Capricorn: Dec.22-Jan.29 The Sundial Primer
created by Carl Sabanski
Capricorn: Dec.22-Jan.29

Mr. Sun The Sundial Primer Index "Sunny Day U" Index Mr. Sun

"SUNNY DAY U"


Universal Ring Sundial Kit

Universal Equatorial (Equinoctial) Ring Sundial: a portable dial which looks similar to a folding version of an armillary dial, but with a movable suspension point to provide latitude adjustment. In some versions, an aperture gnomon mounted on the central axis is used, the position of the aperture being adjusted to suit the sun's declination. This form is self-orientating.

Aperture: a small transparent hole in an opaque surface, designed to let a small beam of sunlight through to fall on a dial plate or alidade.


The universal equatorial ring sundial is a universal sundial and can be used anywhere in the world. All you have to do is position it correctly and it will tell you the time. This sundial is normally made of brass and is small enough to fit in your pocket. The following sundials are not pocket sized but are still fun to build and use.

This sundial is available with a string gnomon and an aperture gnomon. Figure 1 shows the kit for a string gnomon and Figure 2 for an aperture gnomon. A vernier scale is included to accurately set the latitude pointer to the nearest 1/4. To learn more about the vernier scale visit the Standard Time Equatorial Sundial page.

Figure 1: Universal Ring Sundial Kit with String Gnomon

Figure 1: Universal Ring Sundial Kit with String Gnomon  (CAD)

This first set of kits is for a universal equatorial ring sundial with string gnomon. There are three kits available; one for the Northern Hemisphere, one for the Southern Hemisphere an one for both combined. If you would like to download a PDF file of the "Universal Ring Sundial Kit with String Gnomon" just open the door that works for you.

Universal Ring Sundial with String Gnomon Kit - Northern Hemisphere Universal Ring Sundial with String Kit - Northern & Southern Hemispheres Universal Ring Sundial with String Kit - Southern Hemisphere
Northern Hemisphere Combined Southern Hemisphere

Once the sundial is completed adjust the latitude pointer to your latitude. A paper clip can be used to hold the rotating ring in position. Rotate the hour ring until it is perpendicular to the latitude ring and use a couple of paper clips to hold it in position. The sundial is now ready to use. The sundial must be turned until the upper end of the string gnomon points to the celestial pole. If you would like to build a universal ring sundial that is self-orienting then read on.

Figure 2: Universal Ring Sundial Kit with Aperture Gnomon

Figure 2: Universal Ring Sundial Kit with Aperture Gnomon  (CAD)

This sundial is also available with an aperture gnomon. There are three kits available; one for the Northern Hemisphere, one for the Southern Hemisphere an one for both combined. If you would like to download a PDF file of the "Universal Ring Sundial Kit with Aperture Gnomon" just open the door that works for you.

Universal Ring Sundial with Aperture Gnomon Kit - Northern Hemisphere Universal Ring Sundial with Aperture Gnomon Kit - Northern & Southern Hemispheres Universal Ring Sundial with Aperture Gnomon Kit - Southern Hemisphere
Northern Hemisphere Combined Southern Hemisphere

Once the sundial is completed adjust the latitude pointer to your latitude. A paper clip can be used to hold the rotating ring in position. Rotate the hour ring until it is perpendicular to the latitude ring and use a couple of paper clips to hold it in position. Set the date scale slider to the correct date. The sundial is now ready to use. Hold the sundial by the string and turn it to the north and rotate the date scale towards the sun. Perform these two steps until a small beam of light passes through the aperture (hole) and strikes the hour band on the centre line. The sundial now indicates solar time.

Universal Ring Sundials - Folded

This photo shows the universal ring sundials folded together. The sundial with the string gnomon is on the left with the Southern Hemisphere latitude scale visible. Note that in the position the Northern Hemisphere hour ring is visible. The other sundial has the aperture gnomon and has the Northern Hemisphere latitude scale and Southern Hemisphere hour ring visible. The Northern Hemisphere side of the aperture gnomon is visible.

Universal Ring Sundials - Open

This photo shows the sundials  opened and ready to use. The latitude pointer is set to 50 N. A couple of paper clips help to hold the hour ring in position, perpendicular to the latitude scale. The 1/4 vernier scale is visible.

Happy Dialling!