Motor Selection for Lifting 1kg in a Drone: A Comprehensive Guide

When designing a drone capable of lifting 1kg of weight, the choice of motor is crucial. The motor must balance efficiency, power-to-weight ratio, and performance parameters to ensure stable flight. This guide will help you understand the key considerations and select the right motor for your project.

Motor Types

Typically, brushless DC (BLDC) motors are the preferred choice for drone applications. They are efficient, have a long lifespan, and provide optimal power-to-weight ratios. However, for smaller or less demanding applications, brushed DC motors may also be utilized.

Brushless DC Motors (BLDC)

BLDC motors are the most common choice for drones. They offer several advantages:

Efficiency: BLDC motors convert a higher percentage of electrical energy into mechanical energy, making them more efficient than brushed motors. Longevity: BLDC motors have fewer moving parts, leading to a longer lifespan. Performance: They provide reliable and consistent power output, essential for stable flight.

Brushed DC Motors

Brushed DC motors are a simpler and more affordable option for certain applications. However, they are generally less efficient and have a shorter lifespan. They may be suitable for smaller, less demanding drones or educational projects.

Motor Size and Specifications

The size and specifications of the motor play a significant role in determining the performance of your drone. Key considerations include:

KV Rating

KV Rating (KV per volt): This rating indicates how fast the motor will rotate for a given voltage. Higher KV motors spin faster, but they produce less torque. Lower KV motors provide more torque at lower speeds, which can be beneficial for high-torque applications like lifting 1kg of weight.

Thrust-to-Weight Ratio

To ensure stable flight, it is recommended to aim for a thrust-to-weight ratio of at least 2:1. For 1kg of payload, this means the motors need to generate at least 2kg or 20N of thrust. This calculation helps in determining the total thrust required from the motors to lift and maintain the desired weight.

Propeller Selection

Choosing the right propeller is crucial for balancing thrust and power requirements. Key factors include:

Propeller Size and Pitch

The size and pitch of the propeller affect the thrust generated. Larger propellers can produce more thrust but require more power. You should optimize the combination of motor and propeller to match the weight and desired flight characteristics of your drone.

Battery Voltage

The battery voltage has a direct impact on the power available to the motors. Common drone battery configurations include 3S (11.1V), 4S (14.8V), and 6S (22.2V). The higher the voltage, the more power the motors can draw, which can influence the overall performance and efficiency of the drone.

Recommended Motor Sizes

For a 1kg drone, motors in the 2212 to 2814 size range are commonly used. The specific size may vary depending on the propeller size and the desired flight characteristics. These motor sizes provide a good balance between thrust, efficiency, and power-to-weight ratio.

Examples of Motors

2205/2306 Series: These motors are suitable for racing drones and provide a good balance of thrust and efficiency. They are lightweight and compact, making them ideal for high-speed applications.

2812/2830 Series: These motors can provide higher thrust and are often used in heavier drones. They are more powerful and can handle a greater load, ensuring stable flight even under challenging conditions.

Summary

To lift 1kg of weight, choose a brushless DC motor with a suitable KV rating, propeller size, and thrust capability. Ensure that the combined thrust from all motors exceeds 2kg to achieve stable flight. Always consult motor and propeller specifications to find the right combination for your specific drone design.

By understanding the key considerations and making informed decisions, you can select the perfect motor for your drone, ensuring optimal performance and reliability in your lifting applications.