Intro To FPV - Propellers
Propellers make a big impact on how a miniquad performs & how long a battery lasts.
I tried to think of a car analogy but couldn’t come up with a single part - they are the equivalent of tyres *and* the gearbox. Tyres because they govern how much grip you have when cornering and gearbox as they effect the acceleration and top speed you get from your motors.
A prop is described by its diameter, its pitch and how many blades it has.
Diameter is pretty self explanatory, it’s the measurement across the circle that the tips of the blades draw when spinning. Generally you fit the biggest props your quad can take - it’s makes no sense to run 2” props on a 5” quad!
The pitch of a prop is how twisted each blade is. The higher the pitch, the more it bites onto the air and hauls the quad forward. It’s also puts more load on your motors, drawing more amps through your system and shortening your flight time. So like everything with miniquads, it’s a trade off. This time between thrust and efficiency. Like the diameter, pitch is also measured in inches - a prop with a pitch of 4, for example, screws itself forward 4 inches every rotation (in a perfect world). Realistically it’s just a way to compare one prop with another.
Once upon a time, at the dawn of miniquads, we only had 2 bladed props. Then HQProp made a 3 bladed prop and saw that it was good. Then things got silly for a while! Manufacturers went a little crazy; if 3 blades are good then 4 must be better, right? But then why not go to 6 blades?! Happily things have settled down now and 3 bladed props are the sweet spot, although 2 bladed props still have their place, certainly in 6” and above.
How does that equate to product listings on our website? Props tend to be described in a couple of different ways depending on the manufacturer. The first way is “diameter x pitch x blades”. A three bladed, 5” diameter, 4” pitch HQProp for example is called 5x4x3. DAL and Gemfan like to use 4 digits to describe diameter and pitch - 5040 in this case describes the same 5” diameter, 4” pitch prop. We’ve got another post on DAL's naming convention here
Our top tip for new pilots is to stick with a fairly low pitch prop. It's tempting to go for a 5050 straight away to give you maximum performance but learning to maintain a steady altitude is much easier with a lower pitch. If you find yourself ballooning 50 feet into the air every time your try corning tightly, try and less aggressive prop.