Sr. Mechanical Engineer - Electromechanical Subsystems

About Bots Unlimited

Bots Unlimited is a San Antonio based product development and hardware company that designs, produces, and supports high performance technology for drones, robotics, automation, and edge AI systems. We create advanced camera modules, long range wireless solutions, embedded compute platforms, and propulsion electronics, working closely with trusted manufacturing partners to deliver reliable hardware with a globally resilient supply chain. We also provide customers with supply chain support and manufacturing services to help bring complete products to market.
We operate in a fast moving, execution focused environment where team members own their work end to end and are trusted to manage themselves with a high level of accountability. Our team values initiative, clear communication, and a strong sense of responsibility, qualities that let us move quickly and ship production-ready hardware.
If you thrive in a setting where you can take full ownership, solve complex challenges, and build products used in real world scenarios, we may be the right fit for you!

Position Overview

We are seeking a highly experienced Senior Mechanical Engineer – Electromechanical Subsystems to lead mechanical design, documentation, and manufacturability for our brushless DC motors, motor housings, rotors, stators, and other rotating/electromechanical assemblies. This role will own the full mechanical design lifecycle from concept through detailed CAD modeling, drawing release, supplier/vendor handoff, and manufacturing support.

We are looking for self-managed, Type A personalities: people who thrive in fast-moving environments, can work independently, and push projects forward without constant direction. Your work will directly enable our drone, robotics, and mobility products, turning prototype motor designs into production-ready hardware that meets tight tolerance, material, and performance requirements.

This is a hands-on, onsite role based in San Antonio, TX. You'll work closely with the electrical, test, and manufacturing teams in our lab environment to build, validate, and iterate on real hardware. Our team operates at startup speed, and you’ll be expected to contribute directly to hardware that ships to customers on aggressive timelines. The role includes working with mechanical tools and prototypes, participating in daily engineering discussions, and being physically present for assembly, test, and debug efforts.

Key Responsibilities

• Develop 3D CAD models and detailed mechanical assemblies for motors, housings, rotor/stator sub-assemblies, shafts, bearings, and related components.
• Produce full mechanical drawings: dimensioned parts, GD&T, tolerance stacks, material specifications, surface-finish and plating/coating details.
• Manage and maintain mechanical data and revision control in our PLM system (e.g. Duro or equivalent).

• Create manufacturing-ready documentation (BOMs, vendor quotes, machining/assembly work instructions, QC/inspection checklists).

• Perform DFM/DFMA reviews to ensure designs are optimized for cost, manufacturability, and reliability.

• Collaborate with electrical/firmware teams to ensure mechanical design supports motor performance, thermal requirements, and integration with ESC/housing.

• Interface with vendors and manufacturing partners: issue RFQs, review vendor drawings, negotiate tolerances, and coordinate prototype builds.

• Lead mechanical validation testing: oversee prototypes, manage assembly/disassembly, coordinate with test lab, and record physical test data (vibration, torque, RPM, thermal).

• Support product release: ensure all mechanical deliverables are complete for first-article inspection, pre-production, and mass production handoff.

• Mentor or guide less-senior mechanical/design engineers where applicable.

