Look for the new menu tab:3D Printing Tips.  Starting this December (2019) NASS begins a series of tutorials using OpenSCAD and other software for designing and printing 3D objects.  As you might guess, we'll focus on creating sundials and other shadow casting objects.  Download your copy of OpenSCAD at http://www.openscad.org and join our tutorials.  If you want even more detail on 3D sundials, join NASS and receive The Compendium with Bill Gottesman, Steve Lelievre, Bob Kellogg and others writing in the regular column "3D Design and Printing Sundials."