I needed somewhere to store my mini-Creeper and Anatomy army, so a Minecraft Chest seemed like the perfect solution.
The two halves of the chest are connected by inserting a piece of 1.75mm filament into the back hinge. You can add a dab of glue to the holes on each side to keep it in place if necessary.
The top and bottom halves include holes for 4mm x 1.4mm disc rare earth/neodymium magnets, which helps hold the lid closed. They aren't necessary, and the lid should stay fully closed without them.
The top half includes .4mm supports to prevent issues with bridging across such a large area. Use the "Detect Thin Walls" feature of most 3d print software to make sure the included supports are used, or turn the setting off if you want to try bridging across the entire surface. All parts can be printed without supports, but a brim is suggested for the main chest halves due to potential warping at the corners.
Each panel can be printed without brim, as it shouldn't warp with such thin parts. The panel for the very top of the box is thinner than the rest, to account for potential sagging while printing the bridges for that piece.
When printing the double-chest, the top and bottom side panels are the same as for the single-chest model. Just print two of the single lid panels as indicated, but only two of the single bottom panels.
The tolerances for the lock are very tight, so it may require some sanding to fit into the lid and panel slots. I felt it was better to have a tight connection than require glue in a loose fit.
Found that three of the panels for the double-chest weren't quite correct. Bottom back, top back and front panels have been re-uploaded with corrected versions.