Size of a gore for a 30-inch globe

Printing the gore, actual size = 47.123890 inches

I printed out a gore last night. Just the vector outline for the continents, so it is very basic in order to get an idea of actual size. And so, just what is the actual size of a gore?

The circumference of a 30-inch globe is 94.24777960769379 inches.

The length of the gore is c/2, which is 47.123890 inches.

The width of a gore spanning 15 degrees longitude is c/(360/15) = 3.926991. The width of a gore spanning 30 degrees longitude is c/(360/30) = 7.853982.

Now, the real question is, have I got enough significant digits? If we take a 15-degree gore whose width has been calculated as 3.926991, and multiply by (360/15), the answer is 94.2477840.

The original circumference was 94.24777960769379, so if we place the 15-degree gores side-by-side at the equator, it looks like we will have an accumulated difference of 94.24777960769379-94.2477840 = -0.00000439230621 inches. Since this is a negative number, we will have a very small overlap.

Hmmm, I wonder if that’s too much of an overlap? I’ll have to get my micrometer and see it looks like in real-life. Standby for further details.

Just outlines, no gradients or artwork yet.
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One Response to Size of a gore for a 30-inch globe

  1. chris says:

    interesting, but dont forget to reduce the dimensions to allow for the paper stretching when wet, usually between 2 – 4 %

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