The Additive Manufacturer Green Trade Association (AMGTA) published its first commissioned university research project, a literature-based systematic review of the environmental benefits of metal AM. The paper, “State of Knowledge on the Environmental Impacts of Metal Additive Manufacturing,” was written by Dr. Jeremy Faludi from Delft University of Technology (TU Delft) and Dartmouth College and Corrie Van Slice, a former senior research engineer at Faludi’s lab at Dartmouth. Van Slice is now a manufacturing sustainability research engineer at TU Delft. According to its authors, the report synthesizes existing academic literature comparing environmental impacts of metal AM with conventional manufacturing methods and provides context with impacts of common metals and processing methods found in a materials database.

Key takeaways:

• While AM generally has much higher carbon footprints per kilogram of material processed than conventional manufacturing (CM) when considering the direct manufacturing process itself, impacts depend greatly on part geometry
• The need for additional life cycle assessment (LCA) studies to quantify environmental impacts to definitively compare metal AM to CM; especially direct comparisons of AM to machining, and for binder jetting and directed-energy deposition (DED); LCAs should also include more of the product life cycle

SDK connects AM to the smart factory

Stratasys software tools integrate its 3D printers in production environments with the factory floor via the GrabCAD Software Development Kit (SDK). Each SDK package includes application programming interfaces (APIs), documentation, and code samples for development partners and manufacturing customers to establish two-way connectivity between Stratasys FDM 3D printers and enterprise software applications. Users can integrate, manage, and support additive manufacturing (AM) for production of end-use parts.

Initial partners for the GrabCAD SDK program include Link3D and Identify3D.

The first two available SDK packages enable users to integrate with GrabCAD Print software and Stratasys manufacturing systems including the F900, Fortus 450mc, and F123 Series of FDM 3D printers.

6K Additive expands metal powder production team

6K and 6K Additive, developer of additive manufacturing (AM) powders derived from sustainable sources, has hired AM experts who bring extensive knowledge in quality, powder manufacturing, and process as the organization begins production of its onyx line of AM premium powders in its recently commissioned 40,000ft² lights-out facility.

Recent additions to the team include:

• Dr. George Meng, Director of Process for Additive
• John Meyer, Director of Technology, AM Products
• Dave Novotnak, Production Process Manager, AM Products
• Joe Muha, Quality Manager, AM Products

EOS, Texas A&M partner on AM professional development

Metal and polymer 3D printing technology supplier EOS has partnered with Texas A&M University (TAMU) to provide a professional development program in industrial 3D printing. Using virtual learning with conventional training methods, the additive manufacturing (AM) program offers a hands-on, expert-led training program to meet evolving industry needs and challenges.

In concert with EOS’ applied engineering group Additive Minds, the TAMU Engineering Experiment Station program takes a deep dive into the latest powder bed AM processes – such as direct metal laser solidification (DMLS) and selective laser sintering (SLS), as well as an understanding of other AM processes, materials, design, case studies, best practices, and troubleshooting. The certificate-level training program was developed by subject matter experts from TAMU (Dr. Alaa Elwany, associate professor of industrial and systems engineering and director of the metal AM laboratory) and EOS’ Additive Minds Consultants Maryna Ienina and Dr. David Krzeminski.

Aircraft can continue to fly if an engine fails however, for quadrotor drones – those with four propellers – such a failure poses a serious problem. With only three working rotors, drones lose stability and inevitably crash unless an emergency control system is used.

Researchers from the University of Zurich and the Delft University of Technology have developed a system to overcome that – if a rotor suddenly fails, built-in sensors can feed data to autonomous control systems to stabilize the drone and keep it flying.

“If a rotor fails, the drone begins to spin around like a ballerina,” says Davide Scaramuzza, head of the Robotics and Perception group at the University of Zurich (UZH) and the National Rescue Robotics Grand Challenge research unit of the Swiss National Science Foundation (SNSF), which finances the study. “The rapid rotation causes conventional controls to fail. Unless the drone has access to very precise position measurements.”

As soon as the drone starts to spin, it can no longer determine its position in space and crashes.

