Propellers are a vital part of any FPV drone, and understanding the fundamentals is crucial for getting began within the passion. The appropriate propellers could make your drone fly quicker, smoother, and extra effectively, whereas the incorrect ones may cause instability and poor efficiency. On this information, I’ll break down every part it’s worthwhile to learn about FPV drone propellers and share my prime suggestions.
Propeller Suggestions
Propellers are available in varied designs and sizes, every tailor-made for particular flight types and functions. Elements like pitch, form, and materials considerably affect efficiency. After years of testing and expertise, I’ve narrowed down a few of the greatest propellers for various use circumstances.
Greatest 5″ Props
Greatest 5″ Props for Sub250
Greatest 7″ Props
Greatest 3″ Props for Freestyle
Greatest 3″ Props for Cinewhoops
Greatest 3.5″ Props for Freestyle
Greatest 3.5″ Props for Cinewhoops
Greatest 2″ Props for Cinewhoops
Greatest Tiny Whoop Props
For Tiny Whoop propeller suggestions, take a look at my suggestions right here: https://oscarliang.com/best-tiny-whoop/#31mm-Propellers-for-65mm-Whoops
How Does a Propeller Work?
Propellers (or simply “props”) generate thrust by spinning quickly, pushing air downward. Every blade has an airfoil form, making a stress distinction: decrease stress above and better stress under. This distinction generates elevate, propelling the drone upward or ahead.
The entrance fringe of the blade known as vanguard, which cuts into the air first. It splits the airflow, directing some over the curved floor (producing low stress) and a few underneath the flatter facet (greater stress). The rear fringe of the blade known as Trailing Edge, the place the airflow recombines. The mixed stress distinction throughout the blade surfaces generates elevate.
Enjoyable Truth: FPV drones can’t fly in house as a result of there’s no air for the propellers to maneuver.
Understanding Propeller Specs
FPV drone propellers are usually outlined by three foremost dimensions: dimension, pitch, and blade rely. These are sometimes written as a set of numbers, equivalent to 5x4x3 or 5040×3.
Measurement (Diameter)
The totally different propeller sizes
The primary quantity, just like the 5 in 5x4x3, represents the diameter of the propeller in inches. That is the diameter of the round space the prop creates when spinning.
- Bigger Props: Generate extra thrust as a consequence of a bigger floor space however require extra highly effective motors. In my expertise, with the suitable FPV drone motor, bigger propeller are typically extra environment friendly.
- Smaller Props: Produce much less thrust however are simpler on the motor.
FPV drone frames are often categorized by propeller dimension – the most important propeller they will run. You need to all the time use the supposed propeller dimension in your body to maximise efficiency.
Pitch
The second quantity, such because the 4 in 5x4x3, represents the pitch of the propeller. This refers to how far the prop would theoretically transfer ahead in a single rotation if there have been no air resistance (measured in inches). It’s much like how a screw strikes by means of a strong materials with every flip.
- Low Pitch Props:
- Simpler to spin by means of the air, enabling faster RPM modifications.
- Present extra responsive management and generate much less propwash vibration.
- Requires much less motor torque and attracts much less present.
- Transfer much less air, leading to decrease thrust and prime velocity.
- Excessive Pitch Props:
- Transfer extra air per rotation, creating larger thrust and permitting for greater prime speeds.
- Require extra torque to vary RPM, which might scale back responsiveness if the motor struggles to supply sufficient energy.
- Sometimes much less environment friendly than decrease pitch props.
How Many Blades?
The third quantity (e.g., the 3 in 5x4x3) signifies the variety of blades on the propeller. Widespread choices embody:
- Two-Blade Props: Recognized for effectivity and low drag, supreme for long-range flying as a consequence of lowered present draw and higher flight time.
- Three-Blade Props: Supply a steadiness of thrust, agility, and effectivity, the preferred alternative for FPV drones, offering glorious grip and secure efficiency.
- 4-Blade Props (or Extra): Generate extra thrust and stability however are much less environment friendly, generally utilized in small cinewhoops for lifting heavier payloads whereas sustaining a compact kind issue.
