Highly configurable square sundial

thingiverse

I enjoyed making Zeiberstein's customizable sundial and learning about the power of OpenSCAD in 3D design. But I found that the sundial itself had many limitations, in particular, it was too small and the graduations were coarse. So I decided to make a square dial, to make the size adjustable with graduations that became finer as the size increased. As the design progressed I included other optional adjustments that are easily made before printing. You do not need to be an expert with OpenSCAD to change any of these things before printing. Here are a few of the changes: (a) Strengthening the root of the gnomon with wedges to help avoid it breaking off due to lack of adhesion between the starting layers and the (by now) cooled dial (b) Subdivisions of hours automatically made depending on scale (i.e. size of sundial) (c) Daylight Saving Time, and if used, this is printed on the back (d) Square dial to give the greatest size of dial (e) Equation of time (EOT) printed at bottom of the dial, instead of including hours when the sun don't shine (most places anyway) (f) EOT may be printed in raised or sunken letters (g) The curved bite cut out of gnomon on north side is made elliptical so the overhanging gnomon does not need support when printing (h) The user can choose between Roman numerals, Arabic numerals or Dots as in Zeiberstein's sundial. Note: Equation of Time, expressed in minutes, is the correction you make to the sundial's reading depending on the day of the year. It can be found using Google though it does not vary much between different places.