Motor Drives for Electric Aircraft

Unrivaled power density – 13 kW/kg continuous. The HPDM-250 is the next step in the evolution of electric motor technology.

Patent Pending

250kW in a 15kg Package

The HPDM-250 is an ultra-high power density integrated motor drive for electric aircraft. It combines the electric motor, inverter, and gearbox into one powerful unit. It is the culmination of H3X innovation in multiple areas including:

Electromagnetics design optimization

DMLS 3D printed synergistic cooling jacket

3D printed copper stator coils

Robust fault tolerance

Thermal resistance reduction

High frequency SiC power electronics

HPDM-250 Target Specifications

The HPDM-250 is optimized entirely for power density and efficiency. It features the highest level of integration on the market, made possible by our holistic design methodologies rooted in first principles and multidisciplinary expertise in power electronics and electric machines.

Show specs with a 4:1 planetary gearbox
H3X can design a high torque density planetary gearbox that is integrated into the front endcap of the machine to achieve your desired torque-speed requirements. The example 4:1 planetary is based on a real design that is 3 kg and 97% efficient.

These specifications are estimates based on electromagnetic, thermal, and structural simulations. Data from dynamometer will be available late 2021.

Peak Torque
120 Nm at 360 Arms
Peak Power
250 kW
Peak Duration
30 seconds
Speed Range
0 - 20,000 RPM
Continuous Torque
95 Nm
Continuous Power
200 kW
Peak Motor Efficiency
Peak Inverter Efficiency
Peak Combined Efficiency
DC Bus Voltage
Up to 800 V
15 kg
6.75 L

Motor Torque vs. Speed

Patent Pending

Revolutionizing Motor Manufacturing

H3X has developed a new kind of stator coil that is additively manufactured using pure copper with >93% IACS conductivity. Our AMcoils™ achieve >70% copper fill factor in the HPDM-250 and offer a 40% improvement over conventional windings in terms of maximum continuous current density.

High fill factor

Thermally isotropic

Streamlined automated manufacturing

Scalable to high volume

Greater design freedom

Faster development cycles

Who We Are

A team of multidisciplinary engineers brought together with the sole purpose of developing the most advanced electric aircraft propulsion systems in the world to enable sustainable aviation.

Why did we start H3X?

For electric aircraft to be commercially feasible, substantial improvements need to be made to electric propulsion system technology.  Today, best-in-class motors and inverters have a combined power density of 3-4 kW/kg.  ARPA-E has determined that for a Boeing 737 to complete a typical five hour flight, the propulsion system must be >12 kW/kg continuous.

We have the solution.

At 13 kW/kg continuous, the HPDM-250 exceeds ARPA-E’s requirements and is at least 3X better than current systems. It is a step change in electric propulsion technology and removes one of the main barriers blocking widespread commercialization of electric aircraft.

Where can the HPDM-250 be used?

Any mass-sensitive, packaging-constrained, or high performance application.

Near-term applications:  Urban air mobility, military, electric boats, motorsports (F1), select regional aircraft markets.

Long-term applications: Large commercial electrified aircraft for short-haul flights less than 1000 miles.

Our investors

H3X Founders

H3X brings together driven minds from the automotive, aerospace, and motorsports industries with deep knowledge in electric propulsion systems and vehicle engineering. We love what we do and are looking to hire people who share that same passion.

As CEO, Jason is responsible for overall business direction and power electronics development at H3X.  His speciality lies at the intersection of business leadership and hardcore engineering. Prior to H3X, he started his own engineering consulting company where he has helped several companies in the automotive and aerospace industries bring their EV product visions to life.  He has a B.S. and M.S. in Electrical Engineering from University of Wisconsin-Madison. Fun fact - Jason (and Max) co-founded UW-Madison’s electric Formula SAE team and built the first AWD electric racecar in the United States.

Jason Sylvestre

Chief Executive Officer

Max is a multidisciplinary engineer with a laser focus on physics fundamentals and deep knowledge in both mechanical and electrical engineering. As CTO, he is responsible for H3X’s overall product engineering, electric motor design, and core technology development. Max’s background includes holding key roles in vehicle modeling, architecture, and electric motor design in both the automotive and aerospace sectors. He has a B.S. in Mechanical Engineering and an M.S. in Electrical Engineering from University of Wisconsin-Madison.

Max Liben

Chief Technology Officer

Eric is responsible for all operations and mechanical design at H3X. In Eric’s prior roles, he has lead projects to develop control systems for electric and hybrid powertrain systems from the ground up. He has a B.S. in Mechanical Engineering from University of Wisconsin-Madison. Eric comes from a proud heritage of craftsmen – from butchers and bakers to electricians and steamfitters. This unique background has enabled to him bridge the gap between advanced engineering theory to practical and scalable solutions.

Eric Maciolek

Chief Operating Officer

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Get in Touch

Development and testing of the HPDM-250 is currently underway.

Contact H3X today to see how you can use our products in your vehicles. We are looking to develop long-term relationships with first adopters and partners interested in revolutionizing the aircraft industry and creating a sustainable future.

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Designed and Made in the United States of America

Designed and Made in the United States of America