Staff Mechanical Engineer – Continuous Improvement for Mechanical Design & Quality Control

About Mainspring 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

Do you have a knack for design of complex mechanical systems? Have you ever invented a tool or changed a process just to make routine installation or service faster and easier? If you're driven by solving real-world design challenges, and working with state of the art mechanical power generation equipment, then this role is built for you. Mainspring Energy is seeking a Mechanical Sustaining Engineer with a focus on design to lead product improvement efforts across our field and production systems. You will work embedded on site at a contract manufacturer to address design and manufacturing issues at their root. You will support manufacturing with a hands-on approach to solve complex dynamic mechanical problems working directly with the product to take measurements, perform testing, and support pilot efforts to develop rework/retrofit processes. You will redesign critical components for durability and ease of service, and integrate your findings back into the development process to ensure the long-term reliability and manufacturability of our products.

Lead the root cause analysis of mechanical failures using data from diagnostics, hands-on testing, and fundamental analysis of bolted joints or material fatigue life Redesign or re-engineer components, fasteners, or assemblies to eliminate failures, reduce costs, or improve serviceability Coordinate design engineering, manufacturing, and quality teams to ensure that changes are thoroughly tested and validated with short feedback cycles Collaborate with NPI, manufacturing quality, and supply chain teams to ensure solutions are optimized for production, vendor capabilities, and field service Predict and prevent failure modes by applying a deep understanding of mechanical system interactions, tolerance stack-ups , and real-world use conditions Implement feedback loops from field issues into design standards and engineering processes to continuously improve product quality and reduce recurrence Manage internal improvement systems that embed learnings into manufacturing process flow and future design development efforts Support the development of service tooling, testing fixtures, or diagnostic aids as needed for improved deployment and serviceability Travel to HQ in Menlo Park, CA required once per quarter

BS or MS in Mechanical Engineering or a similar technical field, minimum BS + 11 years mechanical design experience Hands-on experience with mechanical design, including analysis of bolted joints , stress analysis, and structural integrity Hands on experience with component and system level testing including measurement techniques and data analysis Proven ability to use data-driven root cause analysis to solve complex, cross-functional design issues. Experience addressing and resolving field and production issues Knowledge of DFM/DFA principles and quality system tools (PFMEA, 8D, CAPA, etc.) Deep understanding of tolerance stack-ups and the use of CMMs in inspection processes Familiar with manufacturing processes including tube swaging, crimping, potting, stamping, sheet metal, hydroforming, welding, machining, and fabrication Proficient in SolidWorks or a comparable CAD package; PDM experience preferred Experience with structural FEA and/or is a plus A passion for building robust, field-ready solutions with high reliability and serviceability

Directly influence the reliability and field performance of mission-critical mechanical systems Collaborate with top-tier engineering teams in a fast-paced and supportive environment Be part of an innovation-driven company working on impactful technologies Competitive compensation and a full benefits package Opportunities for technical leadership and long-term growth

We’re committed to building a diverse and inclusive team and welcome candidates from all backgrounds. Even if you don’t meet every requirement, if this role resonates with your skills and passions, we encourage you to apply.