How to Select and Optimize Kv of an RC Brushless Motor

We are able to optimize the kv of a brushless motor by using a correct process. This process includes knowing the application that we intend to run a brushless motor in. The second component to this equation is knowing the intended LiPo battery that you would use. The importance here is the total cell count in order to determine the nominal voltage to be used.

Once these couple items are understood, the kv of a brushless motor can be determined by using a known RPM range for the application. Follow the guidelines on the radiocontrolinfo website for correct RPM ranges. These are unloaded total RPM outputs that we are interested in.

Select a specific RPM within the RPM range. As a very basic rule of thumb, select a higher RPM within the range if you are trying to achieve higher speeds. A lower RPM within the range if speed is not as important.

Lastly, use the RPM and nominal voltage to determine the kv value. This calculated Kv value does not require you to purchase an exact match. It would be rather difficult to find an exact match. Instead, find a suitable motor that is within a small percentage difference of your calculated Kv.

The important part that gets more in to the overall power system selection of your application is this: (outside scope of video)
The load that you place on the power system will ultimately determine the success of your power system. Too large of a load can get you in to serious problems that can destroy components of your power system. Too high of a load can be too large of a prop diameter or pitch for an airplane/boat or too high of a pinion tooth count for an RC car.