What drone parts do you need to build a quadcopter?

The drone industry is growing at a rapid pace. Drones have been adopted across multiple industries, including real estate, healthcare, military, transportation, surveying, retail delivery, construction, and infrastructure. There are 1.1 million drones registered with the Federal Aviation Administration in the United States. There are over a million active drones in India. There were 430,700 drones in Europe in 2021. The drone industry has just started. Many more drones will be operating commercially across multiple sectors and will be privately owned by the end of this decade.

The most common type of drone is a quadcopter. Quadcopters don't just dominate recreational drones; these are common drones used in commercial drone services. Quadcopter is the simplest UAV helicopter with four engines. You can learn about the physics and work behind flying a quadcopter at this link. Building a quadcopter is one of the favorite projects of electronics engineers and hobbyists. But do you know what components or parts are needed to build a radio-controlled quadcopter? Well, we will discuss the same in this article.

Fortunately, you won't need to collect the parts mentioned here from different sources. Several drone kits are available that bring together all of these essential parts and electronic components in a single kit. If you are experimenting with a custom drone design, you may only need to collect the parts and electronics needed to build a quadcopter separately. You definitely need to match the compatibility of components from different sources in this case. For example, you will need to check that the motors you select are compatible with the battery system and electronic speed controller.

Likewise, the battery and charger must be compatible with each other. You can build a quadcopter from an assembly kit or gather parts and electronic components from different sources; the list of parts and components will remain almost the same. Let's start.

Parts of a drone
If you plan to build a radio-controlled quadcopter drone, you will need the following parts.

1. quadcopter frame
2. Drone engines
3. Electronic Speed ​​Controller (ESC)
4. Flight Controller Board
5. Propellers
6. Radio transmitter and receiver
7. Battery and power distribution cables
8. Landing gear
9. Battery charger

The following parts are required to add remote viewing to the drone.

1. Camera
2. First person video

quadcopter frame
The frame forms the skeleton of the drone. Drones used in various commercial applications have frames suited to the specific use. The structure supports motors and provides chassis to accommodate the flight controller, radio receiver, battery, etc. The structure not only allows you to mount other components; It plays a vital role in maintaining the drone's center of gravity and aerial stability.

Quadcopter frames are available in many different materials such as aluminum, carbon fiber, plastic, fiberglass, fiber PCB, etc. Ideally, the structure material should be light, robust and stable. The material must not have any radio interference. Aluminum frames are stronger and more robust, but are heavy and subject to vibrations. With an aluminum frame, strong motors are needed to propel the drone. Carbon fiber frames are light and strong, but they have radio interference issues. Plastic frames are light and free from radio interference, they lack strength and robustness. A poor quality plastic frame can even crack or fade due to excessive exposure to sunlight.

Quadcopter frames cost between $10 and $500. Metal and carbon fiber frames are more expensive. You always have to trade off between a good frame material and the cost. Selection of a good structure should depend on optimizing strength, robustness, firmness/stability, weight, cost and radio frequency interference for the intended application.

Drone Engines

Drones use brushless motors to propel. Selection of suitable engines is very important. A quadcopter has four rotors, so four motors are needed. The essential features of a drone motor are KV rating, voltage, amperage, recommended propeller size, and torque. KV rating and torque are inversely proportional to each other. The higher the KV rating, the faster the engine will rotate, but the lower the engine torque will be. Therefore, a higher RPM motor may run faster but carry less load for a given voltage. The recommended propeller size should be in accordance with the structure of the drone. Motors must be placed on drones at least 3 propellers away from each other.

After selecting a frame, you can sort engines by recommended propeller size. Furthermore, you can select the motor according to the size, KV rating and torque required as per the specific application. Finally, a suitable motor can be selected based on ESC amperage and voltage.

Electronic Speed ​​Controller (ESC)
The electronic speed controller (ESC) controls the speed and direction of BLDC motors. The amperage of the ESC unit must always be greater than the total current drawn by all motors and other components. The more energy the motors consume as the drone flies at higher altitudes. Therefore, the ESC selection determines how high the drone can fly.

The ESC interfaces between the flight controller board and the drone's motor. It converts DC power from the battery into three-phase AC to drive the drone's motors. ESC has four input terminals. Of these, two terminals connect to the LiPo battery. Next, two terminals connect to the flight controller board and carry PWM and ground signals. For interfacing with a three-phase BLDC motor, there are three output terminals on the other side. Some ESCs include a battery eliminator that can provide power to other electronic components.

