This pattern will make a 15" dia. sphere. We will not be making the entire sphere, it is actually 2/3 of the sphere as we will be leaving the bottom five icosa faces off. It will not fit flat. After you have erected it you will see the great circles by following the B sides around the sphere. You will need 15 of these patterns. Cut halfway through the cardboard so that  B hinges. Cut completely through outside perimeter along A struts. Glue A's to A's side to side. Should look like the 1 freq. model that we did before (without a bottom). Do not use these drawings as patterns. They are not to scale. They are for reference only. Work off of measurements.

   The Chord factor for the 2 freq are as follows:
    A chordfactor  =  .54653306
so 15"dia = 7.5"rad x .54653306
so A = 4.09 or 4 & 1/8"

    B chordfactor =  .61803399
so 15"dia = 7.5"rad x .61803399
so B = 4.63 or 4 & 5/8"

Color code:
Where A's come together leave plain
Where B's come together color RED
NOTE: put color code on outside of model so that you can see it.

 

Check out these professional dome modelers and their work on a 2 freq model!
 
 

ON TO THE 4 FREQ. MODEL...

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New Exciting DVD