H3X is redesigning the electric motor to power the next phase of mobility


It’s clear that electric vehicles are the future, but there’s more to be done to make that change than swap out a gas engine for a battery-powered one – especially on airplanes. H3X is a startup aiming to accelerate that future with a redesigned, fully integrated electric motor that is said to outperform anything on the market.

The small founding team – CEO Jason Sylvestre, CTO Max Liben, and COO Eric Maciolek – met in college while participating in an electric vehicle building and racing program. After working in the tech and automotive industries (including at Tesla), the crew reunited when they saw the Department of Energy offering a premium for improved, high-power-density electric motors.

“The problem was uniquely suited to our skills and passions – we’re excited about this stuff. We care about the decarbonization of the various transit sectors, and aviation will become a growing part of the global carbon footprint in the next few decades as electricity improves ground vehicles, ”said Liben. “We simply decided on a leap of confidence and applied to Y Combinator.”

Electric flight is less of a wild idea and more an idea that is at an early, uncomfortable stage. Light vehicles like drones can do a lot with the batteries and motors available, and converted small airplanes like seaplanes can make short flights, but that’s about the limit of today’s situation.

The problem is primarily a simple lack of power: the energy required to propel an aircraft fast enough to generate lift increases exponentially with the size and mass of the aircraft. A handful of kilowatt-hours will be for a drone, and some EV-scale batteries will work for a light aircraft, but beyond that, the power required for flight requires batteries, the bulk and weight of which make flight inconvenient.

Credit: H3X

Of course it doesn’t have to be that way. And there are two general areas for improvement: better batteries or better motors. You can either fit more energy into the same mass or use the energy you have more efficiently. Both are followed by many companies, but H3X claims to have made a huge leap in power density that could open up new industries overnight. Even a 10% or 20% improvement in horsepower per kilogram (e.g. a 50-pound engine with 120 instead of 100 horsepower) would be remarkable. However, according to H3X, the engine provides around 300% of the competitive performance.

How? It’s all about integration, explained Liben. While the parts are in some ways similar to the engines and assemblies, the team basically started from scratch with the idea of ​​maximizing efficiency and minimizing size.

Electric motors generally consist of three main sections: the motor itself, a power supply system, and a gearbox, each of which has its own housing and can be sold and assembled separately. One reason this isn’t all a big machine is temperature: the transmission parts and coolant systems, for example, may not be able to operate at the temperatures produced by the engine or drive system, or vice versa. Put them together and one can cause the other to stick or otherwise fail. The different sections just have different requirements, which seems natural.

Credit: H3X

H3X challenges this paradigm with a novel integrated design, but Liben has carefully clarified what this means.

“We don’t just take the inverter box, open it and call it integrated,” he said. “All components are tightly connected to the same housing and motor. We’re developing a truly integrated design that is one of the first of its kind at this level of performance. “

And by “one of the first” he does not mean that Airbus has one in some drive trains, but that there have been research projects in this direction – nothing that is intended for production.

The idea that no one else went this far to put everything in a box that could be used commercially may sound suspicious to some. You’d think that existing players in the aerospace industry would have barked at this tree for years, but Liben said large companies are too slow to innovate and too invested in other methods, while smaller companies tend to avoid risk by doing Gradually improve successful existing designs and compete with each other. “Nobody’s targeting the level of performance we’re looking at right now,” he said.

Credit: H3X

But it’s not that H3X stumbled upon a single advance that magically tripled the performance of electric motors.

“We don’t rely on any big technology or anything – there is no such thing as a magic bullet,” Liben said. “There are some improvements that are making very significant gains, like 50% better than the prior art, and many areas that add 10% to 20%. It’s good from the technical risk side. “

He went into detail on many of these improvements, but the less technical-minded readers, if they’ve read this far, might close the tab if I tried to tell the entire conversation. In short, it comes down to combining advances in materials, manufacturing, and electrical components so that they work synergistically and make the most of each other.

For example, recently improved power switching hardware can operate at higher temperatures and handle higher loads – this increases performance but also allows for a shared cooling infrastructure. The shared infrastructure can itself be enhanced by using new pure copper 3D printing techniques that allow more cooling to fit inside the case. 3D printing uses custom internal geometries so that the engine, gearbox and power train can be assembled in optimal positions to each other rather than bolted on when existing methods allow.

The result is an all-in-one motor, the HPDM-250, which is smaller than most of its competitors and yet produces far more power. The best series engines are around 3-4 kilowatts per kilogram of continuous output. The H3X prototype produces 13 – coincidentally just above the theoretical power density that mid-range passenger aircraft would allow.

Credit: H3X

There is a risk that stacking state-of-the-art technology will increase costs faster than performance. Liben said that while it is definitely more expensive in some ways, the smaller size and integrated design also translate into new savings in cost, time, or materials.

“People think, ‘3D printing copper is expensive!’ But when you compare it to the super high performance windings you otherwise need and the different ways you make them, it can take a lot of manual steps and people involved … it can be a lot easier to print, ”he said . “It may not be intuitive, but at least from my parts list [bill of materials] Cost, if you sell one thing three times smaller than the other, even if it is made of high performance materials, it is actually not as expensive as you would think. Based on the customers we’ve spoken to so far, we think we’re in a good place. “

The maintenance of a fully integrated motor is also fundamentally more complex than that of a standard motor. Liben noted, however, that maintenance was carefully considered from the start – and that this may be a little harder to maintain – your engine is much easier than servicing even the most reliable and well-known gas-powered engines.

Credit: H3X

Despite the huge profits H3X is claiming, the target market for passenger aircraft is hardly one that they or anyone can easily jump into. Heavily regulated industries like air travel take years of work and technology to change a style of attachment, let alone the propulsion method.

Hence, H3X is focusing on the numerous smaller, less regulated industries that could use a vastly improved electric propulsion system. While cargo drones, electric boats, and air taxis are still rare sights on this planet, a huge hit on engine performance and efficiency can help them move from niche (or vaporware) to mainstream. Certainly all three of these applications could benefit enormously from an improved range or payload capacity.

Completing a passenger flight is not a distant dream, suggested Liben: “We are already on our way – this is not 20 year old stuff. In the last few years the schedules have shrunk dramatically. You might soon have an electric vehicle with a full battery, but it won’t be enough for longer flights. “

Engines like H3X still play a role in hybrid aircraft that use jet fuel, batteries, and perhaps even hydrogen fuel cells interchangeably. Like the switch to electric cars, this doesn’t happen all at once, nor does it have to be for the purposes of their business. “That’s the great thing about engines,” said Liben. “You are so ubiquitous.”

H3X declined to disclose funding or partners, although it’s hard to believe that without significant capital and facilities, the team would have come as far as they did before – this type of project grows out of the garage workshop pretty quickly. With Y Combinator’s demo day taking place tomorrow, it is likely that they will get a lot of calls over the next few weeks. After that, it may be reasonable to expect a starting round to come together.

If the H3X prototypes work as well in the wild as they do on the bench, they can potentially enable a host of new electric transportation applications. We’ll be watching closely how the startup’s game affects the future of electric mobility.


Katherine Clark