How to Build an FPV Drone From Scratch (Analog FPV System)

by Oscar
Published: Last Updated on

I will show you how to build an FPV drone from scratch that uses analog FPV system. I will explain what components are needed, how everything is connected, and how to set it up. This tutorial will hopefully help you in your future FPV drone builds as well.

I will be using 4in1 ESC and analog FPV system in this build, I have another build guide for the DJI FPV system. And here’s an old build log from 2019 that uses separate ESC.

Why Build FPV Drone?

You can just buy pre-built drones, but you are not going to learn anything. Building it from scratch by yourself enables you to repair it later on, and you can select the parts you want and build it to your specification.

Building your first drone is going to be challenging. Whenever you have a question, just ask online (such as intoFPV.com), or ultimately you might end up finding your way by trial and error. Either way, you are going to learn a lot about how an FPV drone work.

Learning the Basics

I tried my best to document as much detail as possible in this tutorial, so any beginners can follow and pick up the basics of building and setting up a mini quad.

Before we begin, you should definitely check out: How to get started with FPV Drones

You can look up technical terms and acronyms here: Acronyms and technical terms in FPV.

No 3D Printer? No Problem!

This build doesn’t require any 3D printed parts.

But you can use 3D print parts to make it easier to build and look nicer.

Anyway I will show you all the steps how to build this FPV drone with and without 3D printed parts. Let’s get started!


Table of Content


Parts List

These are the components I will be using in this build.

This table contains affiliate links. It doesn’t cost you anything extra, but it gives me a small commission when you make your purchase using these links.

Parts Shops
Frame Martian II Special Edition ($25) Banggood | Amazon
FC Diatone Mamba F722 MK2 Banggood
ESC (Option #1) Tekko32 F3 Metal 65A 4in1 ESC Banggood | RDQ | GetFPV
ESC (Option #2) Tekko32 F3 45A 4in1 ESC Banggood | RDQ | GetFPV 
Motors 4x Emax ECO II 2207 2400KV Banggood| GetFPV | RDQ
Propellers 4x HQ 5.1×4.1×3 RDQ | GetFPV | Banggood
Receiver (RX) Crossfire Nano GetFPV | Amazon |NBD
FPV Camera Runcam Eagle 3 Banggood | GetFPV | RDQ
VTX Rush Ultimate Plus Banggood | GetFPV | RDQ
VTX Antenna Lollipop V3 Banggood | RDQ | GetFPV
Misc Parts XT60 Pigtail (14AWG 8cm+) Banggood | Amazon | RDQ
Buzzer Amazon | Banggood
Battery Strap (20x220mm) Banggood Amazon
Battery Pad Amazon | GetFPV | RDQ

You also need the following hardware, you should be able to find these easily on eBay or from you local hardware store.

  • 4x 30mm M3 steel bolts (for FC stack)
  • 4x M3 nuts (for FC stack)
  • 4x M3 nylon lock nuts (for FC stack)
  • Some zip ties
  • Electrical tape
  • Double sided tape

Optional, 3D printed parts for the Martian frame: https://www.thingiverse.com/thing:3582840

Frame

I was looking through all the latest frames for this tutorial, but I still chose the Martian II frame. This is an old frame from a few years back, but it’s very cheap, durable, roomy and easy to build. You just can’t go wrong with the Martian as your first mini quad frame.

Because it’s been around so long and popular, there are a ton of 3D printed part designs available on Thingiverse for enhancement.

Flight Controller

The Diatone Mamba DJI F722 MK2 FC (review) was just released in April 2021. It’s very powerful and versatile, it has all the latest features, as well as supporting both analog and DJI FPV system. It’s so future-proof, you will be able to keep upgrading your drone without spending more on a new FC!

ESC

4in1 ESC’s are generally very reliable nowadays, and they make building so much easier thanks to the less amount of wiring and soldering.

The Tekko32 F3 Metal 65A ESC (review) is one of the beefiest on the market, you basically won’t have to worry about “pushing too hard on your throttle”. It supports both 4S and 6S, so you won’t have to buy a new ESC for quite some time even if you want to upgrade to larger motors or use higher voltage :)

As a cheaper option, the Tekko32 45A ESC listed in the table is also good enough for this build in terms of current rating. But the 65A version has way better noise filtering and it’s more future-proof for a more powerful setup.

