Principal Mechanical Engineer

An educational platform on tribology the science of friction, wear and lubrication Who is it for Engineers, researchers, students and industry professionals Eleven Recruiting is searching for a Principal Mechanical Engineer to join one of our largest aerospace manufacturing clients sitting onsite in Saginaw, Michigan. The Principal Engineer for Ball Screw Design & Development serves as the technical authority for precision ball screw mechanisms used in aerospace, defense, medical, and industrial applications. This role owns the design architecture, analytical approach, materials selection, manufacturing methods, and validation strategy of new ball screw products. The Principal Engineer provides deep subject-matter expertise, leads complex development efforts, and mentors engineering teams to ensure product performance, reliability, and manufacturability. Responsibilities Lead the design, development, and analysis of ball screw assemblies, including screw shafts, nuts, return systems, recirculation mechanisms, and drive interfaces. Define ball screw geometry, preload strategy, lead accuracy, life requirements, and lubrication approaches based on system needs and environmental constraints. Perform detailed analytical modeling: load distribution, Hertzian contact stress, fatigue life, torque prediction, friction modeling, stiffness and compliance, thermal effects, wear, and backlash behavior. Lead FEA/CAE activities involving nonlinear contact, dynamic loading, thermal-mechanical interactions, and structural optimization. Conduct advanced failure analyses (FMEA, root-cause analysis) for wear, spalling, brinelling, lubrication breakdown, material defects, and contamination sensitivity. Define and validate material specifications, heat-treat requirements, coatings/platings, cleanliness, and surface finish to achieve life and reliability targets. Collaborate closely with manufacturing engineering on grinding, thread-rolling, grooving, nut machining, ball sizing, assembly sequencing, and quality control processes. Lead testing strategy including endurance testing, torque characterization, efficiency measurement, load testing, lubrication trials, and environmental qualification. Serve as technical lead or chief engineer for ball screw-related programs, providing guidance to project engineers and designers. Partner with customers on requirements definition, performance trade studies, design reviews, and issue resolution. Drive continuous improvement and innovation in ball screw technologies, including new recirculation architectures, materials, and friction-reduction methods. Ensure compliance with AS9100, aerospace design standards, traceability requirements, and export-control regulations. Prepare and present high-level technical reports, design justifications, risk analyses, and engineering review packages to internal leadership and customers. Required Qualifications Bachelor’s degree in mechanical engineering or related discipline. 10+ years of experience in mechanical design, with at least 5 years specializing in ball screws, actuation systems, or precision motion components. Demonstrated expertise in contact mechanics, tribology, fatigue analysis, and precision mechanical design. Proficiency with 3D CAD and CAE tools (SolidWorks, ANSYS, Abaqus, etc.). Strong understanding of aerospace/industrial product development lifecycles. Deep knowledge of ball screw architecture, geometry optimization, preload techniques, and mechanical efficiency factors. Expertise in failure modes, reliability engineering, and life prediction specific to rolling-element mechanisms. Ability to lead complex projects, mentor engineers, and influence technical direction. Excellent communication and customer-facing skills, able to deliver complex technical material clearly. Strong capability in risk management, trade studies, and data-driven decision making. Preferred Qualifications Master’s or Ph.D. in Mechanical Engineering focused on tribology, contact mechanics, or machine design. Experience with electromechanical actuator systems. Background in high-precision manufacturing or grinding/thread-rolling process development. Experience with DO-160, MIL-STD environmental qualification, or similar aerospace standards. Six Sigma, DFSS, or advanced reliability engineering certification. #J-18808-Ljbffr Tribonet