The way to Construct an FPV Drone Tutorial (DJI O4 Professional Air Unit)

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On this complete tutorial, I’ll stroll you thru the method of constructing an FPV drone from scratch, offering detailed steering for each analogue and digital FPV programs. We’ll cowl the whole lot from choosing the suitable parts, to wiring and meeting, and even share insider suggestions and tips to make sure you have a dependable and pleasurable FPV drone expertise.

Can Novices Construct FPV Drones?

Completely! Even you probably have no prior expertise, rookies can completely construct an FPV drone from scratch.

It may be tempting to only purchase a pre-built drone off the shelf—however the place’s the enjoyable (and studying) in that? By assembling your personal drone, you’ll acquire beneficial hands-on information about every part and the way all of them work collectively. You’ll even be a lot better ready to troubleshoot and restore your drone if something goes incorrect.

Now, I gained’t sugar-coat it—constructing your first FPV drone shall be fairly difficult. It could take hours, and even days, to finish. You may need to hunt recommendation from skilled pilots on-line or determine issues out by trial and error. However belief me—the sense of accomplishment and the talents you acquire will make the journey extremely rewarding.

Let’s dive in and embrace the challenges forward!

Mastering the Fundamentals

Earlier than we embark on this thrilling tutorial, it’s essential to familiarize your self with the fundamentals of a quadcopter.

To get began, take a look at our beginner-friendly information: Getting Began with FPV Drone.

As you discover the world of FPV, you’ll probably encounter many acronyms and technical phrases. When unsure, check with our useful glossary: Decoding Acronyms and Technical Phrases in FPV.

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Components Listing

On this tutorial, we’ll be utilizing the next elements.

Only a fast observe: the hyperlinks supplied are affiliate hyperlinks. Making a purchase order by these hyperlinks gained’t price you something further, however it can earn me a small fee. This assist helps hold the weblog working and permits me to proceed sharing my ardour for FPV drones with you—thanks!

This explicit construct focuses on the DJI O4 Professional Air Unit. If you happen to’re interested by constructing an analog FPV drone, take a look at my different construct log right here: https://oscarliang.com/how-to-build-fpv-drone-analog/

You probably have a small finances, right here is an inventory of the most cost effective 5″ drone elements.

If you would like extra choices, right here is an inventory of elements that I like to recommend.

Body

The body is the sturdy construction (normally carbon fibre) that holds all the drone’s parts collectively.

For this tutorial, I’ve chosen the GEPRC Vapor—a superb alternative because of its excessive construct high quality and reasonably priced worth. It additionally comes with quite a lot of 3D-printed equipment, making for an extremely simple and clear construct.

Take a look at my detailed evaluation of this body, together with step-by-step meeting directions, right here: https://oscarliang.com/geprc-vapor-x5-d5-frame/.

FC and ESC

Shopping for the flight controller (FC) and ESC collectively as a stack shouldn’t be solely cheaper, nevertheless it additionally ensures that they’re plug-and-play proper out of the field, making the drone constructing course of extra simple.

For this tutorial, I’ve chosen the T-Interest VELOX F7 SE FC and V70A ESC stack. Regardless of being one of the vital reasonably priced FC/ESC stacks available on the market, it doesn’t compromise on options. It helps nearly all fashionable functionalities you’d need in an FPV drone. Take a look at my in-depth evaluation right here: https://oscarliang.com/t-hobby-f7-se-fc-v70a-esc-stack/

If the VELOX F7 stack is out of inventory, don’t fear—there are many wonderful options. Right here’s an inventory of my prime suggestions: https://oscarliang.com/flight-controller/#The-Greatest-FC-Suggestions.

Motors

FPV motors immediately are surprisingly related when it comes to efficiency, particularly on the newbie degree. Which means there’s no want to purchase the most costly motors if you’re simply beginning out—most individuals wouldn’t even discover the distinction. Funds choices just like the RCINPower EX2207 are greater than enough for rookies.

For a 5-inch FPV drone, motor sizes similar to 2306, 2207, and 2208 are all viable selections. Personally, I imagine 2207 hits the candy spot when it comes to performance-to-weight ratio. Be taught extra concerning the variations right here: https://oscarliang.com/2306-2207-mini-quad-motor/

One other essential issue to contemplate is motor KV, which is linked to your battery voltage. For a 6S construct, I like to recommend selecting motors with a KV score between 1600 and 2000.