Motors

The Emax ECO II 2207 2400KV are some of the best performing budget motors. FPV Beginners are expected to crash quite a lot, and motors are the most exposed components, so even if you break them it won’t cost as much.

Popular motor sizes for a 5″ build are: 2306, 2207 and 2208. Since we will be using 4S LiPo to power it, 2400KV is a good KV number. You can use between 2300KV to 2600KV, higher KV tends to be more aggressive and power hungry.

6S is also popular among experienced pilots (using 6S LiPo battery), and motor KV is much lower, usually around 1800KV. But the higher voltage makes the drone harder to tune and it can sometimes cause more issues, therefore I don’t recommend it to beginners. 4S is easier as your first build.

FPV Setup

The Eagle 3 (review) and Rush Ultimate Plus (review) is a great combo when it comes to analog FPV setup.

Receiver

Your choice of radio transmitter will determine what receiver (RX) you can use. If you follow my radio recommendation, then your radio should support TBS Crossfire.

I recommend TBS Crossfire because of its top notch performance, reliability and ease of use. I exclusively use their Crossfire Nano receivers in almost all my FPV drones, because they are very compact, and gives me more than enough range.

To use Crossfire nano receiver, you will also need to get a Crossfire TX module that plugs into the module bay on your radio.

You can learn more about the Crossfire RC System here.

Other FPV Equipment

You will also need the following accessories to fly a quadcopter in FPV. You can take a look at what gear I use everyday for some ideas, I will summarize what you will need here.

A Radio Transmitter (Buyer’s Guide) is used for controlling the drone, right now (April 2021) I recommend getting the Radiomaster TX16S (see my review). It’s affordable and versatile. It does basically everything you need in FPV.

A pair of FPV Goggles for watching real-time video from the drone, here is my FPV Goggles Buyer’s Guide. The best in class analog FPV Goggles right now would be the Skyzone SKY04X. But if that’s beyond your budget, you can also check out the Skyzone Cobra X (review) which I think is the best budget “box goggles” at the moment.

As for LiPo batteries, some 4S 1500mAh would be the way to go, see this post for my LiPo Recommendations. Make sure to spend time learning about LiPo in this Battery Buyer’s Guide, because if you don’t handle them carefully they can be dangerous.

Finally, you will also need a battery charger, here is my LiPo charger recommendations. Again, take your time reading about how to choose LiPo chargers and power supply.

To check out other FPV products that I have tested and recommend: https://oscarliang.com/tag/recommend/

Tools and Material for Building FPV Drone

You will need most if not all the tools listed in this article under “Essential Tools”. And you will also need these tapes too:


Steps of Building FPV Drone

Click the link will take you to the section in this article:

  1. Frame Preparation and Assembly
  2. Installing Motors
  3. Wiring Diagram
  4. Installing ESC
  5. Installing FC
  6. Testing Motors and ESC Setup
  7. Setup Receiver
  8. Connecting FPV Setup
  9. Finishing off
  10. Using 3D Printed Parts
  11. Setting up Betaflight
  12. How to Tune Mini Quad
  13. Learning How to Fly a Racing Drone

1. Frame Preparation and Assembly

It’s optional but a good practice to “prepare” the frame:

  • First, sand down sharp edges on carbon fibre pieces, especially the outer side of the arms, and plates, sharp edges could cut your wires and battery strap in a crash. The chamferred edges can also prevents carbon sheet from delamination
  • After sanding, wash all carbon fibre parts in soap water to remove any carbon dust that remains, then dry with towel

Assemble the frame and install the 8 aluminium standoffs.

We will be using the four 30mm M3 bolts for the FC stack, tighten down with M3 nuts.

2. Installing Motors

You can now mount the four motors to the arms.

It’s recommended to use thread locker on the motor screws. That’s because motors make vibrations and there is a chance those screws can wiggle free over time. Make sure to use the blue liquid one, the red liquid is intended for permanent use and you will have a hard time undoing those screws!

There is no need to use washers.

Finally, make sure the motor screws are not touching the motor winding – check visually, or even better check with a multimeter if your motor screws are too long.

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3. Wiring Diagram

Make a plan on how to connect all the components, draw the connections on a piece of paper. If you are using the components I recommended, here is a wiring diagram you can follow.

