Design and Development of an Autonomous 6-Dof Robotic Arc Welding Prototype for Horizontal Metal Joints

The automation of arc welding processes offers significant advantages in terms of repeatability, quality, and operator safety. However, the high cost, complexity, and fixed installation of traditional industrial robotic welding cells render them inaccessible for small and medium enterprises (SMEs), educational institutions, and field applications. This paper addresses this gap by presenting the design and development of a compact, low-cost, and autonomous robotic welding kit specifically engineered for horizontal fillet and butt joints. The system is architected around a custom-built, six-degree-of-freedom (6-DOF) Cartesian gantry mechanism, providing precise linear travel and cross-seam adjustment. A commercially available Shield Metal Arc Welding (SMAW) is integrated as the end-effector. The core of the system's autonomy is an embedded control unit, which executes pre-programmed welding procedures. User-defined parameters, including travel speed, voltage, electrode feed rate, and weld length, are input via a simple keypad and display interface. The entire kit is designed for portability and rapid setup on standard workshop workbenches. A series of experimental welds was conducted on 5 mm thick standard mild steel plates in a horizontal position to validate the system's performance. The results demonstrated consistent bead geometry with acceptable penetration profiles, as confirmed by micrographic analysis. The system successfully produced repeatable welds with minimal spatter and defects across multiple test runs, achieving a dimensional deviation of less than ±0.5 mm in bead width when compared to the programmed path. The developed robotic welding kit proves to be a viable and cost-effective solution for automating horizontal welding tasks. Its simplicity, affordability, and ease of use make it particularly suitable for training, small-batch production, and applications where investment in a full-scale industrial robot is not justified. Future work will focus on integrating seam tracking sensors to enhance adaptability and expanding the system's capability to handle simple curvilinear joints.