Drone Building for Dummies: An Easy Guide for FPV Quad Building

You're a beginner. You're excited. You can't wait to start building your own FPV quad, but the more you read, the more you feel overwhelmed by the sheer amount of information available. Fear not! We've got a quick and dirty guide that helps you focus only on what's necessary, so you can start building your dream quad in no time.

The Unconventional Method: Learning Just Enough

The traditional approach to drone building has always been about understanding each and every component before getting started. But we understand the beginner's dilemma - the amount of information can be daunting. This is why we've decided to break the mould. Our goal? Help you pick the right quad parts for your initial build, get you up to speed with the basics, and point you to resources where you can learn more as you get deeper into the hobby.

Selecting the Right Frame for Your Quad

Remember, a drone is purpose-built, and the frame you pick should reflect your flying ambitions. Consider availability, price, and reviews when selecting a frame. We recommend beginners opt for a frame that's popular among the drone community. This way, if you're scratching your head over a problem, chances are, someone else has already found a solution.

Frame sizes are typically denoted in inches, signifying the propeller size they can hold. However, in some parts of the world, frame sizes are given in millimeters, representing the diagonal distance between the motors.

Here is a handy list of rough guidelines for frame sizes based on wheelbase, prop size, and typical use cases.

Flight Controller: The Brain of Your Drone

The flight controller is the central hub of your quad. It's the maestro that connects all electronic components and processes inputs and outputs. If you're a beginner, look for a flight controller with a mount size that fits your drone frame. You'll find some frames offering both center and rear mounts, giving you more options for your electronics setup.

Popular mount sizes include the 30 x 30mm, found on many mini and full-size quads, the 25.5 x 25.5mm for Whoops and toothpick quads, the 20 x 20mm for micro and mini quads, and the tiny 16 x 16mm.  This measurment represents the distance between teh mounting holes, and many frames will say what size mounting holes they support.

When it comes to the processor, beginners are safe with the F4, F7, or H7 models. These have modern processors and are compatible with the latest firmware. The F4 is a tried-and-true and cost-effective choice, while the H7 is more recent and a bit pricier.  To start a F405 based flight controller will be your best bet.

You might also want to consider whether to go for a stack or an All-In-One (AIO) flight controller. These come with the essential components either as a set or built into the board. By choosing an AIO or stack, you save yourself the task of buying additional parts separately. Time to take that first step towards building your drone and ruling the skies!

Here are the common mount sizes:

ESC: The Quad’s "Gearbox"

Electronic Speed Controllers (ESC) are often compared to the gearbox of a quad, managing the voltage from the battery, processing signals from the flight controller, and determining motor rotation. ESCs can come integrated with a flight controller or be chosen as separate components.

One of the most important aspects to consider while choosing an ESC is the Amp Rating. This denotes the continuous amperage that the ESC can handle. Selecting an under-rated ESC might fry it or even cause a fire, especially under high throttle conditions.

Hence, it's best to choose an ESC that's rated for a slightly higher amperage than your motor and propeller combination's full throttle draw. Keep in mind, typical ESC amp ratings align with the frame size and your flying style.

There are two types of ESCs: 4-in-1 and single. Each motor needs its own ESC, but for beginners, a 4-in-1 ESC is recommended because it fits well on the frame. In a 4-in-1 ESC, the amp rating is applicable to each individual ESC. So, a 20A 4-in-1 ESC can handle a total of 80A. These ESCs typically come in the same mount sizes as flight controllers and frames. For single ESCs, they're usually fixed to the frame arms.  For a typical 5" drone (most common to start with) I would suggest you try get a 40A-50A ESC.

Here is a list of typical ESC amp ratings for each frame size that you could get:

Motors: The Powerhouse

Choosing motors for an FPV drone can seem complex, given the wide array of options. But don't worry, this guide will help you make sense of it all.

Motor sizes are denoted as stator sizes. For instance, a 2207 motor has a 22mm width and 7mm height. These dimensions can provide insights into the motor's performance. Typically, smaller frames use smaller stator sizes, while larger frames use larger stator sizes.

Here is a list of typical stator size range for each frame size:

Then comes the concept of Kv. A high Kv means the motor can rotate the propeller faster, but at the cost of torque. Low Kv motors have more torque but rotate slower. As a rule of thumb, larger propellers pair with low Kv motors, while smaller propellers pair with high Kv motors. In terms of battery pairing, pilots typically use 4S batteries with high Kv motors and 6S batteries with low Kv motors.

For example, for a 2207 size motor, when running on 4S battery power, you would want a motor with around 2500kV, and on 6S you would use a 2207 1800Kv motor.

Propellers: Your Quad’s Wings

Exploring different propeller combinations can lead to exciting results. And you're likely to replace them frequently because crashes tend to break propellers.

The propeller's length should match the size of your frame. Propellers are named in two formats: Length x Pitch x Blades (3.5x2x3), or LengthPitch x Blades (3520 x3). In both cases, it's a 3.5-inch length, 2-inch pitch, 3-blade propeller.

Longer props and pitch increase speed but demand more power, while shorter length and pitch spin faster and are more responsive. You'll mostly find 2 or 3-blade propellers in the market. Fewer blades yield a more efficient quad that consumes less power, while more blades increase inefficiency and power draw.

Propellers can be bullnose-shaped for more thrust or regular pointed for less power consumption. They usually come in sets labeled Clockwise (CW) and Counterclockwise (CCW), indicated on the prop itself. For your quad to fly accurately, you need 2 of each, placed correctly. The CW/CCW inscription should be visible when correctly oriented.

