created by Carl Sabanski
Digital Equatorial Sundial Kit
Equatorial Sundial: a dial in which the dial plate is parallel to the equatorial plane and the polar-pointing gnomon is perpendicular to it.
The digital equatorial 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.
The digital equatorial sundial lies parallel to the equatorial plane but does not have a dial plate with hour lines nor a gnomon. It does have a reading line that is located on the polar axis of the sundial. The hour numbers are cut through a semi-circular ring. These numbers and any other time indicators are located in the hour planes of the times to be indicated. The sun shines through these indicators and projects them as lighted images along the reading line. Thus the term digital in the descriptor.
Figure 1: Digital Equatorial Sundial Kit (CAD)
This sundial kit comes in four models that are 9 inches in diameter. The first model is made completely from paper and requires you to cut out the hour numbers and diamonds. This requires a sharp craft knife so be very careful not to cut yourself. Figure 2 shows this sundial. The second model is similar to the one described for the second transparent model below. I am not sure how easy it will be to cut out some of the numbers. You can give it a try.
Figure 2: Digital Equatorial Sundial Paper Model
have made up two kits so that you can build this digital equatorial sundial for the Northern or Southern Hemisphere. All you need are scissors,
cardboard, glue and tape. If you would like to download a
PDF file of the "Digital Equatorial Sundial Kit" just open the door that
works for you.
The next two models use clear transparency for the hour ring. No cutting of the numbers or diamonds is required. Figure 3 shows the first model. This sundial is identical to the one above but less dangerous to make.
Figure 3: Digital Equatorial Sundial Transparency Model
The final model is slightly different. The height of the numbers and diamonds are the same as those in Figure 3 but the width gets progressively narrower as the move way from noon. This change in width compensates for the distortion of the numbers when they are projected on to the reading line and make them appear more normal. You can see the change in the numbers and diamonds if you look carefully at Figure 4.
Figure 4: Digital Equatorial Sundial Transparency Model - Compensated
If you would like to download a
PDF file of the "Digital Equatorial Sundial Transparency Kit" just open the door that
works for you. Each kit contains the templates for both types of hour
When you have completed the sundial all you have to do is set up and it will tell you solar time. The compass directions on the sundial pretty much tell you how it has to placed.