Including Extra Blades
Rising the variety of blades successfully will increase the floor space, permitting the propeller to provide extra thrust. That is much like utilizing a bigger propeller however you may match it in a smaller disk space. Nevertheless, with extra blades it requires extra torque kind the motors to spin it. If the motor isn’t highly effective sufficient, it reduces responsiveness. It could possibly additionally scale back your flight time considerably as a result of greater present draw.
Widespread Makes use of
For FPV drone pilots, each two and three-blade propellers are common choices. Most pilots desire three-blade propellers for racing and freestyle, as they’ve a extra balanced efficiency when it comes to effectivity and energy, they supply extra grip within the air as a result of further floor space in comparison with two-blade. Then again, two-blade is often extra environment friendly as they creates much less drag and draw much less present, therefore they’re extra common for lengthy vary builds.
There are propellers with greater than 3 blades, equivalent to quad-blade, 5-blade and hex-blade propellers. Quad-blade propellers are stated to be nice for indoor tracks and cornering, however they’re much less environment friendly than tri-blade and spin at a decrease RPM at a given energy. Hex-blade propellers are usually not really helpful for regular flight as a consequence of its excessive inefficiency, however micro cinewhoops generally use propellers with excessive blade rely to enhance energy with out sacrificing their compact kind issue.
Weight
The burden of a propeller considerably impacts drone efficiency. Typically, lighter propellers provide higher efficiency as a consequence of their decrease second of inertia, permitting motors to vary RPM extra rapidly. This makes your drone really feel extra responsive and nimble. Heavier propellers have extra mass on every blade and require a extra highly effective motor to spin them. This could result in greater torque loading, making the motor work more durable and presumably lowering general efficiency, together with responsiveness and effectivity. Lighter props additionally work higher with a wider vary of motors as a result of they require much less torque to spin up.
The burden distribution of the blades additionally issues. With the middle of mass nearer the hub makes the prop simpler to spin and cease, bettering responsiveness. Nevertheless, meaning the tip can be the thinner and could also be extra vulnerable to breaking in crashes. With the load nearer to the tip, you’d expertise larger drag and makes it more durable to speed up or decelerate, decreasing agility.
Propeller Rotation
Propeller Route: CW and CCW
Propellers are designed to spin in a particular course: both clockwise (CW) or counter-clockwise (CCW). The one exception is 3D props, which might spin in each instructions however are utilized in area of interest purposes.
In a quadcopter, two motors spin CW and the opposite two spin CCW, so it’s essential to match the propellers to the motors primarily based on their supposed course of rotation.
Enjoyable Truth: Why Two CW and Two CCW?
You would possibly surprise why FPV drones use a mixture of clockwise and counter-clockwise propellers.
Two propellers generate CW torque, whereas the opposite two generate CCW torque, successfully canceling out the rotational forces. With out this counteraction, the drone would spin uncontrollably in the other way of the motors—very like a helicopter with a broken tail rotor (a state of affairs you’ve doubtless seen in motion pictures).
Moreover, this opposing torque can be utilized to create rotational motion for the quadcopter (aka yaw motion).
To find out the course a propeller ought to spin, have a look at its vanguard (the facet that cuts into the air) and trailing edge. The propeller’s form and curvature point out the supposed course of rotation. Some propellers are additionally labeled with CW or CCW close to the hub for straightforward identification.
When you mount a propeller within the incorrect course, it’s going to push air within the reverse method, inflicting the drone to flip over or fail to take off.
FPV drone propellers are usually offered in packs of 4: two CW and two CCW.
Varieties of Propeller Mounting
Typical FPV drone motors use one of many three widespread mounting strategies: Prop Nuts, T-Mount, and Press Match. Every sort has its benefits and is fitted to particular drone sizes and purposes. Be sure you perceive which setup your motors use earlier than choosing up propellers to keep away from incompatibility.
