be very useful.
I designed these 3D printed parts specifically for the Martian II frame, they make the build so much cleaner! If you don’t have a 3D printer, I can print and send them to you, get them here.
11. Mounting Receiver Antennas
The XSR and R-XSR receiver have two antennas for diversity. For the best result, keep the two antennas at roughly 90 degree.
Here is a trick for mounting your RX antennas: you can wrap a zip-tie around the arms, then use heatshrink tube to affix the antenna to the zip-ties to keep it away from spinning propellers.
12. ESC Protectors
Another useful trick is adding some covers to your ESC’s using plastic sheets. This will prevent “prop strike”, where spinning propellers get bent and hit the ESC in crashes.
I normally just recycle old props, cut them into rectangular shapes and put them on top of the ESC, wrap the plastic cover, ESC and arm with electrical tape, or zip-tie. You can also get the plastic covers from water bottles, or any plastic sheet you can find :)
Here is how the quad looks like so far.
13. Top Plate and Battery Mounting
We can now put the top plate on. I am installing an HD camera mount on top of the frame for my GoPro Session. The camera mount is 3D printed in TPU. If you don’t have one you can ignore it.
For mounting the battery, I am using a IntoFPV battery strap, and Ummagrip battery pad. I really like the Ummagrip, it keeps your battery safely away from the bolts, and it sticks to the battery really well. Alternatively you can just use the good old velcro.
When mounting battery, make sure the centre of gravity is as close to the centre of the drone 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.
It’s important to make sure the COG (centre of gravity) right at the centre of four motors. 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.
The XT60 pigtail is held in place by a 3D printed mount I personally designed. A very neat and practical solution.
If you don’t have 3D printed part, you can simply strap it to the top plate like so with a heavy duty zip tie. (make sure you’ve chamfered the edge of the top plate). It’s not very pretty, the goal is to keep your battery lead away from spinning propellers.
Pro Tip: Don’t leave the battery balance lead hanging around, it can get chopped up by propellers. I usually put a rubber band on the battery to hold the balance lead in place.
14. Racing Drone Build Finished!
Finally, it’s done! Now 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.
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
The quad weighs 350g, without Battery and HD camera.
15. Setting up Betaflight
To setup Betaflight for your first flight, follow the instructions in this guide “how to setup Betaflight for the first time“.
16. How to Tune Mini Quad
Tuning your quad is basically making it to fly and behave exactly the way you want. You don’t have to tune your quad, and it will fly just fine. But if you are serious about performance, then you have more stuff to learn! :D
For me, tuning a mini quad is basically going through these settings and get them dialed in:
- RC Rates and Expo
- Other Betaflight settings (min throttle, antigravity, feedforward, throttle boost etc….)
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.
- RC Rate: 1.3
- RC Expo: 0.24
- Super Rate: 0.66
[Updating… ] I will be testing Betaflight 4.0. Will come back and update my settings here soon.
17. Learning How to Fly a Racing Drone
If you have little to no experience in flying a mini quad, you should definitely check out these tutorials to get started:
- Practice with FPV simulators
- Tips and Exercises to learn FPV flying
- Finding FPV flying difficult? Here are some advice from many different pilots
Flight with this quad:
Here are some other videos with the Martian frame.
More Quadcopter Builds?
Looking for more examples and inspiration? Here are some of my latest builds and parts list.
Pre-Built Racing Drone Options
I don’t want to build, which pre-build drone to buy? There are a lot of options on the market, but many are garbage or simply overpriced. Here are some of the best ones that are worth looking into:
- Dec 2017 – Article created
- Mar 2018 – Added different FC option
- Apr 2019 – I re-wrote the whole tutorial, updated the parts list and all the images