The Journey of Building a SLS 3D Printed FPV Drone

FPV (First Person View) racing drones offer an immersive flying experience, allowing pilots to fly through the air as if they were in the drone. This is achieved through cameras mounted on the drones, relaying live video to goggles worn by the pilots, blending the thrill of racing with precise aerial maneuverability.

In this project, the team made the strategic decision to employ Selective Laser Sintering (SLS) 3D printing technology for constructing our drone. The choice was driven by the desire to push the boundaries of drone design and performance, utilizing the precision and flexibility offered by SLS and the Sintratec S2 system. SLS uses lasers to fuse powder material layer by layer into solid structures, enabling the creation of parts that are not only strong but also lightweight and complex in design. This method provides significant advantages in terms of durability, weight, and component precision, which are crucial for the performance of racing drones.

This article will guide you through bringing an SLS 3D printed drone to life. Each step we went through is crucial to achieving a high-performing racing drone from the initial design phase to the detailed printing process using the SLS technology and through the assembly and rigorous testing phases.

The journey includes challenges we faced along the way, solutions to overcome them, and the final results of outdoor flight tests, which demonstrate the capabilities of this uniquely manufactured SLS 3D printed drone.

The Design Phase

The idea for our project came from a desire to push the boundaries of what’s possible with drone technology, particularly in the FPV racing sector. The aim was to create a drone that wasn’t just fast and agile but also represented a leap in how drones are made. This led us to explore 3D printing, a method that has yet to be mainstream in drone racing.

The design phase was intense and took about 8 hours of focused work. The goal was to sketch a drone frame that could be created using additive manufacturing, specifically Selective Laser Sintering (SLS).

This wasn’t just about trying something new; there were solid reasons behind choosing SLS. This method allows for printing parts that are robust and intricate to fit the drone’s needs perfectly. Traditional manufacturing might limit design possibilities or increase costs, but SLS opens up a new world of design freedom. You can create parts that fit together seamlessly and withstand high-speed flight stresses.

During these 8 hours, every line we drew and every measurement taken was aimed at leveraging the strengths of SLS printing. The design had to consider the material properties of the nylon 12 powder used in the printing process, ensuring that the final parts would be light enough for flight yet sturdy enough to withstand crashes.

The outcome of the design phase was a set of CAD (Computer-Aided Design) files detailing every curve, angle, and dimension of the 3D printed drone frame. These files were the blueprint for our Sintratec S2 system printer to follow, turning digital designs into physical reality.

Selective Laser Sintering (SLS) Explained

Selective Laser Sintering (SLS) is a 3D printing method that uses a precise laser to fuse small particles of material, like nylon powder, into solid objects. Picture a thin layer of powder spread out on a surface. A laser then moves across this powderbed, guided by a computer generated 2D path of the 3D model. Wherever the laser hits, the material melts and binds together, layer by layer, building up the final shape from the bottom up. This method is excellent for making complex shapes that would be hard to do with traditional manufacturing.

SLS was the team’s top choice for creating the 3D printed drone frame for two main reasons: durability and design flexibility.

Drones, especially racing ones, need to be both light and robust. The polyamide 12 nylon material used in SLS printing is perfect, resulting in parts that are tough enough to handle crashes but light enough to soar through the air. Plus, SLS lets you design and print shapes that would be almost impossible to make any other way. This means you can optimize every part of the SLS 3D printed drone for performance and weight without being limited by the usual manufacturing rules.

Choosing SLS for the drone frame allowed us to create a drone that’s unique in appearance but also superior in performance, thanks to the combination of advanced materials and the freedom to design complex, optimized structures.

From Power To Drone

Turning the design into a physical 3D printed FPV drone involved printing seven unique components. For this, we used PA12, known for its strength and flexibility. This material is perfect for parts that need to be durable yet lightweight. The entire printing process was done using our Sintratec S2 system, a sophisticated SLS 3D printer designed for professional use.

Our Sintratec S2 carefully layered the nylon powder, with the laser selectively fusing the powder into the shapes of the drone’s parts. Once the printing was complete, each of the seven parts of the drone frame had been created with exact dimensions and specifications, ready for the next steps.

However, our journey from powder to 3D printed FPVdrone wasn’t over yet. The printed parts had to be depowdered and then underwent post-processing to enhance their appearance and physical properties.

First, they were sandblasted, which cleans up any excess powder and smooths the surface, giving each piece a uniform texture. This step was crucial for preparing the parts for the final finish.

After sandblasting and polishing, the parts were coated with black acrylic paint. This gave the drone a sleek, professional look and added a layer of protection to the nylon material. The paint chosen was specifically suited to adhere well to the slightly porous surface left by the SLS process, ensuring a durable and even coat.

