The term drone was first coined in the 1920s, associated with Fairy Queen. Initially, drones were used for military purposes; it slowly gained traction in the commercial sphere and is today used for a variety of purposes racing, agriculture, monitoring and speculating architectural structures, photography, or casual usage as a toy.
The most essential component of a UAV is the drone frame, which forms the pivot of an entire system. The frame of a drone varies from purpose to purpose; for instance, a racing drone would usually employ a drone frame which facilitates lightness and durability. Conversely, a drone which will be flown indoors will require a frame which is small and lightweight.
Classification of frame sizes of drones
The size of a drone is one of the most essential aspects of a frame. Drone frame size is calculated based on the distance between two motors. This measurement is conducted diagonally, across the center of a frame.
The classification of frame sizes allows two types – micro and mini. In case a frame is measured below 150 mm, it is classified as a mini frame, and if the drone size is above 150 mm, it is considered a micro drone frame.
In case, the distance between each pair of polar motors is not uniform, for instance in a hexacopter, the largest inter-motor distance is considered as the size of a FPV drone frame. If a drone has no polar motors such as in a tricopter, a similar principle is employed to measure the size.
The drone community has collectively posited a drone frame size chart which provides information on the size of propellers, motor kind and the KV of a motor as per the size of a frame.
|Motor kind||Propeller size
|KV of motor|
|235 – 280||2205 – 2308||6||1600 – 2500|
|200 – 220||2204 – 2306||5||2100 – 2800|
|150 – 180||1306 – 1408||4||Above 3000|
|120||1104 – 1106||3||Above 4000|
|100||1102 – 1104||2||Above 6000|
Materials used in drone frames
When you set out to know how to make a drone, your first point of consideration should be the material used for the drone body. It determines factors like strength, weight, durability, and also the look of your drone.
The most popular material used to manufacture drone bodies is Carbon fiber. It owes its popularity to the high strength and lightness of the material. It is manufactured by bringing together plates of carbon fiber into a rigid structure following the principle of the epoxy matrix.
The second most used material for drone frames is HDPE or high-density Polyethylene. While it compromises on strength compared to carbon fiber, it is a sought-after material for the leeway it provides to enhance its durability comprehensively. Regardless, a frame made of polythene is heavier than carbon fiber drone frames.
Nevertheless, the best drone frames are made of a combination of different raw materials. For instance, carbon fiber and aluminum is a popular combination.
Different shapes of drone frames
Drone frames also differ in terms of their shapes. Each shape offers its own set of advantages and disadvantages. Consequently, when you are purchasing a frame, consider the shapes to make an informed decision.
As a quadcopter is the most commonly made design of all drones, these below-discussed shapes are among the most popular applications –
1. True X
The shape of a True X design resembles the alphabet X. The distances between the polar motors are uniform and thereby in your pursuit of how to measure drone size consider the diagonal length from one polar motor to another. Due to its uniform diagonal distances, the design provides stability to a drone when airborne.
2. Stretch X
This shape is largely used in racing drone frames as it offers more stability in the vertical or pitch axis. It enhances maneuverability during competitive circumstances. The stretch X shape is designed with the front motor heads and rear motor heads being in a smaller distance from each other and further from one another.
3. Dead Cat
Such design is heavily employed in larger quadcopters. It is a unique shape, where the front drone motors are at a larger distance from one another, while the two rear motors are at a relatively closer distance.
This design is popular to facilitate camera usage. As the front motors are broadly spread, HD cameras can capture wider scenery without such motor heads compromising the media product.
4. Wide X
It can be considered as a rotated stretch X, wherein the front motor heads are at greater distance from one another compared to the distance between a pair of front motor and rear motor in the Y-axis.
This design is commonly used in freestyle drone frames. As the centric space is broader compared to many other shapes, a camera can easily be fitted in that area.
This design is achieved by stacking a pair of rear and front motors on top of another, intersecting in the centric region. This shape enhances the controllability of the prop wash. It is the distributed mass of air which is exerted by propellers in the direction opposite to that of the flight.
It improves the flight quality as any vigorous force of frontal wind is evenly distributed across the body to avoid turbulence.
6. Vertical arms
In this design, the motor arms are vertically slanting, mostly upwards. It reduces the surface area of drones, thus allowing it to pass through congested spaces such as between trees and through structures.
Types of drone frames
When you are purchasing a drone body, there is another variant – unibody and separate arms – you should take into consideration.
In case of a unibody frame, such body comes in one piece, and there is no need for assembly. These body types are usually costlier, but lightweight. They are also stronger compared to replaceable arms as the impact force would be evenly spread through the body. A single-arm design would not be as effective in such a scenario.
In case of replaceable arms, they are usually cheaper as they require assembly. However, they are heavier due to additional usage of nuts and bolts. These frames facilitate low cost replacement, as any impact damage would be likely on a single-arm which can be separately bought.
Apart from the body frame, when assembling a drone, you should also consider the weight of the frame in response to the frame size. For instance, 100g is ideal for width above 200 mm.
You should also take into account where you want to put batteries depending on the usage. In case you will be using it for races, it would be ideal if you install such batteries at the bottom to ensure lightness and easy maneuverability.
A drone frame is quintessential to an unmanned aircraft. A significant portion of drone functionality and performance relies on it, and therefore, you should carefully consider the factors mentioned above to make an informed decision.