Terminal Case
Summary
The objective is a waterproof, corrosion-resistant, chemical-resistant, impact-resistant, lightweight, accessible, versatile, modular container for electronics and other hardware.
For recyclability, the use of a single frame material is optimal. Aluminum alloy (ex. Al6061) is corrosion and chemical resistant, machinable and weldable, and has a relatively high strength to weight ratio. A rectangular frame with low height minimizes geometric complexity and material use (for low-height technologies like circuit boards).
For maximum waterproofing, the terminal case should have minimal failure points. Accessibility inside the terminal case from just 1 face (ex. top face) provides the greatest waterproofing to accessibility ratio (at least where area-access technologies like circuit boards are concerned).
A seal designed for disassembly involves the application and release of tension on a sealing material that surrounds the inner volume. The seal material should be elastic, non-porous, and of a fine stick surface (with low adhesiveness for disassembly) for water-tight contact volume with the frame material. Certain types of rubber fit those criteria; rubber rod is most accessible and versatile (for other applications as well).
The frame should have a mechanism to hold the seal material in place and minimize exposure of the seal material with substances outside the terminal case. A groove or slot (slot is easier to make) along the top face of the perimeter frame material improves seal material holding; provides space into which the seal material can be compressed for reducing the seal exposure and improving the proximity-durability of the seal (ex. without a groove/slot, the seal material gets entirely flattened into a thin sheet (resulting in low tensile strength and vertical elasticity), whereas a groove/slot better retains the volume of the seal material along all 3 axes)
The seal tension is applied between the base frame and the lid. Tensioning methods include C-Clamps (greater modularity, but greater relationship between impact events and waterproof level - ex. if the CClamps get hit, seal tension changes a lot) and screws (more compact, but more complex, less compatible, and more waterproofing failure points).
Diagram
