Proper Prop Care: Your Drone Maintenance Guide

Something that people often overlook with their drones is how to care for the props so they last longer, get more time in the air (efficiency), and, you know, don't shatter mid-flight and cause a crash...!

When do I need to replace my drone props?

Drone propellers are not indestructible!  Remember, that when you land in a field of peas, or snip off some branches on a lilac bush on your landing, there's a good chance that you're causing damage to your props.  Props are not meant to come into contact with stuff.  Period!

But in reality, your drones propellers will frequently end up shearing off the odd blade of grass, or dandelion, and it is quite common to bring'er in for a perfectly soft landing, only to see that the blades are covered in bug juices...

In all likelihood, your props are probably going to be fine in the above cases.  If you clip a tree branch, however, or something along those lines, you will likely be looking at a replacement.

You should always have at least two sets of spare props!

Props are cheap; especially compared to the cost of replacing a broken drone.  It costs around $30-40 for a new set of props.  There is no reason that you should have several $250+ batteries, and only one good set of props.

You need to understand that a drones propellers spin at insanely fast speeds (nearly 12000 RPM at max exertion).  When you fly at full speed, and then "slam on the breaks" - or descent and then ascent rapidly - you are putting a HUGE amount of stress on the props.  You can't tell by looking at the drone, but the plastic is bending like crazy all throughout the flight as the blades slice through the air.  All it takes is the slightest scratch on a critical section of the blade to cause the plastic to fracture...

So you're wondering:

How do I properly maintain my drone props?

First things first, from a safety standpoint, you should inspect your props after/before each flight for any hairline fractures, chips, dents, or scratches.  Also, you should be cleaning off any bug juice that has been deposited on your props (this often happens when flying in the evening when the mosquitoes, dragonflies, and gnats start to swarm.

You should also look for any discoloration in the plastic, and other visible changes in the properties of the plastic (texture, shape, sheen,etc.).  If you notice anything that makes you question the integrity of the blade - toss it.  It is not worth the consequences.  Which brings me back to my recommendation - always have 2 spare sets of props.  You won't feel as bad about replacing a single prop.

You should log your props like you log your batteries.

It is important for pilots to keep log books, tracking hours on the machine, battery charging records, usage times for batteries, etc.  People often don't think about tracking the usage of your props.  You may think this is overkill, but if you track information about your flights already, it shouldn't be much more effort to track when a prop begins it's operational life.

Start dates and end dates, that's all you need.  Number your props with non-corrosive permanent ink on the underside near the hub.  Mark down the first day that a prop is used - that's it.  If you keep a running tally (see below), then you can feel more comfortable switching out a single propeller.

Your prop log doesn't need to be any more complicated than this:

UAV Pilots Propeller Log

Propeller #: 6
Date of first use: 4 Nov 2016
Date of last use: 15 Jun 2017
Notes: Hit a tree (replaced 2 props)

Propeller #: 7
Date of first use: 2 Mar 2017
Date of last use: 15 Jun 2017
Notes: Hit a tree (replaced 2 props)

Propeller #: 8
Date of first use: 4 Jul 2017
Date of last use: 
Notes: replacement for "tree incident"

etc.

It is as simple as that, and you can protect yourself against possible litigation if anything ever goes wrong.  Always keep in the back of your mind that if anything were to go wrong, there are several parties who are directly, or indirectly trying to point the finger at your - whether it is your fault of not!

So protect yourself by running a tight ship!

What about the wear and tear that affect a drones propellers?

All it takes is a small scratch to cause a propeller to essentially discintigrate in mid air...

All it takes is a small scratch to cause a propeller to essentially discintigrate in mid air...

Sometimes your props can get damaged if they are left in the sun too long.  It happens!  You fly your drone at the family picnic, then you leave it sitting next to the picnic blanket in the blazing sun while you head off for a game of beach volleyball.  The plastic is not meant to undergo heat like that, and the plastic can break down if it is sitting in the sun like that every now and then.

Store your drone in it's case, in a shady place if you're out on a hot day with it.  A black box will get extremely hot inside (that kind of heat is terrible for batteries by the way!) if it is left sitting in the sun!  Never do that!  Be mindful of the boxes placement in the car as well - if it is in the truck in full view of the sun for an extended period of time, you could be literally cooking the batteries and sensitive plastics inside the box...

The biggest thing is to be aware of the sensitivity of the props.  Don't underestimate how fragile they can be!  Always take care with every aspect of your drone to mitigate risk!

It is also a good idea to replace your drone props every year or two (depending on how much use you are putting on your machine). 

What else do I need to know about drone maintenance?

To learn more about how to properly care for and maintain your drone propellers, batteries, air-frames, cameras, sensors (and more!), please see our other blog articles such as "Is it too hot to fly my drone?", "Props and Drops: Why Drones Fall From the Sky," and "Weather: The Drone Killer"

You can also learn how to be a Transport Canada certified drone pilot, by registering for the M3 Aerial UAV Ground School.  Learn more about our Ground School here.

Matthew Johnson

M3 Aerial Productions, Wolseley, MB,

I am a professional educator, serving member of the Canadian Armed Forces, UAV pilot, and owner of M3 Aerial Productions.

I am pleased to provide the community with amazing images they have never seen before, of their homes, farms, cottages, and more.