91社区

Very few gadgets can act as both a child's plaything and a form of military surveillance, or be equally useful in containing wildfires, delivering emergency medical services and gathering aerial photography at a wedding. The versatility of the unmanned aerial vehicle (UAV) is why so many individuals, companies and organizations are investing in it...and why we can expect 3D printed drones to be taking flight in the not-too-distant future. Additive manufacturing is here to streamline the drone manufacturing process.

Commercial drones are being used across a wide range of industries. In agriculture, they can monitor livestock and irrigation systems. Retail companies are making plans to deliver products using UAVs to shorten the time between order placement and customer receipt of goods. Drones equipped with scientific equipment are used to observe storms and other natural disasters. Cartologists and surveyors utilize advanced 3D imaging equipment installed in a drone to survey landscapes and terrains. These are just a few examples of what drones can do; applications and functionality will likely expand and improve when companies start using 3D printing in the drone manufacturing process. 

Additive manufacturing has already proved tremendously useful in the aerospace and defense industry. In 91社区's Aerospace and Defense Manufacturing Trends survey, seven out of 10 decision-makers stated that 3D printing has already changed the way they think and operate. Through design for additive manufacturing, aerospace and defense engineers are simplifying systems components, experimenting with new, more effective structures and much more. It's no exaggeration to say that 3D printing in aerospace and defense will be a key capability differentiator.

In some ways, 3D printing offers the same benefits in drone manufacturing as it does in any other type of manufacturing: the drone prototype can be accomplished more quickly. Time-to-market is accelerated. Easy and affordable low- to mid-volume production is achieved. There can be substantial time and cost savings. 

These benefits are needed across all industries. But there are some advantages of additive manufacturing specifically in the production of these unmanned aerial systems. 

1. Strike the Right Balance of Weight and Power 

English novelist and playwright Douglas Adams once quipped that there's a knack to flying: you throw yourself at the ground and miss. This glib advice summarizes the quandary of creating an air vehicle, especially one like a drone that's designed to carry equipment, parcels and other cumbersome payloads. 

How do you build something strong enough to fly a package any number of miles but keep it light enough to defy the raw force of gravity constantly sucking it down to the inflexible surface of Earth? 

Propelling something through the air without allowing it to hit the ground. It is extraordinarily simple - and mind-bendingly difficult. 

Achieving an aerodynamic, minimum operational weight is one of the biggest challenges in drone design and production. Drones require a delicate balance between weight and power. Right now, many drones face a problematic cycle. Namely, they operate by battery, and while carrying payloads, they require greater reserves of power. To generate more power, they require bigger batteries. But bigger batteries add weight, which must be counteracted with more power, which requires bigger batteries, which requires more power, which...well, you get the idea.  It is an unforgiving spiral in the wrong direction.

Additive manufacturing enables companies to print complex geometries, such as a lattice design. Lattices are two- or three-dimensional micro-architectures comprised of a network of nodes and beams (or struts) that can dramatically reduce the weight of a product while retaining structural integrity. 

The lattice structure may be relatively new to manufacturing (enabled by the advent of 3D printing about three decades ago), but it isn't a new concept. The Eiffel Tower - construction started in 1887 - relies on a lattice structure to keep its 1,063-foot peak rising high above the Champ de Mars.  

But that isn't the only way 3D printing can reduce drone weight; additive manufacturing also allows part consolidation and creating tight packaging of subcomponents. For example, a fan within a ducted cooling system is made up of as many as 73 labor-intensive and time-consuming parts. Through Design for Additive Manufacturing (DfAM), this fan can be consolidated down to a single part. But the benefits go beyond design. This capability allows manufacturers to optimize the mass of UAVs. 

2. Utilize Composites (and a Range of Materials) 

Today, almost all UAVs are incorporate carbon fiber composite material. The use of carbon fiber goes back to 1963, when the costly material was reserved exclusively for military aviation and spacecraft construction. Lightweight elements of carbon fiber gradually replaced heavy metal components, enabling greater acceleration and higher speeds.  

