Choosing Motors/Batteries/Props

Owned by Brielle Chenier
Last updated: 2022-06-02
2 min read

Motor Naming Conventions

Motors are named using common conventions which allow you to easily compare some before looking at datasheets. The first number is the motor diameter and the second one is the motor height. [1]

The KV rating is the max speed a motor will rotate (RPM) for every volt applied. This means using a motor that is 1000KV, it can rotate up to 1000KV*12.6V=12,6000RPM. While having a high RPM can be very helpful when using small props, as props get larger they will create more resistance, slowing down the RPM, and therefore can have smaller KV ratings [2]. Motors with higher RPM will also draw more current, reducing flight time.

Propeller Naming Conventions

The first number in a propeller's name is the diameter and the second number is the pitch. In the case of our 10x4.5 propellers, the diameter is 10” and the pitch is 4.5. The pitch means that for each revolution, the prop will pull the plane forward 4.5” [3]

Sometimes propellers will also be named such as 8045 which would be an 8” diameter prop with a pitch of 4.5.

It is important to note that just because props have the same measurements, they can still perform pretty differently based on the brand and material of the prop (plastic, wood, carbon fiber)

Motor Thrust

When speccing out motors for drones, the thrust required should be 50% of the motor max thrust. This is important as the lower the thrust required, the more efficient the motor will perform, allowing it to fly further distances. It will also ensure the drone can still properly maneuver in the air since turning will require more thrust than simply hovering.

Choosing Batteries

The first thing to choose when looking at batteries is how many batteries in a series you want. Generally, we fly with batteries between 3S-6S. Each cell has a voltage of –. That means a 3S cell has a voltage of --.

Batteries also have mAh ratings. This is the total amount of current a battery can supply, for example: for a 3000mAh, the battery is capable of supply a total of 3A for 1 hour. This can be extrapolated to find the total flight time of a drone.