Drive system VESC

3D-printed OpenTorque Actuators

A powerful, compliant actuator for legged robotics

OpenTorque is an open-source implementation of the quasi-direct-drive actuation scheme pioneered by the MIT Biomimetics lab. The basic premise is this: use the largest possible motor with the smallest possible gear reduction. This results in an actuator that is robust, highly backdrivable, and capable of proprioceptive force sensing and open-loop impedance control. These are all ideal attributes for building legged robots.

Read more about the project here


  • Peak torque (theoretical): 56 Nm
  • Continuous torque (measured): 28 Nm
  • Weight: 1.2 kg
  • Gear ratio: 6:1
  • Cooling: Air-cooled
  • Cost: Approx. $150


I also made a modified dual-version for a similar hip motion as the Agility Robotics Cassie robot. For my next project I will print 6pcs of the single and 2pcs of the dual-version. I will Use 10 Maytech 100A VESC´s (one for each actuator) to control each joint.



Credit for the Actuator goes to Gabrael Levine





Chief Technology Officer with a demonstrated history of working in the internet industry. Skilled in Business Planning, Computer-Aided Design (CAD), Quality Process Development, and SolidWorks. Strong business development professional with a Higher Education Diploma with specialization in Mechanical Engineering focused in Product development from Blekinge Institute of Technology.

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