Tips on how to Construct an FPV Drone Tutorial (DJI O4 Professional Air Unit)

16.7K

On this complete tutorial, I’ll stroll you thru the method of constructing an FPV drone from scratch, offering detailed steerage for each analogue and digital FPV programs. We’ll cowl all the pieces from choosing the fitting parts, to wiring and meeting, and even share insider ideas and methods to make sure you have a dependable and satisfying FPV drone expertise.

Can Learners Construct FPV Drones?

Completely! Even when you’ve got no prior expertise, rookies can completely construct FPV drones.

Positive, it is perhaps tempting to easily purchase a ready-made drone off the shelf—however the place’s the enjoyable (and studying) in that? By assembling your personal drone from scratch, you’ll acquire priceless hands-on data about every part and the way all of them work collectively. You’ll even be significantly better ready to troubleshoot and restore your drone if something goes mistaken.

Now, I received’t sugar-coat it—constructing your first FPV drone can be difficult. It might take hours, and even days, to finish. Alongside the best way, you’ll want to hunt recommendation from skilled pilots on-line or determine issues out by way of trial and error. However belief me—the sense of accomplishment and the abilities you acquire will make the journey extremely rewarding.

So, 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 doubtless encounter many acronyms and technical phrases. Don’t let these intimidate you! When doubtful, check with our useful glossary: Decoding Acronyms and Technical Phrases in FPV.

---

Elements Record

On this tutorial, we’ll be utilizing the next elements to information you thru the FPV drone constructing course of.

Only a fast observe: the hyperlinks supplied are affiliate hyperlinks. Making a purchase order by way of these hyperlinks received’t price you something additional, however it can earn me a small fee. This assist helps hold the weblog operating 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. For those who’re fascinated 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 that holds the entire drone’s parts collectively.

For this tutorial, I’ve chosen the GEPRC Vapor—a wonderful alternative because of its excessive construct high quality. It additionally comes with a wide range of 3D-printed equipment, making for an extremely straightforward and clear construct.

Try my detailed assessment 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 will not be solely extra reasonably priced, however it additionally ensures that they’re plug-and-play proper out of the field, making the drone constructing course of a lot smoother and extra simple.

For this tutorial, I’ve chosen the Speedybee F405 V4 stack. Regardless of being one of the reasonably priced FC/ESC stacks in the marketplace, it doesn’t compromise on options. It helps nearly all fashionable functionalities you’d need in an FPV drone. Try my in-depth assessment of the Speedybee F405 V4 right here: https://oscarliang.com/speedybee-f405-v4/.

If the Speedybee F405 V4 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 as we speak are surprisingly comparable when it comes to efficiency, particularly on the newbie stage. Meaning there’s no want to purchase the most costly motors once you’re simply beginning out—most individuals wouldn’t even discover the distinction. Funds choices just like the EMAX ECO II sequence are greater than enough for rookies.

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

One other essential issue to think about is motor KV, which is linked to your battery voltage. For a 6S construct, I like to recommend selecting motors with a KV ranking between 1600 and 2000. Larger KV motors ship extra aggressive and power-hungry efficiency. On this construct, I’ve chosen 1900KV motors, as the following decrease choice (1700KV) feels a bit too low for my style.

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

FPV Setup

There are a number of FPV programs obtainable in the marketplace, however the DJI O4 Professional can be my best choice for a 5-inch freestyle drone. It affords one of the best picture high quality and sign reliability, and top-notch construct high quality. If you wish to study extra concerning the completely different FPV programs and their professionals 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 need to use. For those who 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 may 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 in the marketplace and works properly.

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’ll additionally want the next instruments and provides. You might have already got a few of these objects, if not, they need to be simply discovered on-line or at your native ironmongery shop.

Important:

Optionally available however really helpful:

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

---

Steps of Constructing FPV Drone

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

---

1. Body Meeting

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

That you must full the body meeting to this stage earlier than shifting on to the following steps.

2. Putting in Motors

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

The EMAX ECO II motors include screws of various lengths. Use the screws with a 7mm thread size, that are appropriate for 5mm thick arms.

It’s extremely really helpful to make use of threadlocker (resembling Loctite) on the motor screws, as vibrations could cause them to loosen over time.

Some motors include threadlocker pre-applied (showing as a blue coating on the threads), however the ECO II motors don’t, so that you’ll want to use it your self.

Some builders use solely three screws and even two to save lots of weight, however I like to recommend utilizing all 4 screws for optimum sturdiness.

Essential: Earlier than absolutely tightening the motor screws, be sure they don’t seem to be too lengthy and aren’t urgent in opposition to the motor windings. For those who’re uncertain, comply with this information: https://oscarliang.com/check-motor-screws-touching-winding/

^ Again to Prime

3. Wiring Diagrams

For those who’re utilizing the parts I really helpful, check with this wiring diagram for steerage.

