Did you know that the size, pitch, design, and weight of a quadcopter prop can greatly affect the way your aircraft flies? These props can be described by their power, grip, efficiency, speed, maneuverability, and durability. In this article, we will discuss how to distinguish between different types of props and how to choose the one that best suits your needs.
Understanding the numbers
When looking at quadcopter props, you may notice that they have a series of numbers associated with them. While different companies may use different naming conventions, these numbers can provide useful information about the prop’s characteristics. Let’s discuss how to interpret these numbers.
Manufacturers use 2 types of formats:
L x P x B or LLPP x B
L- length, P – pitch, B – number of blades
We will use HQthe V1s series 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, which 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.
Characteristics
Propeller Size
Props range from Tiny Whoop class 31mm variety, o 6”+ long-range size, to even bigger for commercial or Prosumer applications like DJI Inspire or Phantom.
Prop Pitch
The prop’s pitch can be thought of as using a paddle in a canoe. Pushing straight back with the paddle parallel to the water will provide the maximum force, but each push will be slower. Pushing at a high angle allows you to move faster through the water, but with less force. Similarly, a prop with a high pitch will provide less thrust but will spin faster, while a prop with a lower pitch will provide more thrust but will spin slower.
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.
A prop with a higher pitch will provide more thrust and also spin faster, but it will also have a higher amp draw which will demand more power from the battery. This can be beneficial in some situations, such as when you need more speed or lift, but it can also put more stress on the battery and drain it more quickly. It’s important to consider the balance between the increased thrust and the added power demands when choosing a prop with a high pitch.
Number of blades
The number of blades on a prop can affect both flight performance and efficiency. Fewer blades will generally result in more speed and less amp draw, making the flight more efficient. However, fewer blades also mean less control in the air. More blades can provide more control, but at the cost of lower efficiency and lower speed. It’s important to consider how many blades you want on your prop, depending on the flight characteristics you desire.
A common compromise when choosing a prop is to use a 3-blade prop for most 3-7 inch quadcopters, as it provides a balance of speed and control. For high-speed builds, 2-blade props are often used to maximize speed and efficiency. For indoor crafts where control is prioritized over speed, 4-blade props are often used. It is important to consider the specific needs of your build and the type of flying you will be doing when choosing the number of blades for your prop.
Material
Props today are most commonly made of polycarbonate. Different combinations of materials, colors, and ingredients can affect the stiffness of the prop. A more rigid prop can allow for very fast speeds, but it can also be more prone to breaking on impact. A more flexible prop can be more durable, but it may not perform as well at high speeds. It’s important to consider the intended use of the aircraft and the type of flying when choosing a prop, as it will affect the trade-offs between speed and durability.
Motor and propeller pairing
When choosing a prop, it’s important to match it with the appropriate motor. A smaller motor like 2205 will not be able to efficiently push a high-pitch prop like an HQ 5×4.8 v1s and will drain the battery quickly. It would be better suited for a lower-pitch prop like a 5×4.3 v1s.
A larger and heavier motor like 2207, can handle a larger prop and provide maximum straight-line performance, but it will also demand more power from the battery. It’s important to keep in mind that as you increase the size of the prop, you will also increase the power demands on the battery and the motor.
When testing a new prop, it’s important to land and checks the motor temperatures, as well as monitor the voltage readout on the On Screen Display to avoid over-discharging the battery.
Installing Propellers
Installing props on your quadcopter requires a tool to tighten or loosen the propellers. An 8mm wrench or socket wrench will work, but it’s recommended to use a dedicated prop tool such as the Piroflip branded one.
Pro Tip: A pro tip is to keep multiple prop tools with you. It’s easy to misplace or forget a tool, so having a backup can ensure that you can change a prop even if you’ve misplaced one. For smaller T prop sizes, you will want a 1.5mm hex driver. This will make sure that the props stay tight and secure during flight, and can be easily removed and replaced when needed. It’s important to have the right tools on hand to ensure you can make repairs or adjustments as needed while out flying.
Propeller Direction
There are two propeller direction options: traditional and reverse. In the traditional beta flight setup, all propellers turn inwards. In the reverse setup, the propellers turn outwards. Both options should feel the same in the air, but the reverse setup can help to push the quadcopter away from objects, while the traditional setup will pull it in.
However, the downside to the reverse setup is that it can throw debris such as cut grass, dirt, or grime into the center stack of the quadcopter when landing. It’s essential to consider the environment in which you’ll be flying and choose the propeller direction that best suits your needs.
