Using https://www.thingiverse.com/thing:2536972 Corners, we are now going to build a 20' closed container with doors on one shortside which, of course, can be opened. You can also have doors on both shortsides.

You always need the same amount of Corner and Corner_mirror, because the oval hole in the corner should be longside in the upper and lower position of the container. So if you are building a standard container you need to print four Corner_3 and four Corner_3_mirror.

For one sidewall you need Longside_1 at both ends and Longside_2 in the middle. For roof it is Roof_1 at both ends and Roof_2 in the middle.

Container_Door_Hinge_B fits with A if you don't use 3D-printed doors with hinges B. You can of course use any material for wall/roof/doors. Hinges might need some sanding to work smoothly.

Youtube link: https://youtu.be/S83Cjz6E4JE

Alu-profiles length for standard 20': H: 161mm W: 152mm L 20': 403mm

Parts needed: Alu-profile 10x10x1mm Small screws M2x8 to 10mm, four of those to door hinges. M3x170mm threaded rod, four of those to dummy lock. Some glue to mounting profiles, wall and roof parts. Floor: wood, sheet metal, plastic, cardboard or whatever (or roof parts).