One possible solution is to give the drone a reference position using GPS. However, corresponding signals cannot be received in all environments. Rather than relying on a GPS measurement, the scientists use the visual information from multiple built-in cameras.

Researchers equipped quadrotors with standard cameras that recorded several images per second at a constant speed and event cameras with independent pixels only activated by a noticeable change in light. The team’s algorithms combine information from both sensors to track the quadrotor’s position. The on-board computer controls the drone while it flies with only three working rotors.

Tests showed that both types of cameras work well in normal lighting conditions.

“However, when the light decreases, standard cameras show motion blur, which ultimately causes the drone to crash. The event cameras, on the other hand, work well even in very little light,” says first author Sihao Sun and postdoc in Scaramuzza’s laboratory.

The scientists believe that their work can improve the flight safety of quadrotors in areas where the GPS signal is weak or absent.

The researchers have made their controller and algorithm open source.

Delft University of Technology

University of Zurich

Literature: Sihao Sun, Giovanni Cioffi, Coen de Visser, Davide Scaramuzza: Autonomous Quadrotor Flight despite Rotor Failure with Onboard Vision Sensors: Frames vs. Events. Jan. 5, 2021, IEEE Robotics and Automation Letter. DOI: 10.1109/LRA.2020.3048875.

Aerospace manufacturers must be aware of how technology is changing to be ready to adopt smart systems to compete at a national and global level. Smart factories gain clear visibility into process flows, and they are better able to manage the complexity of high-mix production.

Insights into how well work flows through operations allow business leaders to manage priorities if issues occur and they can make the necessary changes using process control.

What needs to happen to successfully install these systems and achieve a competitive advantage? James Crean, co-founder, president, and CTO of Crean Inc., says it’s about fully integrating three key aspects – people, processes, and technology.

“The technology is there, and it’s continuing to evolve very rapidly,” Crean says. “It’s critical to not just have a technology solution but a people solution and a process solution that goes along with that and is integrated. Technology is only one part of the equation.”

Photos courtesy of Crean Inc.

Keep the end in mind

When identifying how to adopt smart technologies, companies should develop a clear list of solid goals and objectives for specific projects.

“For business leaders who are implementing a smart factory, they need to understand that it takes an integrated approach with a cross functional team, and whether that includes outside experts or not, you’ve got to have the right folks on the team to begin with,” Crean says.

Smart factory transformation requires integrating people, processes, and technology at the same time. Crean says there can be a tendency to over-focus only on technology. To avoid this, companies need outstanding people, leading-edge technology, and modern, flexible process methods that deliver faster, establish competitive cost objectives, and target game-changing performance.

“The technology solution, in a lot of ways, is often the easiest part,” Crean adds. “But at the same time, it’s very easy to make mistakes in an ever-evolving technology space. Manufacturers must select the right technology and have a full understanding of what their goals are to ensure the technology is capable of achieving those goals.”

For example, Crean often helps clients with asset tracking. Many technology options track assets with radio frequency identification (RFID), Bluetooth low energy (BLE), ultra-wide band (UWB), magnetic loops, ultrasound, and cameras with machine learning.

Users must have the right expertise to make sure they select the right hardware tracking solution, and then they must choose the right software to deliver the data necessary for their environment. Every environment has its own factors that need to be considered.

Asset tracking helps organizations ensure the right things are in the right place at the right time, delivering data companies can use to significantly improve operational efficiency.

“You can also integrate the tracking and tracing of work in process with digital routers and digital work instructions,” Crean adds. “That can help you significantly improve productivity even more. And it can also ensure that you’re always delivering the right information to each operator as they work on a part or assembly. And, it also can help you with training and making sure the right operators are getting trained for the work they’re being asked to do.”

Process solution

With technology options chosen, company leaders must recognize that technology adjustments change the process itself. For instance, Crean works with clients who are looking to automate a manual inspection process. While they might expect that they’ll get a 10% or 20% improvement in productivity by automating their inspection process, there’s an assembly step that meters the rate of inspections at the same rate as production. Overall factory productivity won’t change even if managers record an increase in inspection productivity.

