How one can 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 every little thing from deciding on the proper parts, to wiring and meeting, and even share insider ideas and methods to make sure you have a dependable and pleasurable FPV drone expertise.

Can Newcomers Construct FPV Drones?

Completely! Even if in case you have no prior expertise, freshmen can completely construct FPV drones.

Certain, it is likely to be tempting to easily purchase a ready-made drone off the shelf—however the place’s the enjoyable (and studying) in that? By assembling your individual drone from scratch, you’ll achieve invaluable 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 mistaken.

Now, I received’t sugar-coat it—constructing your first FPV drone can be difficult. It could 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 via trial and error. However belief me—the sense of accomplishment and the talents you achieve 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, try 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. Don’t let these intimidate you! When doubtful, 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 components to information you thru the FPV drone constructing course of.

Only a fast be aware: the hyperlinks offered are affiliate hyperlinks. Making a purchase order via these hyperlinks received’t value you something further, however it should earn me a small fee. This assist helps preserve the weblog operating and permits me to proceed sharing my ardour for FPV drones with you—thanks!

This specific construct focuses on the DJI O4 Professional Air Unit. In the event you’re taken with constructing an analog FPV drone, try my different construct log right here: https://oscarliang.com/how-to-build-fpv-drone-analog/

When you’ve got a small funds, right here is an inventory of the most cost effective 5″ drone components.

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

Body

The body is the sturdy construction that holds all the drone’s parts collectively.

For this tutorial, I’ve chosen the GEPRC Vapor—a superb alternative due to 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 overview 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 is just not solely extra reasonably priced, nevertheless 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 easy.

For this tutorial, I’ve chosen the Speedybee F405 V4 stack. Regardless of being one of the vital reasonably priced FC/ESC stacks in the marketplace, it doesn’t compromise on options. It helps nearly all trendy functionalities you’d need in an FPV drone. Try my in-depth overview 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 glorious options. Right here’s an inventory of my high suggestions: https://oscarliang.com/flight-controller/#The-Finest-FC-Suggestions.

Motors

FPV motors at this time are surprisingly related by way of efficiency, particularly on the newbie stage. Meaning there’s no want to purchase the most costly motors whenever you’re simply beginning out—most individuals wouldn’t even discover the distinction. Price range choices just like the EMAX ECO II collection are greater than ample for freshmen.

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

One other vital 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. Greater 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 glorious motors price contemplating—try my full record of suggestions right here: https://oscarliang.com/motors/#Suggestions

FPV Setup

There are a number of FPV programs out there in the marketplace, however the DJI O4 Professional can be my best choice for a 5-inch freestyle drone. It provides 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 execs and cons, try 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. In the event you 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 possibly can 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 likely one of the cheaper choices in the marketplace and works nicely.

That will help 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. Chances are you’ll have already got a few of these gadgets, if not, they need to be simply discovered on-line or at your native ironmongery shop.

Important:

Non-obligatory however really helpful:

For these actually passionate concerning the pastime, right here’s a complete record 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

Comply with 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 transferring 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 avoid wasting weight, however I like to recommend utilizing all 4 screws for max sturdiness.

Necessary: Earlier than totally tightening the motor screws, be sure that they aren’t too lengthy and aren’t urgent towards the motor windings. In the event you’re uncertain, comply with this information: https://oscarliang.com/check-motor-screws-touching-winding/

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3. Wiring Diagrams

In the event you’re utilizing the parts I really helpful, check with this wiring diagram for steering.

Earlier than reducing and soldering any wires, you’ll be able to “dry match” all of the parts within the body. This course of means that you can gauge how lengthy the wires needs to be, decide one of the best location on 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 via the center, it’s greatest to rotate the ESC 180 levels. This implies you’ll should 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 are going to solder the motors to the ESC. In the event you’re new to soldering, check with the tutorial “How one can Solder for Newcomers“.

There are three frequent 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 simple, 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 result of longer wires (a number of further grams).
3. Tight, stacking routing (my favourite): Wires are lower as brief as potential. Very clear aesthetic, however tougher to solder because the wires are stacked on high one other.

Safe the motor wires on the arms with material 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 at all times higher to depart slightly 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 offered heatshrink tubes, shorten and bend the legs.

Solder the capacitor onto the battery pads (+ and -) on the ESC. Take note of polarity – the destructive 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, bettering the flight efficiency of your drone. Study extra about why capacitors are vital: 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 facility pads on the ESC, take note of polarity (constructive and destructive). That is maybe probably the most difficult step on this construct, as a result of quantity of warmth required to soften the solder on the massive copper pads and thick wires. Be affected person and use the next temperature in your iron.

