Propellers are the cheapest part of a drone and the easiest to get wrong. Here is what the numbers mean and when to replace them.

Reading the numbers

Propellers are marked like 8045 or 9x4.5: the first number is diameter in inches, the second is pitch – the theoretical distance the prop travels in one revolution. Larger diameter moves more air and is more efficient; higher pitch moves the drone faster but draws more current. Camera drones are engineered around a specific prop, so the practical rule is simple: replace like with like. You will find matched sets in the propellers category.

Direction matters

Quadcopters spin pairs of props clockwise and counter-clockwise to cancel torque. Props are marked CW or CCW, or marked A and B on camera drones. A drone that flips on takeoff almost always has a prop on the wrong motor – check direction before you suspect the flight controller.

Balance and vibration

An unbalanced prop shakes the whole airframe, and that vibration shows up as jello in video footage and prematurely worn motor bearings. If video turns grainy or wobbly after a crash, suspect the props first, the gimbal second. Balancing tools exist, but for small camera drones a fresh set is cheaper than your time.

When to replace

  • Any visible nick, crack, or chips on a blade edge – cracks propagate fast.
  • After any prop strike, even if it "looks fine." Flexed props lose their shape.
  • When flight times shorten or the drone hums louder than usual.
  • When the hub or mounting hole is worn loose – a slipping prop is worse than a chipped one.

Small props, real consequences

It is tempting to keep flying on a marginal prop. But a failed propeller mid-flight is a guaranteed crash, and replacement props cost a fraction of the arms, motors, and camera modules that a crash will need. We keep a spare set in every kit we fly, and we recommend you do the same. If you are not sure which set fits your model, send the model code via the contact form.