Mechanical Engineer I

3Si Security Systems•Jefferson City, MO

2d•Onsite

About The Position

3Si is seeking a detail-oriented Mechanical Engineer to join its engineering team in Jefferson City, Missouri. This role offers the opportunity to apply engineering knowledge, build hands-on design experience, and contribute to production-ready components and assemblies. Working with experienced engineers and cross-functional teams, the Mechanical Engineer supports products from concept through production, with an emphasis on designing parts for injection molding and high-volume manufacturing. The role develops knowledge of Design for Manufacturability (DFM), tooling considerations, and material selection while helping optimize designs for cost, quality, and manufacturability. The position is based in person in Jefferson City, Missouri, Monday through Friday, 8:00 a.m. to 4:30 p.m. Central Time. Travel is less than 5%.

Requirements

Bachelor’s degree in Mechanical Engineering or a related field.
0–3 years of relevant mechanical engineering or product design experience.
Foundational understanding of mechanical engineering principles, materials, and manufacturing processes.
Familiarity with CAD software through coursework, academic projects, internships, or professional experience.
Strong attention to detail and a practical approach to problem-solving.
Ability to organize tasks, manage competing priorities, and communicate progress with guidance from the team.
Effective communication and teamwork skills, including willingness to ask questions, seek feedback, and learn from others.

Nice To Haves

SolidWorks experience.
Exposure to injection molding, die casting, or DFM through coursework, projects, or work experience.
Interest in learning about injection molding and/or die casting, including part design and tooling considerations.

Responsibilities

Design and develop mechanical components and assemblies to meet project specifications and applicable industry standards.
Collaborate with engineers, project managers, manufacturing and quality personnel, and tooling vendors to support product development.
Use CAD software to create and modify designs, ensuring accuracy and adherence to project timelines.
Prepare and update technical drawings, specifications, and related documentation for manufacturing and assembly.
Support prototype development, testing, and analysis; document results and help identify opportunities for design improvements.
Participate in design reviews and assist with resolving design and manufacturing issues throughout the product lifecycle.
Learn and apply DFM principles, including material selection and tooling considerations for injection molding and/or die casting.
Continue developing technical skills and knowledge of mechanical design, materials, and manufacturing processes.