Dodeca sphere

[TaffGoch]

Dan might like this one. It's simple; 20 identical parts.

The folds are not straight lines, but arcs.

-Taff

[TaffGoch]

Dan,

I leave the connector tabs to you. If you want tabs added to the pattern, I can easily add them. You can, during assembly, cut off any superfluous tabs.

[homespun]

Taff,

   This is definitely tempting.  But first I am going to explore a little more origami.

                Dan

[TaffGoch]

Hmmm,

Are you sure I can't entice you, with a full net....

[homespun]

 

Taff,

     Oh, my goodness!  It sure is pretty - need time to figure it out how it works.

     At the moment I am making a simple origami dodecahedron out of the very same gyroscope module I used to make the buckyball.

                         Dan

 

----- Original Message -----

From: TaffGoch

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[TaffGoch]

As a geometric note, the inner arcs ARE circular, but the outer arcs are NOT.

When assembled, both, inner and outer arcs become circles, which are, indeed, planar.

The outer arcs, in the net pattern, are not circular, because the "unfolding" of the edge of the spherical surface distorts the circle into an arc that approximates sections of 5 parabolas (parabolae?)

It's a minor deviation from a circular arc, and gave me fits, when trying to model it. At small scale, it probably wouldn't be noticeable, either way.

[TaffGoch]

By the way, this is where I found the initial photo:

http://www.flickr.com/photos/elelvis/296890381/

[TaffGoch]

From the same flickr source.

The circular holes/faces can be made much more complex, while still using a planar net. (Central sections are conical slices, folded in/out, during assembly.)

[homespun]

Taff,

    Seem like each section has to be large enough to overlap onto the next so that it can be glued.

    Please make one detailed pattern that I can work from.

                          Dan

----- Original Message -----

From: TaffGoch

To: geodes...@googlegroups.com

Sent: Thursday, December 27, 2012 9:45 PM

Subject: Re: Dodeca sphere

By the way, this is where I found the initial photo:

http://www.flickr.com/photos/elelvis/296890381/

--

[homespun]

Taff,

   Attached modified pattern.  Would this work?

            Dan 

----- Original Message -----

From: TaffGoch

To: Geodesic Help Group

Sent: Thursday, December 27, 2012 5:19 PM

Subject: Dodeca sphere

Dan might like this one. It's simple; 20 identical parts.

The folds are not straight lines, but arcs.

-Taff

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[TaffGoch]

Dan,

Here's the single-node pattern, with tabs. Obviously, you're going to have to cut off some extraneous tabs, when assembling 20 together.

I made the image large enough that you should be able to print a sheet-size pattern, without losing detail.

Note that the only folds are curved folds. There are no straight folds to worry about. Let the paper take a curved shape, as you crease along the solid arc lines. It will take on the proper curved shape, on its own. (Pretty cool, actually.)

-Taff

[homespun]

Taff,

   It is surprising that it will allow itself to be folded along the curve.  I may have to see it to believe it.

                                                                                                    Dan

----- Original Message -----

From: TaffGoch

To: geodes...@googlegroups.com

Sent: Thursday, December 27, 2012 11:27 PM

Subject: Re: Dodeca sphere

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[TaffGoch]

You have to "pinch" the paper, working along the line, a little pinch at a time.

This style of folding has an online following, with some impressive examples....

[homespun]

Taff,

   That was so easy.  I never imagined this was even possible.  It opens a whole new universe for me to explore.

              Thanks,

                    Dan

----- Original Message -----

From: TaffGoch

To: geodes...@googlegroups.com

Sent: Thursday, December 27, 2012 11:44 PM

Subject: Re: Dodeca sphere

[andrew777]

hello all:

As a matter of trivia these structures are variations of Bucky's fly eye dome.

I always wondered how to make one, this is it.

Andrew

[homespun]

Found this:  http://www.youtube.com/watch?v=fN6eKFxLjTU

And also pictures (attached)

         Dan

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[TaffGoch]

Andrew,

First thing I thought, when I saw it.

The paper model has the advantage of using a flat sheet of material. The curves are "simple" curves. (I.e,; they are not "compound" curves.)

The fly-eye domes rely on the strength of compound curves, which is why the "curbs" extend outward, rather than in, as in the paper model. If a structural project is to be molded, then compound curves always provide much greater strength, and is the way to go.

[TaffGoch]

Dan,

This will blow you away. Image-search for "curved fold" origami:

https://www.google.com/search?as_st=y&tbm=isch&as_q="curved+fold"+origami

Sorry, I fear that future exploration will keep you busy for life....

[TaffGoch]

The best search terms are:

curved folding
https://www.google.com/search?as_st=y&tbm=isch&as_q=curved+folding

curved crease
https://www.google.com/search?as_st=y&tbm=isch&as_q=curved+ crease

These are the most-common usage, accepted terms for the practice/art.

[Dick Fischbeck]

From our friend Ron Resch. RIP.

https://vimeo.com/36122966

http://synergeticscollaborative.org/snec.meeting.2003.01.html

[TaffGoch]

A worthwhile film to watch.

It's 41 minutes long, and I encourage readers to take the time to view.

Thanks, Dick

[homespun]

Dick, 

   Thanks for posting the link to the Ron Resch video.  I immediately watched the whole thing.  Most interesting.

                              Dan

----- Original Message -----

From: Dick Fischbeck

To: Geodesic Help

Sent: Friday, December 28, 2012 2:21 PM

Subject: Re: Dodeca sphere

[homespun]

Taff,

   Here are a couple of pictures of the completed model of the Shperical Dodecahedron.

   That was fun.  Thanks for talking me into it.

                     Dan

----- Original Message -----

From: TaffGoch

To: geodes...@googlegroups.com

Sent: Friday, December 28, 2012 10:47 AM

Subject: Re: Dodeca sphere

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[TaffGoch]

Great job, Dan! Happy to have entertained your mind.

I like your result so much that I'm going to make a physical model, myself, using sheets of flexible plastic from the local hobby store.

_______________________

I have modified the SketchUp 3D model, to incorporate additional conical slices, which "fill in" the holes. (Image attached.)

For those interested, I have posted the SketchUp model at Google's 3D Warehouse:

http://sketchup.google.com/3dwarehouse/details?mid=97bf2a27729d4f646554b7d01658d0a6

(Paper patterns are included in the 3D model.)

-Taff

[homespun]

Taff,

   Cool!  Be sure to posts pictures when it's done. 

   You may have noticed that I used all the tabs and let them show.  Made for a nice, strong connection.

                                  Dan

----- Original Message -----

From: TaffGoch

To: geodes...@googlegroups.com

Sent: Saturday, December 29, 2012 1:47 PM

Subject: Re: Dodeca sphere

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[TaffGoch]

Hey, Dan, how big is your finished model?

It's hard to tell, without any scale reference in your photos.

[homespun]

Taff,
The diameter is about 14 inches. I just took your pattern, inserted
into a Word Doc, with .5" width border.

Dan

----- Original Message -----
From: "TaffGoch" <taff...@gmail.com>
To: "Geodesic Help Group" <geodes...@googlegroups.com>
Sent: Saturday, December 29, 2012 2:13 PM
Subject: Re: Dodeca sphere

> Hey, Dan, how big is your finished model?
>
> It's hard to tell, without any scale reference in your photos.
>

> --

[TaffGoch]

Nice size, for a shelf-display model....