Soma Capital Portfolio Jobs

Sr. Mechanical Engineer

H3X Technologies

H3X Technologies

Louisville, CO, USA
Posted on Wednesday, March 22, 2023


At H3X, we are building the most advanced electric propulsion systems in the world to enable sustainable electric aircraft. At 12 kW/kg continuous, the HPDM family of integrated motor drives is a step change in electric propulsion technology and removes one of the main barriers blocking widespread proliferation of electric aircraft. We have several power classes of motors ranging from 30kW to 3MW and are selling to markets of aviation, aerospace and defense, marine, and specialized ground vehicles.

H3X is looking to hire an experienced mechanical engineer to take charge of design and prototype development across different motors in the HPDM product line. The engineering team operates like Skunkworks - small, highly technical, and very fast. A high degree of self-motivation and responsibility is required as you will be given significant freedom and will be directly responsible for flight-critical parts.



  • Identify root cause of failures
  • Establish requirements for given sub-systems


  • Design parts & assemblies utilizing SolidWorks
  • Conduct PDRs & CDRs for responsible sub-systems


  • Compile & source Bill of Materials for responsible sub-systems
  • Generate engineering drawings via SolidWorks
  • Perform tolerance stack-ups and convey via GD&T in engineering drawings
  • Create build instructions for responsible sub-systems


  • Execute testing and characterization of responsible sub-system
  • Post process test results, identify root-cause of potential new issues and make design recommendations to meet the highest level of reliability and performance


  • Integrate sub-system into full system
  • Support future production builds or complete system tests


  • Identify workplace hazards and implement safe processes
  • Maintain testing and production equipment where necessary


  • Bachelor’s or Graduate Degree in Mechanical Engineering or similar
  • Hands-on experience assembling mechanical systems
  • 5+ years of CAD software experience (SolidWorks preferred)
  • 5+ years’ experience with producing 2D part drawings & GD&T
  • Strong experience with structural & modal FEA (ANSYS)
  • Experience with manufacturing processes (machining, Metal AM, & composites)
  • Excellent written and verbal communication
  • Exceptional understanding of physics fundamentals
  • Action biased, results oriented mentality
  • Willingness to learn and adapt quickly
  • A high degree of emotional intelligence: ability to collaborate closely with coworkers in a respectful and empathetic manner
  • Fundamentally curious and motivated by first principles
  • Position requires access to CUI/ITAR/EAR controlled information

SALARY RANGE: $100,000 - $160,000 USD


  • Employee equity incentive plan
  • Health insurance: medical, vision, dental, short-term disability, and life
  • Gym membership stipend
  • Flexible hours (deliverable-based goals)
  • Flexible-time off (just need manager approval)
  • Mental health coverage
  • Relocation package
  • Epic/IKON Ski & Snowboard Pass
  • Company laptop
  • Bi-weekly company happy hours


H3X Technologies is a U.S.-based manufacturer of electric motors for sustainable aviation, marine, industrial, and defense applications. They have developed a family of integrated motor drives that can scale in power from 30kW to 30MW with power densities as high as 12 kW/kg and best-in-class efficiency. This high performance is enabled by novel scalable core technology and proprietary manufacturing processes for motor stacking, winding, and assembly. The design, manufacturing, and testing of their products is done in-house at their headquarters in Louisville, Colorado.

H3X’s world-class team is composed of experts from Tesla, SpaceX, GE Aviation, and Siemens with deep knowledge in electric machines, power electronics, material science, control systems, and advanced manufacturing. H3X takes pride in their multidisciplinary approach, relentless dedication, high capital efficiency, and Skunkworks-style execution.

H3X has raised over $20M with backing from top VC firms and strategic firms, including Lockheed Martin, Hanwha, Y Combinator, Cubit Capital, Metaplanet, TechNexus, and Liquid 2 Ventures.

H3X is poised to become the world’s leading supplier of advanced electric motors by 2030 to drive deep decarbonization in aviation, marine, and heavy industrial applications and unlock next-generation electrified defense technology to strengthen national security.

H3X is an equal opportunity-affirmative action employer and considers all qualified applicants for employment based on business needs, job requirements and individual qualifications, without regard to race, color, religion, sex, age, disability, sexual orientation, gender identity or expression, marital status, past or present military service or any other status protected by the laws or regulations in the locations where we operate.