3D-Printed USB Enclosure | Lid and Port Fit Revision

A self-initiated CAD study of a two-piece electronics enclosure. Revision A had two fit problems: the 72.4 × 44.4 mm lid lip was too large for the 72 × 44 mm cavity, and the 10 × 5 mm USB opening sat 1 mm below the intended plug center. Revision B reduces the lip to 71.4 × 43.4 mm for 0.30 mm nominal clearance per side. The front opening grows to 12 × 7 mm and its center rises from 8 to 9 mm above the base. The design reference is an 11 × 6 mm rounded plug envelope, giving 0.50 mm nominal clearance per side. The lid seats on the rim and uses four screw positions. Each revision includes a body and lid in both STEP and STL, with a dimensioned comparison. Reimported STEP solids showed interference in A and zero overlap in B at the seated lid and plug positions. STLs were checked for closed meshes. Physical fit and screw engagement still need a test print.