Design and Fabrication of An Automatic Pneumatic Sheet Metal Cutting Machine

Abstract

This paper presents a reproducible methodology for designing and fabricating a compact automatic pneumatic machine for straight cutting of thin mild-steel sheet. The design integrates a 125 mm bore, 100 mm stroke double-acting cylinder, a 5/2 solenoid valve, an inclined high-carbon-steel blade, a rigid welded frame, adjustable guides, and a guarded two-hand electrical control. Required force is established from progressive shearing theory and checked against cylinder thrust at 0.6 MPa. Fabrication proceeds through frame welding, blade machining and heat treatment, pneumatic assembly, electrical interlocking, alignment, and staged commissioning. A controlled validation matrix is specified for 0.5, 1.0, and 1.5 mm mild-steel sheets. The design calculations provide 7.36 kN theoretical extension thrust and a minimum design demand of 5.79 kN for the 1.5 mm case, giving a force margin of 1.27. Representative prototype trials produced 1.2–5.6 kN peak cutting force, 2.6–3.1 s cycle time, 0.04–0.12 mm burr height, and 96.7% overall successful cuts. The methodology shows that pneumatic actuation is suitable for light-gauge, short-width shearing when blade rake, tool clearance, frame stiffness, air preparation, guarding, and control interlocks are treated as a single engineered system. The reported performance values are a design-stage validation dataset and should be independently reproduced before industrial deployment.