How to choose the right propeller for your racing drone
What is the best racing drone propeller? To be honest, there isn't just one! It all comes down to what you want as a pilot. Do you want efficiency? More response? Raw power? I'm going to run through a few thing that will help you find the prop you're looking for.
First, let's talk about prop "values" or I guess you would call them "specs". The little numbers in the name of the prop. These basically indicate WHAT the propeller is.
- You'll usually see something like "<brand name> 504530 Propeller" or "<brand name> 5x4x3 Propeller"
- These numbers represent the size, pitch, and number of blades. They're how you can compare propellers briefly on paper.
- When you see 50, or 5x it will mean it's a 5 inch propeller. The diameter of the circle made by the propeller tips is 5 inches.
- 5040 or 5x4 means it's a 5 inch propeller with a blade pitch of 4. A lot of people will tell you that pitch is the angle of the blade in relation to the hub. But no! A pitch of 4, is a pitch of 4 inches, which is how far the blade would move if you put it in jelly, and spun it one revolution. The more you know!
- 504030 or 5x4x3 means it's a 5 inch propeller, with a pitch of 40, and 3 blades. 3 blade props are basically the standard right now.
- What kind of propeller would a 6x3x3 be?
Now that you know how to read the name of propellers, I'll talk about what the different values can mean. I'll mainly focus on 5 inch props, because they're the most common.
- "Lower" pitch props fall into the 5040 to 5045 range. These "slice" through the air more like a butter knife on bread. This means your motor can spin it easier, because there is less air resistance, and this makes your quad feel more responsive because it takes less time for the propeller to reach the rpm you need. It can sacrifice top end speed, but the better control can often makes up for it.
- "Higher" pitch props fall into the 5045 and above range. These props are visually less "flat" compared to props with lower pitch, so the way they move through the air isn't as slicey like a butter knife. It's more like if you tilted your butter knife up, and were scraping the vegemite off your toast to replace it with marmite. These props hit the air, and force it down into thrust! These will give you higher top end speed, but depending on your motor, it may impact how controlled your quad feels.
- Another difference between low and high pitch is efficiency. Low pitch props slice through the air like a breeze (get it?) so your motor and battery don't need to work quite as hard. High pitch props will demand more juice from your battery at higher throttle, but when you're at that higher throttle, the speeds will blow you away (I need to stop)!
Now, you're probably thinking "it sounds like low pitch is way better because it's more efficient, responsive, and the top speed you might lose is made up for by the extra control, because I don't fly in straight lines anyway!"
You'd be right to think that... Kind of... On smaller, 2205 size motors, lower pitch is great. Smaller motors don't have the extra torque of their bigger brothers, so on a light (low pitch) prop, they really shine because the prop is easier to spin up. It's not fighting the propeller as much.
However, putting a light prop on a big motor is almost like making the big motors job too easy. It will spin a light prop so easily, that there's almost no point in having the bigger motor!
On a bigger motor, let's say a 2207, it will be able to spin your heavier props in the same way your 2205 would spin lighter props. This will be less efficient, but the power difference will be immense, so you will have similar response and control as a light prop, but with a lot more zing and power!
I want to make the choice as easy as possible for you, so while I do suggest you read this, then make a semi informed decision on the next prop you try, I'm also going to suggest specific props to try with certain motors and the flying style you're aiming for..
Here we go.
If you're just starting out, and are more interested in being a freestyle pilot, I would always recommend leaning towards the lighter side of propellers. Freestyle usually isn't geared toward top speed, rather efficiency.
My 3 propeller choices for freestyle are:
- HQ 5x4.3x3 V1S (https://goo.gl/66FSpE)
- HQ 5x4.5x3 V1S
- DAL T5046C Cyclone *Best used on 2207 or 2306 motors* (https://goo.gl/XvSBMG)
If you're looking at being a racer, it depends more so on what kind of setup you have. If you build a lightweight race drone, you've probably chosen smaller, lightweight motors like a 2205 size.
My 3 choices for that style of build are actually the same as my 3 freestyle choices. But instead, I would get a motor with higher KV (2500-2600kv).
That means the motor will still be able to spins the propellers easy enough, but the extra RPM from the higher KV will give a bit more punch and response to the propeller.
If you have sacrificed a little bit of weight for bigger, more powerful motors then the pool of propellers to choose from is a little bigger!
Like I said previously, with bigger motors, comes more power! This means you get the joy of lots of power, with no cost to response! You use a little more power though.
My 3 choices for racing with hefty motors are:
- HQ 5x5x3 V1S (https://goo.gl/A3nxDP)
- DAL T5046C Cyclone (https://goo.gl/XvSBMG)
- DAL T5050C Cyclone (https://goo.gl/TTq972)
If you run big motors, but find these propellers too much, you can still get a lot out of the lighter propellers that I've listed previously too.
The best advice I can give, is really just try as many propellers as you can. Buy a few sets of each, then buy more of the ones you like best. This was a blog aimed at helping you understand what makes props perform differently, and why.
I hope it was informative.
Thanks for reading!
Posted: Tuesday 15 May 2018