I engineered an advanced smart electric toothbrush, blending tight internal component packaging with a premium waterproof exterior. The internal CAD assembly houses the high-frequency vibration motor, rechargeable battery cell, and custom PCB, using tongue-and-groove joints with silicone gaskets for a watertight seal. I delivered fully detailed 2D engineering drawings with precise GD&T tolerances for manufacturing, alongside stunning, photorealistic renders highlighting the sleek matte finishes.