Modern manufacturing expo takes off with additive manufacturing

@AuManufacturing has partnered with the upcoming Modern Manufacturing Expo in Sydney in September which will showcase US-based eVTOL business, LIFT Aircraft Inc. This startup is on a mission to make flight accessible to all, which they are on their way to achieving with HEXA — a new type of aircraft that anyone can fly. The challenge was to be the first to market without compromising on safety

From the outset, a physically fast aircraft was never the priority for LIFT. Designing and developing a safe eVTOL aircraft for urban mobility in a short space of time was.

But the challenge facing this dynamic business was significant. How could they successfully blend safety, certainty, and speed in order to reach their goals?

LIFT Aircraft CEO Matt Chasen said: “A lot of different technologies have matured and lined up to make right now exactly the right time for this type of business.

“3D printing is one of them.”

This trust in newer technologies was more than just an afterthought, it had its place in the project from the very beginning said Balazs Kerulo Chief Engineer at LIFT.

Kerulo said: “The first thing I started thinking about was how we can use new enabling technologies, new manufacturing technologies, to evolve designs really quickly. We got the Materialise team involved really early on for that reason.

“At the same time, I started looking at software that could do generative design to come up with lots of design options within certain constraints that we’d then refine further.

“Generative design pairs very well with 3D printing because — like 3DP — it doesn’t really care about the old constraints of traditional manufacturing processes.”

The powerful combination of 3DP and generative design has allowed Balazs and the team to print, test, and fine-tune parts at pace, enabling rapid evolution between aircraft prototypes.

Early on in the process, the team identified an ‘ultralight aircraft’ category in the US as their ideal go-to-market strategy as they require no FAA/EASA certification and no pilot’s license to fly.

Choosing this route, however, presents other significant challenges. Most notably, minimising weight to meet classification without any compromise whatsoever on safety.

Balazs said: “We’ve got a distributed powertrain. That means we have 18 motors and 18 batteries.

“Great for safety, but it also means that the weight of any part to do with the powertrain has to be multiplied by 18.”

Coupled with this was the addition of ENDY, a unique part with the sole purpose of reinforcing the most critical joints of HEXA’s overhead rotor plane during a worst-case scenario — contributing to structural integrity during a parachute opening should the pilot need to make an emergency landing.

When activated, the parachute’s explosive canisters can expose the airframe to a momentary load of up to 11.5 g’s — comparable to that of a space launch – in that instant, the crown and its propulsion batteries will weigh almost two tons.

Unsurprisingly, it takes six ENDYs to keep it together, preventing the overhead props from being torn down and getting too close to the pilot while still spinning.

What was needed was a solution that could provide the best strength-to-weight ratio.

The development team decided from the outset that the END-Y parts should be manufactured additively — just like well over a hundred other components on the aircraft — this time choosing to print using titanium due to the part’s load-bearing requirements.

LIFT turned to to Materialise’s expertise in designing for AM. Together, they planned to leverage the freedoms of generative design and 3D printing to full effect while setting the safety factor for specific parts at much higher levels than necessary.

Solution – combine generative design with 3D printing

Based on the CAD data provided, the Materialise team first carried out a static simulation using SOLIDWORKS software. Doing so provided the comparative values they needed to redesign the ENDY using Siemens NX.

Firstly, they used the NX topology optimisation module to define the design space and the boundary conditions, such as the position of the fixation points, force attack points, and the direction and strength of the forces that the component would face in practice.

Using this information, the software created a component model with visualized force flows, from which the 3D printing experts gradually developed the new component using free-form modelling within the NX Realise Shape Tool. A few iterations later, the perfect design was found.

Bal;asz said: “The computer came up with a really good solution straightaway that we liked, and that worked.

“And that structure could really only be made using 3D printing.”

The next step was to simulate the printing process with the Materialise Magics simulation module.

Having seen the results, the engineers optimised the component’s orientation within the installation space and made some final improvements to the part and its supports.

The Materialise team then carried out a static simulation, which proved that they would withstand all loads, while the first prints showed that all length tolerances were within the DCTG 8 (Dimensional Casting Tolerance Grade).

In addition, the deformation of the component during printing was lower than that of the original design, as were the residual stresses during printing.

“Working with the team at Materialise, we confirmed the feasibility and fine-tuned the design based on their recommendations, ultimately making the part easier to print and more economical in terms of material usage,” said Balazs.

“That’s really how we’ve been working with the team ever since. We send our parts, and the feedback that comes back is very constructive and has really helped us refine designs.

“Together, we’ve managed to design and produce this part with a safety factor of 10. Incredibly high.”

This incredible machine went from prototype to flight- ready in just 13 months

Result – from dream to reality in just 13 months

Overall, LIFT Aircraft’s two initial goals — to reduce both mass and errors during printing — were met, with results that almost exceeded expectations. The final ENDY weighs about 40 percent less than the original, weighing in at 152 grams instead of 250 grams.

With six ENDY parts in each aircraft, this accounts for a reduction of almost 600 grams from that part alone. On the other hand, by significantly reducing the stresses on the support structures, the team ensured that the ENDY part no longer detaches from the support structures and building plate during printing, leading to far less waste due to rejected prints.

Together, these improvements helped LIFT get off the ground in record time. In less than 13 months, Matt and his team went from novel idea to successful first manned flight, leveraging semi-autonomous flight control, electric propulsion, and a great deal of design skill and entrepreneurial enthusiasm to get there.

All while maintaining a strict ‘safety first’ approach to every aspect of part development and production.

The final ENDY part (left) weighs about 40% less than the original (right), weighing in at 152 grams instead of 250 grams.

As one of the very first production eVTOL aircraft in the world, LIFT’s HEXA is already breaking new ground. CEO Matt Chasen believes this is a pioneering position the company is well equipped to maintain thanks to valuable lessons the team has learned and the technologies in play.

“Because we don’t have to obtain certifications, we can aim for product cycles that are much closer to what we see in the tech sector.

“We’re aiming for a cycle of two to three years, instead of 20 to 30 years, which is what’s typical in the aviation industry. And part of what enables that is 3D printing.”

Chasen said that with additive manufacturing you don’t have to invest in huge quantity orders that require molds that only make sense if you need tens of thousands of a particular part. If you’re only going to make a thousand of something, it’s much more economical to 3D print.

“And then it’s also quicker, so we can iterate faster, and that next version can come out much sooner.

“Better still, you can achieve all this and still prioritise safety. And that’s what it all boils down to.

“We’ve got a great responsibility. We’re going to be the first to launch a service where people can fly ultralight, electric aircraft with vertical take-off and landing.

“We take that responsibility really seriously. Which means we take the design and manufacturing technologies we use very seriously too.”

The Modern Manufacturing Expo takes place from 20-21 September, 2022 at the Sydney Showground, Sydney Olympic Park, Homebush. It is designed for key decision-makers and management looking to explore the latest automation and digital offerings for future growth and features a showcase of technology advancements to innovative operational practices for manufacturers. Free Expo Registration here. Enquiries: Margo Metcalf IEC Group, [email protected] or 03 95969205.

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