There are various different wonderful motors price contemplating—take a look at my full checklist of suggestions right here: https://oscarliang.com/motors/#Suggestions

FPV Setup

There are a number of FPV programs obtainable available on the market, however the DJI O4 Professional could be my best choice for a 5-inch freestyle drone. It gives one of the best picture high quality and sign reliability, and top-notch construct high quality. If you wish to be taught extra concerning the completely different FPV programs and their execs and cons, take a look at my purchaser’s information: https://oscarliang.com/fpv-system/

Radio Receiver

Your alternative of radio transmitter dictates the kind of receiver (RX) you should use. If you happen to adopted my radio suggestions, your radio ought to assist ExpressLRS (ELRS), which is presently my best choice for a radio hyperlink. ExpressLRS is reasonably priced, high-performance, and extremely dependable: https://oscarliang.com/expresslrs/

Quite a few producers produce receivers and transmitter modules for ExpressLRS. You’ll be able to select any of those, and so long as they’re ExpressLRS, they’ll work collectively. For this tutorial, I’ve chosen the BetaFPV ELRS 2.4GHz Nano, which is among the cheaper choices available on the market and works effectively.

That can assist you arrange ExpressLRS, I’ve put collectively a step-by-step tutorial: https://oscarliang.com/setup-expresslrs-2-4ghz/

To fly a quadcopter in FPV, you’ll want the next equipment. Check out my on a regular basis gear for inspiration. Here’s a abstract:

Instruments and Provides

To construct the drone, you might want the next instruments and provides.

Important

Non-obligatory

For these actually passionate concerning the pastime, right here’s a complete checklist of instruments that you could be discover invaluable in your FPV drone-building journey.

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Steps of Constructing FPV Drone

Click on the hyperlink will take you to the part on this article:

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1. Body Meeting

Observe my detailed step-by-step tutorial to assemble the GEPRC Vapor body: https://oscarliang.com/geprc-vapor-x5-d5-frame/

You have to full the body meeting to this stage earlier than transferring on to the following steps.

2. Putting in Motors

Now, it’s time to mount the 4 motors on the arms.

The motors include screws – they’re 7mm lengthy, that are good for 5mm thick arms.

Threadlocker (similar to Loctite) is non-obligatory, however really useful. Vibrations may cause the screw to loosen over time, making use of threadlocker to the screws can forestall that. Some motors would possibly include screws with threadlocker pre-applied (showing as a blue coating on the threads), however the motors we’re utilizing don’t, so we have to apply it ourselves. A really small drop is sufficient for all of the motor screws in a construct.

Some builders might use solely 3 screws, and even 2 generally, to save lots of weight, however I like to recommend utilizing all 4 screws for optimum reliability.

Necessary: Earlier than totally tightening the motor screws, make sure that they aren’t too lengthy and aren’t touching the motor windings. If you happen to’re uncertain, observe this information: https://oscarliang.com/check-motor-screws-touching-winding/

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3. Wiring Diagrams

If you happen to’re utilizing the parts I really useful, check with this wiring diagram for steering.

In case you are utilizing the Speedybee F405 V4 stack:

Insert the “longer” rubber grommets in each FC and ESC boards – the longer half must be on the backside.

The FC and ESC are linked by way of a 8-pin cable, it must be plug and play, however please double test the pinout simply in case.

Earlier than reducing and soldering any wires, you need to “dry match” all of the parts within the body. This course of lets you gauge how lengthy the wires must be, decide one of the best location in your parts, and determine any potential spacing points.

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4. Putting in ESC

Begin by putting in the 4 lengthy bolts that include the Vapor body into these holes.

Slide the 4in1 ESC and FC boards onto the bolts.

Usually, the ESC’s energy pads (+ and -) ought to face the rear. Nonetheless, as a result of the Vapor body routes the battery lead by the center of the highest plate, it’s greatest to rotate the ESC 180 levels. This implies you’ll need to remap the motor order in Betaflight later (however don’t fear, I’ll clarify how).

Verify rigorously, there must be loads of room between the body and ESC, between the ESC and FC boards. This ensures the ESC will get enough air move for cooling, and room for cable to go by.

Subsequent, we’ll solder the motors to the ESC. If you happen to’re new to soldering, check with the tutorial The way to Solder for Novices: https://oscarliang.com/soldering-guide/.