Prop Nuts
Prop nuts are the commonest mounting methodology for five″ FPV drones and bigger rigs. The propeller is positioned onto a motor shaft with an M5 thread and secured with a self-locking nylon nut.
T-Mount
In T-Mount setups, the propeller is secured to the motor bell utilizing two small M2 screws. The motor shaft, usually 1mm or 1.5mm in diameter, helps middle the prop. The light-weight design is right for smaller, much less highly effective drones. It presents a safe match with out requiring massive threaded shafts or nuts. This mounting is common in small 2″ to 4″ FPV drones.
Press Match
In press-fit mounting, the propeller is pushed onto the motor shaft utilizing friction to carry it in place. Motor shafts are usually 1mm or 1.5mm in diameter. No screws or nuts are wanted, decreasing weight and makes altering propeller easy. Nevertheless, propellers could fly off if the motors spin too quick, or in collisions. That is common in toothpicks (ultralight) drones and tiny whoops.
Materials
FPV propellers are usually produced from sturdy plastic, particularly polycarbonate. This materials is light-weight, versatile, and resilient, permitting propellers to bend or warp in crashes with out breaking simply. It’s a really perfect alternative for the calls for of FPV drones.
There are additionally propellers produced from carbon fiber or wooden, which supply elevated stiffness and precision. Nevertheless, these are typically utilized in planes or bigger multirotors that aren’t supposed to crash, as they’re dearer and susceptible to break.
Stick to plastic props—they’re reasonably priced, straightforward to exchange, and well-suited for many flying types.
Tips on how to Set up Propellers?
Right here’s a step-by-step information to correctly putting in propellers in your FPV drone:
1. Verify Motor Orientation
By default, Betaflight expects the motors to spin in particular instructions, as proven within the diagram under (you may also discover this diagram within the Motors tab in Betaflight Configurator).
- Set up CW props on the front-left and rear-right motors.
- Set up CCW props on the front-right and rear-left motors.
Professional Tip: To make it simpler to recollect, all entrance props spin towards the FPV digital camera, whereas rear props spin towards the again of the drone.
2. Determine the High and Backside of the Propeller
- The prime facet of the propeller is usually shiny or shiny, and close to the hub, it might function extruded textual content just like the mannequin or dimension numbers.
- The backside facet usually has a matte end.
Ensure that the shiny/textual content facet faces up when putting in the propellers. If the props are mounted the wrong way up, the drone’s efficiency will probably be severely lowered—or it would flip over once you attempt to take off.
3. Match Propellers to Motors
Guarantee CW propellers are mounted on CW motors, and CCW props are mounted on CCW motors. Incorrect set up may cause the drone to flip over when taking off.
4. Safe the Props
Connect the props securely utilizing the offered screws, lock nuts, or different fasteners. Unfastened props can fly off mid-flight, resulting in a crash.
5. Double-Verify Set up
Spin every propeller by hand to substantiate it’s put in within the appropriate orientation. When spinning, every prop ought to push air downward.
Understanding Props In and Props Out
FPV drones will be configured in two methods: props in or props out, relying on the course the propellers spin. The default configuration in Betaflight is props in, and for those who reverse the instructions of all 4 propellers, it’s props out.
This configuration impacts airflow and the way particles is thrown away from the drone. You’ll be able to study extra about the advantages and trade-offs of every configuration in my detailed information: https://oscarliang.com/reversed-motor-prop-rotation-quadcopter/
Pusher Configuration
The pusher configuration is widespread in Cinewhoops, the place the motors are mounted the wrong way up, and the propellers “push” air upward as a substitute of pulling it down.
This configuration does not have an effect on how props are mounted. You continue to observe the identical guidelines for matching CW and CCW props with the proper motors primarily based on their rotation course.
Tips on how to Select Propellers
FPV drone sizes are usually categorized by the utmost propeller dimension that can be utilized in that body. The most well-liked FPV drone dimension might be 5-inch as a consequence of its versatility, as it may be used for racing, freestyle, cinematic and lengthy vary. It could possibly comfortably carry a full-size GoPro digital camera, thus it’s usually used for capturing cinematic pictures as effectively. The 7-inch builds are extra fitted to long-range flights as a result of it could actually carry a a lot bigger battery and the bigger 7″ propellers are sometimes extra environment friendly that smaller 5″. I gained’t go into an excessive amount of element right here, you may find out about all of the totally different drone sizes on this put up.
