Associate Mechanical Engineer

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.