Flight controller board
The flight controller is a microcomputer board that controls the entire flight of the drone. It is equipped with multiple sensors such as accelerometer, gyroscope, barometer, and digital compass/magnetometer, which are used to track and record the drone's position, altitude, rotation, and orientation. Many flight controllers also include GPS sensors and a 'return to home feature'. Using this feature, the drone precisely returns to the exact GPS location; he took off.

Flight controllers are generally generic microcomputer boards loaded with flight control software. Typically, flight controllers do not have compatibility issues with other parts of the drone. Still, selection could be based on preferred flight control software and microcomputer specifications. The other vital criteria could be the sensors integrated into a flight controller board.

Propellers
The propellers produce downward thrust to lift the drone into the air. They are also called pushers because drone propellers come in pairs of two. One pair of propellers rotates clockwise and the other pair rotates counterclockwise. When the propellers rotate, they create a region of low pressure above and a region of high pressure at the bottom. This allows the drone to rise into the air.

The critical factors to consider when selecting propellers are length and pitch. The better the pitch, the better the propeller will cut through the air and create more of a pressure difference. The other important factor is the length of the propeller. Longer propellers provide more substantial lift, even at lower RPM. However, they force engines to consume more energy and have a lower rate of change in RPM. Shorter propellers allow you to quickly change the speed of the drone and still place less load on the BLDC motors; they decrease the drone's payload capacity.

Radio transmitter and receiver
A radio transceiver or radio controller is a remote control that connects the pilot to the drone. It is only possible with a radio controller that a drone pilot can maneuver the drone. Radio controllers operate on one of the fixed radio frequencies. The frequency used by the radio controller depends on your geographic location and regulations.

The compatible receiver unit interfaces with the drone's flight controller board. The transmitter, which looks like a gamepad, is used by the drone pilot to change the drone's altitude, speed, direction and orientation. The radio controller must have at least four channels to control the aircraft effectively.

Battery and power distribution cables
Generally, lithium polymer batteries are used in drones. LiPo batteries have high energy density and provide a higher voltage of 3.7V per cell. A pack of three or four batteries in series and two or three batteries in parallel, such as a 3S2P or 4S LiPo battery configuration, is enough to power a drone flight. The battery capacity determines the drone’s flight time.

The battery is specified by its amperage/voltage setting and current rating. For example, a LiPo battery for a drone with a specification of 2200 mAh 3S 30C has a capacity of 2200 mAh, an output voltage of 3*3.7V or 11.1V and a current output of 30*2200 mA or 66A. Similarly, a LiPo battery for a drone with specification 8000 mAh 4S 35C has a capacity of 8000 mAh, a voltage output of 4*3.7 or 14.8V and a rated current of 35*8000 mA or 280A.

The greater the battery capacity, the more significant the flight time can be. The higher the voltage and current, the more power it can provide to BLDC motors. The battery should be selected based on the combined current draw of the BLDC motors and other components and the desired flight time. The power distribution cable is necessary to connect the battery to the ESC and other components.

Landing gear
Landing gear is necessary for safe landing of the quadcopter. It may or may not be necessary, depending on the specific application and also the experience of the drone pilot. There are two types of landing gear – fixed and retractable. The landing gear should be selected according to the structure of the drone. If the landing fear is installed on a drone, the material of the equipment also plays a vital role in the stability and stability of the drone. Installing the landing gear adds extra payload to the drone. Therefore, it should be installed only if necessary and selected wisely.

Battery charger
A compatible battery charger must charge the LiPo battery. Typically, batteries come with a compatible charger. Otherwise, it's not too difficult to find one for whatever LiPo battery you choose for a drone.

Camera
You need a camera if you want to record videos from your drone. Many people use their cameras or Go Pros with the drone. The footage is sent to a first-person video (FPV) device. There are also many FPV cameras available that are capable of not only recording but also transmitting video footage. The camera or FPV camera can be installed on a drone according to the need and budget.

First person video
FPV is a ground station consisting of a video receiver and a display. It receives video from an FPV camera on the drone's frequency and is streamed live on a display unit. Many FPV units only display 2D video images, while VR-type FPV units provide an immersive 3D view. Commonly used drone frequencies for video transmission include 433 MHz, 869 MHz, 900 MHz, 1.2 GHz, 2.4 GHz, or 5.8 GHz. FPV can be added to a drone according to needs and budget .