Principal Mechanical Design Engineer

STS Aviation Group; Milwaukee (WI); On-site; USD 120,000 - 180,000; Full time

Job summary

STS Technical Services seeks a Principal Mechanical Design Engineer – Electrical Equipment Enclosures in Milwaukee, WI. This onsite, direct-hire role focuses on mechanical design, structural analysis, thermal management, and validation of electrical power distribution enclosures.

A hands-on engineer with 12+ years of direct design experience is required. You will lead enclosure development, perform advanced analyses, and drive prototype testing and production readiness, collaborating with

Qualifications

• Bachelor’s degree in Mechanical Engineering or a related engineering discipline.
• 12+ years of direct design experience with enclosures for electrical power distribution equipment.
• Demonstrated expertise using ANSYS or comparable simulation software for structural, dynamic, or short‑circuit‑force analysis.
• Experience modeling thermal performance, airflow, heat transfer, and temperature rise in enclosed electrical equipment.
• Experience owning the mechanical design of enclosures and structures through analysis, prototype development, certification testing, and production release.
• Deep knowledge of fabricated sheet metal structures, welded assemblies, bolted joints, fasteners, materials, tolerances, and design for manufacturing.

Responsibilities

• Own the structural and mechanical design of enclosures, frames, doors, covers, barriers, mounting structures, bus supports, and bracing systems for electrical power distribution equipment.
• Translate electrical ratings, short‑circuit requirements, thermal loads, environmental requirements, and manufacturing constraints into robust mechanical designs.
• Establish structural and thermal design criteria, safety margins, calculation methods, and reusable engineering standards across product families.
• Make material, thickness, joining, fastening, gasketing, and reinforcement decisions based on analysis, testing, cost, and manufacturability.
• Lead finite element analysis (FEA) of short‑circuit forces, structural loading, stress, deformation, vibration, and dynamic response using ANSYS or comparable software.
• Lead thermal and airflow analysis to predict heat rise, hot spots, ventilation performance, and component or bus temperature limits.
• Develop simulation models that represent actual enclosure construction, joints, supports, materials, bus structures, and boundary conditions.
• Correlate simulation results with prototype and laboratory test data, continuously improving model accuracy and design rules.
• Use engineering analysis to identify design risks before certification testing and recommend changes that improve the probability of passing on the first test.
• Own the mechanical and thermal portions of verification plans, design reviews, instrumentation, acceptance criteria, and failure analysis.
• Provide mechanical and thermal technical leadership before, during, and after product and certification testing.
• Partner with product-development engineers to meet product layout and performance requirements while developing and validating enclosure and structural designs.
• Work directly with manufacturing teams on sheet metal fabrication, welding, hardware, assembly, finishing, prototypes, first builds, and design‑for‑manufacturing improvements.
• Document engineering assumptions, calculations, analysis results, design decisions, and lessons learned for inclusion in the product‑development system.

Skills

Mechanical design

Enclosures

FEA

ANSYS

Thermal analysis

Structural analysis

Prototype testing

Certification testing

Sheet metal fabrication

Manufacturing processes

Technical leadership

Education

Bachelor’s degree in Mechanical Engineering

Tools

ANSYS

CFD

Job description

STS Technical Services is hiring a Principal Mechanical Design Engineer – Electrical Equipment Enclosures in Milwaukee, Wisconsin, for a direct-hire opportunity focused on mechanical design, structural analysis, thermal management, and validation of electrical power distribution enclosures.

This position requires onsite attendance five days per week and is designed for an experienced mechanical engineer with extensive knowledge of electrical equipment enclosures, structural design, finite element analysis (FEA), and manufacturing processes.

We’re seeking a hands‑on engineering professional with 12 or more years of direct design experience who can lead enclosure development, perform advanced engineering analysis, and validate designs through prototype and certification testing.

The successful candidate will provide technical leadership for enclosure integrity, short-circuit withstand, thermal performance, simulation, and production‑ready mechanical designs.

Position Details

• Job Title: Principal Mechanical Design Engineer – Electrical Equipment Enclosures
• Location: Milwaukee, Wisconsin
• Employment Type: Direct Hire
• Work Arrangement: Onsite, 5 Days Per Week

Position Summary

The Principal Mechanical Design Engineer provides expert technical leadership for the mechanical design and analysis of electrical power distribution enclosures.