Earlier than slicing and soldering any wires, you’ll be able to “dry match” all of the parts within the body. This course of permits you to gauge how lengthy the wires must be, decide one of the best location to your parts, and establish any potential spacing points.

^ Again to Prime

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 way of the center, it’s finest to rotate the ESC 180 levels. This implies you’ll need to remap the motor order later in Betaflight (don’t fear, I’ll clarify how).

Verify rigorously, nothing ought to contact between the underside of the ESC and the body, and between the ESC and FC boards.

Subsequent, we’ll solder the motors to the ESC. For those who’re new to soldering, check with the tutorial “Tips on how to Solder for Learners“.

There are three widespread methods to route and solder motor wires:

1. Easy and informal routing: Simply solder the wires on to the ESC pads. It’s quick and straightforward, however the construct received’t look as clear. If you’re not good with soldering, do that.
2. Neat routing round stack screws: Wires loop neatly across the screws. Seems to be cleaner however barely heavier as a consequence of longer wires (just a few additional grams).
3. Tight, stacking routing (my favourite): Wires are lower as brief as attainable. Very clear aesthetic, however more difficult to solder because the wires are stacked on prime one other.

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

Measure and lower motor wires, it’s all the time higher to go away a little bit slack.

Strip about 2mm off the tip of the wires and tin the ends.

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).

Don’t fear concerning the order of the motor wires—you’ll be able to simply reverse motor spin path later in Betaflight.

Now, solder the capacitor that comes with the Speedybee stack. Insert the supplied heatshrink tubes, shorten and bend the legs.

Solder the capacitor onto the battery pads (+ and -) on the ESC. Take note of polarity – the adverse 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 decreasing noise attending to the gyro, enhancing the flight efficiency of your drone. Study extra about why capacitors are essential: https://oscarliang.com/capacitors-mini-quad/

The capacitor can now sit securely contained in the included TPU mount.

Now, solder the XT60 energy result in the ability pads on the ESC, take note of polarity (constructive and adverse). That is maybe essentially the most difficult step on this construct, because of the quantity of warmth required to soften the solder on the big copper pads and thick wires. Be affected person and use a better temperature in your iron.

Soldering Suggestions:

• Use an excellent quantity of solder and solder flux (solder paste) for the big pads, making certain the solder joints are shiny and full. For those who can see the wire strands, you haven’t utilized sufficient solder.
• Apply extra flux if the solder “sticks” to the tip once you take away it from the joint.
• Be at liberty to make use of a excessive temperature when soldering giant solder pads, however be fast and keep away from overheating the pads for too lengthy. Use 450°C (840°F) for motor wires and XT60, and 380°C for sign wires.

^ Again to Prime

5. Testing ESC and Motors

We are going to now check the ESC and motors by connecting the battery.

However earlier than plugging in a LiPo battery for the primary time, guarantee there aren’t any electrical shorts. Utilizing a multimeter in continuity mode, check the constructive and adverse terminals of the XT60 (or immediately on the ESC energy pads). If there’s a brief 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 brief circuit.

For extra info 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 as a consequence of capacitors charging. That is regular and shouldn’t trigger concern. So long as it stops beeping after a second or two you need to be effective.

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

It’s extremely really helpful to make use of a smoke stopper when plugging in a battery for the primary time. Whereas not obligatory, 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, and it’s best to have the ability to spin up the motors – do that one after the other, transfer the slider to round 1100 is sufficient.

You wan to verify 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 mistaken (most certainly mistaken as a result of we rotated the ESC 180 levels in our construct), you’ll be able to simply repair it by clicking the “Reorder Motors” button within the motors tab, and simply comply with the straightforward directions. You can too repair it utilizing CLI instructions however it’s fairly difficult, so simply use the device 🙂

As soon as the motor order is right, it’s essential confirm if they’re spinning within the right path. To reverse a motor path, there are just a few methods, the best is to use the Betaflight Configurator (Motors tab) as defined right here.

Troubleshooting ideas:

• If motors aren’t spinning, make sure the battery is related 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. Ensure that the ESC is related to the FC, and that the pin connections are right.
• If all motors spin apart from one, that specific ESC, motor, or the ESC sign from the FC is perhaps 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

^ Again to Prime

6. Receiver Setup

Begin by soldering the supplied wires to the receiver.

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

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

The body features a TPU holder the place you’ll be able to neatly put the receiver in.

