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[Howto]: The giant hourglass (585 rods) / The 297-Water Drop

PostPosted: Wed Jun 16, 2021 1:19 am
by Eric
Here is the step by step construction of my giant 585-hourglass and the 297-Water Drop (click on the photos to enlarge).

[Edit]: Warning! Deprecated method. You will find a faster and more efficient way to build hourglass bulbs here.
This old construction method should be replaced by the one mentioned above.
Once you've built your 2 bulbs, you can resume here in this thread (from the second picture).

The set of rods (294) to build one of the two bulbs:
As I changed the color scheme at the very end I don't have quite the right number of color rods here. But that's not a big deal, it doesn't change anything at the construction stages.

First, build a simple Lobel frame with a triangle as central polygon.
0-Hour Glass 01_2.jpg

0-Hour Glass 02_2.jpg

Re: [Howto]: The real giant hourglass (585 rods)

PostPosted: Wed Jun 16, 2021 1:50 am
by Eric
0-Hour Glass 03_4.jpg

0-Hour Glass 04_3.jpg
On this kind of Lobel frame if you look closely you will see a straight line of rods in alignment with each vertex of the central polygon. Which here is a triangle.

Stop when you reached 5 successive rows of triangles around the central triangle.
In an attempt to save time I tried to apply my final color scheme at this point.
So I replaced some silver rods with colored ones. But at the very end, that's not the one I kept. Never mind. Nice try ;) .
0-Hour Glass 05_3.jpg
In fact, by reshaping the Lobel frame a little, you realize that it is a simple tetrahedral pyramid. But for what we want to do, we have to keep this rounded shape.

Re: [Howto]: The real giant hourglass (585 rods)

PostPosted: Wed Jun 16, 2021 2:34 am
by Eric
You have to start shortening the rows of triangles to close the construction and get the bulb shape. To do so, you have to form a hemisphere. The construction scheme will therefore change from now on.
0-Hour Glass 06_3.jpg
As you can see you get 6 outward facing pentagonal pyramids at the end of this sequence.

You have to reverse them and turn them inward. Once this is done you observe that the pentagons are separated vertex to vertex by 1 rod. The corresponding model of sphere is this truncated icosahedron (more commonly known as a soccer ball ;)). This is how you have to close the bulb.
0-Hour Glass 07_3.jpg

0-Hour Glass 08_3.jpg

Re: [Howto]: The real giant hourglass (585 rods)

PostPosted: Wed Jun 16, 2021 2:45 am
by Eric
0-Hour Glass 09_3.jpg
Final color scheme on the 4th photo ;)

Now that you have completed your first bulb, make a second one :D:
Add 3 rods and a sphere on top of each and you get the 297-Water Drops

All you have to do is stack them, remembering to remove the upper triangle (3 rods and 3 spheres) from one of the two.

And tada! You have your real giant 585-hourglass.

Re: [Howto]: The giant hourglass (585 rods) / The 297-Water

PostPosted: Sat Jul 24, 2021 4:12 pm
by Tychi
Wau, i must built IT.

Re: [Howto]: The giant hourglass (585 rods) / The 297-Water

PostPosted: Tue Aug 17, 2021 6:50 pm
by Tychi
Thank you very much for the inspiration

Re: [Howto]: The giant hourglass (585 rods) / The 297-Water

PostPosted: Thu Aug 19, 2021 7:43 pm
by Peter Jepsen
Very nice Tychi! And of course again super compliments to Eric.

I feel like a jerk for not having built it yet..