This position is responsible for enclosure integrity, short‑circuit withstand, thermal management, simulation, and design validation.

Working directly with product development, certification, and manufacturing teams, the engineer will help transform new equipment concepts into safe, repeatable, production‑ready designs.

The role requires hands‑on involvement in engineering calculations, simulation models, mechanical design decisions, prototype development, and product testing.

Key Responsibilities

Enclosure Design and Technical Ownership

• Own the structural and mechanical design of enclosures, frames, doors, covers, barriers, mounting structures, bus supports, and bracing systems for electrical power distribution equipment.
• Translate electrical ratings, short‑circuit requirements, thermal loads, environmental requirements, and manufacturing constraints into robust mechanical designs.
• Establish structural and thermal design criteria, safety margins, calculation methods, and reusable engineering standards across product families.
• Make material, thickness, joining, fastening, gasketing, and reinforcement decisions based on analysis, testing, cost, and manufacturability.

Engineering Simulation and Structural Analysis

• Lead finite element analysis (FEA) of short‑circuit forces, structural loading, stress, deformation, vibration, and dynamic response using ANSYS or comparable simulation software.
• Lead thermal and airflow analysis to predict heat rise, hot spots, ventilation performance, and component or bus temperature limits.
• Develop simulation models that represent actual enclosure construction, joints, supports, materials, bus structures, and boundary conditions.
• Correlate simulation results with prototype and laboratory test data, continuously improving model accuracy and design rules.
• Use engineering analysis to identify design risks before certification testing and recommend changes that improve the probability of passing on the first test.

Design Validation and Certification

• Own the mechanical and thermal portions of verification plans, design reviews, instrumentation, acceptance criteria, and failure analysis.
• Provide mechanical and thermal technical leadership before, during, and after product and certification testing.
• Partner with product-development engineers to meet product layout and performance requirements while developing and validating enclosure and structural designs.

Manufacturing Integration and Documentation

• Work directly with manufacturing teams on sheet metal fabrication, welding, hardware, assembly, finishing, prototypes, first builds, and design‑for‑manufacturing improvements.
• Document engineering assumptions, calculations, analysis results, design decisions, and lessons learned for inclusion in the product‑development system.

Required Qualifications and Experience

• Bachelor’s degree in Mechanical Engineering or a related engineering discipline.
• 12 or more years of direct design experience with enclosures for electrical power distribution equipment.
• Demonstrated expertise using ANSYS or comparable simulation software for structural, dynamic, or short‑circuit‑force analysis.
• Experience modeling thermal performance, airflow, heat transfer, and temperature rise in enclosed electrical equipment.
• Experience owning the mechanical design of enclosures and structures through analysis, prototype development, certification testing, and production release.
• Deep knowledge of fabricated sheet metal structures, welded assemblies, bolted joints, fasteners, materials, tolerances, and design for manufacturing.
• Ability to make and defend technical decisions using calculations, simulations, test evidence, and sound engineering judgment.

Preferred Qualifications and Experience

• Experience designing switchgear, switchboards, motor control centers, busway, panelboards, or other high-current electrical equipment.
• Experience analyzing electromagnetic short‑circuit forces and the mechanical response of bus supports, barriers, and enclosures.
• Experience with coupled structural and thermal simulation, computational fluid dynamics (CFD), multiphysics analysis, or nonlinear contact analysis.
• Experience preparing designs for UL, IEEE, ANSI, NEMA, IEC, or related certification and high‑power laboratory testing.
• Experience building simulation methods and design standards for a new or expanding product platform.

Success Profile

The successful Principal Mechanical Design Engineer:

• Is a technical expert who uses engineering tools and evidence to reduce design and certification risk.
• Does not rely on excessive material or conservative sizing as a substitute for analysis.
• Balances short‑circuit performance, thermal performance, manufacturability, cost, and scalability.
• Remains hands‑on with models, calculations, designs, prototypes, and laboratory testing.
• Establishes reusable methods that improve the technical capability of the broader engineering team.