Design and Fabrication of a Low-Cost Automated Waste Sorting and Recycling System

This project presents the design and fabrication of a low-cost automated waste sorting and recycling system, developed to enhance solid waste management efficiency through smart sorting mechanisms. The system comprised key components such as a mild steel structural frame, PVC conveyor belt, sensor array, and servo-driven flap diverters, all controlled via an Arduino microcontroller. Using computer-aided design (CAD) tools like SolidWorks and AutoCAD, the frame was modeled with dimensions of 1500 mm × 600 mm × 1000 mm, ensuring structural integrity under a 1000 N load with a safety margin (σ = 1.25 MPa << σy = 250 MPa). The conveyor belt, made from durable 3 mm PVC, was rated safe under a 7.5 kg load with tension below its rated capacity. Mechanical calculations confirmed the roller shaft, powered by a 20 W DC geared motor, operated within safe torsional limits (τ = 103 MPa < 150 MPa). The MG995 servo motors, rated at ≥ 0.6 Nm, successfully actuated the flap diverters requiring only 0.441 Nm. Sensor accuracy using TCS3200 color sensors reached 92%, enabling correct sorting of 52 out of 60 test items, yielding a sorting efficiency of 86.7%. The conveyor operated at 0.209 m/s, with synchronized flap actuation ensuring near-perfect timing (Tsync ≈ 0.96 s). Overall, the system demonstrated a composite performance efficiency of 70.14%, proving both technically viable and cost-effective for small-scale waste segregation and recycling. The results validate the system’s potential as a sustainable solution for automated solid waste management in developing regions.