Brainstorming and Developement

Brainstorming began after identifying key limitations in ARM 2.0, where joints were structurally integrated into the tube stock, making link length changes between shoulder and elbow impossible without redesigning the entire arm. Additional issues included backlash from REV gearboxes, and separate motors, controllers, and wiring, which increased complexity, weight, and failure points.

This led to research into integrated motor modules, commonly used in robotics to combine motor, reducer, encoder, and controller into a single unit. Design requirements were defined as modular, compact, lightweight, high torque, low backlash, and adaptable, enabling independent joints that could interface with variable-length tube links while reducing wiring and improving reliability. Harmonic drives were selected due to their high torque density and near-zero backlash, and modules were designed around Harmonic Drive 17-100-118879-11 reducers sourced second-hand. Each module integrates an ODrive controller with magnetic encoder feedback and is housed in a single-piece CNC aluminum structure.

As part of the Master Validation Plan, I designed and machined an initial module to retrofit ARM 2.0 using a NEO 1.1 motor, validating mechanical interfaces, tolerances, and manufacturability before committing to full deployment. Following successful validation, the ARM 3.0 motor modules were contract manufactured, establishing a fully modular joint architecture independent of the arm structure.

2026 ARM 2.0

Verification and Manufacturing