Principal Mechanical Engineer at ETA

JOB DESCRIPTION 

Purpose

The Principal Mechanical Engineer at ETA is a key member of the engineering team,  responsible for the mechanical design, thermal performance, and physical integration of  electric motors within ETA products. 

This role focuses on delivering robust, manufacturable motor designs — ensuring that  rotor and stator constructions operate reliably under real-world conditions, meet  performance targets, and can be validated through structured testing. 

The role covers the full development cycle from concept through to validation and  production readiness. 

Location

Hethel Engineering Centre, Chapman Way, Hethel, Norfolk NR14 8FP

Duration

Permanent. 

Hours

Core hours are 8.30am – 5.00pm, Monday to Friday inclusive. Additional hours may be  required dependent on business needs. 

Salary

To be negotiated. 

To start

End May or early June. 

Application

CV to hr@eta-gp.com 

Reporting Structure

Reports to: Lead mechanical engineer 

Key Contacts

Internal: Engineering, Procurement, Project Management. 

External: Customers, Suppliers, Regulatory and Testing bodies. 

Key Responsibilities

Lead the mechanical design and integration of electric machines, including: 

• Rotor construction (magnet selection, placement, and retention systems)
• Structural integrity at speed (burst strength, fatigue, containment)
• Shaft, bearings, and housing design  

Define and develop thermal management strategies using air cooling, including: 

• Cooling paths and airflow management
• Thermal interfaces and material selection
• Validation of temperature limits under real operating conditions

Own the design and integration of key motor components, including: 

• Permanent magnets and retention methods 
• Flux return paths and flux rings
• Stator windings and their mechanical integration
• Electrical insulation systems

Integrate sensing solutions, including:  

• Speed and position sensing (selection and packaging, not core sensor design) 
• Temperature sensing within stator and associated structures  

Work closely with electromagnetic and control teams to:  

• Translate performance targets into practical, manufacturable designs 
• Ensure mechanical and thermal solutions support efficiency and durability 

Carry out and guide design analysis, including:  

• Mechanical stress and deformation 
• Rotor dynamics, balance, and vibration
• Thermal behaviour and heat flow
• Tolerance stack-up and manufacturability

Lead and contribute to failure analysis and robustness activities, including:

• Design Failure Mode and Effects Analysis (FMEA) 
• Identification and mitigation of mechanical and thermal risks
• Root cause investigation and corrective actions

Own the definition of test and validation plans, ensuring all motor designs are  verified against performance, durability, and thermal requirements, including:  

• Performance testing across speed and torque range 
• Efficiency mapping and loss breakdown
• Thermal testing and temperature mapping 
• High-speed and durability testing
• Environmental and operational condition testing

Work with the test team to ensure: 

• Test plans are clear, complete, and executable
• Required instrumentation and setups are defined
• Data collected is sufficient to validate design intent

Review and interpret test results to: 

• Confirm performance against requirements
• Identify issues and failure modes
• Drive design improvements and corrective actions

Ensure designs are suitable for manufacture and scale-up, including: 

• Assembly methods and tooling considerations 
• Material selection and supply chain awareness
• Cost-effective and repeatable production

Support internal and customer-facing activities by clearly explaining design  decisions, trade-offs, and performance outcomes.

Responsibilities & Accountabilities

• Delivery of motor designs that meet performance, durability, and cost targets
• Mechanical and thermal integrity of motor designs across all operating conditions
• Completion and maintenance of robust FMEA and risk mitigation activities
• Definition and execution of structured validation and verification plans
• Successful validation of designs through build and testing 
• Support for transition from development to production 

Experience

• Proven experience in electric machine design, with strong focus on mechanical and  thermal aspects 
• Experience designing rotor systems, including magnet retention and high-speed  operation 
• Experience with stator construction and winding integration 
• Practical experience of motor build, testing, and validation 
• Experience conducting and leading FMEA and failure analysis activities • Understanding of air-cooled thermal management approaches 
• Experience working within multi-disciplinary engineering teams 

Qualifications

• Engineering Degree or equivalent professional accreditation. 

Skills/Abilities/Knowledge/Qualities

• Strong understanding of motor construction and real-world behaviour • Knowledge of materials used in electric machines, including electrical steel,  magnets, and conductors 
• Experience with mechanical and thermal analysis tools 
• Ability to balance performance, durability, manufacturability, and cost • Structured, evidence-based approach to engineering decision-making • Good communication skills, able to explain technical concepts clearly.  
• Ability to travel to other territories in order to meet business and customer needs. • Empathy with the mission, vision, values and ethos of the company.