Although carbon fiber is a strong material option for general use, manufacturers need to consider a wide range of criteria when selecting drone material. For instance, the stiffness-to-weight ratio (also called "specific stiffness" or "specific modulus"). This refers to how much a material will bend when loaded down with weight, a huge concern for aerospace engineers. 

In aerospace applications, stiffness is crucial. For one, the hardware structure must possess high structural stiffness to maintain its aerodynamic shape. Second, rotating blades such as rotors, propellers or engine fan blades and structures undergoing pressurization cycles require high stiffness or else the thrust distorts the blade profile and reduces propulsion efficiency. 

When it comes to reliable drone materials, it's hard to beat composites. Because drones are unmanned aircraft, they need to be able to communicate with ground stations through either wireless or satellite communications. Composites can be adjusted to absorb certain electromagnetic frequencies and pass other frequencies. For this reason, they're often used to construct structural, weatherproof enclosures ("radomes") that protect the transmit and receive antennas.

Composites are a fast-growing material in 3D printing. Almost 70% of 3D printing decision-makers in the defense and aerospace industry are using composites. Although composites can also be used in traditional manufacturing methods, there are several drawbacks: the need for the manual layup of the layers of a composite and the use of expensive curing equipment and tooling, like molds. With 3D printing, this process can be automated and streamlined. It is by far the more efficient method. 

But as the applications of drones continue to increase, manufacturers may need to explore more material options. Some up-and-coming cases for drone usage may require certain specifications and abilities. For instance, firefighters can use UAVs to monitor and help control the spread of wildfires. In this situation, it's necessary to utilize a heat-resistant material to avoid damaging the drone or creating an environmental hazard. 

And who knows what materials may replace composites in the future? Almost 60% of respondents in our aerospace and defense survey said that they are investing in innovative materials, and there's no telling what new engineered materials may emerge. 

3. On-Demand Manufacturing and Repair for Military Drones 

In its , Teal Group (a market analysis and forecasting group specializing in aerospace and defense) identified UAVs as "one of the most dynamic sectors" in the defense market. The report goes on to predict almost $99 billion in worldwide military UAV production over the next decade. The U.S. military alone is expected to invest $2.7 billion in 2029 in research and development and an additional $2.5 to $3.3 billion in procurement. That isn't accounting for classified programs that could add billions of additional dollars.  

Applications for drones in the military are wide-ranging, including intelligence, surveillance, target acquisition and reconnaissance. In these endeavors, additive manufacturing may provide tremendously useful.  

On-demand manufacturing and repair may prove critical as the military comes to rely on UAVs to carry out missions. They may require a drone or spare parts (like the propeller) quickly in an area where delivery is difficult or in a situation where speed is essential. In this case, local production - enabled by additive manufacturing - maybe the quickest and most reliable method of procurement. And if the military unit is stationed at a base that contains a 3D printer, it will be even easier and faster. Large-scale as well as compact 3D printers can be quickly deployed close to operational theatres. This can be of particular value when integrating printed electronics in a layering process, a common technique used for mission-specific drone activities. 

4. Enable Drones with the Right Certifications

Delivery trucks may have a new competitor: drones. In dense cities like New York, an overwhelming percentage of all goods are delivered by truck. Every day, approximately  move into and around Manhattan. Now, we see a variety of companies seeking approval by the Federal Aviation Administration (FAA) for delivery drones that could alleviate traffic from constrained areas. 

But in order to take off (no pun intended), drones need to meet the right qualifications. The aerospace industry has a list of design and manufacturing requirements to drive high confidence in an air vehicle's reliability; that's why many companies that deliver products and services within the aerospace sector work to earn AS9100 certification.  

At 91社区, we've used additive manufacturing to meet these standards. In fact, some of the industries where additive manufacturing can offer the greatest benefit are the industries that have the most extensive qualification and compliance requirements. 3D printing keeps our products safe and compliant with regulations around the world. 

Drones are changing the world as we know it. Soon, you may have a drone-delivered package sitting on your doorstep or rely on information from a storm-chasing UAV to prepare for a hurricane. There's no telling what the future may hold, but one thing is sure: the 3D printed drone technology will be a game-changer.