Soldering Suggestions:

• Use an excellent quantity of solder and solder flux (solder paste) for the massive pads, making certain the solder joints are shiny and full. In the event you can see the wire strands, you haven’t utilized sufficient solder.
• Apply extra flux if the solder “sticks” to the tip whenever you take away it from the joint.
• Be happy 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.

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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 destructive terminals of the XT60 (or straight on the ESC energy pads). If there’s a brief circuit, the multimeter will beep constantly. On this case, don’t plug within the battery, as it could harm your parts. As an alternative, troubleshoot and repair the problem that’s inflicting the brief circuit.

For extra info on utilizing a multimeter to check your drone, try this tutorial.

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

Now, join the FC to the ESC utilizing the offered 8-pin cable, and join the FC to your laptop by way of 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 is 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 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 on.

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 may as well repair it utilizing CLI instructions nevertheless it’s fairly sophisticated, so simply use the instrument 🙂

As soon as the motor order is right, it’s worthwhile to confirm if they’re spinning within the right path. To reverse a motor path, there are a number of 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 Brief Saver if you’re utilizing it. And the ESC ought to beep as quickly as you plug within the battery. Ensure the ESC is related to the FC, and that the pin connections are right.
• If all motors spin aside from one, that individual ESC, motor, or the ESC sign from the FC is likely to be defective. To troubleshoot, swap the non-functioning motor with a working one on the identical quad to find out if the problem 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 offered wires to the receiver.

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)
• 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 completed, we will 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 (by way of UART)” in Receiver Mode and select “CRSF” in Serial Receiver Supplier. Allow Telemetry. Click on Save.

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

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

When you’ve got any questions, submit 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 Speedybee flight controller couldn’t be less complicated—simply plug within the offered cable and also you’re good to go. The O4 Air Unit can be mounted on high of the receiver.

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

In the event you’re controlling the drone utilizing ExpressLRS, it’s possible you’ll wish 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 related could cause conflicts in case you’re utilizing the identical UART for one more machine.

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

In the event you’re new to flying, you would possibly wish to begin with a decrease digicam tilt angle like 10° to fifteen°. As you change into extra snug and begin flying sooner, you’ll be able to improve the lean to twenty° and even 30° for higher ahead visibility at pace.

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

I’ve a full step-by-step information right here if you’d like 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 parts and transfer them round as you want. Be sure to’ve chosen HD below Video Format so you’re utilizing all of the display screen house out there. 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 rubber grommet because it might cut back vibration damping and defeat the aim of soppy mounting.

Subsequent, set up the highest plate.

Listed here 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 could not take off or might flip over when attempting to.

Use M5 nylon lock nuts to carry the propellers securely on the motor. Tightening is likely to 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 whenever you attempt to rotate it along with your hand whereas holding the motor bell.

A devoted prop nut instrument 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 potential. To examine if the battery is positioned appropriately, seize the center of the highest plate with two fingers and see if the quad stays stage. It’s important to keep up the COG on the middle of the 4 motors. For example, if the quad is front-heavy, the entrance motors will work more durable than the rear motors when attempting to keep up its place, negatively impacting flight efficiency.

And we’re prepared for a check 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 every little thing and guarantee nothing is missed, comply with my full newbie’s tutorial right here: https://oscarliang.com/betaflight-firmware-setup/

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10. Tuning

Tuning your quadcopter includes adjusting it to fly and behave the best way you need. Betaflight has come a great distance; you don’t should tune your quad, and it’ll probably fly simply advantageous with inventory settings. Nonetheless, in case you’re critical about efficiency, there’s extra to study!

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

Tuning is kind of technical and generally includes using Blackbox logs. In the event you don’t know the way to use Blackbox, that is the way to tune your FPV drone in 10 easy steps. In the event you’re conversant in Blackbox, try this in-depth information on tuning filters and PID.

Earlier than tuning, although, I’d suggest flashing Bluejay firmware to the ESC if they arrive with BLHeli_S firmware, it gives 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 provides smoother flight with barely much less torque. I like to recommend 48KHz. You may as well allow bi-directional Dshot, and activate RPM filter when you’ve flashed Bluejay. It’s probably the greatest filters out there 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 attempt my tune, take into account subscribing: https://oscarliang.com/patreon-support-announcement/

11. Studying How one can Fly

When you’ve got little to no expertise flying a mini quad, take into account testing these tutorials to get began:

When you’ve got any questions, be at liberty to ask within the feedback.

You possibly can examine my previous construct guides (some data is outdated):