Strong, Accurate, and Low-Cost Robot Manipulator

2025-07-21

AI Summary

Existing low-cost educational robotic arms suffer from limited payload capacity, poor positioning accuracy, and insufficient structural stiffness. Method: This work introduces Forte, a high-performance six-degree-of-freedom robotic arm fabricated entirely via 3D printing and driven by a novel umbrella-gear-based cable-drive mechanism, combined with synchronous belt transmission and topology-optimized lightweight structures. Contribution/Results: Achieving a material cost under USD 215, Forte reduces backlash and enhances rigidity without requiring high-power electronics or precision machining. Experimental evaluation demonstrates a 0.63 kg payload capacity, a 0.467 m operational reach, and sub-millimeter (<1 mm) repeatability—performance approaching industrial-grade standards. As an open-source, reproducible, and easily deployable hardware platform, Forte is particularly suited for robotics education, AI algorithm prototyping, and hands-on research in resource-constrained environments.

Technology Category

Intelligent Robots: ManipulationComputer Vision: Low Level & Physics-based VisionPhilosophy and Ethics of AI: Safety, Robustness & Trustworthiness

Application Category

Responsible Web: Machine-in-the-loop, human agency and autonomyEconomics, Online Markets and Human Computation: Cost models of using LLMs in production systemsSystems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments

Abstract

This paper presents Forte, a fully 3D-printable, 6-DoF robotic arm designed to achieve near industrial-grade performance - 0.63 kg payload, 0.467 m reach, and sub-millimeter repeatability - at a material cost under $215. As an accessible robot for broad applications across classroom education to AI experiments, Forte pushes forward the performance limitations of existing low-cost educational arms. We introduce a cost-effective mechanical design that combines capstan-based cable drives, timing belts, simple tensioning mechanisms, and lightweight 3D-printed structures, along with topology optimization for structural stiffness. Through careful drivetrain engineering, we minimize backlash and maintain control fidelity without relying on high-power electronics or expensive manufacturing processes. Experimental validation demonstrates that Forte achieves high repeatability and load capacity, offering a compelling robotic platform for both classroom instruction and advanced robotics research.

Problem

• Design a low-cost, high-performance 3D-printable robotic arm
• Achieve industrial-grade performance with minimal material cost
• Provide accessible robotics for education and AI experiments

Innovation

• Fully 3D-printable 6-DoF robotic arm
• Capstan-based cable drives and timing belts
• Topology optimization for structural stiffness