ENGINEERING A SMALL-SCALE NUT-CRACKING MACHINE: COMPUTATIONAL AND EXPERIMENTAL VALIDATION FOR RUBUS FRUTICOSUS PROCESSING

Abstract

Processing Rubus fruticosus nuts requires effective, environmentally friendly equipment to minimize mechanical damage and retain bioactive substances like anthocyanins and polyphenols.  Advanced engineering solutions are required since traditional approaches frequently lead to inefficiency and nutrient loss.  Through careful calculations for pulleys, shafts, and keys, this study sought to create a nut-cracking machine that was optimized for Rubus fruticosus nuts, with an emphasis on high cracking efficiency, little mechanical damage, and structural integrity.  A mild steel frame of 600 mm by 400 mm by 500 mm, a “Type A” V-belt, and a 2 HP (1.492 kW) electric motor were all used in the design.  Shaft diameter (70 mm), key length (100 mm), and pulley size (driver: 120 mm, driven: 240 mm) were all calculated. Frame integrity was evaluated using Autodesk Inventor 2023's Finite Element Analysis (FEA).  Cutting, welding, and buying common parts like belts and bearings were all part of the fabrication process.  The machine produced a torque of 12.344 N·m, a V-belt pitch length of 1201.42 mm, and a design horsepower of 1.939 kW.  With a deflection of 2101.468 µm, the shaft withstands a maximum bending stress of 732.821 MPa and a shear stress of 36.061 MPa.  A maximum frame displacement of 0.017 mm and a primary stress of 10.511 MPa were found using FEA, which is significantly less than the mild steel yield strength of 250 MPa. The strength of the key was ensured by its safety factor of 401.761.  For processing Rubus fruticosus nuts on a small scale, the nut-cracking machine that was created is both efficient and structurally robust.