Polaris Finder Diagram Stencil v1.2

thingiverse

This stencil adds a Polaris finder diagram to a field map, notebook, nautical chart, or other navigation aid for use in the northern hemisphere when a compass is unavailable; it also looks great on a backpack. Handwrite a note that constellations rotate around Polaris and from wherever you are standing except at the north pole; north is in the direction of Polaris and not affected by where constellations appear around it. This stencil was inspired by seeing an American military evasion chart designed for downed pilots, which is a topographical map with survival, medical, signaling, and navigation tips and diagrams on the edges; printed on Tyvec they are waterproof and rip resistant just like polymer sheets National Geographic Adventure Maps and Riese Know-How maps. The northern hemisphere evasion charts include a similar diagram using the same navigation stars found on this stencil. To get star locations I used select-area-grab with gnome-screenshot while running Stellarium and imported that into Gimp where I put my pointer over each star and used the edge ruler reading to locate the stars in this OpenSCAD file. This stencil lines out the Ursa Major (AKA Big Dipper) pointer stars and shows Casopia to orient one's eyes to find the tail tip of Ursa Minor (AKA Little Dipper). Cephus and the two bright stars of Ursa Minor are commented out in the OpenSCAD code as I feel they clutter the diagram but you can uncomment them if desired. There is also a north pointing arrow with a N below to identify Polaris, remove it if you think it could cause confusion that the N-arrow actually points north. This stencil prints a 35x75mm stencil 0.5mm thick with 0.7mm lines 2mm star dots and a ~4mm Polaris 5 sided star, the diagram and star markers are large to make them easy to see and use in darkness. Curved arrows show direction of sky rotation for constellations to remove potential confusion that constellations are fixed or the configuration shown is the only one which indicates north. These markings can all be commented out and recompiled in OpenSCAD. 8-8 Added a de-confusing star to N to make a N-★ for North Star but that might still be confusing so I commented it all out in the code. 8-8.1 added direction of rotation for constellations to remove confusion that constellations are fixed or the configuration shown is the only one which indicates north. I also have available a compass rose map stencil to add highly customizable 360 degree compass roses to your maps. http://www.thingiverse.com/thing:1663674 Thanks to (c) 2010 Juan Gonzalez-Gomez (Obijuan) juan@iearobotics.com for the parametric star code, it is released under the GPL license.