How to make a sphere for rolling robot

[oracid]

 

I use to make topics in the Theme "LEGO Mindstorms and Robotics" but in this case, I thought that this could interest other people.

In this new video, I show how to make a big Lego sphere. It is a kind of grail which, to my knowledge, has never been resolved in Lego, except with bricks.

Some will say that the axes are arched and that consequently the solution is not admissible. Too bad for them !

This sphere could be used for an inverted Self Balancing or as a fairing for a drone. It was this latter possibility that inspired me.

I think my solution is not quite a soccer ball. The soccer ball, I believe, is based on 3 pentagons with one hexagon in the middle, or 5 hexagons and one pentagon in the middle. Which amounts to the same.

While in my solution, we do have 5 hexagons and a pentagon in the middle, but we don't have 3 pentagons and a hexagon in the middle.

To tell the truth, I didn't do it on purpose. It would surprise me a lot that I could innovate in this area, but who knows, this may interest some tiler ...

Edited February 15, 2020 by oracid

[pleegwat]

In a soccer ball, every vertex borders two hexagons and a pentagon.

https://en.wikipedia.org/wiki/Truncated_icosahedron

[oracid]

2 hours ago, pleegwat said:

In a soccer ball, every vertex borders two hexagons and a pentagon.

https://en.wikipedia.org/wiki/Truncated_icosahedron

Thank you for the link.

So, I understand that my sphere is not an icosahedron.

 

Edited February 15, 2020 by oracid

[WvG_853]

Fascinating! Thanks for sharing ... 

[oracid]

34 minutes ago, WvG_853 said:

Fascinating! Thanks for sharing ... 

Thanks to you.

[Boots]

Amazing! Thanks for sharing...

[BusterHaus]

The sphere looks great, but I'm not sure if it will stay in one piece if it's rolling. May have to resort to the Kragle. 

[Didumos69]

You made yourself a non-vertex-transitive vertex-truncation of the icosi-dodecahedron by a rhomb-triacontahedron. If you make the pentagons in the image below smaller, the hexagons will be more close to regular hexagons like in your model, but they will never be regular. (Source)

Edited February 15, 2020 by Didumos69

[oracid]

Thanks all.

1 hour ago, BusterHaus said:

The sphere looks great, but I'm not sure if it will stay in one piece if it's rolling. May have to resort to the Kragle. 

I don't know Kragle, but yes, we can stick. Personally it doesn't bother me.

 

1 hour ago, Didumos69 said:

You made yourself a non-vertex-transitive vertex-truncation of the icosi-dodecahedron by a rhomb-triacontahedron. If you make the pentagons in the image below smaller, the hexagons will be more close to regular hexagons like in your model, but they will never be regular. (Source)

This is a great link ! Thank you. Is it your blog ? Do you mind if I put it in my video description ?

[Didumos69]

21 minutes ago, oracid said:

This is a great link ! Thank you. Is it your blog ? Do you mind if I put it in my video description ?

It's not my blog. I made a study into this once.

You can also look at it as if it were a dodecahedron with sliced off (truncated) edges.

Edited February 15, 2020 by Didumos69

[oracid]

5 minutes ago, Didumos69 said:

It's not my blog. I made a study into this once.

I sent a mail to the owner. Thank you anyway.

[oracid]

3 hours ago, Didumos69 said:

You can also look at it as if it were a dodecahedron with sliced off (truncated) edges.

What you say is funny because at the beginning I started to build your dodecahedron.

Then on each big pentagon, I built a little pentagon connected to each vertex of each big pentagon with an axle.

Then I have suppressed the side (axles) of the big pentagons. And the result is the sphere I made.

Hope you understand what I say. Not easy to explain.

 

Livio Zefiro wrote a comment.

Edited February 15, 2020 by oracid