Thrust
Thrust is measured in grams. On your drone to hover, the propeller wants to provide not less than 1 gram of thrust for each gram that your drone weighs. To carry out stunts, and even simply to take off or fly ahead, your drone wants greater than 1 gram of thrust per gram of weight.
Propellers produce extra thrust after they spin quicker and fewer after they spin slower. The velocity of the drone additionally impacts the quantity of thrust produced. Some props carry out effectively when the drone is stationary, however not so effectively throughout a cruise, whereas others carry out effectively at excessive speeds however poorly when hovering. You desire a prop that balances these elements and might create a great quantity of thrust at totally different speeds.
To search out one of the best prop in your drone, search for motor thrust checks to see what prop dimension work greatest together with your motor. Needless to say props carry out wildly otherwise when strapped to a thrust stand in a static setting in comparison with after they’re really flying by means of shifting air. Props can produce 20-30% much less thrust within the air than on the bottom.
To precisely assess prop efficiency, it must be examined on the velocity your drone usually flies at. Nevertheless, few individuals have entry to wind tunnels for such a testing. So, take efficiency checks with a grain of salt as they is probably not an correct illustration of real-world use.
Smoothness
Within the passion, individuals usually use the time period “smoothness” to explain the standard of a motor or propeller. It’s not one thing that may be measured quantitatively, however extra of a sense that pilots have. In my expertise, decrease pitch props are typically smoother as a result of the motor can change RPM extra simply and rapidly. This permits the drone to reply quicker to appropriate errors and reduces one thing referred to as “prop wash”.
Pace
A propeller that creates a number of thrust with excessive pitch doesn’t essentially make a drone quicker than a decrease pitch propeller that generates much less thrust. Because the propeller’s velocity will increase (which is measured in rotation per minute – RPM), so does the drag, requiring extra torque from the motor to show.
The theoretical most velocity of an plane will be calculated utilizing the equation:
Max Pace (in inch per second) = Max RPM * Propeller's Pitch / 60
In actual life, elements equivalent to air resistance, head wind, and angle of assault and many others can all have an effect on a drone’s velocity.
Thrust impacts acceleration and angle of assault, whereas RPM impacts prime velocity. To attain one of the best velocity in your FPV drone, you want a steadiness between thrust and RPM.
Are Bigger Props Higher?
1. Responsiveness: A bigger prop means a better second of inertia, resulting in lowered responsiveness. That is notably noticeable when utilizing motors that usually drive 5-inch props just like the 2207 dimension. On these motors, a 7-inch and even 6-inch prop will probably be much less agile in responding to fast, sharp management inputs in comparison with a 5-inch prop. You will want a much bigger motors to compensate however it’s going to add weights and requires extra highly effective battery and electronics.
2. Thrust and Effectivity: Bigger props generate extra thrust, making them extra environment friendly – they will carry extra weight, even with the identical motor. The elevated effectivity means you get extra thrust for a similar energy or the identical thrust at a decrease energy requirement.
3. Vibration: As you improve prop dimension, anticipate extra vibration. That is amplified by bigger, much less stiff frames.
4. High Pace and Prop Wash Dealing with: Bigger props are likely to have a decrease prime velocity however higher prop wash dealing with. Nevertheless, they’re usually extra environment friendly, able to sustaining greater speeds over longer intervals.
Angle of Assault
The angle of assault refers back to the angle at which air meets the propeller blades throughout flight, and this will considerably affect the effectivity of your propellers primarily based in your drone’s perspective and velocity.
