Geodesic tunnel - dome

[Viceroy]

Hey I need to know an angle for a geodesic structure.

The material is wood.  Wondering the angle of the cuts.


A set of five triangles are made starting at 2.00 minutes in this video:
http://www.domerama.com/geodesic-dome-plans/


What are the exact dimensions of the individual "stick" and what are the angles?

At 4.30 he shows his template and his practical method of construction.


He does not mention the angle of the rip of the angle of the end cut, which I presume is 60 degrees.

What is the rip angle?  I presume it is dependent upon the length of the legs, what is the formula?

I presume the "rip angle" should be overcut to maximize compression along the outside edge.

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[Elwar]

That is the thing about geodesic domes, I am pretty sure that the angles are not uniform throughout the whole dome.

[Viceroy]

Oh?  I thought they were exactly... if you are making a sphere with equilateral triangles.

[Elwar]

I recall looking into it a long time ago and that is what I found when looking at one set of building instructions. Though I could be wrong.

[Viceroy]

I found this but it's been a while since I've needed to calculate trig.

https://geodesichelp.googlegroups.com/attach/316454004b926a2e/DB2_page_106.jpg?view=1&part=4
https://geodesichelp.googlegroups.com/attach/316454004b926a2e/DB2_page_107.jpg?view=1&part=5


In the tape video he seems to imply he ripped the triangle at some "secret" angle.  I'm guessing the angle is related to the diameter of the dome.