There are 3 frequent methods to route motor wires:

1. Easy and informal routing: Solder the wires to the ESC pads casually. It’s fast and simple, the construct may not look as skilled, however if you’re new to soldering, that is simpler to do.
2. Neat routing round stack screws: Wires loop neatly across the screws. Appears clear, the motor wires are hidden when the FC is mounted on prime, nevertheless it requires longer wires so it provides a couple of grams of additional weight.
3. Tight stacking routing (my favourite): Wires are minimize as quick as potential. Very clear aesthetically, however you should minimize the wires to sure lengths fairly exactly, and it may be difficult to solder because the wires are stacked on prime one other. Solely really useful for skilled builders.

Safe the motor wires on the arms with material tape or electrical tape. The Vapor body equipment consists of plastic tubes for wire safety, they do look neat {and professional}, however I discovered them impracticable and heavy.

Measure and minimize motor wires, it’s normally higher to depart a bit of additional size for flexibility. If wires are too lengthy, you possibly can twist them collectively or safe with tape or zip tie. You need to keep away from dangling wires so that they don’t get minimize by the spinning propellers, or introduce vibrations.

Strip the motor wires: not too far again, about 2mm is sufficient (as a lot as wanted to connect with the solder pads). Then tin the ends.

Additionally tin all of the motor pads on the 4in1 ESC (fill the pads with a pleasant dome of solder first earlier than soldering the wires).

I extremely advocate making use of flux to all of the wires and pads you’re about to solder. Flux can clear the oxidation off the metallic floor and improves the move of the solder, making soldering a lot simpler and the joints extra dependable.

Soldering information for rookies: https://oscarliang.com/soldering-guide/

Don’t fear concerning the order of the motor wires—you possibly can simply reverse motor spin course later in Betaflight.

Now, solder the XT60 energy result in the ability pads on the ESC, take note of polarity (optimistic and detrimental).

You want about 9-10cm lengthy of wires.

Soldering the XT60 wire to the ESC might be probably the most difficult step on this construct. It’s even more durable when you don’t have a correct soldering iron. These energy pads are primarily a big piece of copper, along with the big gauge wires, they only sucks quite a lot of warmth, so it takes a large amount of warmth to soften the solder on these pads. Be affected person and use excessive temperature in your iron.

Soldering Suggestions:

• Use a superb quantity of solder and solder flux (solder paste) for the solder pads, making certain the solder joints look shiny and full. If you happen to can see the person wire strands within the joint after soldering, it’s an indication that you just didn’t use sufficient solder.
• Apply extra flux if the solder “sticks” to the soldering iron tip if you take away it from the joint.
• Don’t be afraid to make use of greater temperature, particularly when soldering massive solder pads. However be fast and keep away from overheating the pads for too lengthy. My common rule of thumb is: 450°C (840°F) for motor wires and XT60, and 380°C for sign wires.

Now, solder the capacitor that comes with the 4in1 ESC. There are 2 capacitors:

• 35V 1000uF for 6S construct
• 50V 1000uF for 8S construct

Ideally you need to put some heatshrink tubes over the capacitor legs to stop quick circuit. If you happen to don’t have heatshrink, merely take some discarded motor wires we minimize earlier – take away the centre wire and hold the silicone insulation.

Solder the capacitor onto the battery pads (+ and -) on the ESC. Take note of polarity – the detrimental leg is marked by a light-colored stripe on the capacitor.

Why a Capacitor?

A capacitor reduces voltage spikes and electrical noise from the motors and ESC, defending your electronics in addition to lowering noise attending to the gyro, enhancing the flight efficiency of your drone. Be taught extra about why capacitors are essential: https://oscarliang.com/capacitors-mini-quad/

The capacitor ought to sit comfortably contained in the TPU mount.

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5. Testing ESC and Motors

We’ll now take a look at the ESC and motors by connecting the battery.

However earlier than plugging in a LiPo battery for the primary time, guarantee there are not any electrical shorts. Utilizing a multimeter in continuity mode, take a look at the optimistic and detrimental terminals of the XT60 (or instantly on the ESC energy pads). If there’s a quick circuit, the multimeter will beep repeatedly. On this case, don’t plug within the battery, as it could harm your parts. As an alternative, troubleshoot and repair the difficulty that’s inflicting the quick circuit.

For extra data on utilizing a multimeter to check your drone, take a look at this tutorial.

Professional-Tip: A brief beep adopted by silence might happen when testing continuity on account of capacitors charging. That is regular and shouldn’t trigger concern. So long as it stops beeping after a second or two you have to be nice.

Now, join the FC to the ESC utilizing the supplied 8-pin cable, and join the FC to your laptop by way of a USB cable.