Assembly and Initial Testing

After the parts were printed and treated, our 3D printed FPV drone was assembled with the necessary electronics.

Each of the seven 3D printed pieces had its specific place, designed to fit together seamlessly. The team’s first task was to insert brass press-in nuts into the fuselage, the drone’s main body. These nuts were essential for providing solid and reliable points where screws could be fastened without damaging the nylon structure. We used a soldering iron to slightly melt the surrounding nylon to secure these nuts in place, allowing the nuts to be embedded firmly.

Next came attaching the arms to the fuselage. Each arm, equipped with a brushless motor, was carefully screwed onto the body, ensuring a tight and secure fit. The motors are the heart of the drone, responsible for spinning the propellers that lift and maneuver the craft. Wiring these motors to the electronic speed controllers (ESC) and ensuring everything was correctly connected was a delicate task. Soldering was required to ensure the electrical connections were solid and wouldn’t come loose during flight.

With the mechanical and electrical components in place, it was time for us to try an initial test flight, conducted indoors to minimize risks. The drone lifted off, but the celebration was short-lived. The drone crashed into a wall, breaking the antenna for video transmission. The crash revealed a design flaw: the antenna was too rigidly attached to the fuselage, making it vulnerable.

For this improvement, we turned to our TPE elastomer, a material known for its flexibility and excellent dampening properties. By designing a new antenna mount using TPE, we addressed the rigidity issue and introduced an element capable of absorbing impacts. This choice was crucial, as it meant that the antenna could flex and bend rather than break in the event of a crash, significantly reducing the likelihood of damage. The TPE’s ability to withstand repeated stress without losing its shape or functionality was a game-changer, ensuring that the drone’s communication systems remained intact even under duress.

The Outdoor Test

Before taking the drone outside, we had some fine-tuning to do. Adjustments were made to the flight controllers, and the headset was set up perfectly. These steps ensured the drone would fly well and send clear video feedback to the pilot, which is crucial for navigating during the race.

The real test came when we took the drone to an open area near the Sintratec headquarters in Switzerland. During the test flight, we also brought out a store-bought drone known for its speed and agility for comparison. To make things interesting, we set up a gate as a target to fly through, testing the drone’s precision and control under pressure.

The moment of truth arrived, and despite a confident start, we lost control and crashed behind the gate on our first attempt, causing one of its arms to break off. However, the design’s modularity meant it could be quickly fixed on the spot, allowing the test to continue.

After the quick repair, the drone was back in the air, gracefully maneuvering through the gate and demonstrating its capability to compete with commercially available drones. The outdoor test showed that, with a bit more practice for the pilot, this 3D printed drone could match, if not outperform, its off-the-shelf counterparts in terms of speed and stability.

Flexibility and Repairability

The crash put the drone’s design to the test regarding flying capability and how well it could handle accidents. The damage was manageable thanks to the modular design and the fact we can use a 3D printer for drone parts. With 3D printed spare parts on hand, the broken arm could be quickly replaced in the field, showcasing the drone’s repairability. This quick fix meant we could get the 3D printed FPV drone back up and flying in no time, turning a potential disaster into a minor hiccup.

This experience highlighted two essential strengths of the drone: its flexibility and ease of repair. Given the high likelihood of crashes during high-speed maneuvers, such features are crucial for any racing drone. Making fast repairs on the spot without needing specialized tools or parts is a significant advantage.

Conclusions and Future Directions

Looking back at the project, our SLS 3D Printed drone proved itself in many ways. Its speed and stability, even when tested outdoors against a commercial drone, were impressive. The design and manufacturing process, leveraging Selective Laser Sintering (SLS) technology, allowed for precision and durability that demonstrated the potential of 3D printing in drone construction.

Despite the challenges, such as the crash during the outdoor test, our drone’s repairability, flexibility, and the fact we can use a 3D printer for drone parts highlighted its practicality for real-world use.

There’s always room for improvement, and our project has opened up several avenues for future exploration. The next steps could be to enhance the design for even greater durability, explore the use of different materials for varied components, or even integrate more advanced electronics for better control and video transmission. The potential for customizing drones for specific racing conditions or pilot preferences also presents an exciting area for development.

For those interested in seeing every twist and turn of this SLS 3D Printed drone, the videos we created provide a closer look at the design process, the challenges overcome, and the drone’s performance in action.

If you like what we’ve done with our drone and want to try making one yourself, we’ve got good news. You can find all the parts you need to print your own drone online.

Just head over to Thingiverse to get the files.

Taking To The Skies • The Journey of Building a SLS 3D Printed FPV Drone