Polaris Finder Diagram Stencil v1.2 by Biketool

Last crawled date: 3 years, 1 month ago

This is a stencil to add a Polaris(aka The North or Pole Star) finder diagram to a field map, notebook, nautical chart, or other navigation aid for use in the northern hemisphere in case a compass is unavailable to use; it also looks pretty cool on a backpack. Handwrite a note that the constellations rotate around Polaris and from wherever you are standing except the north pole; north is in the direction of Polaris and not affected by where the constellations appear around it. This was inspired by seeing an American military evasion chart designed for downed pilots; which is a topographical map with survival, medical, signalling, and navigation tips and diagrams on the edges; printed on Tyvec they are waterproof and rip resistant just like the polymer sheet 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. I hope the direction of apparent celestial spin makes the diagram easier to understand than the military one. To get star locations I took a 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 if you think it could cause confusion that the N-arrow actually points north.
This 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.