The exciting world of drone propellers! While we might not think of drone props as very exciting, they are of the utmost importance.
I think of props like tires on a vehicle. Tires are the only thing connecting a vehicle to the road. Likewise, props connect the drone with the air.
Tires in good shape can serve as protection on the road and have performance benefits. Props in good shape on a drone assist in safe flight and help with flight efficiency.
Similarly, just as you would check your tires for wear, rotate them, and change them, so too with drone propellers.
While drone manufacturers don’t specifically say to change your props after x-amount of hours or flights (most likely due to liability issues), DJI support and other drone manufacturers have been known to suggest changing propellers after 200-300 flights, whereas others suggest changing props between the 300-500 flight hour range.
Many professional drone operators recommend changing them sooner than this, regardless of flight range, time, or the manufacturer.
To ensure safe flights, you should change your drone props when they have been on for too long, when they appear to be worn and/or damaged, or when they have hit an object.
We will discuss this in more detail.
Why propellers should be inspected (and changed)
If you drive, would you ever go on a long trip with the family and not check to make sure the tires on your vehicle are in good shape?
Or, conversely, if you have an extremely expensive car or SUV, wouldn’t you check the tires regularly and change them if they show signs of wear or damage? Most people do.
Why? To ensure, for the most part, that they get themselves and/or their family to their destination in a safe manner, as well as protect the vehicle from accidents.
Now think about the drones many fly. Quite a few folks fly toy drones.
Toy drones might be inexpensive, but you would still want to check the props to ensure the drone is safe enough to fly around others.
Many are buying the newer lines of DJI drones, which are rising in price, from the ever-popular DJI Mini 2 to the much more expensive DJI Mavic 3, all the way up to the extremely expensive Matrice series.
These owners check their props to ensure the drone flies safely, as well as protect their investment.
Then there are those professionals that have graduated past the prosumer lines of drones and are flying custom quads and octocopters with gear totaling tens of thousands of dollars.
These operators, likewise, are checking their props to ensure the drones are flying safely while also protecting their investments (the drone, the gear, and payloads the drone is carrying).
Regardless of the drone you are flying or planning on flying, or your budget, prop maintenance is very important and, at times, can have serious results if neglected.
What to look for (to determine if props need to be changed)
Here we will discuss some of the things to look for when determining if drone propellers should be swapped out, as well as why doing so is important in each case. Later we will also discuss suggestions for maintenance.
What is a warped propeller? Simply put, a warped prop is one that no longer conforms to its original shape. A warped propeller will appear to be slightly or even drastically bent, compared to props in pristine condition.
Propellers warp for several reasons. One of the reasons is that the propellers were left on the drone while the drone was in a protective case and the case has compressed the props, warping them.
Another reason props may warp is because of prop holders being left on for too long, thus warping the blades. Rapid heating and cooling of propellers can also cause them to warp.
When you first pick up a drone propeller, it might not be evident that the prop is warped. If the propeller is attached to the drone at the time of inspection it might be even harder to determine.
If looking at the prop doesn’t yield any results in recognizing if the propeller is warped, you just might be able to slide the props between your fingers and feel the warp, if it is pronounced enough.
If you still can’t tell, then you can compare the props on the drone with brand new, unused ones you might have on hand from when the drone was initially purchased.
If none of these ways make it apparent if the props are warped, there is another way, which we’ll discuss further down in the sound section.
If you find your props are warped, remove them from usage (i.e. throw them away!), as they can cause undesirable flight issues and possibly prove unsafe.
Cracks, Chips, Dings, and Dents
These types of damage are easier to detect than warps and occur for many reasons.
You can get dings and dents in your propellers by simply flying through the environment.
I personally fly around a lot of waterways and beaches, and I don’t fly with any sensors on. When near freshwater, many times I’ll fly close to marsh flora, and sometimes clip some of the taller plants growing out of the water.
Sadly there are times when a “not too quick” dragonfly will get in the way. That’s a prop ding or dent waiting to happen.
When I fly at the Gulf beaches, simply flying through the environment causes small dings and dents from sand at lift-off and touchdown or the ever-present sand in the air on breezy days.
Cracks and chips can occur when flying near trees, or if you happen to clip branches. Although the drone might not plummet to the ground and shatter after clipping said branches, the props may suffer damage not immediately apparent.
If you have indeed clipped a branch or another obvious object, it is advisable to immediately stop your flight and inspect all of the props.
If you don’t find any obvious dents, cracks, or chips with your finger, run your nail along the edge of the propeller, as this should pick up hairline cracks.
If you do encounter a fracture, replace the affected prop(s) immediately.
