What is the best number of rotors for a drone?
The tech website MakeUseOf published an article on November 17 analyzing the optimal number of motors for drones, stating that it depends on your intended use.
The article says that most commercial drones available today are quadcopters, which have four motors. However, quadcopters are not the only form of drones, and not all drones have four motors. The number of motors and the shape of the frame greatly affect the stability, flight time, speed, etc. of the drone.
According to the article, a drone needs one motor and one propeller to take off. The rotation of the propeller generates an airflow that creates lift. But flying a drone is not just about taking off; it also requires directional control through speed differential. Therefore, a single propeller is not feasible in principle and at least two engines are needed. Adding more motors can also make the drone more stable and carry more load.
A dual-rotor drone has two motors, and the frame is usually in the shape of a V. The reduction in propellers means lower stability, making it more susceptible to weather conditions. Dual-rotor drones can only fly in two directions toward the motors. However, they have longer flight times. Manufacturers have begun making dual-rotor helicopters, where each motor needs to be installed on a servo motor so that the angle of the propeller can be adjusted to make it fly forward.
Tri-rotors are more versatile than dual-rotors and can handle heavier loads, with Y- or T-shaped configurations. However, even in light winds, it will still be a bit shaky. It has a certain degree of stability, but it lacks speed and performance compared to quad-rotors. However, the slower the speed, the better the maneuverability.
Quad-rotors are the most common multi-rotor configuration, and the X and H configurations are the most popular, which are loved by DIY manufacturers and commercial drone manufacturers. Because it has been proven that it achieves a perfect balance of price, performance, stability, and flight time. There are many DIY resources available to build your own quad-rotor, and you can even build one without a flight controller using an Arduino development board.
Six-rotors are more stable and can handle heavier loads. Of course, with more motors, it also consumes more power, which makes its endurance shorter. But six-rotors are also more stable, with higher redundancy. Even if one motor fails in the air, the six-rotor can still land safely, while the quad-rotor will crash.
Currently, octocopters are the highest form of commercial multi-rotor drones. While it is possible to build drones with more rotors, it is not necessary now. The load capacity of octocopters is already very strong and the flight is very stable. But it has high energy consumption (at least requires a 4S lithium battery) and a huge size. Eight-rotor drones are often used to film movies or for professional purposes, and they can carry heavier cameras and lenses.
Is a drone with more motors and propellers better? The article believes that the key is to weigh the pros and cons. More motors can make it more stable and carry more load, but also means more power consumption, heavier weight, and more parts. And for DIY drones, there is also a consideration factor of resource availability. Your first drone should be a quadcopter because there is a larger online community, and you can even download a 3D printable frame model for free.
