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2024–2025

6-DOF Robotic Arm with 3D-Printed Cycloidal Gearboxes

A low-cost 6-axis robotic arm with 3D-printed cycloidal gearboxes at the high-load joints, running C++/ROS motion code on an ESP32.

Personal project — design, fabrication, and software

RoboticsC++ROSESP323D PrintingMechanism DesignOnshape

An ongoing personal project to build a capable 6-axis arm without the cost of commercial servo gearboxes. I do everything on it myself: mechanism design, fabrication, electronics, and software.

Gearboxes

The high-load joints need more torque than hobby motors provide directly, and machined gearboxes with usable ratings cost more than the rest of the arm combined. I designed cycloidal gearboxes that print reliably on a desktop printer instead. Cycloidal drives tolerate shock loads well and don’t depend on fine tooth geometry, which makes them a good match for FDM printing.

Software

Motion code is written in C++ with ROS, running on an ESP32. The arm currently supports edge tracking and drawing on a plane.

CAD

The viewer below shows the disc geometry at the center of the gearbox design. The assembly models live in Onshape, and I’ll add embed links once the document is cleaned up for public sharing.

CAD

Cycloidal gearbox disc

Loading model…
Sample disc geometry from the gearbox design. Drag to orbit, scroll to zoom.
Download STL ↓