Portable Solar Dial

Based on a description in an old (1984) education magazine I build a virtual replica of a portable sun dial which was inspired by a medieval portable sundial from Canterbury. This device is also known as a "Shepard's Dial".
What I originally planned to do was make a temporal or 12-hour sun dial making it a decorative object only. This is a sun dail for modern equal hours, the example is for 52 degrees latitude, northern hemisphere. The OpenScad file is included and be set for different north-south locations.
I tried to base the dimensions on proper calculations, but couldn't get it right. It looks like the original, so I did something right :-). A smarter person than me may find the proper solution.

Usage:
The object requires a thin pole stuck through the proper month hole (roman numerals) until it reaches the opposite hole. Then orient the pole to the direction of the sun, so a vertical shadow appears. The end of the pole shadow should indicate the natural hour.

If the weather improves, I'll add real live images :-).

Source:
The original inspiring article appeared in "BulkBoek JAARGANG 13/NR 143 from 1984". It was a special on "School Subjects in Midieval Perspective". The drawing is from J.A.F. de Rijk. https://www.bulkboek.nl/

Print Settings

Printer Brand:

Prusa

Printer: 

I3 MK3S

Rafts:

No

Supports: 

No

Resolution:

0.15 mm layer, 0.4 mm nozzle

Infill: 

15%

Filament:

Any brand; PLA Colour: As you like it 
 

Notes: 

The four parts for the sides of a short pillar, and should be kept in place with the top and bottom (red).

The pole of 112 mm should be about 1.5 mm.

A "M600" filament change was inserted before the second last layer.

The panels tend to warp after printing, so I used some glue in the middle of the long sides.

The original was intended with the MMU2 and printed upside down, but the results looked less good.

How I Designed This

Mainly by reading the relevant Wikipedia topics:

https://en.wikipedia.org/wiki/Sun\_dial#Vertical\_sundials

https://en.wikipedia.org/wiki/Solar\_zenith\_angle

https://en.wikipedia.org/wiki/Position\_of\_the\_Sun#Declination\_of\_the\_Sun\_as\_seen\_from\_Earth

Category: Physics & Astronomy