Senior Mechanical Engineer — Actuation at Walden Robotics · Cambridge

At Walden Robotics, we envision a world where general-purpose robots dramatically improve the quality of life for all people—supporting us at home, at work, in factories, on farms, and beyond. To accomplish this, we are building a team of exceptional professionals who combine world-class technical skills with creative vision, grounded in humility and collaboration.

Position Summary:

We are hiring a Mechanical Design Engineer to design, build, and improve mechanical hardware across our robot. In this role, you will develop structures, mechanisms, enclosures, sensor and electronics packaging, cable routing, and other integrated hardware. You will own defined components and small assemblies from concept through prototyping, testing, and release, working closely with senior engineers and cross-functional partners.

Core Responsibilities:

• Design and deliver mechanical components and assemblies across the robot, including structures, mechanisms, brackets, covers, sensor mounts, and electronics packaging.
• Validate designs using hand calculations, FEA, tolerance analysis, and material and manufacturing process selection.
• Create production-quality CAD, drawings, and BOMs, applying GD&T and supporting DFM/DFA with suppliers and manufacturing.
• Build and test prototypes, support robot assembly and integration, and troubleshoot mechanical issues.
• Partner with electrical, controls, firmware, manufacturing, and robot build teams to resolve interfaces and improve performance, reliability, and serviceability.

Required Qualifications:

• BS in Mechanical Engineering or a related field and 3+ years of relevant design experience, or an MS and with relevant hands-on experience.
• Strong mechanical design fundamentals, including structures, mechanisms, fasteners, materials, tolerances, and load paths.
• Proficiency with 3D CAD such as SolidWorks, CATIA, or NX, as well as engineering drawings and GD&T.
• Hands-on experience prototyping, assembling, testing, and troubleshooting mechanical or electromechanical hardware.
• Strong communication, ownership, and ability to work effectively in a cross-functional environment.

Preferred Qualifications:

• Direct experience with robotic systems, preferably humanoid and/or manipulation robots.
• Experience designing high-torque-density actuators with frameless/BLDC motor integration.
• Experience with custom gearbox design (planetary and harmonic or cycloidal drives), experience with gear analysis tools such as KISSsoft or similar software and high-volume manufacturing of precision mechanical components.
• Direct experience with robotic systems, preferably humanoid and/or manipulation robots.
• Experience designing high-torque-density actuators with frameless/BLDC motor integration.
• Experience with custom gearbox design (planetary and harmonic or cycloidal drives) and high-volume manufacturing of precision mechanical components.
• Experience with integrated position/torque sensing (absolute encoders, strain-gauge or magnetic torque sensors) and how sensor placement affects mechanical design and control loop performance.
• Experience with bearing selection and preload/stiffness analysis for compact, high-stiffness joints (cross-roller, four-point contact, angular contact bearings).
• Experience characterizing backlash and joint compliance to support controls tuning, understanding how mechanical tolerance stack-up affects closed-loop performance.
• Experience with Hertzian contact stress and gear tooth bending fatigue analysis.
• Experience with thermal design and motor cooling for frameless BLDC integration in sealed or space-constrained housings.
• Track record taking an actuator from prototype through DFM iteration to production release, including supplier tolerance capability assessment.
• Experience with lubrication and sealing selection (grease life, IP rating) for joints exposed to duty cycles.
• Familiarity with functional safety standards relevant to powered joints (ISO 13849, IEC 61800-5-2).
• Experience designing for serviceability and field-replaceability of actuator modules.
• Experience mentoring junior engineers or driving design reviews across a subsystem.

Walden Robotics offers a competitive total compensation program, including salary, annual cash bonus, company equity, company-subsidized insurance programs, 401(k) with company match, flexible PTO, daily lunch, and other benefits. The pay ranges noted on our posts is for salary only.

Walden Robotics is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to age, ancestry, color, family or medical care leave, gender identity or expression, genetic information, marital status, medical condition, national origin, physical or mental disability, political affiliation, protected veteran status, race, religion, sex (including pregnancy), sexual orientation, or any other characteristic protected by applicable laws, regulations, and ordinances. If you need assistance and/or a reasonable accommodation due to a disability during the application or the recruiting process, please send a request to hello@waldenrobotics.com.

Walden Robotics participates in E-Verify. If you receive an offer of employment from Walden, you will need to go through the E-Verify process of digital verification of your employment authorization documents as provided on the Form I-9. Participation in E-Verify does not limit your right to work and verification will only be completed after you become