Lightweighting, topology optimization and digital workflows are all enabled by 3D printing.
In many respects, unmanned aerial vehicles (UAVs) represent the cutting edge of aerospace engineering: from the novel designs in airframes and powerplants to innovative methods of manufacturing. Similarly, 3D printing represents the cutting edge of aerospace manufacturing, enabling new geometries, part consolidation as well as unlocking new materials.
As such, it should come as no surprise that additive manufacturing (AM) offers many benefits to UAV design, including topology optimization, lightweighting and digital workflows. These benefits should give any engineer reason to revaluate how UAVs are designed and built – from small hobbyist and racing models to the large autonomous aircraft that are reshaping the battlefields of the 21st century.
Computational design for drones
At the dawn of the aviation industry, aerospace engineers spent thousands of hours working on blueprints, taking meticulous notes by hand with pens and pencils. The introduction of computer aided design (CAD) transformed the way engineers create aerospace components, moving them into the virtual world before being translated into physical objects.
Today, with the use of topology optimization, engineers can design drones by inputting functional constraints – such as load requirements or mounting points – and generate high-performance geometries consisting of highly complex, organic shapes. These structures would be virtually impossible to produce using conventional manufacturing methods, such as machining, especially when they incorporate fine lattices, curved channels or hollow internal features.
AM is the technology that enables these designs to be translated from digital ideals into physical components, with some smaller drone bodies being produced in their entirety in a single build. Even something as comparatively simple as a wing with an internal lattice for support would be practically impossible on five-axis mill, or at least extremely expensive.
Lightweighting UAVs with 3D printing
It’s hard to overstate the importance of reducing weight in aerospace engineering and this is especially true for drones where, particularly in the case of the smallest class, Group 1. Even in larger units, such as those deployed for delivery and other logistics applications, operators of calculate their costs down to gram given that the weight of the UAV constrains payload capacity.
Utilizing lattice structures inside wings, landing gear and even the airframes themselves, engineers can achieve high strength-to-weight ratios using a variety of materials, including not only metals such as titanium and aluminum but also polymers, such as PA-12 Nylon. These options are only available because the relevant 3D printing technologies – primarily laser powder fusion – are able to build complex geometries using a material library that is growing all the time.
It should be noted, however, that the mechanical properties of drone parts are subject to the limitations of the 3D printing process as well as the material. Fused deposition modelling (FDM), for example, can be useful for producing prototypes to test fit and – to a limited extent – function but tends to produce anisotropic parts that are weaker along the Z-axis.
Digital workflows in drone design
As just noted (and is generally well-known) 3D printing is an ideal technology for prototyping, and that includes prototypes for UAV designs. However, additive manufacturing offers even more advantages in the case of drones due to its iterative speed and design flexibility.
In the old days, even slight design changes to aerospace components could require reworked tooling, but AM enables aerospace engineers to implement design changes digitally and print them in the same day. This is particularly advantageous for companies looking to iterate rapidly on drone designs to optimize configurations for different payloads, flight durations or regulatory requirements.
Even when AM doesn’t obviate tooling by enabling engineers to 3D print drone parts directly, it can make it the design and production of tooling for drone parts much faster using CAD-driven designs for molds or carbon fiber layups. These can be leveraged to produce short-run, highly customized tooling without the expense of metal molds.
Together, computational design, lightweighting and digital design workflows demonstrate that 3D printing technologies are just as much of a game-changer for UAVs as UAVs are for the aerospace industry as a whole. In combination, the benefits of AM for drones give manufacturers a competitive edge in performance, cost and innovation.