Why? Because, although there might only be a slight hairline fracture, this can turn into a crack over time and then open into a full-blown break, which could then cause a crash, which is a safety issue.
Regardless of whether you have had a crash or not, if you noticed cracks, chips, dings, and dents, it is time to retire that particular set of propellers.
This is an interesting one, as the damage to the propellers is not entirely obvious to those new to flying drones.
How can discoloration give one a hint that their props are going bad? Most drone propellers on the newer line of drones are fairly thin. Some might be translucent, others lightly opaque.
When they are left in the sun too long, or subject to drastic temperature changes over a long period, they begin to lighten in color or begin yellowing. Sometimes this is drastic, other times just slightly.
When drone props begin to discolor it means that their composition is beginning to weaken. The plastic now becomes brittle, and easier to break. As we know, most drone props are already fairly flimsy to begin with.
If you were to bend (slightly) your new props, they will “give” somewhat and return to shape. Try this with compromised (discolored) props and they will most likely snap sooner than the new ones.
If you personally have propellers that are no longer the same color as when they were new, there is a strong possibility they have gotten weaker and should be replaced to minimize the possibility of a future failure.
Like discoloration, this is another of those obscure or unthought-of areas of concern to look out for when talking about prop damage.
Just like a tire on a vehicle that might be damaged and making odd noises, so too with drone propellers. Props of the same make and type have the same pitch and sound.
However, when a prop is warped or damaged in a way not immediately obvious, there may be a change in the sound of the prop. While this is a rarer case, it does occur.
If you ever notice your propellers are sounding different than they did prior, or they changed sound during flight, check them for warps, cracks, chips, dings, or dents, as these may have occurred mid-flight.
If you spot a defect, remove and replace the props as soon as possible, to avoid future mishaps.
Implementing Prop-Check Procedures
We have seen why propeller health is so important when flying drones and when to change the props should these conditions arise. Now we will discuss best practices for ensuring our propellers are in good condition for each flight.
1. Visual Inspection
Before heading out to fly, a visual inspection of all props (those installed on the drone and those in our drone bags/cases) is a good idea.
The reason we’d want to include inspecting the propellers in our drone bags, especially the new and unused ones, is to ensure they are not warped (due to being compressed in one of the compartments) or discolored due to age.
Likewise, we’d want to check the props installed on the drone to ensure those are not warped (due to storage) or have sustained damage due to the drone being jostled or bumped while in its case.
During flights, a visual inspection of the props is not a bad idea between landings, especially if we are flying in areas full of branches and other hard-to-see obstacles that could be clipped accidentally.
Also, during our landings, we want to pay attention to hard landings or landings where the drone might have tipped over, which is something that particularly occurs in the DJI Phantom line of drones when landing hastily.
Depending on where the drone tipped when landing, for instance, concrete, we’d want to ensure the props are not damaged.
After the flight has been completed, visually and physically inspecting the propellers is suggested. You really want to look and feel for the cracks, chips, dings, and dents that might have occurred during the flights.
If any damage is discovered, discarding the damaged props should be done when possible.
2. Schedule Changing Props
This entire section is subjective and should be based on how YOU fly your drone and what the purpose of flying is.
If you are a casual flyer, spending only an hour or two in-flight a week, how often you change props would be different than someone who might fly drones as a professional, with dozens of flight hours a week.
It was mentioned earlier that, although there is no specific, hard written rule as to when to change your drone props, it is often agreed in the drone community, on the hobby level, that after a few hundred flight hours is a great time to change propellers, whether damage has occurred or not.
One might think this a waste of money, however, manufacturer (OEM) props for most consumer/prosumer drones are pretty affordable.
When you think of how a drone can be lost due to failing props, the insurance of having new propellers installed on the drone regularly cannot be overstated.
Below are links to the original manufacturer’s propeller sets for some of the more popular drones.
How to locate the number of flights your drone has
If you are flying a newer DJI drone with the DJI Fly App, and would like to change propellers after a certain number of flights or flight times, finding this information is fairly quick and painless, as you don’t even need to be connected to your drone to do so.
- Open the DJI Fly app.
- Once in, go to Profile.
- You will now see the flight information for your drone.
As can be seen here, my DJI Air 2S is used quite often for client shoots. Because of the number of flights weekly and the diverse areas flown (Woods, Beaches, etc.) I have a more aggressive schedule for changing props.
What works for me might be considered overkill by some but not enough by others.
Regardless of your drone flying habits, regularly inspecting and changing propellers is a very good habit to implement.
If your props have been on for a long period, in a drone bag or case for an extended period, chipped, cracked, dented, or dinged, or if you’ve hit something with your drone, it is definitely time to change propellers.