It’s extremely really useful to make use of a smoke stopper when plugging in a battery for the primary time. Whereas not necessary, it’s a helpful funding to keep away from damaging parts.

Don’t placed on propellers but.

To check the motors, plug within the battery and join the USB cable to the flight controller. Open Betaflight Configurator, and go to the Motors tab.

Select DShot300 in ESC Protocol. Click on Save and Reboot.

Now, allow motor management (test “I perceive the dangers”), and you need to be capable to spin up the motors by transferring the slider up (beneath 1100 is sufficient). Do that one after the other.

You wan to ensure the motor that’s spinning matches the quantity within the diagram, e.g. motor #1 is the rear proper, motor #2 is entrance proper and so forth.

If the motor order is incorrect (almost certainly incorrect as a result of we rotated the ESC 180 levels in our construct), you possibly can simply repair it by clicking the “Reorder Motors” button within the motors tab, and simply observe the straightforward directions. You may also repair it utilizing CLI instructions nevertheless it’s fairly difficult, so simply use the software 🙂

As soon as the motor order is appropriate, it is advisable confirm if they’re spinning within the appropriate course. To reverse a motor course, there are a couple of methods, the simplest is to use the Betaflight Configurator (Motors tab) as defined right here.

Troubleshooting suggestions:

• If motors aren’t spinning, make sure the battery is linked and also you’ve turned on the Quick Saver if you’re utilizing it. And the ESC ought to beep as quickly as you plug within the battery. Be sure that the ESC is linked to the FC, and that the pin connections are appropriate.
• If all motors spin aside from one, that exact ESC, motor, or the ESC sign from the FC may be defective. To troubleshoot, swap the non-functioning motor with a working one on the identical quad to find out if the difficulty lies with the ESC or motor.

For additional help, ask within the discussion board: https://intofpv.com

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6. Receiver Setup

Begin by soldering the supplied wires to the receiver.

Professional Tip: When soldering parts to the flight controller (FC), keep away from routing wires throughout the board. Dangling or loosely routed wires can introduce vibrations that negatively have an effect on gyro efficiency.

Moreover, twist your wires. This not solely helps reduce electrical interference but in addition reduces slacks and provides your construct a cleaner, extra skilled look.

Whereas the wire colours technically don’t matter, following a constant colour scheme makes troubleshooting a lot simpler. I like to recommend utilizing this colour coding:

• Black wire → GND (G)
• Crimson wire → 5V (V)
• White wire → TX (T)
• Yellow wire → RX (R)

The body features a TPU holder the place you possibly can neatly put the receiver in.

Wire the flight controller to the receiver like this (from FC to receiver):

• 5V → V (5V)
• G → G (Floor)
• T1 → R (Receiver RX)
• R1 → T (Receiver TX)

Mount the receiver and antenna securely contained in the body like this.

We will now arrange the receiver in Betaflight configurator:

• Go to the Ports tab and allow “Serial RX” for the UART linked to the receiver (UART1 in our instance, as a result of we linked it to T1 and R1). Click on Save.
• Within the Receiver tab, choose “Serial (by way of UART)” in Receiver Mode and select “CRSF” in Serial Receiver Supplier. Allow Telemetry. Click on Save.

Now, bind your radio to the receiver by following this tutorial: https://oscarliang.com/bind-expresslrs-receivers/.

The receiver must be working. To verify, go to the Receiver tab, and the bars (channel values) ought to change if you transfer the sticks on the radio. If the incorrect channels are responding, attempt a special Channel Map similar to “default (AETR)” or “TAER”.

You have to to setup switches on the radio for arming, flight modes and beeper. Observe this tutorial to learn the way: https://oscarliang.com/setup-switch-mixes/

You probably have any questions, publish within the discussion board: https://intoFPV.com

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7. Putting in DJI O4 Professional

Connecting the DJI O4 Professional Air Unit to the flight controller couldn’t be easier—simply plug within the supplied cable and also you’re good to go.

If you happen to’re controlling the drone utilizing ExpressLRS, you might need to take away the SBUS and GND wires from the O4 connection cable. These wires are meant for the DJI distant controller, and leaving them linked may cause conflicts when you’re utilizing the identical UART for an additional machine.

The O4 Air Unit shall be mounted on prime of the receiver.

Push the 2 O4 Professional antennas securely into the holes within the rear TPU antenna mount.

Mount the digicam between the silicone dampers included with the body.