You can try to “dry fit” all the components – install them in the frame without actually connecting and soldering the wires. This allows you to spot any potential issues with spacing, and how long the wires need to be.

Make sure to install the FC and ESC in the correct orientation, and understand which side of the frame is the front. The front of the frame should have slots (cut out) for the camera mounting plates. The FC has an arrow label pointing forward, and the ESC’s positive/negative solder pads should be pointing to the tail of the frame.

Make sure the ESC is NOT touching either the frame, or the FC. If they are touching, you can use extra spacers/o-rings.

4in1 ESC and FC from the same brand are usually plug and play. But if you are using ESC and FC from different manufacturers, chances are the pin orders are not the same. You must double check before connecting or you could fry your flight controller!

In that case you should rearrange the wires in the connector. Fortunately, the Mamba MK2 FC provides an unfinished cable so you can insert the wires in the connector following my wiring diagram.

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4. Installing ESC

You are about to do some soldering. If you are new to this, please check out my tutorial: How to solder for beginners.

Check how long the motor wires need to be, and cut to length (it’s a good idea to leave a bit of slack just in case).

Then strip the wires (around 2-3mm) and tin the ends.

Tin all the solder pads on the 4in1 ESC. It’s good practice to cover area of the board where you are not soldering with electrical tape. This will prevent solder accidentally dropping onto components and causing electrical shorts.

Soldering Tips:

  • Use a good amount of solder and solder flux (solder paste) for the large pads, and make sure the solder joints are shiny and full; if you can see the wire strands, it’s a sign that you haven’t applied enough solder
  • If the solder tends to “stick” to the tip when you remove it from the joint, then you should apply more flux
  • It’s okay to use high temperature when soldering large solder pads like these, the important thing is to make it quick and avoid heating the pads for too long (I personally use 450°C (840°F) for motor wires and XT60, and 360°C for signal wires)

Solder the motor wires to the ESC. Don’t worry about wire order and motor direction for now, we can change it later in the software.

Cut the capacitor legs shorter, and solder wires to them (18AWG/20AWG). You could use those motor wires you just trimmed off :)

Your XT60 power lead should be at least 8cm long.

Solder the XT60 power lead and capacitor to the power pads on the ESC. Watch out for polarity (positive and negative).

You may wonder, “why solder a capacitor to the power?” Well, it’s for soaking up voltage spikes and reducing electrical noise generated from the motors and ESC. Even if your mini quad is “super clean”, when you have a bent prop, you will begin to get more noise from the motors, and a capacitor can have you covered in situations like this.

See this post to learn more about why adding capacitors to mini quad.

This is what it looks like when the motors and battery plug are all soldered to the ESC.

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5. Installing FC

Solder the radio receiver (RX) to the FC.

I will be mounting the RX under the 4in1 ESC, so make sure the wires are long enough. Of course you can mount it anywhere you see fit, there’s a lot of free space in this frame.

Install the flight controller on top of the 4in1 ESC, and connect the cable from the 4in1 ESC to the FC.

Solder the buzzer to the FC.

To mount the buzzer and capacitor, I simply use some double sided foam tape and just stick it onto the bottom plate.

Don’t block the hole in the buzzer with the tape.

With the capacitor, you can also use a zip tie to strap it to a standoff.

Put nylon nuts on the FC. Don’t over-tighten it, just barely touching the rubber grommet is fine. Compressed grommets = reduced vibration damping.

Mount the RX antenna to one of the arms with a couple of zip ties. Don’t forget to strap the antenna wire to the frame for stress relief.

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6. Motor Test and Setup ESC

Time to test the ESC and motors, which means we will be plugging in a LiPo battery for the first time!

For safety, you should always check continuity first to ensure there is no electrical short. You can do this with a multimeter: put it on continuity mode and use the probes to test the positive and negative terminals of the XT60.

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 be beeping continuously. If this happens, you need to find out what is causing the short and fix it. One common cause is excessive amount of solder used on one solder pad and spill over to or touching neighboring pads.

Pro-Tip: sometimes the meter might beep for a split second then stop. That happens because of the capacitors. When you touch the positive and negative pads with your probes, it charges the caps so there will be a flow of current, and the meter thinks there is a short, but when the caps are charged, the beep will stop. If you get a short beep, that’s normal and nothing to worry about, it should be fine if the meter doesn’t continue to beep.

