Most hobby grade aircraft use them, but did you know the size, pitch, design and weight can vastly impact the way your aircraft flys? Power, grip, efficiency, speed, maneuverability, durability, etc.. are all descriptions we give to different quadcopter props to describe how they help us in the air. Let’s talk about how we can tell the difference between props and pick the best one to suit your needs.
TOP BRANDS AND MODELS
First let’s get familiar with some of the big names in the industry and their flagship models, and what they are known for.
Dal – Cyclone series – Dal is a long time favorite of many free stylers and racers. The most famous are the very responsive and powerful Cyclone 5045 and 5046. The higher pitched 5046 is known for speed and durability and its close relative the 5045 is known as the slightly more efficient version with a little more speed vs control.
HQ – V1S Series – One of the most popular props today for freestylers and racers a like. The most popular sizes have been the HQ 5x4.3x3 v1s
T-Motor – Makers of the outstanding motors ventured into the prop game. They made a very light 5149 prop that was all the rage last summer.
Azure Power – Perhaps the most unique prop design of the bunch, the boomerang style of the Azure Power is very unique and those who fly them are constantly extolling the virtues of these unique props.
Gemfan – Flash Series – A very powerful prop, my personal favorite for 2.5” or 3” props are the Gemfan flash series. They are also the maker of the popular 5152 series. A super powerful and smooth prop, that sometimes suffered from durability issues, but Gemfan went back and made a newer version of this prop with increased durability.
Lumenier – A staple in FPV made by GetFPV, Lumenier makes the Butter Cutter series of props.
Emax – Makers of the Avan series. They now have props in the whoop class size, all the way up to 5”. Noted for their extreme power and smoothness, but have historically been known to draw a lot of amps.
Reading the Prop Numbers
You may notice when looking at props that you commonly see a series of numbers associated with each one. Now different companies may structure the name of their props different leading to some difficulty interpreting but let’s break down how to read these numbers.
Manufacturers use 2 types of format:
L x P x B or LLPP x B
L- length, P – pitch, B – number of blades
We will use HQ V1s series as as an example. One popular model that I use is the HQ 5 x 4.5.x3 v1s. Here we see 3 numbers. The first 5 indicates the size of the prop, in this case 5 means 5”. The second number 4.5 refers to the pitch of the prop. And the last number 3 refers to the number of blades on the prop. V1s is the props designation or model.
Drone propeller Characteristics
Props range from Tiny Whoop class 31mm variety, to 6”+ long rage size, to even bigger for commercial or Prosumer applications like DJI Inspire or Phantom.
Think of prop pitch like using a paddle in a canoe. If you push straight back with your paddle parallel in the water to you, you will have the max force and each push will go slower. If you push at a high angle, you can cut through the water faster, but it will push you ahead with less force.
A lower pitch will always move faster, but push you ahead with less thrust.
A higher pitch will mean more thrust per revolution, for greater speed but less fine control.
Higher pitch will also be providing higher thrust, but in combination with more amp draw. That extra work will demand more from your battery.
Number of blades
The number of blades affect both flight and efficiency. Fewer blades = more speed, and less amp draw or more efficiency. More blades = more control, but lower efficiency and lower speed.
The compromise often is to run a 3 blade prop for most 3-7” quadcopters. But for high speed runs you will often see 2 blades, and for indoor crafts where you want the most control possible vs speed you will often see 4 blades.
Props today are most often made of polycarbonate. Different combinations of materials, colors and ingredients can make for a stiffer or more flexible prop. A more rigid prop can allow very fast speeds, but can also break more easily on impact.
How do you pair a prop with a particular motor and quad?
You will also want to match a prop to a motor. A smaller motor like a 2205, will not be able to push a high pitch prop like an HQ 5x4.8 v1s without draining a lot of battery. It would do much better with the lower pitch 5x4.3 v1s.
A heavier motor like a 2207, will have more power, and ability to push that larger prop to allow you the maximum straight line performance. But as mentioned earlier, this will demand a lot from your batteries.
When testing a new prop, always make sure to land, check motor temperatures, and keep a close eye on your voltage readout on your On Screen Display to ensure you do not over discharge your battery.
Installing props on your quadcopter? What tools do you need? Any 8mm wrench or socket wrench will do. But I always recommend a dedicated prop tool such as the Piroflip branded one.
Also, pro tip, keep more than 1 prop tool with you. I generally have 2. The reason is, sometimes we end up keeping one in your pocket and forgetting to put it back. Nothing like being out at a nice place to fly, and having to go home because you could not get your broken prop off.
