Assembeling 5 intersecting tetrahedra

halalula12345 · Post by **halalula12345** » November 13th, 2005, 8:35 pm

I know have to make the units and how to put them together already but I am having problem on how to assemble the 5 triangles together
can anyone help?

Thanks

Post by **origami_8** » November 13th, 2005, 10:28 pm

What kind of tetrahedra are you speaking of, I know a lot of different ones. (Author? Where can the diagrams be found? ....)

About your signature:
Begging for diagrams isnÂ´t desired in this forum. If you need some diagrams check the origami database and buy the books.

Brimstone · Post by **Brimstone** » November 14th, 2005, 1:33 am

I guess halalula refers to Tom Hull's model. That model is a paon to assemble. My boss bought one of those at a fair and then she put in in a bag threw it on the floor of her car and went drinking. The next day the model was completely disassembled and she took it to the office for me to fix it. I was never able to do it. I used glue to keep it together but i assembled wrong and the model was lost.

I know two pages that show how to do it but even with those instructions I was never able to finish it:

The url's are:

http://www.geocities.com/golics/moduli08_de.htm and
http://www.merrimack.edu/~thull/fit.html

esato · Post by **esato** » November 14th, 2005, 4:16 pm

I was able to assemble it by carefully looking at Tom HullÂ´s page. To make it easier I used paper of the same colors as the pictures of that page.

Unfortunatelly my dog destroyed it... IÂ´ll have to assemble it again.

halalula12345 · Post by **halalula12345** » November 14th, 2005, 10:33 pm

thx u all for helping im going to try to assemble it tonight

hope i can finger crossed

gila o · Post by **gila o** » November 26th, 2005, 9:02 pm

Like Esato My first F.I.T was smashed (not by my dog,but while mooving apartment). So I've done another one.I also used the same colur units as in the instruction and used glue....

Here some photos -work in progres.
http://www.flickr.com/photos/87477835@N00/67188865/

yee245 · Post by **yee245** » November 29th, 2005, 12:11 pm

I've made Hull's FIT several times (maybe about 6 times) in various sizes, and every time, I have just as much difficulty assembling the pieces. It's almost always the third one that gets me. On the last one, it took me about two hours of fiddling (you'd think I'd have gotten it in by accident in that time) but then gave up and resorted to looking at a picture of one and then putting the pieces through in the same orientation as the picture. Then, usually the 4th and 5th go in without many problems.

Alexandre · Post by **Alexandre** » December 15th, 2005, 1:20 am

I used some computer help to make my F.I.T.

First, I downloaded http://www.progonos.com/furuti/Origami/ ... es/fit.wrl and http://www.progonos.com/furuti/Origami/ ... s/fit3.wrl.
They are the VRML (3D) models of the FIT with 3 and 5 tetraedra, cf http://www.progonos.com/furuti/Origami/ ... s/fit3.wrl

Then I changed the colors of the tetraedra to match my colors, with http://www.csv.ica.uni-stuttgart.de/vrml/dune/ (I used it on Linux but it seems to run under MicrosoftÂ©Â® WindowsÂ©Â® too)

Then I displayed the 3D model with http://freewrl.sourceforge.net/ ( it seems to run only on Linux but there is a lot of VRML viewer around).

So with that I could rotate and zoom the 3D model

This is then far more easy to construct the F.I.T.

Calfaile · Post by **Calfaile** » January 11th, 2006, 8:52 pm

Hmmm. . .

I've assembled it several times, it's one of my favorites. (I went through an intersecting frames "phase" awhile ago. . . . But I'm cured now, honest!)

The first one was hard, but the later ones are much easier. I can assemble them on the fly now.

The trick is to be aware of the symmetry. There are two kinds in the FIT: five-fold and three fold. (I highly reccomend the VRML model for your first try)

the five fold faces are the "star" sides. Each "point" of the star is the corner of a different tetrahedra. These trace out a dodecahedron

the three-fold faces correspond to the faces of a single tetrahedron arranged so:
Tetrahedron 1) face
Tetrahedron 2) point (interlocked with tet #1 as described on Hull's page)
Terahedron 3-5) Three edges (one edge of each color ) interlace to form a triangle. This triangle is positioned under the point of tetrahedron #2.

The way I usually do it is assmble the first two tetrahedra (these are easy), then I assemble just a single point (three edges) of the third tetrahedra. I then position this point over one of the faces of the assembled tetrahedra, check to make sure my symmetry is right, then add on the other three edges.

Sorry that this sounds so complicated; it's really easy once you see the pattern. My advice is to get someone who knows how to do it to show you in person. . .

kehom · Post by **kehom** » January 12th, 2006, 1:13 pm

Hey. Is it possible to post pictures of this Three fold thing? Or link to any website about it?
Thanks!

Alexandre · Post by **Alexandre** » January 12th, 2006, 1:42 pm

kehom wrote:Hey. Is it possible to post pictures of this Three fold thing? Or link to any website about it?
Thanks!

read my post upper

gila o · Post by **gila o** » January 13th, 2006, 12:16 pm

Gilad Ayalon has uploaded Few pictures in his website who can help those didn't succeded.
http://giladayalonorigami.fateback.com/ ... ns/FIT.htm

devinejay · Post by **devinejay** » April 4th, 2008, 10:17 pm

I know I might be resurrecting an old topic but I just had a thought.

I constructed the FIT after a few attempts, eventually I found a nice walk through on Youtube that cleared it up a lot. I'm more interested in the geometry of origami than the art so this was right up my ally.

My question is:
Considering that the FIT and a dodecahedron share common vertices, has anyone tried combining the two. I stumbled across this diagram for a dodecahedron http://dev.origami.com/images_pdf/hackysack.pdf and the idea struck me. I may try it over the next while but I'm very busy of late, and also I think I would have to build a new FIT because I made my last one as large as possible with standard paper so to construct a dodecahedron around it might be hard.

Anyone with a smallish FIT willing to try and work out how to build a dodecahedron around it? I'd love to know if it would work!

Jonnycakes · Post by **Jonnycakes** » April 4th, 2008, 11:57 pm

That could turn out to be pretty cool if you folded the dodecahedron with something clear.

origamimasterjared · Post by **origamimasterjared** » April 5th, 2008, 12:01 am

There are a number of origami docedahedra. Dodecahedral frames too. If you change the angle of where the units meet, you should be able to build the frame. However, if you do this directly from the FIT units, they won't hold securely.