Video Transmitter (VTX)

The Video Transmitter (VTX) is the powerhouse of your drone's visual capabilities. This ingenious device processes the video feed from the FPV camera, then transmits it to your goggles' receiver. One of the first crossroads you'll come across is deciding between analogue and digital HD.

For those who favour analogue, you'll need an analogue receiver connected to your goggles. The main determinant here is the VTX's maximum output power. Are you more of a racer? A lower output power like 25mW should serve you just fine. On the other hand, if you're into freestyle flying, consider going for 1W+ VTXs.

When it comes to digital HD flying, the field is dominated by three main players: DJI, HDZero, and Walksnail Avatar. Each has its unique edge - DJI stands out for its top-tier video link, HDZero boasts the lowest latency, while Avatar, utilized by Walksnail and FatShark, is the newest kid on the block showing impressive performance.  If you can afford it I would suggest you stary with DJI O3 FPV system, or Walksnail Avatar.

After you've made your choice between analogue and digital HD, you can proceed to choose a VTX that resonates with your needs. The options here might seem somewhat limited, but they mostly perform in a similar fashion. A key thing to remember is to attach an antenna before powering on the quad, else you risk damaging the VTX.

FPV Cameras

Your FPV (First Person View) camera is your eye in the sky. This little device comes in various types, with digital FPV cameras only compatible with specific digital VTXs. Just remember, an analogue camera won't work with digital systems. For instance, a DJI-compatible FPV camera isn't going to play nice with an HDZero video receiver, and vice versa.

When it comes to choosing an FPV camera, the size should be your first consideration. You want to match the size, denoted by the width between the mounting holes, with the FPV camera mount size supported by your frame. However, there are adapters available that allow you to use different sized FPV cameras, providing you with some flexibility.

The standard FPV camera sizes are Nano (15mm), Micro (19mm), Mini (21mm), and Full (28mm), with DJI being an odd size at 20mm. These days, most FPV cameras are either Nano or Micro.

Don't forget about the aspect ratio and field of view (FOV). These will determine your viewing experience, with aspect ratio providing a wide (16:9) or standard (4:3) view, and FOV defining how wide or narrow your image is. Shorter focal lengths (1.8mm) give a wide field of view, while longer focal lengths (3mm) give a narrower view. It all boils down to what you prefer.

Understanding the Quadcopter Receiver

The receiver of a quadcopter is the unsung hero, seamlessly processing inputs from your radio and communicating precise instructions to the flight controller. The choice of your receiver is a critical aspect of your drone setup and is largely influenced by the radio you're already using - perhaps from a simulator.

Among the array of receiver options available, we have a recommendation for you: consider getting an ExpressLRS (ELRS) receiver along with a compatible transmitter or transmitter module, if you don't own one already. ExpressLRS (ELRS) is a game-changer in the quadcopter space for multiple reasons. It's open-source, allowing the community to continually refine and improve it. Moreover, it's cost-effective, providing a potent combination of price and performance.

But, the real magic of ELRS lies in its performance. It outperforms many other options available on the market, setting new standards for latency, range, and robustness. So, whether you're soaring through the skies or zipping between obstacles, ELRS can help you do it better.

Mastering Antennas

Antennas are the lifelines of your drone's communication system. They play a crucial role in transmitting and receiving signals between the video receiver, video transmitter, radio receiver, and radio transmitter.

Antennas may come with certain drone components, or you may need to buy them separately. Either way, understanding what you're looking for is crucial. There's a dizzying array of antennas available, but let's simplify it down to three key aspects for beginners: frequency, polarization, and connector type.

The antenna frequency on your radio transmitter and radio receiver needs to match. Most commonly, you'll find 2.4GHz and 868/915 MHz frequencies. If you're using a 2.4GHz ELRS receiver, for instance, you'll need 2.4GHz antennas for your receiver and radio. On the other hand, most video transmitters (VTXs) operate on 5.8GHz, so for these, you'll need 5.8GHz antennas.

Video transmitter and receiver antennas often use circular polarized antennas. The catch here is that your antennas need to pair with the same polarization to get the best signal. So, if your goggles have Right Hand Circular Polarization (RHCP) antennas, your video receiver should also have an RHCP antenna(s).

Lastly, you'll want to consider the type of antenna connector your radio, receiver, video transmitter (VTX), and video receiver (VRX) support. Matching these will allow you to connect your antennas without the need for an adapter, which can slightly degrade your signal.

Food for Thought

Taking a step back, it's important to remember why we're doing this - the sheer thrill of flying something you built with your own hands. FPV quad building isn't just about the tech, it's about creativity, learning, and most importantly, fun.

As you embark on this journey, remember that no one ever got it perfect on the first try. It's okay to make mistakes and learn from them. After all, the art of drone building is in iteration and fine-tuning.

So, whether you're looking to take stunning aerial shots or zipping through the trees in a thrilling race, we believe this unconventional method will get you there faster and with more enjoyment. And who knows, you might just be the one revolutionizing drone technology in the future!

Let's Get Flying!

With all these tips and tricks under your belt, we hope you're feeling confident and excited to get started on your drone-building journey. There's a lot to learn, but remember that every expert was once a beginner too.

So, ready to build your first FPV quad and take to the skies? Head over to Unmanned Tech to start assembling your dream drone today.

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If you've found this article enlightening, we invite you to dive deeper into the world of FPV through our regular newsletter. From detailed reviews, like this one, to industry news, insider tips, and innovative tech spotlights, we keep you up to speed with the ever-evolving FPV hobby.

Stay curious, stay informed, and as always, happy flying!