Rugged customizable box with free moving hinges and a firm latch. Scales well.
No hardware required, just use filament through the hinges and latch. I put a small drop of CA glue on the ends of the hinge and latch filaments to prevent any movement.

Use the Customizer to get the size you want. I printed with PLA+, no supports, 15% infill.

I recommend printing the latch laying down on its front face. 

Updates:
- Added 3 checkboxes into the parameters; Render_Box, Render_Lid, Render_Latch so you can select individual parts for rendering and exporting.
Start with them all checked, then set the parameters for the size you want the finished box, then use these checkboxes to turn on/off each part to render and export.
- Made Lid_Height parameter visible.

Made with OpenSCAD 2021.01 and the BOSL2 library.