Setup

To setup the initial layout of the sundial;

  • Mark an approximate layout using a magnetic compass or using a map to find north

  • Find true north

  • Define the layout points NS1, NS2, FP3, and FP4 (survey marks)

Using a magnetic compass, roughly layout the sundial using the dimensions provided. Use a garden hose as the ellipse. A compass only shows magnetic north and our sundial must be lined up with true north. However it’s close enough for the preliminary layout. Keep in mind that this angle can be off by 20 degrees.

After the initial layout, you must find the true north/south line. To do so, mark the shadow at solar noon. (also known as high noon)

A calendar will be supplied with your sundial kit. This calendar will show each day at precisely what time the sun will be the highest in the sky over your school.

 

 

In the above example,solar noon is at 11:23 and 57 seconds. (each day/location is different)

After the north/south line is found, place a string line to extend it. The string line can be held in place and stretched by two bricks (not pictured)

Once true north is marked, the four layout points must be set out. All dimensions used to draw the sundial are referenced from these points.

 

Survey marks NS1 and NS2 are placed on the this north/south string line.

After this, we find the perpendicular by simple geometry.

 In the picture above, the survey marks, NS1, NS2, FP3 and FP4 are installed by temporarily gluing a board onto the concrete. The glue to be used will be something that is easily removable such as an acrylic gap sealant like No More Gaps.

The layout of these marks is achieved by using the inexpensive tool above. The plans for this tool is supplied with your sundial kit.

A wood screw is driven into the wood to locate the survey points. The point of this giant compass will pivot on the screw heads.

The survey points points can be temporary or installed as permanent so that this setup doesn’t have to be done again.

The sundial appears to be as temporary as a coat of paint. However, if the survey points are permanent, the sundial can be erased (painted over) and another class can construct the sundial.

For example;

You want to reconstruct the sundial each year because it’s part of the grade 5 curriculum. If you have three grade 5 classes, you can reconstruct it for each class, or as many times as you like for other classes or situations.

To install the survey points as permanent, pre-drill through the paper and into the concrete with a 4mm or 3/16″ masonry drill bit. Hammer into the concrete a 12 gauge x 10mm or 1/2″ long stainless steel wood screw.

You’re now ready to construct the sundial. Just simply draw triangles that are referenced off the survey marks. The dimensions for these triangles are calculated specifically for your area and provided to you.

extended-compass 550

Reference mark

All dimensions used to construct the sundial are referenced from four survey marks These marks can be temporary or installed as permanent Permanent survey mark installed on concrete Tape paper onto concrete. Draw an ‘X’ onto the paper. Tape over the ‘X’ to prevent tearing of paper. Drill through paper with a 4mm or 3/16″ …

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