So don’t let this ground you, and make sure you have the right tools. For smaller T prop sizes, you will want a 1.5mm hex driver.
There are 2 propeller direction options. The traditional betaflight setup which is props all turning in. And the Reverse which is props turning out.
The both should feel the same in the air, but props turning out can help to push you away from objects, where as traditional props in will pull you in. The downside, is that props out will throw any cut grass, dirt or grime you land into directly into your center stack.
So be warned. It is a great option for some, especially if you fly near a lot of trees, but I personally do the traditional way. There are many ways to remember your prop orientation but I use this method. (for traditional mounting).
If I look at a prop straight on, the blade should point down on the left side, this goes to the top left. If I look at it the same way and the blade points down on the right side, it should go to the top right. Your rear props are the same across the diagonal.
Prop Size Recommendations
31mm or 40mm are the whoop class sizes. These will typically run with Whoop style ducts and be safe to bounce around inside your house with. There are 2-4 blade varieties and new offerings by HQ, Team Black Sheep and Gemfan.
My favorite for this is the 2.5” size. When on 4S with a target weight of 80-100grams dry weight you have enough speed to have fun but still a fairly light craft. This is best for an empty playground to play around.
If populated whoop class is best, because of the 25-35gram weight and the ducted guards that protect if an impact is made. My favorite in this size is the Gemfan 2.5” 2540 Flash series prop. Many also prefer the very attractive HQ.
Or small field, parking lot – 3” – There are 2 main types of 3” props, the traditional size prop nut where the Gemfan 3052 Flash prop is king. Or the T style Mounting prop, where the HQ 3” T style prop is an excellent choice.
Gemfan recently released a Wind dancer version that come with a set of adapters that allow you to run both regular size props or T style mounting props to accommodate a wide range of motors.
For racing, the 5” prop is the standard. You can play with the pitch and pairing of your motor to find the right mix for you.
Like racing the 5” is the standard, but often different pitches can be popular for additional response preferred over top end speed.
This is where you get to 6” and 7” props. These will pull more power, but long range experts have found that pairing with a large battery and the proper mid KV can allow you to achieve impressively long flight times.
For 6", HQ 6x4 and Dal 6x4 are some preferred options. Note that in 6” ( Dal fly smooth but do not have the same durability as the 5” options).
For 7" HQ 7x3.5 fly well at high throttle ranges, but for a good all around option the Dal 7x.56 are regarded as the best.
Long range community has let me know that one thing to look for when you go 7” or larger, is that you want thicker blades.
For wings, while many do run Quadcopter props, APC makes a range of purpose built props specifically for wings. These involve a lot of variation based on your needs, size of wing, weight, specs and purpose. So before you dive in, consult your local Wing Commander for more advice.
When should you change your props?
If you crash and a prop is bent, often times you can bend it back and it will fly fine. Some prop models will bend back to original shape and stay there and will fly fine. Some may keep a crease where the bend was.
Creases, cuts, nicks, or chunks missing will all cause poor flight performance. The newest betaflight software with dynamic filters can filter much of this out, but keep in mind you may be putting additional stress on your electronics in these scenarios.
If you are absolutely low on props you can keep flying but always check your motor temperatures when landing to make sure that bad prop is not warm.
The last thing you want to do is risk burning a pricey motor or electronic speed controller over a fairly inexpensive prop. Rule of thumb? When in doubt? Change it out. Keep in mind, that newer props fly better, smoother and many times faster. And when you are learning you do not want your muscle memory to build up on bad props, so keep those in mind and change them at your discretion.
If I am doing light free style, a set of props can last a long while. But if I am racing, I may change props 2-5 times in a single day to make sure I am getting maximum performance, and when doing hard throttle, on a bend or banged up prop is when you are the most in danger of putting electronics at risk.
How many sets should you keep in your personal stache? Nothing can keep you grounded faster than not having a few $2-3 sets of props. So when the sales hit, stock up, buy big and take advantage of the prop discounts at the large retailers like www.piroflip.com and www.rdq.com.
It’s a good idea for every FPV pilot to both select a favorite quadcopter props and stock up, but also try new offerings always searching for more control, more speed, more durability and a better cost. To have a prop that allows you to fly to your full potential is a constant quest to become better at FPV.
I personally take advantage of the prop bulk pricing discounts and usually order 20-40 sets at a time and keep a large stock. This allows the best bang for the buck, and allows you enough stock that you can combine these bulk discounts with seasonal sales and stock up for the lowest price possible.