Sustainable Design of a Compact 3+1 DOF Desktop Robotic Arm for Energy-Efficient Automation

Abstract

Fatigue, human error, and reduced productivity are common challenges in industrial operations involving repetitive manual tasks. In response, this paper presents the design, fabrication, and performance evaluation of an affordable, low-cost desktop robotic arm featuring 3+1 degrees of freedom (DoF) integrated with a servo-driven gripper. The mechanical structure was modeled in SolidWorks and fabricated via Fused Deposition Modeling (FDM) 3D printing utilizing Polylactic Acid (PLA) material. To optimize torque transmission and ensure smooth, low-backlash operation, actuation is achieved via NEMA stepper motors coupled with a pulley belt transmission system, controlled by an Arduino microcontroller. Test experiments were conducted to assess mechanical reliability, specifically focusing on positioning repeatability using an analog dial indicator and payload capacity constraints. Experimental results indicate that while the primary link maintains excellent positional consistency across successive cycles, mechanical joint play and inconsistent belt tension introduce slight positional deviations along the base and secondary link axes. Furthermore, load testing demonstrated a maximum payload capacity of 150 grams, with optimal operational stability achieved under 50 grams before structural strain occurs. The developed prototype demonstrates a cost-effective automation architecture for light industrial tasks and offers a robust, accessible open-source platform for robotics education. Ongoing development focuses on integrating feedback sensors, such as encoders and limit switches, to transition the platform from manual control to full closed-loop automation.