“You have to understand and analyze the process and have a solid capacity optimization analysis in hand for your process, as part of understanding how technology is going to improve your operation,” Crean says. “Otherwise, you’re wasting time, money, and resources.”

People

Successful people are at the heart of every successful business change or evolution, Crean explains. This includes corporate leaders and those at every level of their organization. Companies cannot successfully transform without skilled people who can focus on implementing that solution. People in the organization will evolve to use new tools and methods that the smart factory promises. Therefore, it’s important for technology solutions to be people centric, allowing workers to be brought into the solution as opposed to being left behind or viewed as victims of the solution.

Smart flow technology

Crean’s smart flow operating system integrates asset tracking and inventory management data to give users visibility into where everything is located to produce their product. It also gives insight into how to improve operations, delivering an essential level of control.

“We provide hands-on smart factory transformation consulting services, and we deliver an integrated, robust solution that’s tailored for the goals and objectives that our clients are trying to achieve,” Crean says. “We’ll use proven technology from a wide variety of technology providers throughout the world to help implement those solutions and ensure that they’re successful.”

Adapt to change

Focus should not only be on developing an optimized logistics operation. Demands will continue to shift as the industry moves forward, and there will be an increased need for customized products. Companies should be able to customize that product, produce it efficiently and effectively, and implement smart factory technologies that allow them to compete globally. This will position a company to be agile for the future as customers demand more customization.

“There’s a huge change that’s happening, and the future for business must include smart factory solutions in order for them to be able to compete.” Crean adds. “Are we ready for that change from my perspective? Despite a very clear uptick in interest by American manufacturers, they’re still far too many that have failed to recognize the competitive and national security imperative around retooling around these technologies.”

Pivoting is essential. Advanced tracking technology and the digital enterprise will allow companies to pivot quickly and keep their workers safe.

“Every successful technology transformation begins and ends with platform leadership, and a commitment at every level of the organization to be part of that integrated smart factory solution,” Crean says.

Crean Inc.

Integrated processes and systems

The ANCA Integrated Manufacturing System (AIMS) connects sequential processes in tool manufacturing, facilitating streamlined tool production and linking separate processes to each other and factory information technology (IT) systems.

AIMS offers functionality adaptable to each factory’s needs; from smaller scale, data-based options to the full AIMS setup across a series of machines. The server manages data flows between the elements of the AIMS system and established IT platforms, such as enterprise resource planning (ERP) systems. Users can choose from a suite of solutions to reduce production costs, resolve labor challenges, and integrate systems to improve product and process quality. AIMS transfers tools between operations with AutoFetch to fully automated tool measurement and process compensation using AutoComp, and managing data via the AutoSet hub.

ANCA Inc.

Radar sensors

DesignCore RS-6843AOP and RS-6843AOPU mmWave miniature radar sensors can implement many different algorithms to measure, detect, and track in robotics and industrial applications. The production-intent sensors feature a 1" cube form factor, heat-spreading metal body, and mounting tabs. They may be used with a PC or embedded platform for field testing, sensing evaluation, algorithm development, and application demonstrations.

Features include the TI IWR6843AOP, a single-chip 60GHz industrial radar sensor integrating a built-in DSP, an MCU, radar accelerator, and antenna array. The IWR6843AOP RF front end integrates a PLL, three transmitters, four receivers, and a baseband ADC. It covers 60GHz with bandwidths up to 4GHz and features 12dBm transmit power and 15dB noise figure or better.

The RS-6843AOP features a header for connection to optional baseboards or hosts providing additional interfaces and functionality. The interface includes I2C, SPI, GPIO, and UART connections. The main interface of the RS-6843AOPU version is a USB-C connector which can act as a power supply input and enumerate two serial UARTS, one for console and the other for processed radar returns or other algorithm output.

D3Engneering

Upgraded angle encoders

The ERA 4000 angle encoder series upgrades increase accuracy, ease of use, logistical flexibility, and are compatible with past models.

