Simplicity domes continues

[J & D Goldman]

Hi Domers,
  Quite sometime ago there was some discussion concerning published
work to follow
the likes of Domebook 2.  I put a detailed outline together back then
and have been chipping away at content additions. With all the natural
disasters that have occurred in just the last few years, the need for
emergency housing has never been greater. Thus, I would think domes
may be getting more notice in the future, rather than less. One of the
chapters is entitled "Simplity Domes", which is devoted to methods and
materials that make domes easy to fabricate and erect, from materials
that are easily obtained and transported.

  One item I wanted to post for possible discussion is the use of a
waste product I see in many scrap yards - aluminum and other thin
metal sheets used in printing.  Just tons of this stuff is dumped
month after month.  A few things came to mind I wanted to bounce off
the group for reaction, and see if others had some thoughts:

1) Roll ups
Even thin metal sheets form a fairly strong strut when rolled into a
multilayered tube(s). For additional strength, they can be rolled
around something else, like a rod, rebar, etc. with their ends
providing a hub connection.  I've seen quite a few web sites and
classroom projects where domes were made from rolled up newspaper, and
this is the same basic principle.  If one can drill or punch a hole in
the end, or perhaps add an endpiece of some kind, at least the frame
could be made.  The cover is another issue.

2) Fold ups
The Dome Builders Handbook by John Prenis had some interesting "model"
methods I have not seen anywhere else. One in particular caught my eye
for simplicity domes.  If there is interest I'll try to post a
diagram, but it goes like this:
  Take a piece of sheet which has the strut length you want, plus at
least 10-20% extra length at the ends (let's say the length is held
left to right), and would be at least 12 inches wide (now up and down)
along the length. Fold in half so now it is 6 inches wide (up and
down) and laying flat with the fold at the top, two edges at the
bottom, one side on top of the other.  Center the strut length and
mark the ends on the fold, so now you have two short stubs and the
longer center marked on the fold.  Now let's work on the right side,
the left being a mirror image.

Use the right mark, at the fold, as a pivot point, with your "compass"
marker to the left of the pivot point. You start at the top, at the
fold, as zero, and then rotate counterclockwise in degrees equal to
the axial angle for that strut.  Make "line 1" here, which goes from
the pivot point down to the edges at the bottom.  Then reset your
reference to zero at line 1, and continue going counterclockwise. This
time you will swing in degrees equal to the axial angle for the strut
that will connect to that point on the dome. Make this line 2, again
from the pivot point down to the edges at the bottom. Now, snip the
metal at line 2, that is, cut off the corner that is left, the area
you did not swing through to on your counterclockwise travel - the
piece left that would put you back on the fold at the top had you gone
a full 180 degrees.  This cut allows you to fold out two "wings" on
the right end, which open away from each other like butterfly wings,
the fold point being at line 1, the first axial angle. These wings are
inserted into the folded end sides of the adjoining strut, also with
its wings bent back to accpet struts that joint to it, etc.
   Obviously a drawing will help, or if you see the one in his book.
Somehow he does not mention the second axial angle perse, but I think
I see what he did. The interesting part is how you can make a dome
frame from  flat sheets, although I'm not sure how big you can make a
strong dome this way from thin metal sheets.  One can use thicker
material or wider sheets if that solves anything. Perhaps one of you
has tried this and can inform the rest of us.

I haven't looked at the economies for shipping flat sheet to a place
to make domes from it via rollups, foldups or some other system in
terms of how much housing you can get from a given weight or volume of
material, but there certainly is little or no waste (and we may be
starting with recycled materials anyhow.).

In any case, if you have thoughts to share on this or any other
Simplicty Domes concept, I'd be interested in hearing them.  I'm still
compiling...

cheers
- Dan G.