Associate Mechanical Engineer

Mainspring Energy; Menlo Park (CA); On-site; USD 90,000 - 120,000; Full time

Benefits offered by this job

Pre-IPO stock options

Job summary

Mainspring Energy is seeking an Associate Mechanical Engineer to contribute to mechanical engineering projects for our Linear Generator platform. You will build practical engineering skills by supporting mechanical design, CAD, drawings, analysis, testing, documentation, troubleshooting, and release activities.

This early-career role focuses on applying fundamentals with guidance, requiring curiosity, attention to detail, hands-on approach, and the ability to execute well-defined tasks while

Qualifications

• BS or MS in Mechanical Engineering or equivalent practical engineering experience.
• Foundational understanding of mechanics, materials, machine design, thermal systems, fluids, manufacturing, or related coursework.
• Experience with CAD tools such as SolidWorks or similar, including part design, assemblies, drawings, or design documentation.
• Ability to execute well-defined engineering tasks, communicate progress, and incorporate feedback from more experienced engineers.
• Interest in hands-on engineering work, including prototyping, testing, troubleshooting, data collection, and design iteration.
• Clear communication and willingness to learn company processes and build practical engineering judgment.

Responsibilities

• Support mechanical engineering projects by completing well-defined design, analysis, testing, documentation, and release tasks with guidance.
• Create and update CAD models, assemblies, drawings, test fixtures, documentation, and engineering reports.
• Assist with basic calculations, tolerance reviews, simulations, test setup, test execution, data review, and troubleshooting.
• Learn company processes for design reviews, drawing release, validation, change control, manufacturing support, and field implementation.
• Communicate progress, questions, blockers, and findings clearly while asking for help early when scope, priorities, or technical approach are unclear.
• Build practical engineering judgment through repeated feedback, hands-on work, and exposure to different design, analysis, test, release, and troubleshooting cycles.

Skills

Mechanical fundamentals

Hands-on engineering

Prototyping

Communication skills

Documentation

Education

BS or MS in Mechanical Engineering

Tools

SolidWorks

Job description

Mainspring Energy manufactures and delivers fuel-flexible, low-emissions local power solutions that rapidly add new capacity and deliver reliable, affordable, and sustainable electric power. The company began commercial shipments of its Mainspring Linear Generators in 2020 and today has hundreds of megawatts in advanced development and field operations for leading Fortune 500 companies, data centers, and utilities. Mainspring also partners with global energy leaders including AEP, NextEra Energy Resources, Schneider Electric, and more.

The core values that ground our work, guide our decisions, and connect us together:

• Pragmatic Optimism
• Excellence without Ego
• Proactive Collaboration

About the Role

Mainspring is seeking an Associate Mechanical Engineer to contribute to mechanical engineering projects for our Linear Generator platform. In this role, you will build practical engineering skills by supporting mechanical design, CAD, drawings, analysis, testing, documentation, troubleshooting, and release activities.

This role is intended for early-career engineers who are developing practical engineering judgment and learning how to apply mechanical engineering fundamentals to real hardware. A strong candidate should be curious, detail-oriented, hands-on, eager to learn, and able to execute well-defined tasks with guidance from more experienced engineers.

Candidates who have already demonstrated independent ownership of defined-scope mechanical engineering work through multiple design, analysis, test, release, or implementation cycles may be better aligned to a Mechanical Engineer role.

Responsibilities

• Support mechanical engineering projects by completing well-defined design, analysis, testing, documentation, and release tasks with guidance.
• Create and update CAD models, assemblies, drawings, test fixtures, documentation, and engineering reports.
• Assist with basic calculations, tolerance reviews, simulations, test setup, test execution, data review, and troubleshooting.
• Learn company processes for design reviews, drawing release, validation, change control, manufacturing support, and field implementation.
• Communicate progress, questions, blockers, and findings clearly while asking for help early when scope, priorities, or technical approach are unclear.
• Build practical engineering judgment through repeated feedback, hands-on work, and exposure to different design, analysis, test, release, and troubleshooting cycles.

Qualifications

• BS or MS in Mechanical Engineering or a similar engineering field, or equivalent practical engineering experience.
• Foundational understanding of mechanical engineering principles, including mechanics, materials, machine design, thermal systems, fluids, manufacturing, or other relevant coursework or experience.
• Experience with CAD tools such as SolidWorks or similar, including part design, assembly design, drawings, or design documentation.
• Ability to execute well-defined engineering tasks carefully, communicate progress, and incorporate feedback from more experienced engineers.
• Interest in hands-on engineering work, including prototyping, testing, troubleshooting, data collection, and design iteration.
• Clear communication skills and a willingness to ask questions, learn company processes, and build practical engineering judgment.

Preferred Qualifications

• Internship, co-op, project team, research, or early-career experience involving mechanical design, prototyping, testing, manufacturing, or hardware development.
• Experience building or testing hardware in a lab, shop, manufacturing, field, or hands-on project environment.
• Exposure to engineering analysis methods such as hand calculations, tolerance stackups, FEA, thermal analysis, fluid analysis, vibration analysis, or data analysis.
• Experience creating drawings, working with GD&T, preparing test plans, documenting results, or supporting engineering release work.
• Exposure to manufacturing processes such as machining, sheet metal, welding, casting, molding, additive manufacturing, or assembly.
• Interest in energy systems, engines, generators, compressors, pumps, thermal systems, fluid systems, structures, electromechanical systems, or industrial equipment.

Important note: This section retained here to preserve content for hiring managers; previous resume guidance text has been removed to ensure a clean candidate experience.

We encourage applicants from diverse backgrounds and experiences to apply. Mainspring Energy is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, or protected veteran status and will not be discriminated against on the basis of disability.

This compensation and benefits information is based on Mainspring Energy's estimate as of the date of publication and may be modified in the future. We generally do not negotiate on salary once we have made an offer. The level of pay within the range will depend on a variety of job-related factors that may include location, relevant prior experience and/or education, or particular skills and expertise. New hires joining the company tend to be paid within the starting base pay range noted above, with opportunities to increase pay over time based on development of additional skills, competencies, and company-specific knowledge.

This position is onsite at our Menlo Park HQ. The salary will be adjusted to reflect local market conditions based on employee location as well as the experience of the employee. Along with the base salary, Mainspring offers pre-IPO stock options + benefits.