ERA 4000 angle encoders consist of a steel drum at various diameters with the 20µm, 40µm, or 80µm graduation on the outer diameter, and a scanning unit that reads the graduation. As an incremental system, reference marks are available as distance-coded or one per revolution.

Heidenhain Signal Processing (HSP) allows dynamic control of the LED, and the scanning unit learns of the signal quality coming back from the drum, then adjusts LED intensity on the next signal period. HSP operates in an analog way and increases the speed of the encoder system to 1MHz scanning, a 285% increase.

Two other upgrades to the scanning units are a status LED on the side of the scanning unit, providing unit status during mounting, and the addition of a smaller M12 connector which saves space and is more robust.

Heidenhain

The XB-1 is Boom Supersonic’s demonstrator aircraft, unveiled in October 2020, that brings the return of supersonic air travel closer to reality. Slated to begin flight testing in 2021, XB-1 is a one-third scale demonstrator for the full-sized Overture airliner scheduled to debut in 2025.

Early in the project, Boom Supersonic’s design and engineering team studied additive manufacturing (AM) to produce some of their most complex part designs.

“There are many reasons for choosing AM technology over others,” says Boom Engineer Byron Young. “Much of the time and effort in aircraft design goes into joints, the interfaces between components. By designing directly for AM, we can reduce the number of parts and joints, which also reduces time and effort. And part consolidation cuts significant weight.”

Geometric freedom

Many of Boom’s 3D-printed parts channel air using complex vanes, ducts, and louvers. Some of the air routed through these parts exceeds 500°F.

“If fast moving air is touching it, we care about that surface from an efficiency and performance standpoint,” Byron says. “So, when designing these parts, you generally start with aerodynamic profiles and then trim, fillet, and thicken surfaces to create the solid part. The resulting parts are very complex – they definitely needed to be fabricated through AM.”

VELO^3D Applications Engineer Gene Miller worked closely with both Boom Supersonic design engineers and Duncan Machine Products (DMP), the supply chain partner that handled printing and post-processing.

“The unique types of geometries Boom created for directing flow, with a focus on weight savings, couldn’t be done with sheet metal or casting or any other way,” Gene says. “To reap the benefits of complex design and weight reduction together, the only option was to do it with metal AM.”

Having worked with VELO^3D on trial parts in 2019, the Boom Supersonic team chose the company’s next-generation laser powder-bed fusion (LPBF) technology to produce:

• Printed titanium manifolds for the variable bypass valve (VBV) system that routes air released by the engine compressor to the aircraft’s outer mold line (OML)
• Exit louvers for the environmental control system (ECS) that cools the cockpit and systems bay
• Louvers that direct the center inlet’s secondary bleed flow to the OML
• NACA ducts and two diverter flange parts. NACA ducts are often used in high-speed aircraft to capture exterior air and channel it into the aircraft to cool the engine bays.

All parts were printed on the VELO^3D Sapphire system. In almost every case, the Sapphire was able to print parts directly from Boom’s CAD data, preserving original design intent.

“We did use our system’s Flow pre-print software to add some structural ribbing on the thinner walls of the NACA ducts that had to be constrained,” Gene says. “But for the most part the other components all printed as-is, with no compromise to the design.”

Byron from Boom was impressed with Sapphire’s ability to accurately produce the extremely thin-walled parts. “The Sapphire system allowed us to print walls as thin as 20 thou (0.02" or 750µm), with a surface finish that didn’t require additional machining in most cases.”

The high height-to-width aspect ratio made possible by the VELO^3D machine’s non-contact recoater system – which distributes each new layer of powdered metal to be fused by dual lasers – was another plus. To remove mass, the vanes on the center inlet’s bleed louvers were printed hollow, and the parts were designed with thin walls along long spans.

“Because our technology can print that very high aspect ratio in this kind of design, we didn’t need excess material for strength inside the structures, and we could grow those duct vanes up very high without any interference from the recoater,” Gene says.

Titanium

One of the project’s big challenges was working with the titanium material Boom chose for the 3D-printed parts.

