Fold Kamiya's geometric models without knowing wht they are

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Re: Fold Kamiya's geometric models without knowing wht they

Postby tschobigami » August 13th, 2017, 10:50 am

yep, thats the same thing i got. before, i accidently had some extra lines so the tetrahedon lies flat.
to me it is a very weird model, as it doesn't look cleaned up, and there are many places where 2 raw edges meet and kind of leave an opening
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Re: Fold Kamiya's geometric models without knowing wht they

Postby Brimstone » August 13th, 2017, 12:55 pm

It seems odd that Kamiya would publish a cp for such an incomplete model but apparently he did unless we are all missing something here.
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Re: Fold Kamiya's geometric models without knowing wht they

Postby FlareglooM » August 13th, 2017, 12:55 pm

My guess is that the tetrahedron will fit in the cube.

Giving you something like this internally:

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Mainly because I can rotate it on the top diagonal.
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Re: Fold Kamiya's geometric models without knowing wht they

Postby Brimstone » August 13th, 2017, 8:15 pm

FlareglooM wrote:My guess is that the tetrahedron will fit in the cube

I'm more for your first option, a cube with a tetrahedron atop the diagonal of it's top side, so the length of the diagonal of the side of the cube is the same as the side of the tetrahedron.
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Re: Fold Kamiya's geometric models without knowing wht they

Postby tschobigami » August 13th, 2017, 9:38 pm

I am convinced of the second option.

First, it is indeed an interesting model, mathematically and geometrically.

Second, when checking the cp again, I realized, that the tetrahedron indeed does consist of equilateral triangles, with their side-length being sqrt(2)*sidelength(cube), which means that the tetrahedron indeed does fit perfectly.

Third, it explains why I said that the design doesn't look clean to me. By having one geometric object inside the other, one has to fold and look inside, so a clean lock doesn't make sense.

To me this one is solved by Flaregloom, even if not folded yet.
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Re: Fold Kamiya's geometric models without knowing wht they

Postby origami_8 » August 14th, 2017, 12:04 pm

After quite some fiddling around, I managed to collapse the tetrahedron inside the cube. So it is possible. It would however only make sense if you fold the model from translucent paper, otherwise no one will know there is a tetrahedron inside the cube.

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Re: Fold Kamiya's geometric models without knowing wht they

Postby Brimstone » August 15th, 2017, 12:34 pm

origami_8 wrote:After quite some fiddling around, I managed to collapse the tetrahedron inside the cube. So it is possible. It would however only make sense if you fold the model from translucent paper, otherwise no one will know there is a tetrahedron inside the cube.

Wow Anna I knew if someone could pull this one off it would be you. Thanks for the colored cp.
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Re: Fold Kamiya's geometric models without knowing wht they

Postby origami_8 » August 15th, 2017, 6:53 pm

Some hints about the collapse: Starting of with the upper two horizontal lines in place, bring in the pink 22.5 degree lines in the upper middle two squares. Then you have to make the two points at the bottom of the big triangles concave. Good luck. On the right side this should make the diagonal of the upper middle square align with the line the goes up just right to the centre, so that they can be mountain folded together.
After closing the bottom of the cube and forming the tetrahedron inside it, you can lock the tetrahedron in place by closing the top of the cube.
In theory it sounds a lot easier than it actually is, especially if you try to fold it from transluscent foil that just doesn't want to behave the way you want. No photos, sorry.
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Re: Fold Kamiya's geometric models without knowing wht they

Postby Brimstone » August 18th, 2017, 1:10 am

The first cp folded from ordinary paper looks something like this:

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