If you don’t have access to a grassy area with soft earth, you can improvise. Fill a small bucket with sand or gravel and plant the stick directly in the center of it.
If you want the greatest amount of accuracy, use chalk to mark each pebble with the exact time you placed it on the ground. The shadow will move in a clockwise direction. [6] X Research source
Start preparing the plate at around 11:30 a. m on a sunny, cloudless day.
Pick out the colors you want to use and, if you like, a drawing or illustration to put on the face. Sketch out a few different designs until you’ve settled on something final.
Start with the number 12 at the very top, like a clock’s face. Measure where the center of the circle is, then use the straightedge to draw a precise line from the 12 to the center.
Then start over with 1 again until you end up back at the original 12 at the very top. The numbers are now accurately marked onto the paper. The full 24 hours is represented for the most precise accuracy. When seasons change, so does the position of Earth. In summer, days are longer. In winter, they are shorter. There are days in the summer when there are more than 12 hours of daylight. [12] X Research source
The length of the pipe and the gnomon tip should be no longer than three inches total. Paint the gnomon in whatever color you’d like. This will keep it from rusting.
To get this angle, subtract your current latitude from 90 degrees. For example, if you are located at 40 degrees N. latitude, you would draw a 50 degree angle on the 4x4.
Then measure the center of the sundial’s face and drill a hole there. [15] X Research source Test the attachment of the post to the sundial face with a 5/16-inch lag screw, just to make sure everything fits together properly.
Permanently put the post in place by pouring and setting it in cement. Allow a few days to go by before mounting the sundial face, so that the cement has dried completely.
You should be able to see the lag screw in the flange’s center hole. Use your right hand to screw the gnomon pipe into the flange, which you should hold in your left hand.
Now tighten the lag screw. Do not move the sundial face as you do this. Drill holes for the four screws and then screw the flange onto the sundial. Lastly, screw the gnomon in.