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

• 4V5 → V (5V)
• G → G (Floor)
• T6 → R (Receiver RX)
• R6 → T (Receiver TX)

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

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

As soon as that’s executed, we are able to arrange the receiver in Betaflight configurator:

• Go to the Ports tab and allow “Serial RX” for the UART related to the receiver (UART6 in our instance, as a result of we related it to T6 and R6). Click on Save.
• Within the Receiver tab, choose “Serial (through UART)” in Receiver Mode and select “CRSF” in Serial Receiver Supplier. Allow Telemetry. Click on Save.

After this, the receiver must be working. To verify, go to the Receiver tab, and the bars (channel values) ought to change once you transfer the sticks on the radio. If the mistaken channels are responding, strive a special Channel Map resembling “default (AETR)” or “TAER”.

You will want to setup switches on the radio for arming, flight modes and beeper. Observe this tutorial to find out how: https://oscarliang.com/setup-switch-mixes/

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

^ Again to Prime

7. Putting in DJI O4 Professional

Connecting the DJI O4 Professional Air Unit to the Speedybee flight controller couldn’t be easier—simply plug within the supplied cable and also you’re good to go. The O4 Air Unit can be mounted on prime of the receiver.

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

For those who’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 supposed for the DJI distant controller, and leaving them related could cause conflicts for those who’re utilizing the identical UART for an additional system.

Mount the digital camera between the silicone dampers included with the body.

For those who’re new to flying, you may need to begin with a decrease digital camera tilt angle like 10° to fifteen°. As you turn out to be extra comfy and begin flying quicker, you’ll be able to enhance the lean to twenty° and even 30° for higher ahead visibility at pace.

Now we’ll configure OSD (On-Display screen Show) to indicate essential flight information like battery voltage, flight time, and warnings immediately 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 related the O4 to (in our instance that’s UART1).
• That’s it.

Now, head to the OSD tab, allow your favorite components and transfer them round as you would like. Ensure you’ve chosen HD underneath Video Format so you might be utilizing all of the display area obtainable. I’ve my very own OSD layouts if you wish to copy: https://oscarliang.com/betaflight-osd/#My-OSD-Setup-CLI-Instructions

^ Again to Prime

8. Ending Off

Safe the flight controller (FC) with nylon nuts.

Tighten solely by hand to keep away from over-compressing the rubber grommet because it may cut back vibration damping and defeat the aim of soppy mounting.

Subsequent, set up the highest plate.

Listed below are the weights of the finished drone:

• Drone together with propellers and battery strap: 453g
• Drone + 6S 1100mAh LiPo: 645g
• Drone + 6S 1100mAh LiPo + GoPro 13: 802g

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 attempting to.

Use M5 nylon lock nuts to carry the propellers securely on the motor. Tightening is perhaps difficult at first however will turn out to be simpler over time. Keep away from overtightening to forestall prop hub shattering. Tighten simply sufficient so the prop can’t transfer once you attempt to rotate it along with your hand whereas holding the motor bell.

A devoted prop nut device can pace up prop adjustments.

When mounting the battery (and GoPro), make sure the COG (middle of gravity) is as near the drone’s middle as attainable. To test if the battery is positioned accurately, seize the center of the highest plate with two fingers and see if the quad stays stage. It’s important to take care of the COG on the middle 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 attempting to take care of its place, negatively impacting flight efficiency.

And we’re prepared for a check flight!

^ Again to Prime

9. Setting Up Betaflight

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

^ Again to Prime

10. Tuning

Tuning your quadcopter entails adjusting it to fly and behave the best way you need. Betaflight has come a great distance; you don’t need to tune your quad, and it’ll doubtless fly simply effective with inventory settings. Nonetheless, for those who’re critical about efficiency, there’s extra to study!

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

Tuning is sort of technical and generally entails the usage of Blackbox logs. For those who don’t know the right way to use Blackbox, that is the right way to tune your FPV drone in 10 easy steps. For those who’re aware of Blackbox, take a look at this in-depth information on tuning filters and PID.

Earlier than tuning, although, I’d advocate flashing Bluejay firmware to the ESC if they arrive with BLHeli_S firmware, it offers you higher efficiency. When doing so, you’ll want to decide on between the 24kHz or 48kHz variations. The 24kHz model offers higher responsiveness and torque, whereas the 48kHz model affords smoother flight with barely much less torque. I like to recommend 48KHz. You can too allow bi-directional Dshot, and activate RPM filter when you’ve flashed Bluejay. It’s probably the greatest filters obtainable in Betaflight and makes your quad flies higher.

I’ll share my PID and Filter tune for this construct in my Patreon shortly, if you wish to strive my tune, contemplate subscribing: https://oscarliang.com/patreon-support-announcement/

11. Studying Tips on how to Fly

You probably have little to no expertise flying a mini quad, contemplate trying out these tutorials to get began:

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

You may test my previous construct guides (some data is outdated):