This is a project to develop a 3d printable storage unit for storing different types of cards in separate boxes attached to each other in a circular configuration. Different size boxes are allowed. It is planned to be easily configurable for different games. There is a minimum of three boxes and the size of the front of one box can not be bigger than the total size of all the other boxes, or else they can't be arranged in a circle. The plan is to set up the boxes so there inside facing sides are chords of a circle and touch those of the neighboring boxes. This forms a cyclic polygon which will have the maximum area for a given list of side lengths. Closed forms calculations for this quickly become intractable, so numerical calculations need to be used instead. There are three cases depending on whether the center of the circumscribed circle is inside, on the border or outside of the cyclic polygon and the calculation method needs to be tweaked for each case. I'm using Halley's irrational method to iterate to the circumradius. The boxes are held together interally be their base, so the base will need some real thickness. This is so there can be a gap for extracting cards easily. Externally there will be a curved connection between the sides of adjacent boxes, the height of the lower box. This will also need some real thickness to hold things together. The default box settings will probably end up being what I use for Dragons Down, since that use is what inspired this project. The source is for use with Openscad, which can output an stl file to be used by a slicer to produce gcode for a 3d printer. For example: `openscad -o card-storer.stl card-storer.scad` You can also get a 2d preview, using for example: `openscad -o card-storer.png card-storer.scad` I split the Dragons Down boxes into two rings. To render the second ring use: `openscad -Ddd=2 -o card-storer.stl card-storer.scad` Note that radius.pl was used only for development (testing the approach to calculate he circumradius) and is not used to build any artifacts.