When installing propellers, it’s important to be aware of the direction they’re facing. In traditional mounting, the blade should point down on the left side when viewed straight on and be mounted on the top left. If the blade points down on the right side, it should be mounted on the top right.
The rear propellers are installed in the same way, across the diagonal. This is one method to remember the orientation of the propellers, but you may find other methods that work better for you. It’s important to keep in mind that the traditional mounting may be preferable if you fly near a lot of trees as it can reduce the chance of debris being thrown into the center stack of the quadcopter when landing.
Size Recommendations
Indoors
Quadcopter propellers, also known as props, play a crucial role in determining how your aircraft flies. The size, pitch, design, and weight of the props can greatly impact the power, grip, efficiency, speed, maneuverability, and durability of your aircraft.
When choosing props, consider the number of blades, the material they are made of, and how they match up with your motor. When installing props, make sure to have the right tools and pay attention to the direction of the props. Also, it’s important to keep in mind that the propeller’s size also varies, 31mm or 40mm are the whoop class sizes and are typically safe to fly indoors. Always test new props and keep an eye on your battery to avoid over-discharge.
Small Playground
When it comes to quadcopter props, I personally prefer the 2.5” size. This size is perfect for a 4S setup with a target weight of 80-100 grams dry weight as it provides enough speed for a fun flight, yet the craft remains relatively light. This size is ideal for flying in an empty playground.
Another great option is the whoop class due to its 25-35 gram weight and the added protection of ducted guards, which can prevent damage in case of impact. My top choice in this category is the Gemfan 2.5” 2540 Flash series prop. Many pilots also prefer the attractive design of the HQ prop.
Large playground
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 comes 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.
Racing
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.
Freestyle
Like racing the 5” is the standard, but often different pitches can be popular for additional response preferred over top-end speed.
Long Range
When it comes to 6″ and 7″ props, these sizes will require more power, but experienced long-range pilots have discovered that by pairing them with a large battery and the appropriate mid-KV motor, they can achieve extended flight times. Popular choices among 6″ props include the HQ 6×4 and Dal 6×4, with the latter being known for its smooth flight but less durable than 5″ options. When it comes to 7″ props, the HQ 7×3.5 is a good option for high throttle ranges, but for overall versatility, the Dal 7x.56 is considered to be the best. One important thing to keep in mind when going for 7″ or larger props is to look for ones with thicker blades, as suggested by the long-range community.
Wings
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 the props?
When a crash occurs and a prop becomes bent, it’s common to bend it back into place and continue flying. Some prop models may return to their original shape and remain undamaged, while others may retain a crease. Any damage such as creases, cuts, nicks, or missing chunks will negatively affect flight performance. The latest Beta Flight software with dynamic filters can help mitigate some of these issues, but it’s important to be aware that these scenarios may put additional stress on your electronics. If you are running low on props, it’s possible to continue flying, but it’s crucial to always check motor temperatures when landing to ensure that any damaged props are not causing overheating.
It is important to avoid risking damage to expensive motors or electronic speed controllers by replacing inexpensive props when they are damaged. As a general rule, if you have any doubts about a prop’s condition, it is best to replace it. Keep in mind that newer props typically provide better, smoother, and faster flight performance. When learning to fly, it is important to avoid developing muscle memory with faulty props, so it is best to replace them as needed. If you are doing light freestyle, a set of props may last a long time, but if you are racing, it may be necessary to change props multiple times in a single day to ensure maximum performance. When pushing your quadcopter to its limits with a hard throttle, it is especially important to be mindful of damaged props as they may put your electronics at risk.
It’s important to always keep a good supply of props on hand. Running out of props can quickly ground your flights. To avoid this, it’s a good idea to stock up on your favorite props, especially when they are on sale. By taking advantage of bulk discounts and seasonal sales, you can get the most bang for your buck. Consider purchasing 20-40 sets at a time to keep a large stock.
Conclusion
As an FPV pilot, it’s important to have a variety of props on hand. While it’s a good idea to have a favorite set and stock up on them, it’s also important to try new options in order to find the best balance of control, speed, durability, and cost. Finding the perfect prop that lets you fly to your full potential is a constant journey. To get the best value, I take advantage of bulk pricing discounts and order 20-40 sets at a time, keeping a large stock. This allows me to combine bulk discounts with seasonal sales and stock up at the lowest price possible.