Mechanical Engineering Intern

About the CompanyArn Autonomy is building autonomous, non-humanoid robotic systems to construct infrastructure in extreme, unstructured environments, starting with next-gen construction job sites. Our vision is to disrupt the $16 trillion global construction industry by pioneering a new Deep Tech philosophy that blends robotics, AI, and systems engineering at the frontier. Our flagship product, GRID, is an autonomous rebar-tying robot deployed with rebar and concrete contractors on live job sites. About the RoleWe're seeking a Mechanical Engineer Intern to join the team building GRID, our rebar-tying mobile robot. You'll work on real hardware: the tying mechanism, gantry, chassis, and powertrain. This is a hands-on, cross-disciplinary role spanning mechanical design, prototyping, and system-level testing, in close partnership with our software, electrical, and manufacturing teams. You'll get mentorship from senior engineers and a high degree of autonomy, and you'll see your designs built, tested, and run on live construction job sites. ResponsibilitiesMechanical Design: Design mechanisms, gantry, chassis, and structural components for a mobile robot operating outdoors, with durability, serviceability, and performance in dust, vibration, temperature swings, and weather in mindCAD & Drawings: Turn 3D models into complete drawing packages for machined parts, including GD&T, materials, finishes, and inspection requirements; maintain BOMs and engineering change documentationElectromechanical Integration: Integrate motors, sensors, bearings, cabling, and power transmission into robust, field-ready assemblies, using off-the-shelf and custom componentsPrototyping & Fabrication: Build and instrument prototypes and test setups; design parts for 3D printing and CNC machining and choose the right process for eachAnalysis: Size components with hand calculations and run structural analysis (FEA) on load-bearing parts to validate designs under real operating conditionsTesting & Root Cause Analysis: Plan and run tests on GRID, troubleshoot mechanical subsystems, and work with the responsible team to resolve issues and failuresManufacturing Readiness: Support DFM/DFA for machined, 3D-printed, and welded parts, and help build test fixtures and proceduresDocumentation: Document designs, test procedures, and results for traceability and knowledge sharing; contribute to design reviews and, where relevant, invention disclosuresLearning from Senior Engineers: Work alongside mentors to develop reliable mechanical designs for a range of robotic tasks RequiredCompleted a bachelor's or graduate degree from an accredited program in Mechanical Engineering, Robotics, Mechatronics, or a similar field, with no ongoing coursework, so you can commit to the internship full time and in personWorking knowledge of statics, mechanics of materials, and machine design fundamentalsProficiency in at least one CAD package (for example SolidWorks, Fusion, CATIA, or similar), with a working understanding of GD&T and tolerancingHands-on experience building or testing mechanical or electromechanical hardware, from coursework, a robotics team, or personal projectsAbility to analyze problems and work with teammates to find well-reasoned solutionsA self-starter with proven examples of self-directed learning, who stays productive with minimal supportAvailable to work full-time (40 hours/week) for an internship lasting at least six monthsAuthorized to work in the United StatesThis is an in-person role, five days a week, in the San Francisco Bay Area. You must be based in the Bay Area or willing to relocate for the internship. PreferredProficiency in a second CAD package and strong GD&T and tolerance-stack fundamentalsExperience running FEA and sizing structures by hand calculationPractical knowledge of CNC machining, 3D printing, and welded fabrication, and when to choose eachExperience sizing electric motors and gearboxes from payload, speed, slope, and duty-cycle requirementsExposure to mobile or outdoor robotic platforms (AMRs, construction or ag equipment, off-road vehicles) and how wheeled or tracked chassis behave over uneven terrainFamiliarity with IP-rated enclosures for dusty or wet environments, and with reliability testingPrior internship, co-op, or substantial project experience (robotics clubs and competition teams count)Ability to rapidly learn, evaluate, and adopt new AI tools and platforms as project needs evolve BenefitsWhy join us:Work on a real product: your designs ship on GRID, a robot deployed on live construction job sitesHands-on experience in mechanical design, integration, testing, and debugging on real hardwareCollaborate with electrical, software, and manufacturing engineers in a small, fast-moving teamMentorship and professional development from senior engineersWe're a startup moving fast, and being in the room together is how we build.Kaiser Gold HMO health planRelocation supportDaily lunchesPet FriendlyArn Autonomy is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, gender identity or expression, sexual orientation, national origin, age, disability, veteran status, or any other characteristic protected by applicable law.