All 20XX KV motors in the one place at Rising Sun FPV
"KV" refers to the motor's velocity constant, and it is a crucial specification that provides information about the motor's performance characteristics. KV is measured in RPM (Revolutions Per Minute) per volt and represents the rotational speed of the motor when subjected to a certain voltage. Here's what you need to know about brushless motor KV:
KV is a unit of measurement that tells you how many revolutions per minute (RPM) a brushless motor will turn for each volt applied to it. For example, a motor with a KV rating of 1000KV will rotate at 1000 RPM when supplied with 1 volt.
Inversely Proportional to Torque:
KV and torque are inversely proportional. A motor with a higher KV rating will generally have higher RPM but lower torque, while a motor with a lower KV rating will have lower RPM but higher torque. This relationship is important when choosing a motor for a specific application.
Different KV ratings are suitable for different applications. Here are some general guidelines:
High KV motors (e.g., 2200KV) are suitable for applications that require high RPM and less torque, such as racing drones and high-speed quadcopters.
Low KV motors (e.g., 800KV) are better for applications that require high torque and lower RPM, such as aerial photography or heavy-lift drones.
KV is closely related to the choice of propeller size. To optimize the motor's performance, you need to match the KV rating with the propeller size and the desired application. Using the wrong combination can lead to inefficient operation or overheating.
The actual RPM of the motor depends on the voltage supplied. For example, a 1000KV motor will spin at 10,000 RPM with a 10V power supply. To estimate the RPM for other voltages, you can simply multiply the KV rating by the voltage.
The choice of battery voltage is also important when selecting a motor with a specific KV rating. Using a higher voltage battery will result in higher RPM, while a lower voltage battery will reduce the RPM. This flexibility allows you to tailor the motor's performance to your needs.
Efficiency and Heat:
Motors operating at lower RPM (lower KV) are generally more efficient and generate less heat. This can be advantageous for applications where prolonged operation or heat management is a concern.
Control and ESCs:
When using brushless motors, the Electronic Speed Controller (ESC) plays a crucial role in controlling the motor's speed and direction. Make sure to select an ESC that is compatible with the motor's KV rating and the specific needs of your application.
In summary, the KV rating of a brushless motor is a key factor to consider when choosing a motor for your application. It determines the motor's RPM at a given voltage and influences the motor's torque characteristics. Matching the KV rating with the application's requirements, propeller size, and battery voltage is essential for achieving optimal performance and efficiency.