Props are the cheapest part of a quad and they change how it flies more than almost anything else. They are also easy to buy wrongly, because brands write sizes in different ways.
How to read a propeller name
Every prop name carries the same three facts: diameter, pitch and blade count.
- HQProp 5x4.3x3: 5-inch diameter, 4.3-inch pitch, 3 blades.
- Gemfan 7040-3: 7.0-inch diameter, 4.0-inch pitch, 3 blades. Gemfan runs the numbers together.
- Gemfan 1050-3: 10-inch diameter, 5.0-inch pitch, 3 blades.
- HQProp T3.5x2x3: the T marks a T-Mount hub.
- Gemfan D90S-3: a 90mm ducted prop. Ducted props are often sized in millimetres.
Diameter comes from your frame
Do not choose diameter by preference. Your frame sets the maximum, and props that overlap an arm or a duct will not spin safely. A 5-inch frame takes 5-inch props, and the listing tells you the rest.
Pitch changes the character
Pitch is how far a prop would move forward in one turn, in theory.
- Lower pitch feels smooth and efficient, with quicker response and less current draw. The HQProp Ethix S3 at 3.1-inch pitch has a floaty freestyle feel.
- Higher pitch gives more top speed and bite, and asks more of your motors and battery. The V2S at 4.3 inches balances speed against low-end punch.
If motors run hot, a lower-pitch prop is often the simplest fix.
Blade count: two or three
Three blades give more grip and thrust from the same diameter, which is why they dominate 5-inch freestyle. Two blades mean less drag and lower current draw, which is why they suit long range. The Gemfan Long Range 7035-2 is a good example.
For 7-inch, you have both options: the HQProp DP 7x3.5x3 prioritises efficiency in three blades, and the Gemfan Flash 7040-3 suits faster flying.
Check the mount
This is the mistake that leaves you with props you cannot use.
- 5mm shaft hole: the standard for 5-inch and 7-inch motors.
- T-Mount: two or three small screws on a 1.5mm shaft motor, used on cinewhoops and small builds. The HQProp T3.5x2.5x3 is one.
- 1.0mm and 1.5mm press-fit: used on whoops. These do not interchange, so match your motor's shaft.
Some props ship without adapter rings, so check the listing if your motor needs one.
Check the pack size
Props come in clockwise and counter-clockwise pairs, and a quad needs two of each. Pack sizes vary:
- Most 5-inch and 7-inch sets include 2 CW and 2 CCW, enough for one quad.
- Large props such as the Gemfan 8040-3, 1510-3 and HQProp 13x8x3 come as 1 CW and 1 CCW, so a quad needs two packs.
Material
Polycarbonate flexes and survives crashes, which is why nearly every 5-inch prop uses it. Glass fibre reinforced nylon stays stiffer under load, which suits heavy-lift props such as the Gemfan 1050-3.
Fitting props safely
- Remove props on the bench. Never test motors or plug in a battery at home with props fitted.
- Match rotation. Each prop must suit its motor's direction. A reversed prop can flip the quad on take-off.
- Replace damaged props. Bent blades cause vibration, which heats motors and adds noise to the video.
Frequently asked questions
Which prop should a 5-inch beginner buy?
A mid-pitch, three-blade polycarbonate prop such as the HQProp Juicy J37 or Freestyle V2S. Buy several sets, because you will go through them quickly.
Can I fit a bigger prop for more thrust?
Only if the frame clears it and the motor can handle the load. Bigger props draw much more current, so check with the motor guide first.
Need a prop matched to your motor? Email info@aeroflow.in with the motor and frame.