Principal Mechanical Design Engineer
CV-LibraryTongham, Surrey, South EastpermanentPosted: 19 March 2026
Apply NowPrincipal Mechanical Design Engineer – Complex Electro-Mechanical SystemsAre you an experienced Mechanical Design Engineer ready to take the next step in your career? We are seeking a Principal Mechanical Design Engineer to lead the design and development of complex electro-mechanical systems for highly regulated markets. This is a senior, hands-on role offering technical ownership, leadership, and innovation opportunities.
About the RoleAs a Principal Mechanical Design Engineer, you will:
Lead the design, development, and documentation of complex electro-mechanical systems
Take technical ownership of projects from concept through to production, testing, and commissioning
Mentor and guide junior engineers, providing leadership across multidisciplinary teams
Collaborate closely with electrical, software, and systems engineers to deliver integrated and compliant solutions
Support continuous improvement initiatives and provide innovative solutions for challenging design problems
As part of the Mechanical Design team, the Principal Mechanical Design Engineer will provide technical direction for mechanical engineering activities across assigned projects and major work packages, ensuring robust engineering decisions, effective cross-functional delivery, and successful progression through the gated development process. This role combines deep engineering capability with strong delivery leadership. The Principal Mechanical Design Engineer will lead complex problem resolution, guide mechanical decision-making, coordinate technical activities with minimal intervention, and act as a key interface between Mechanical Design and other business functions, suppliers and customers. They will also support and mentor other engineers across the business.
The ideal candidate will have significant experience designing complex moving mechanical systems, such as gearboxes, actuators, powertrain systems, rotating machinery, or turbomachinery, bringing proven expertise in tackling high-complexity mechanical challenges.
Key Responsibilities of a Principal Mechanical Design Engineer
Deliver robust mechanical designs for electro-mechanical systems used in high-regulated environments
Produce CAD models, detailed drawings, and Bills of Materials (BOMs) using SolidWorks
Conduct design reviews, risk assessments, and technical validation
Manage and optimise design for manufacturability (DfM) and assembly (DfA)
Liaise with suppliers and manufacturing teams to ensure designs are practical, cost-effective, and compliant
Provide leadership and mentorship to design and engineering teams, fostering technical excellence
Skills & Experience of a Principal Mechanical Design Engineer
Degree-qualified in Mechanical Engineering or related discipline
Extensive experience in mechanical design of complex electro-mechanical systems
Proven experience designing complex moving mechanical systems (gearboxes, actuators, powertrain systems, rotating machinery, turbomachinery)
Strong SolidWorks expertise and CAD modelling capabilities
Proven experience in high-regulated markets, e.g., automotive, aerospace, or defence
Strong understanding of mechanical components, assemblies, tolerance stack-ups, and manufacturing methods
Demonstrated leadership and ability to mentor junior engineers
Excellent problem-solving, communication, and organisational skills
Why Apply?
Take ownership of high-impact, technically challenging projects
Lead and shape the work of a growing, innovative engineering team
Work in an environment that values innovation, quality, and professional growth
Opportunity to make a real difference in complex, cutting-edge product development
If you are an experienced Principal Mechanical Design Engineer with a strong track record designing complex electro-mechanical and moving mechanical systems, we want to hear from you
About the RoleAs a Principal Mechanical Design Engineer, you will:
Lead the design, development, and documentation of complex electro-mechanical systems
Take technical ownership of projects from concept through to production, testing, and commissioning
Mentor and guide junior engineers, providing leadership across multidisciplinary teams
Collaborate closely with electrical, software, and systems engineers to deliver integrated and compliant solutions
Support continuous improvement initiatives and provide innovative solutions for challenging design problems
As part of the Mechanical Design team, the Principal Mechanical Design Engineer will provide technical direction for mechanical engineering activities across assigned projects and major work packages, ensuring robust engineering decisions, effective cross-functional delivery, and successful progression through the gated development process. This role combines deep engineering capability with strong delivery leadership. The Principal Mechanical Design Engineer will lead complex problem resolution, guide mechanical decision-making, coordinate technical activities with minimal intervention, and act as a key interface between Mechanical Design and other business functions, suppliers and customers. They will also support and mentor other engineers across the business.
The ideal candidate will have significant experience designing complex moving mechanical systems, such as gearboxes, actuators, powertrain systems, rotating machinery, or turbomachinery, bringing proven expertise in tackling high-complexity mechanical challenges.
Key Responsibilities of a Principal Mechanical Design Engineer
Deliver robust mechanical designs for electro-mechanical systems used in high-regulated environments
Produce CAD models, detailed drawings, and Bills of Materials (BOMs) using SolidWorks
Conduct design reviews, risk assessments, and technical validation
Manage and optimise design for manufacturability (DfM) and assembly (DfA)
Liaise with suppliers and manufacturing teams to ensure designs are practical, cost-effective, and compliant
Provide leadership and mentorship to design and engineering teams, fostering technical excellence
Skills & Experience of a Principal Mechanical Design Engineer
Degree-qualified in Mechanical Engineering or related discipline
Extensive experience in mechanical design of complex electro-mechanical systems
Proven experience designing complex moving mechanical systems (gearboxes, actuators, powertrain systems, rotating machinery, turbomachinery)
Strong SolidWorks expertise and CAD modelling capabilities
Proven experience in high-regulated markets, e.g., automotive, aerospace, or defence
Strong understanding of mechanical components, assemblies, tolerance stack-ups, and manufacturing methods
Demonstrated leadership and ability to mentor junior engineers
Excellent problem-solving, communication, and organisational skills
Why Apply?
Take ownership of high-impact, technically challenging projects
Lead and shape the work of a growing, innovative engineering team
Work in an environment that values innovation, quality, and professional growth
Opportunity to make a real difference in complex, cutting-edge product development
If you are an experienced Principal Mechanical Design Engineer with a strong track record designing complex electro-mechanical and moving mechanical systems, we want to hear from you