This is a large coin bank. It prints in one piece, and can only be opened by breaking it apart. It is 120 mm tall and 115mm in diameter. The coin slot is 28 x 2.5 mm and has been tested with coins in the United States.
Let's be honest, this is a difficult object to print. It looks deceptively simple. You have to get your slicer settings just right, or it won't work. The main difficulty is that it is hollow and has a 36 degree overhang (where 90 deg is straight up, no overhang). You can't use supports, since there is no way to remove them from the inside.
Print it with one side of the pentagon on the build platform, and the coin slot vertical. Then use 0.10 mm layers. One outline (shell, perimeter, or whatever). And 100% infill with the pattern at 45 degree angles to the walls of the bank. Then slow the print down to as slow as you have patience for.
If you use more outlines, or don't have your infill at a 45 degree angle to the walls, the the top of the print will not turn out well. Structurally the overhang will not hold together well.
The 100% infill is required for strength. The walls of this bank are just 2 mm thick, but it has no problems standing up to the weight of a full load of coins.
The Banks in the photos took me 24.25 hours to print, each, on a highly modified Replicator 2. I have printed them in as little as 14 hours, but they don't look as nice.