Ellipse intersection shape

This OpenSCAD script will generate a 2D shape based on two partially overlapping ellipses
The radii of both ellipses are controlled by specifying the final width and height of the created shape as well of the ratio of the depths of each side
there is also an option for rounding the shape while preserving it's dimensions with controllable radius

Author: Mark Gaffney
Version: 1.3
Date: 2013-03-19

Todo:

Warning:
If band_depth > band_width the alignments might not work correctly
If ro