Senior Mechanical Engineer, Machine Design

Senior Mechanical Engineer, Machine Design Location: San Diego, CA Job Type: Full-Time $130,000 - $140,000 Machine Design Own the design of precision mechanical systems including frames, motion elements, fixtures, and actuation mechanisms Perform tolerance stack-ups and define GD&T for precision assemblies Develop and manage mechanical error budgets (alignment, motion accuracy). Analyze stiffness, deflection, vibration, and fatigue using analytical methods and FEA Design mechanisms that balance performance, cost, manufacturability, and reliability Thermal Control Hardware Design thermal control systems including heaters, heat exchangers, insulation, cold plates, airflow systems, and structural thermal paths Translate temperature stability and uniformity requirements into hardware specifications Perform thermal modeling and first-principles heat transfer calculations (conduction, convection, radiation) Develop and maintain thermal error budgets (drift, gradients, response time) Collaborate with electrical and firmware engineers on sensor placement and control strategy integration Fluid Control Hardware Design Design fluid handling assemblies including manifolds, tubing routing, fittings, valves, pumps, and reservoirs Perform flow calculations (pressure drop, flow rate, Reynolds number) Support material selection for chemical compatibility and biocompatibility Integrate fluidic subsystems with thermal and mechanical assemblies Develop leak testing and validation strategies Analysis & Validation Build structured analytical models to predict mechanical, thermal, and fluidic performance Maintain subsystem-level error budgets (mechanical, thermal stability, flow accuracy) Design and execute validation testing for temperature stability, fluid accuracy, drift, and mechanical robustness Perform structured root cause analysis when performance targets are not met Support DFMEA and risk assessment activities Prototyping & Integration Assemble and debug mechanical, thermal, and fluidic prototypes Instrument systems for temperature, flow, and mechanical performance measurement Iterate quickly based on test results and integration feedback Support alpha and beta system builds Manufacturing & Documentation Create detailed mechanical drawings with proper GD&T Participate in DFM/DFA reviews Work with vendors on machined, sheet metal, molded, and fluidic components Support transition from prototype to low-volume production Qualifications Required B.S. or M.S. in Mechanical Engineering or related field 5–8+ years of experience in precision machine design, thermal systems, and/or fluid handling hardware Strong foundation in tolerance analysis and error budgeting Experience performing thermal and fluid flow calculations Proficiency in 3D CAD (e.g. SolidWorks) Hands‑on experience building and testing hardware Preferred Experience in bioinstrumentation, medical devices, diagnostics, or scientific equipment Experience designing closed‑loop temperature‑controlled systems Experience with microfluidic or low‑volume reagent handling systems Familiarity with FEA tools for structural and thermal analysis Experience selecting materials for chemical compatibility Experience supporting early‑stage production builds What We’re Looking For Analytical thinker who quantifies performance limits and tradeoffs Strong mechanical fundamentals with systems‑level intuition Comfortable owning subsystems end‑to‑end Hands‑on builder who enjoys working in the lab Clear communicator across electrical, firmware, fluidics, and systems teams We are an equal opportunity employer. We thrive on diversity and collaboration. #J-18808-Ljbffr Foresite Labs (Stealth Co)