square tray 3d model

Generate a lightweight, 3D printable STL model of a square resin tray base. Specifications: – Overall outer dimensions: 42 mm x 42 mm. – Corner fillet radius: 5 mm. – Base thickness: 1 mm nominal thickness. – Add a continuous perimeter wall on top. – Wall height: 2 mm. – Wall thickness: 1 mm. Weight reduction optimization: – Hollow the base internally leaving a 0.8 mm bottom skin. – Add a cross-shaped rib structure underneath (two perpendicular ribs). – Rib thickness: 1 mm. – Rib height: 1 mm. – Maintain a 3 mm solid perimeter ring under the wall for structural strength. Requirements: – No overhangs exceeding 45 degrees. – Designed for PLA FDM printing. – Flat bottom surface. – Units in millimeters. – Export as STL. – Ensure model is manifold and watertight