For the first time plugging in a battery, use a smoke stopper (review). This is a great and simple device to avoid magic smoke! Smoke stopper is optional, but it’s a worthy investment that I can’t recommend enough.

Now it’s time to test the motors, but DO NOT install propellers yet!

Plug in a battery, then go to the Motor tab in Betaflight Configurator, and try to spin up the motors one by one (just move the slider to 10-20%), and verify if the motors are spinning in the right direction (instructions).

If a motor is spinning the wrong direction, then you should reverse it.

There are two ways to reverse motor direction.

You can either swap around two of the three motor wires.

Or more simply, you can reverse the motor in BLHeliSuite32 (computer program). 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 change ESC settings to optimize performance. The two settings i always change are PWM frequency (to 48KHz, or 96KHz if allowed), and Motor timing (to Auto). See this post to learn about these BLHeli_32 ESC Settings.

Something went 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 when you plug in the battery? Did you connect the ESC to the FC?

If all motors are spinning except one, it’s possible that the ESC or that motor is faulty. You can try swapping that motor with a working one on the same quad, this will help rule out whether it’s the faulty ESC or motor.

If you need further assistance, just ask in our forum: https://intofpv.com

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7. Receiver Setup

First of all, you need to bind the receiver to the radio (TX module), I have a whole guide explaining how to setup Crossfire. Then in Betaflight configurator, you need to do the following:

  • Go to Ports tab, find UART1, and enable “Serial RX
  • In the Configuration tab, under “Receiver” section, select “Serial-based receiver“, and choose “CRSF” as the provider

Once that’s done, you want to confirm the receiver is fully working in the Receiver tab. When you move the sticks on the radio, 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 radio (instructions), one for arming, and the other for buzzer. You might also want a 3rd switch for flight mode or turtle mode. Again, confirm it’s working in the receiver tab, the two switches should show up in channels AUX1 and AUX2.

If you have any questions, post in our forum: intoFPV.com

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8. Installing FPV Setup

Let’s move on to our FPV system.

Solder up the VTX to the FC as shown in my wiring diagram, there are only four wires (VCC, GND, SmartAudio and Video).

Pro tip – twisting the video/VCC/GND cables is a great way to help reduce unwanted RF interference.

Use electrical tape to cover any metal contacts on the side that will be resting on the carbon fibre frame, and stick it down to the bottom plate with double sided tape.

I mount my VTX and antenna like this in the frame, simply with zip ties. It’s so much better with 3D printer parts as I will show you in a minute, but this will do for now. We have to run with whatever we’ve got :)

Now you need to setup SmartAudio and VTX Table in Betaflight. This will allow you to change VTX channel and settings using OSD menu.

To setup SmartAudio, go to Betaflight Configurator, Ports tab, under “UART 3“, Peripherals, select “VTX (TBS SmartAudio)“.

To setup VTX Table, simply copy and paste this snippet in the CLI:

vtxtable bands 5
vtxtable channels 8
vtxtable band 1 BOSCAM_A A FACTORY 5865 5845 5825 5805 5785 5765 5745 5725
vtxtable band 2 BOSCAM_B B FACTORY 5733 5752 5771 5790 5809 5828 5847 5866
vtxtable band 3 BOSCAM_E E FACTORY 5705 5685 5665 0 5885 5905 5925 0
vtxtable band 4 FATSHARK F FACTORY 5740 5760 5780 5800 5820 5840 5860 5880
vtxtable band 5 RACEBAND R FACTORY 5658 5695 5732 5769 5806 5843 5880 5917
vtxtable powerlevels 4
vtxtable powervalues 14 23 27 29
vtxtable powerlabels 25 200 500 800
save

Pro Tip: DO NOT power the VTX without antenna attached! Otherwise it could overheat and burn out.

Power on the quad with Smoke Stopper again, and see if you are getting a clear image in 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 the bands and channels.

And you can now change VTX channel and settings with Betaflight OSD menu.

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9. Finishing Off

It’s good to cover/protect the motor wires with plastic sheets. You can cut up a water bottle, or blades from old propellers. This will prevent “prop strike” in a crash, where spinning propellers could be bent and cut the motor wires.

