Senior Manufacturing Engineer - DFM

Manufacturing Engineer

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, Next Era 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

We are seeking a highly capable Manufacturing Engineer with a strong mechanical engineering foundation to bridge the gap between product design and scalable production.

In this role, you will partner closely with Mechanical Design Engineering to ensure our products are not only functional, but manufacturable, scalable, and robust  will play a critical role in shaping design decisions early—driving DFM/DFX, tolerance strategies, and assembly error-proofing into the product architecture.

This is not a downstream role. You will actively challenge and influence design concepts, ensuring they are suitable for high-volume production—not just prototype success.

The ideal candidate combines strong mechanical design fundamentals with hands-on manufacturing experience and thrives in collaborative, fast-paced environments.

What you'll do

Partner with Mechanical Design Engineers to translate product concepts into manufacturable, scalable solutions

• Drive DFM/DFX initiatives, including tolerance stack-ups (GD&T), datum strategy, and assembly sequencing
• Convert assembly process learnings (error-proofing, access, ergonomics) into clear design requirements
• Actively influence and challenge product design decisions using first-principles engineering and manufacturing constraints
• Contribute to design decisions with understanding of stress, interfaces, and system integration

Design and develop fixtures, jigs, and assembly equipment with a focus on precision, repeatability, and cost

• Perform tolerance analysis and support detailed 2D drawing creation for fabrication
• Support early validation through prototyping, testing, and iteration
• Select and integrate actuators, sensors, and standard components; define functional sequences for automation
• Emphasize simple, robust solutions using off-the-shelf components where possible

• Own the transition of assembly processes from prototype builds to scalable production systems
• Plan and validate production processes using PFMEA, DOE, and capability studies (Cpk, GR&R)
• Collaborate cross-functionally with Quality, Supply Chain, and Operations to move from prototype to volume production
• Support factory layout, line design, capacity planning, and continuous improvement efforts

What you'll bring

• Bachelor's or Master's degree in Mechanical Engineering or related field
• 5+ years of experience in mechanical design, manufacturing engineering, or a hybrid role

• Proficiency in CAD tools (e.g., Solid Works, CATIA)
• GD&T and tolerance stack-up analysis
• 2D drawing creation for manufacturing
• Datum strategy and precision assembly
• Demonstrated experience influencing product design for manufacturability
• Experience designing assembly processes and scaling from prototype to production

• PFMEA, 8D, DOE
• Process capability (Cpk), GR&R
• Assembly technologies (fastening, machining, laser metrology)
• Willingness to travel internationally up to 15%

What Sets You Apart

• Ability to challenge design decisions with data and first-principles thinking
• Strong intuition for "what will break at scale" vs. what works in prototype
• Hands-on mindset—you're comfortable on the floor validating your ideas
• Bias for simple, cost-effective solutions over over-engineering

$116,000 - $136,000 a year This position is onsite at our Menlo Park HQ. The salary will be adjusted to reflect local market…