[Howto]: Thoughts about Lobel Frame

[Howto]: Thoughts about Lobel Frame

Postby Eric » Mon Dec 07, 2020 1:27 am

Along my wanderings of the day I played today with my first (very simple) lobel frame :-)
Here is the plin/rayh/rivf/36p58p2.C6 diagram I used.
This model counts 60 rods and 31 spheres

20201206_182809.jpg

20201206_182832.jpg

The Lobel frame is complete on each following photo
The reinforcement pentagonal pyramid (green on several photos) can be positioned inward or outward depending on which direction you want to go.
This Lobel frame is malleable. You can deform it without disconnecting any rod to give it the desired shape. You can then constrain it and freeze the shape by placing additional rods (white ones on some photos).

20201206_184658.jpg

Using Lobel frames, not as such, but as part of something bigger surely opens up a whole world of new possibilities. After all, aren't 3D models in video games made of a mesh of triangles?
Why not go further. Who will show us how to integrate lobel frames in more ambitious constructions?

Lobel frames are explained by Karl in the wiki and illustrated in his gallery.
Rafael dealt with it too.
Alain LOBEL's web site http://www.equilatere.net doesn't work anymore but you can access the files directly.
Examples I found: from Peter, Galan, Graham aka AFKAN, Amafirlian (not directly tagged as Lobel frame but sort of) and Geomag Shop Fox Town.
Last edited by Eric on Mon Jan 11, 2021 9:00 pm, edited 2 times in total.
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Re: Thoughts about Lobel Frame

Postby Eric » Mon Dec 07, 2020 1:38 am

20201206_183405.jpg
Place the reinforcement pentagonal pyramid inwards

20201206_183255.jpg
Tuck the corners in

20201206_183033.jpg
and there you have a strong rounded plinth with a basic pentagonal shape on top to mount a tower, a vase, a cup or whatever
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Re: Thoughts about Lobel Frame

Postby Eric » Mon Dec 07, 2020 1:47 am

20201206_190642.jpg
Another rounded star-shaped plinth with a basic pentagonal shape on top. That only waits to be loaded with a bigger structure above.

20201206_190258.jpg
Look at that smooth 3D curve

20201206_182720.jpg
It reminds me of the front fairing of the Hayabusa 8-)
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Re: Thoughts about Lobel Frame

Postby Eric » Sun Dec 13, 2020 7:30 pm

Wow look at these great practical applications of Lobel frames:

In the district of Les Halles in Paris:
Bulle-dhiver-Novotel-Paris-les-Halles-extérieur-_-630x405-_-©-Novotel-Paris-Les-Halles.jpg
This one is a little more than a half Truncated icosahedron or football (soccer ball).


On the Eiffel tower:
507349-la-terrasse-dhiver-de-bulle-parisienne-sur-la-tour-eiffel-8.jpg
It's another Truncated icosahedron but not with the same proportions. Its vertices are cut shorter than the one above. You can see that on this animation.
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Re: Thoughts about Lobel Frame

Postby Eric » Sun Dec 13, 2020 7:36 pm

Let's take a closer look highlighting the pentagons:
Capture2.JPG

Capture.JPG
from a better angle
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Re: Thoughts about Lobel Frame

Postby Eric » Sun Dec 13, 2020 8:00 pm

Now let's do it with Geomags!!!

Small riddle before starting: how many rods for each model?
I would never have thought from the pictures that there was such a huge difference. 165 rods for the one in the district of Les Halles and 425 rods for the one on the Eiffel Tower.

The first one with 165 rods (60 silver and 105 blue):
20201213_163932.jpg

20201213_164047.jpg

I'm disappointed that I didn't manage to give it a rounder shape. When you look closely, in the photos of the Parisian domes, the pentagonal pyramids are much flatter. Is it due to the size of the spheres? Or maybe they cheated with the size of the rods in the inner structure of the pentagons ...

The howto will follow below.
Last edited by Eric on Sun Dec 13, 2020 8:48 pm, edited 1 time in total.
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Re: Thoughts about Lobel Frame

Postby Eric » Sun Dec 13, 2020 8:37 pm

I added red rods to the previous structure to build the big one. I didn't think I would need that much ... :o
You can see the proportion of blue rods to red ones ;)

The second one with 425 rods (60 silver, 105 blue, 260 red):
20201213_181855.jpg
Much too angular for my taste

The second one with 395 rods and 6 panels ;-):
20201213_202915.jpg
I cheated too ;-)
Still sad about this not round enough shape :cry:

Capture.JPG
Side by side to compare
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Re: Thoughts about Lobel Frame

Postby Eric » Sun Dec 13, 2020 9:56 pm

Let's go for the small one of 165 rods (60 silver and 105 blue):
Howto1.jpg

Howto2.jpg

Howto3.jpg
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Re: Thoughts about Lobel Frame

Postby Eric » Sun Dec 13, 2020 10:14 pm

Howto4.jpg

20201213_163932.jpg
This is it

Important note: if you continue like this, you can close the sphere and get the truncated icosahedron as described in the wiki by replacing the reinforcements of the pentagons with panels.

As I did with my world cup trophy ;-):
20200604_101728.jpg
World cup trophy
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Re: Thoughts about Lobel Frame

Postby Eric » Sun Dec 13, 2020 10:55 pm

And now the big one with 425 rods (60 silver, 105 blue, 260 red) :D
Howto5.jpg

Howto6.jpg

Howto7.jpg
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