How the Formula Works
This guide recommends propeller sizes based on motor stator diameter and flight style.
Motor Stator Size
The motor size (e.g., 2207) breaks down as:
- Stator Diameter (22mm): Determines the maximum safe propeller size
- Stator Height (07mm): Affects torque and power
Propeller Size Rules
| Motor Diameter | Recommended Prop | Application |
|---|---|---|
| ≤ 13mm | 1.6″-3″ | Tiny whoops, micro quads |
| 14-22mm | 5″ x 3.8-4.8 | 5″ racing/freestyle/cinematic |
| 23-28mm | 6″-7″ | Long-range, camera platforms |
| 29mm+ | 10″-15″ | Heavy-lift, gimbal platforms |
Flight Style Adjustments
- Racing: Higher pitch (4.3-4.8) for max top-end speed
- Freestyle: Medium pitch for balance of thrust and control
- Cinematic: Lower pitch for smooth, efficient flight
- 6S High-Voltage: Lower pitch to handle higher RPM
FAQs
1. How do I read propeller size notation?
Prop size is written as Diameter × Pitch × Blades. Example: 5″ x 4.3″ x 3 means 5-inch diameter, 4.3-inch pitch, 3 blades.
2. What happens if my propeller is too large for the motor?
The motor draws more current, overheats, and may burn out or demagnetize. Excess current also damages ESCs.
3. What happens if my propeller is too small?
The motor is inefficient and produces less thrust than its potential. You lose flight performance and battery life.
4. Do more blades mean more thrust?
Yes, but at the cost of efficiency and battery life. 2-blade props are most efficient, 3-blade balance thrust/efficiency, 4-5 blades are for racing (shorter pitch).
5. How does battery voltage affect prop choice?
Higher voltage (6S) spins props faster, so use lower-pitch props to stay within motor limits. Lower voltage (3S/4S) can handle higher pitch.
6. What does KV mean and how does it relate to props?
KV is RPM per volt. High KV motors need smaller props; low KV motors run larger props. This keeps prop tip speed within safe limits.
7. How do I know if my props are too aggressive?
Watch for excessive current draw, motor heat, ESC heat, or visible prop flex. These indicate the prop demands more than the motor can safely deliver.