If you happen to’re new to flying, you would possibly need to begin with a decrease digicam tilt angle like 10° to fifteen°. As you change into extra comfy and begin flying quicker, you possibly can improve the lean to twenty° and even 30° for higher ahead visibility at velocity. To be taught extra about how digicam angle have an effect on your flying take a look at this information: https://oscarliang.com/camera-angle/

Now we’ll configure OSD (On-Display screen Show) to indicate essential flight knowledge like battery voltage, flight time, and warnings instantly in your DJI goggles.

I’ve a full step-by-step information right here in order for you extra element: https://oscarliang.com/how-to-setup-dji-o4-pro/

To summarize the method:

• In Betaflight Configurator, go to the Presets tab.
• Seek for “OSD for DJI”.
• Choose the preset you discover.
• Within the choices, choose “map to displayport”, “set HDOSD”, and the UART you’ve linked the O4 to (in our instance that’s UART2).
• That’s it.

Now, head to the OSD tab, allow your favorite parts and transfer them round as you want. Be sure to’ve chosen HD beneath Video Format so you’re utilizing all of the display house obtainable. I’ve my very own OSD layouts if you wish to copy: https://oscarliang.com/betaflight-osd/#My-OSD-Setup-CLI-Instructions

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8. Ending Off

Safe the flight controller (FC) with nylon nuts.

Tighten solely by hand to keep away from over-compressing the silicone grommets (or rubber gummies) because it may cut back vibration damping and defeat the aim of sentimental mounting. Examine the gummies, there ought to’t be any seen hole between them, and ideally your flight controller ought to have a slight quantity of play when pressed. This flexibility permits the gummies to correctly take up body vibrations.

Safe the capacitor within the TPU mount utilizing a small zip tie. Route the digicam cable within the TPU mount to keep away from dangling wire.

Subsequent, set up the highest plate.

Listed below are the weights of the finished drone:

• Drone together with propellers and battery strap: 436g
• Drone + 6S 1100mAh LiPo: 628g
• Drone + 6S 1100mAh LiPo + GoPro 13: 805g

When putting in the propellers, take note of the completely different rotations—CW (clockwise) and CCW (counter-clockwise). Guarantee they’re put in on the right motors; in any other case, your quad might not take off or may flip over when making an attempt to.

Use M5 nylon lock nuts to carry the propellers securely on the motor. Tightening may be difficult at first however will change into simpler over time. Keep away from overtightening to stop prop hub shattering. Tighten simply sufficient so the prop can’t transfer if you attempt to rotate it together with your hand whereas holding the motor bell.

DO NOT use thread locker on prop nuts! Firstly you don’t must, the nylon nut is self locking. Secondly, thread locker will weaken the propeller plastic.

A devoted prop nut software can velocity up prop adjustments.

When mounting the battery (and GoPro), make sure the COG (heart of gravity) is as near the drone’s heart as potential. To test if the battery is positioned appropriately, seize the center of the highest plate with two fingers and see if the quad stays degree. It’s important to take care of the COG on the heart of the 4 motors. As an example, if the quad is front-heavy, the entrance motors will work more durable than the rear motors when making an attempt to take care of its place, negatively impacting flight efficiency.

And we’re prepared for a take a look at flight!

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9. Setting Up Betaflight

We’ve already lined a lot of the Betaflight setup throughout this construct. Nonetheless, to double-check the whole lot and guarantee nothing is missed, observe my full newbie’s tutorial right here: https://oscarliang.com/betaflight-firmware-setup/

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10. Tuning

FPV drone tuning is a complete rabbit gap in itself.

Tuning your quadcopter entails adjusting it to fly and behave the best way you need. Betaflight has come a good distance; you don’t actually need to tune your quad and it’ll probably fly simply nice with inventory settings. Nonetheless, when you’re not proud of how the quad flies, there’s extra to be taught!

For most individuals, tuning an FPV drone entails adjusting these settings:

 

Tuning is sort of technical and generally entails using Blackbox logs. If you happen to don’t know how you can use Blackbox, that is how you can tune your FPV drone in 10 easy steps. If you happen to’re conversant in Blackbox, take a look at this in-depth information on tuning filters and PID.

I generally share customized PID tunes for the BNF drones I reviewed on my Patreon, if these issues curiosity you, take into account subscribing: https://oscarliang.com/patreon-support-announcement/

11. Studying The way to Fly

You probably have little to no expertise flying a mini quad, take into account testing these tutorials to get began:

You probably have any questions, be happy to ask within the feedback.

You’ll be able to test my previous construct guides (some information is outdated):