I know everyone is concerned about how much filament they use, but sometimes we want something to be solid. This coin base was made using Tinkercad.com. I selected cylinder, but it made it a bit geometric instead. Regardless it does the job well, it fits into the base of the coin sorter and takes the flex out of the main part, provides a little weight to help keep it from tipping, and gives the US version the height it needs to match the coin chute. I did not lock it in place, but I am also able to lift up the whole sorter without the base falling out. I just started making some of my own things and wanted to start simple, this was the first thing I made.

Lower base is 25mm (.98 inches... close enough), the upper part is 12mm to fit inside the lower cone of the sorter.