Apparently it is actually pretty easy to strap a flame thrower to a drone and start lighting stuff on fire, so surely it would be just as easy to make a drone to help put the fires out, right? It turns out no, it isn’t easy to build a drone to help fight fires. Despite there being hundreds of drone variants and designs available, in order for one to be useful in a firefighting scenario the drone would need to be customized based on what role it would be expected to fill. A customized drone design can cost upwards of $60,000, and that doesn’t include the highly specialized, and expensive, equipment that would need to be added to it.
Additionally, most commercially manufactured drones use inexpensive carbon fiber materials for the frame, which may be sturdy enough to hold everything together but will crumble if it’s crashed or collides with another object. Whether due to pilot error, or as a victim of high winds, a likelihood during a massive fire, most drones are going to end up crashing at some point. Not to mention the fact that the average battery life of a drone is twenty to thirty minutes. All of that combined makes the idea of using custom made drones a rather costly investment that would hardly be worth it.
Drones and Unmanned Aerial Vehicles (UAVs) are far more suited to less dangerous tasks that can be performed in far calmer environments. Things like aerial photography, collecting topographical data, monitoring crops, and monitoring traffic and weather conditions are all far more appropriate uses than fighting fires. Still, it isn’t hard to imagine that a drone could come in handy when firefighters are planning on the best way to deal with a brush fire or out of control forest fire. Drones could be used to monitor the movement of the fire, check for homes or people who could be at risk or trapped and even bring back useful footage and data of the fire from an aerial point of view.
It was some of these potential benefits, and the challenges that current technology offered, that inspired a team of engineering students from Melbourne University to see if they could make it work. In order to produce a drone that would effectively aid firefighters the students would need to find a way to extend the battery life and build a more durable, but lighter body and frame. If they were to succeed, they would need to build a drone that was strong enough for repeated field usage by the Victorian Metropolitan and Country Fire Brigades (MFB) and capable of hovering in place in extremely hot environments while sending real time thermal images back to the firefighters.
The students decided that the best way to extend the battery life was to change the design of a typical UAV into a shape more aerodynamically effective. Altering the shape would potentially reduce drag on the drone while in the air, and by extension make the battery last longer. They came up with a set of airfoil-shaped arms and a custom designed aerodynamic frame that would make the drone considerably lighter than one a traditionally manufactured. Because the new arms and drone frame had very unique shapes it would have been impossible to manufacture them using traditional fabrication processes, especially with a material like carbon fiber.
The team opted to have the parts 3D printed in titanium because it was stronger, lighter, could withstand high temperatures and give them more freedom to design aerodynamic as possible. They turned to the 3D printing division of Commonwealth Scientific and Industrial Research Organisation (CSIRO), Lab 22, located in Clayton Victoria for help. Thankfully they allowed them access to their Concept Laser M2 metal 3D printers.
Lab 22 experimental scientist Daren Fraser also helped the students optimize their design so it would remain light and aerodynamic, as well as keep the manufacturing costs down. The airfoil arms required a full day to 3D print, while the remainder of the titanium parts were all printed on the next day. The Lab 22 team then used a sandblaster to spray the printed parts with a titanium alloy powder that removed any loose material. The next step was an easy one, the students just had to assemble the drone and take it for a test drive.
The design was a complete success, the six airfoil arms ended up reducing drag by almost sixty percent, and the new design extended the battery life to beyond forty five minutes. Not only is that double the time of other drones, but their design is lighter and more durable as well. And even if a part is damaged after a crash or from wear and tear it can easily be replaced with a new 3D printed part. The design was so successful that the team of engineering students won an Autodesk CAD prize and a Wade Institute Entrepreneurship Prize for their work.