1. Reading propeller markings

The numbers and letters describe prop geometry. Two common formats are 5043x3 and 5x4.3x3; they mean the same thing.

505.0 inch diameter434.3 inch pitchx3three blades
5043x3 = 5 x 4.3 x 3.The first value is diameter, the second is pitch and x3 is the blade count.

2. Parameters and flight feel

Diameter

7-10 inch props offer thrust and efficiency for long range but change RPM more slowly. Smaller 3-5 inch props have less inertia and a sharper response for freestyle and racing.

Pitch

Low pitch around 3.0-3.8 creates less load and can extend flight time. High pitch around 4.3-5.0+ can add top speed, current draw and heat.

Blade count

Bi-blades are efficient, tri-blades are the FPV all-rounder, and four or more blades can provide cinewhoop grip with a significant efficiency penalty.

System load

Size, pitch and blade count affect motor, ESC and battery load. Do not increase pitch blindly; check current draw and motor temperature.

Three-inch tri-blade propeller
3 inch: light and quick
Five-inch tri-blade propeller
5 inch: freestyle
Six-inch bi-blade propeller
6 inch: efficient
Seven-inch bi-blade propeller
7 inch: long range

3. Rotation direction: CW vs CCW

Props are supplied as clockwise (CW) and counter-clockwise (CCW) pairs. Install each one by the configured motor direction, not just by how it looks.

Props InThe front props spin inward toward the camera. This is the usual default.
Props OutThe front props spin outward. It can move grass and small obstacles away from the camera and changes the feel in turbulent turns.

Both layouts work in Betaflight. Check motor direction and prop orientation with props removed first.

4. Materials and mounting

Polycarbonate

The standard FPV material: resilient and flexible enough to survive minor impacts better than very rigid props.

Rigid composites

Fiberglass and carbon composites can be rigid but brittle. Keeping spare polycarbonate props is more practical for a first build.

M5 nut

A standard 5 mm shaft nut, common on five-inch and larger motors.

T-mount

Two M2 screws, commonly used on 1-3 inch systems. The mount must match the motor rotor.

5. Pre-flight checklist

  • The raised, curved blade face points upward toward the sky.
  • Each prop matches the motor direction: CW or CCW.
  • No blade has cracks, chips or white stress marks.
  • After a hard landing, check for deformation to avoid vibration and video jello.
  • After a prop change, make short checks for motor temperature and current draw.
Replace a prop with a white stress mark near a bend. Its material strength has already been compromised.

Build a safer propeller setup

Choose the frame, motors, battery and flight style in the builder to see whether the prop physically fits and whether the power setup needs attention.

Open the builder