Wrap the plastic piece over the wires with electrical tape or zip-tie.

We are almost done! Here is how the quad looks like so far.

Install the top plate.

Put a battery strap under and through the top plate. And stick some battery pads on the top. Use as much as you need, I am being stingy here.

The finished drone build weighs:

  • Drone = 380g
  • Drone + 4S 1500mAh LiPo = 570g
  • Drone + 4S 1500mAh + GoPro 7 = 690g

When mounting the LiPo battery, make sure the COG (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, and see if the quad stays balanced.

It’s important to make sure COG is right at the centre of the four motors. For example, if the quad is front heavy, the front motors will have to work harder than the rear motors in order to maintain level, and this will impact flight performance.

When installing propellers, be aware of the different CW and CCW props and install them in the correct motors. Otherwise your quad is going to flip over when trying to take off.

5″ FPV drones use M5 nylon lock nuts to hold the propeller on the motor. It can take some effort to tighten down, but you don’t want it too tight, or the prop hub can shutter when you crash. Just tight enough that the prop can’t move is enough.

Using a proper prop nut tool like this can speed things up too.

And we are ready for a test flight!

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10. Using 3D Printed Parts

If you want a cleaner build, you should use 3D printed parts.

I designed most of these parts myself and I will share the STL files in the parts list if you choose to print them. If you don’t have a 3D printer, you can ask someone else to print them for you, like using East Sussex 3D Printing Service. You can contact them on Facebook or email: 3dprintsfpv AT gmail DOT com

I also printed a GoPro mount (not my design) to get some 4K HD footage.

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11. Setting up Betaflight

To setup Betaflight for your first flight, follow the instructions in this guide “how to setup Betaflight for the first time“.

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12. How to Tune Mini Quad

“Tuning a quad” is basically to make it fly exactly the way you want. Betaflight has come a long way, you don’t have to tune your quad and it will probably fly just fine with stock settings. But if you are serious about performance, then you have a few more things to learn! :D

For me, tuning a mini quad is basically going through these settings and get them dialed in:

  • RC Rates and Expo
  • PID
  • Filters
  • Other Betaflight settings (min throttle, antigravity, feedforward, throttle boost etc….)

Betaflight has a pretty neat tuning guide, which is a good starting point: https://github.com/betaflight/betaflight/wiki/4.2-Tuning-Notes

Or you can just copy my settings and give them a try. Make a backup of your settings first!

My PID Tune

My Rates

My Filter Settings

You should enable RPM filter first, it’s easy to do and almost always improves flight performance instantly.

When changing filter settings, always make incremental changes, try flying it for 20-30 seconds, then land to check motor temperature. If it’s noticeably warm, then you should probably revert back to the previous value. You don’t want to burn your motors :)

13. Learning How to Fly an FPV Drone

If you have little to no experience in flying a mini quad, you should definitely check out these tutorials to get started:

Flight Videos!

First ever flight of this quad:

https://youtu.be/afPsrzThcGw

Some of my older FPV videos:

https://www.youtube.com/watch?v=Ob5lkMKCxb4

https://www.youtube.com/watch?v=Qlw041F7dko

https://www.youtube.com/watch?v=F1PCN1Ewbv0

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5 comments

Abutalib 22nd May 2021 - 2:33 pm

Hi Oscar .. best content for drones on the web . Thanks .. would you please post a complete iNAV built ?

Reply
LM 14th May 2021 - 1:26 am

:) , a bit cost conscious , do you think Diatone F50 Pro won’t be good? I checked through thrust test results that and specs of the motor that for 6” it’s Amp is well below 50

Reply
Oscar 14th May 2021 - 11:13 am

Yes that ESC is also good enough for this build in terms of current rating :) It won’t be as good as the Tekko32 65A when it comes to noise filtering and handling of more powerful setup, but you should be fine with that ESC

Reply
LM 13th May 2021 - 8:37 pm

Thanks. Basis your suggestion on the choice of props, I have a 250 mm carbon fiber frame, will it fine to use 2306/2400 KV motor and 6″ Tri-blade prop?
or as I am a beginner, you think this configuration will be good enough for me.

Reply
Oscar 13th May 2021 - 11:06 pm

Sure it should be fine, the ESC I suggested should be able to handle it.

Reply