Hardware

Belt Drive

A belt drive is a power transmission that couples two pulleys with a flexible belt, in robotics almost always a toothed synchronous (timing) belt that prevents slip while allowing the motor to be mounted away from the driven joint. Belts reduce reflected inertia at distal joints, run quietly, tolerate shock loads, and add elasticity, but they stretch over time and require tensioning, trading some stiffness and precision against gears.

Why it matters for physical AI

Remote motor placement via belts keeps arm inertia low, improving both dynamic performance and collision safety, a design pattern common in low-cost arms used for learning research and in high-speed pick-and-place hardware.