Hovering and Low-Pace Flight
When a drone is hovering, the airflow is primarily vertical, and the propeller blades depend on their pitch to generate thrust. A decrease pitch propeller is mostly extra environment friendly on this state of affairs, because it strikes air easily with out requiring excessive torque. For instance, if the pitch is simply too excessive (e.g., near 90 levels), the propeller finally ends up “slapping” the air slightly than effectively displacing it, leading to wasted vitality and lowered thrust.
Ahead Flight and Excessive-Pace Cruising
Because the drone tilts ahead to fly, the angle of assault modifications, and air begins coming into the propeller blades at an angle slightly than instantly from under. At this level, Increased pitch propellers develop into more practical as a result of they’re higher suited to displacing air in ahead movement. They generate extra thrust with every rotation, making them supreme for drones that keep excessive cruising speeds or want fast acceleration. In case your objective is to cowl lengthy distance as a substitute of lengthy flight time, attempting some greater pitch props could be a good suggestion.
Discovering the Optimum Setup
It’s only a generalization, it’s completely essential to experiment with totally different props to seek out the optimum setup in your particular drone setup and flight model.
Climate and Temperature
Chilly climate poses vital challenges for drones. As defined in our information “Tips on how to fly FPV within the winter“, not solely does it negatively affect battery efficiency, however it could actually additionally have an effect on propellers. Relying on their materials, propellers could stiffen and develop into brittle in chilly temperatures, rising the chance of breaking upon collision.
Influence of Altitude
Altitude can drastically have an effect on air density and, consequently, the efficiency of your FPV drone. In areas of decrease air density, equivalent to excessive altitudes, you’ll expertise much less thrust from the identical motor RPM. This ends in the drone feeling extra sluggish and fewer highly effective, much like the impact of utilizing lower-pitch propellers. Subsequently, when flying at excessive altitudes, it’s advisable to make use of higher-pitch propellers to compensate for the lowered air density.
Influence on Tuning
Altering propellers can affect your drone’s PID and filter tuning. Props of various design, dimension, pitch or blade rely can have impact on RPM, throttle/thrust linearity, vibration and many others.
Say in case you are simply swapping out the HQ 5×4.3×3 with some Gemfan Hurricane 51466, it’d in all probability nonetheless be flyable, however in case you are a perfectionist you in all probability need to tune your quad for a particular sort of props.
The distinction is much more pronounced once you use props of fully totally different dimension or blade rely. For example, 2-blade propellers are likely to have a stronger 2nd harmonics in motor noise band, whereas for 3-blade the third harmonics is often stronger than the 2nd.
Noise Issues
The noise and sound profile of propellers is an often-overlooked side when choosing props in your FPV drone, however it could actually considerably affect your flying expertise—particularly in city areas or indoor.
Elements That Have an effect on Propeller Noise:
- RPM (How Quick It Spins): Increased RPM creates higher-frequency noise, usually perceived as a loud whine. Some cinewhoop would use props with a better blade rely with the intention to scale back RPM whereas sustaining the identical thrust output, which may end up in a quieter drone at the price of effectivity.
- Propeller Design: The form, pitch, and floor space of the blades have an effect on airflow and noise. Wider or thicker blades could create a deeper sound, whereas thinner blades will be extra high-pitched. Toroidal props have a singular form that produces a softer, extra nice sound profile to the human ear. Be taught extra about them right here: https://oscarliang.com/toroidal-propellers/
- Body Design: Cinewhoops, with their ducted frames, are notably noisy as a result of method air is pushed by means of the ducts at excessive RPM. Open-frame designs typically produce much less noise compared.
Closing Ideas
Propellers are one of many best and most cost-effective parts to experiment with on an FPV drone. By understanding the fundamentals of dimension, pitch, blade rely, and materials, you may select the suitable props to match your flying model and drone setup. Don’t be afraid to strive totally different mixtures and see what works greatest for you.
Joyful flying!
Edit Historical past
- 2017 – tutorial created.
- 2023 – article up to date, URL shortened, up to date product hyperlinks.
- Jun 2024 – Added suggestions for extra propeller sizes.
- Sep 2024 – up to date merchandise.
- Dec 2024 – up to date information.
