I got kind of tired of rewriting the same OpenSCAD code to build rounded boxes for things and messing up the minkowski sum math in the process, so I built a simple module to do it for me.
Usage is simple:
include <rounded_case.scad>
rounded_case(25, 25, 10, 2);
The paramaters are:
rounded_case(X, Y, Z, T, LID, LID_OFFSET)
Where:
X, Y, Z : Inside dimensions of box
T : Thickness of walls
LID : optional, bool : true to also make a lid
LID_OFFSET : optional : how much smaller to make the "lip" of the lid that fits inside the top of the box
The outside dimensions of the box will be the inside dimensions + 2 x T. E.g. if the X dimension is 20mm, and T is 2mm, then the width of the box will be 24mm (20 + 2 + 2). The example above will make a box that is 29mm x 29mm x 14mm (with the lid on) on the outside, and 25 x 25 x 10 on the inside.
Get it here:
rounded_case.scad