Required Qualifications

• Bachelor’s or Master’s degree in Mechanical Engineering, Mechanical Design, or equivalent engineering discipline.
• Minimum 5–10 years of mechanical design experience, with substantial time spent designing rotating equipment, motors, or mechanical powertrain components (shafts, bearings, housings, etc.).
• Expert proficiency in 3D CAD software (e.g. SolidWorks, Autodesk Inventor, Creo, etc.) — able to create complex assemblies and prepare detailed 2D drawings with GD&T.
• Solid understanding of GD&T, tolerance analysis, material properties, surface finish, coatings/plating, fasteners, and mechanical fit/clearance principles.
• Proficiency in using standard mechanical engineering tools and instruments such as calipers, micrometers, gauges, dial indicators, and other measurement or inspection tools required for prototype validation, fit/clearance checks, and vendor QA collaboration.
• Experience with PLM or PDM systems (e.g. Duro, Windchill, Arena, similar) to manage part revisions, BOMs, and release workflows.
• Familiarity with manufacturing processes: CNC machining, sheet-metal, casting, magnet assembly/stacking, rotor balancing, assembly tolerances, vendor sourcing.
• Strong documentation skills: ability to draft manufacturing instructions, inspection checklists, QC requirements, and vendor drawing packages.
• Experience working with or specifying bearings, shafts, rotor-stator assemblies, magnets, housings, and mechanical/magnetic tolerances relevant for motor design.
• Ability to collaborate with multidisciplinary teams (electrical, firmware, mechanical, quality) and vendors to drive designs through to production.
• Excellent communication skills (written and verbal), and ability to work onsite in San Antonio — vendor visits and hands-on builds expected.
• Travel: Willingness to travel periodically throughout the year to support key product milestones and collaboration efforts. Examples include visiting manufacturing partners for first article builds, production testing, and process improvements; traveling to design partners for technical alignment or strategy meetings; and attending select trade shows or industry events to support product demonstrations or team visibility.

Preferred Qualifications

• Prior experience designing or supporting brushless DC motors, electric motors, or electromechanical actuators / gear-driven mechanisms.
• Experience with rotor balancing, vibration analysis, shaft alignment, and mechanical durability / lifecycle testing.
• Familiarity with motor housings, magnet assemblies, stator laminations, and shielding or coating processes (paint, plating).
• Previous experience with supplier sourcing, vendor negotiations, vendor-managed manufacturing, or DFM with overseas manufacturers.
• Background in design for assembly (DFA), design for manufacturing (DFM), cost-driven design optimization.
• Experience writing or reviewing first-article inspections, quality control plans, tolerance audits, and mechanical verification documents.
• Familiarity with rotating systems standards and safety requirements (e.g. balancing, critical speed, vibration, run-out tolerances, rotational safety considerations).

Physical and Mental Requirements

• Ability to sit and/or stand for periods of time. 
• Ability to use a keyboard, mouse, and other equipment with or without accommodation(s). 

• Ability to maintain awareness during business hours. 

• Ability to lift 15 pounds. [MAYBE MORE IF WAREHOUSE]

• Excellent written and verbal communication and good command of the English language. 

• Ability to learn and memorize routine tasks. 

• Reasonable accommodations will be provided to any person with a disability to be able to perform the essential job functions of this position. 

• Company retains the right to change or assign other duties as required for this position.  

Why Join Us

• Work on cutting-edge electromechanical products (motors/actuators) destined for drones, robotics, and advanced mobility platforms.
• Be in a high-impact role — you will own mechanical design end-to-end, and your work will directly determine manufacturability, cost, and product reliability.
• Collaborate closely with electrical, firmware, RF, and manufacturing teams — gain broad exposure beyond conventional mechanical design.
• Onsite role in San Antonio — hands-on work, close collaboration, and tangible output (not just desk-work).
• Fast-moving environment with opportunity to influence design practices, vendor selection, and manufacturing workflows from day one.

Selection Process

• Hiring team reviews applications 
• 15-minute pre-screen with recruiter 

• 30-minute phone screen with the hiring manager 

• Take home project 

• In-person or video interview with hiring team 

Benefits

• Comprehensive medical plans with Rx
• 100% employer paid dental and vision insurance premiums
• Automatic 401k employer contribution with vesting
• Paid vacation and personal time off
• 11 Paid holidays
• 5 days of sick leave

We are an equal-opportunity employer and prohibit discrimination and harassment against any employee or applicant because of race, color, gender (including pregnancy), age, gender identity, creed, religion, national origin, sexual orientation, marital status, genetic information, disability, political affiliation, protected veteran status, or any other status protected by federal, state, or local law.