“A positive aspect of using titanium is the material allowables at temperature,” says DMP Additive Manufacturing Engineer Aaron Miller (no relation to Gene). “There’s less loss of strength at high temperatures compared to aluminum or carbon fiber, and it has a higher strength-to-weight ratio.”

But lightweight, extremely heat-resistant titanium can be delicate and difficult to work with, no matter how it’s manufactured. If titanium is cooled too rapidly, it becomes brittle and is prone to cracking.

Titanium parts can be manufactured conventionally via casting, which has a slower cooling rate to prevent cracking, Gene notes. But the extremely thin walls in the aircraft hardware designs would have been nearly impossible to cast.

“That’s really one of the driving forces behind using 3D printing for these parts because we can print large, thin-walled titanium sections without the high scrap rate of cracked cast parts,” Gene says.

He acknowledges the learning curve. “Boom designed a part family that was new to us, really pushing the envelope for weight reduction and thin-wall geometries, and we had a lot to learn as far as printing these components from titanium and what to expect from the physics of printing. How is it going to move? What can be printed without supports? What areas needed support?”

Process control is critical

VELO^3D’s AM process optimizes the print parameters and sequences to produce robust titanium parts.

“This reduces the amount of internal stress in the substrate as the material is being deposited in the Z build-direction,” Gene explains. “It diminishes the possibility of cracking by mitigating internal stresses formed during cooling.”

Quality control is integrated throughout the entire build, starting with Flow pre-print software, executed through the Sapphire system, and validated with Assure’s quality assurance. Pre-build machine calibration is achieved with a single click, automatically checking laser alignment, beam stability, and powder-bed quality. In-process metrology monitors key metrics and flags anomalies. Comprehensive build reports for all parts are compiled for future reference.

Once Boom’s titanium parts were 3D printed, they were sliced off the build plate with sawing or wire-cutting EDM. The DMP machinists found post-processing to be relatively straightforward.

“After cutting off the build plate, we had very little to do in the way of post-machining apart from minimal support removal,” Aaron says. “You don’t have any tiny supports in small crevices or hard-to-reach places because the SupportFree technology eliminates the need for those. Parts come out of the Sapphire system almost finished, just needing a little handwork with a screwdriver or grinder. We also ream out pilot holes (on larger parts to be joined) with a mill to ensure they’re the correct size. It’s part-dependent, but probably just a half-hour of machining per part, which is not a big deal.”

Part geometries brought an additional challenge when creating fixtures to hold the parts during finishing. Aaron adds, “There’s almost no surface that’s perfectly flat or round on an aircraft, which makes them difficult to grab on to. But we used the parts’ CAD models and quickly designed and 3D-printed custom plastic fixtures (on a separate FDM printer) that were appropriately squared or rounded for us to grab with our finishing tools.”

Part finish out of the machine was tested with a profilometer, registering about 250Ra on average.

“If the customer wanted to go to 125Ra it would take just a few minutes with a vapor hone to achieve that,” Aaron says.

Finished parts were heat treated and/or hot isostatic press (HIP)-processed to enhance fatigue life. “Supersonic flight introduces a number of different phenomena and stresses you generally don’t see with conventional air travel,” Gene notes.

“The main forces being applied aren’t generally pressure loads from breaking the sound barrier,” Byron adds. “In many cases, it’s an induced strain caused by the overall structure of the aircraft flexing around your part. Parts with dissimilar thermal expansion coefficients mounted to each other can produce significant stresses. Designing these 3D-printed parts to be very thin and flexible can actually mitigate some of these issues.”

Try, learn, and iterate

The companies that successfully produced the 3D-printed parts for Boom Supersonic’s XB-1 supersonic demonstrator learned a lot from their collaboration. The Boom team found that AM was more complex than they had envisioned but could also deliver on their original design intent. Duncan Machine Products expanded their 3D-printing expertise significantly, eventually purchasing a third Sapphire machine. “We’re getting a lot of new business because of our capabilities in additive manufacturing,” Aaron says.

Boom Supersonic

Duncan Machine Products

VELO^3D