Tank containers collection (HO scale)

This is a collection of highly-detailed intermodal 20ft tanks. To have more variety on your layout, this design can be printed in several variants of different appearance and complexity.

Main page for the project is here: https://positron96.gitlab.io/projects/container-collection/tank-containers.html. 

The mounting holes/pins are compatible with PIKO H0 flatcars and my previous 20ft container, but even better aligned. This time I decided to not create bottom pins with 3D printer, because 0.8mm pins are fragile, and not everyone needs them. Instead, there are holes both at top and bottom, and if you need the pins, you can melt in or glue pieces of paperclip or 0.8-1mm copper wire, or even thinner (0.5mm) if the wire is rigid enough, e.g. phosphor bronze wire or a guitar string. 

Here is a diagram of combinations that you can create with this design:

Picture description in text:

Basically there are 2 variants of frames: Frame-1 (yellow) is easy to print, Frame-2 (red) has more parts and is more complex to assemble.

Frame-1 can have 2 kinds of tanks: Tank-1 (round in cross-section) and Tank-2 (round-rect in cross-section).

Tank-1 is available in 2 variants - with 2 sets of valves at the top (Tank-1-2) and with 1 set (Tank-1-1).

Frame-2 only has 1 tank variant, Tank-3. It has 2 sets top valves. Tank-3 is slightly smaller than others, so its valves are slightly taller and are stored as separate parts.

There is one option for side ladder and 3 options for top steps (Ceiling-1, Ceiling-2 and Ceiling-3). Ceiling-1 was designed to go with tanks with 1 set of valves, Ceiling-2 and Ceiling-3 go with 2 sets of top valves. But in general you can intermix them as you want.

Halves of tanks have holes for 1.75mm filament pieces for precise alignment. Tanks also have cutouts for alignment with frame pieces. 

If you are going to lift the tanks by crane or want to add weight to wagons, it is a good idea to add around 10g of weight inside the tanks (steel nuts and bolts, lead weights, even stones or sand).

All the files have one flat face that should be at the bottom when printed. I used 0.08mm layer height for higher precision, 0.4mm standard nozzle. To speed things up, variable layer height can be used for tanks themselves (0.08mm for tank caps, 0.2 for cylindrical sections)

Assembly

The files required for each big component are the following:

• Frames:
  • Frame-1 (yellow, simpler)
    Frame-1 front
    Frame-1 back
    Frame-1 top
    Frame-1 bottom
  • Frame-2 (red, complex)
    Frame-2 front
    Frame-2 back
    Frame-2 top
    Frame-2 bottom
    Frame-2 diagonal 1 (x2)
    Frame-2 diagonal 2 (x2)
    Frame-2 diagonal with support 1 (x2)
    Frame-2 diagonal with support 2 (x2)
• Tanks:
  • Tank-1 (round)
    • Tank-1-2 (2 hatches at top)
      Tank-1 B
      Tank-1-2 F
      Tank-1 top valves big
      Tank-1 top valves small
    • Tank-1-1 (only 1 hatch at top)
      Tank-1 B
      Tank-1-1 F
      Tank-1 top valves big
  • Tank-2 (round-rectangular)
    Tank-2 F
    Tank-2 B
    Tank-1 top valves big
    Tank-1 top valves small
  • Tank-3
    Tank-3 B
    Tank-3 F
    Tank-3 top valves big
    Tank-3 top valves small
• Ladders and railings:
  Ladder
  Ceiling-1
  Ceiling-2
  Ceiling-3