i’m new in the world of drones and i really want to make a drone with the cheap chinese bldc motors so can i use high kv like 2200kv or should i stick with kv used in youtube videos (1400kv) ,and why ? and if i used the 2200kv motor can it fly normal or i will face problems and can i use 1000kv motors
Navigating the KV ratings of brushless motors in drones is indeed akin to finding the sweet spot between enjoying a cheeky sprint and ensuring you don’t end up with a spectacularly unplanned disassembly mid-air. Here’s a rundown to help demystify how KV, battery cells (S rating), and voltages play together.
Understanding KV and Voltage in Drones
KV Rating: This indicates how many revolutions per minute (RPM) a motor will make per volt of electricity without a load. It’s a crucial figure because it determines both the speed and torque characteristics of your motor.
Voltage (from the battery): Higher S ratings on batteries mean higher voltages. For instance:
- A 4S battery, which stands for 4 cells in series, typically provides about 14.8V (3.7V per cell).
- A 6S battery steps it up to about 22.2V.
Why Different KVs for Different Voltages?
It’s all about balance and the law of “too much power equals the potential for a spectacular crash.” Higher voltages (more cells) provide more power. Pairing that with a high KV motor could lead to excessive speeds that aren’t practical or safe for controlled flying, especially for non-racing setups.
For 2207 Motors:
- 1800 KV on a 6S Battery (22.2V): This setup offers a balanced approach, giving you ample speed without going overboard. The lower KV with higher voltage compensates by maintaining high RPMs without excessive battery drain or motor overheating. This combo is good for efficient and responsive flights, suitable for both freestyle and racing while keeping the drone manageable.
- 2500 KV on a 4S Battery (14.8V): This is more tailored towards speed within a controlled range. Since the voltage is lower, the higher KV rating ensures that the motor can still spin the propellers fast enough to generate sufficient lift and responsive control. It’s more typical for faster flying styles but within a voltage that maintains battery life and motor health.
Practical Application:
When choosing a motor and battery setup:
- High KV + High S (Voltage): You get a rocket ship, but perhaps too hot to handle unless you’re experienced.
- High KV + Low S (Voltage): Fast but more controlled, suitable for racing at manageable speeds.
- Low KV + High S (Voltage): Slower, torque-rich performance, excellent for heavy loads, aerial photography, or training purposes where stability and longer flight times are preferred.
It boils down to what your drone is expected to do and your comfort with speed and control. Higher voltages provide more power, and adjusting the KV rating accordingly helps manage that power into practical performance rather than just turning your drone into an uncontrollable beast. Think of it as tuning a car’s engine to get the best blend of horsepower and torque for the type of driving (or flying) you plan to do.