This is a parameterizable ring made in OpenSCAD with a "BHat" logo for the Baltimore Hack-A-Thon.It was created as part of the Nickel for Scale project, which you can learn more about at http://nickelforscale.com/You'll need both real_bhat_ring.scad and B.dxf to render a custom-sized ring.To resize the ring without Nickel for Scale:To resize the ring with Nickel for Scale:To change the letter: I used Inkscape to generate the B. To use it with OpenSCAD, I saved a copy as Encapsulated Postscript (.eps), and chose the option to convert the text to a path. I then used pstoedit to convert the .eps to a .dxf, which is the format that OpenSCAD expects.