Creating an Icosahedron

[rob]

I'm creating an icosahedron by joining the the corners of three golden ratio rectangles (see the picture) Each triangular face is made by joining three points together. Currently I am Constructing  a Plane through three points then sketching the triangle for each face with the line tool. It is time consuming and I will end up with 20 planes and 23 objects when I'm done. My question is, is there a better way of doing this?  

[TheCADWhisperer]

http://www.inventortales.com/2012/10/all-for-fun-creating-20-sided_26.html

About 15 minutes first time through.

Now that I have done it - could probably repeat in about 5 minutes.

[Anonymous]

I downloaded your files and noticed, that the triangles are not all equal. Can you help me creating a Icosahedron with equal triangles? 🙂

[TheCADWhisperer]

File>Export and then Attach your *.f3d attempt here.

[HotMetalArtist]

To All:

I tried making 20 components, each having a single equilateral triangle body.

This proved to be a tedious effort to join edges and create contact sets. I spent several hours but could not get the assembly to close up. Fusion wants to make assumptions and "helps" too much. I gave up after several hours.

For the record, I did this same exercise in Inventor 2015 years ago in about 10 minutes.

After a few hundred hours seat-time in Fusion 360, I'm still struggling to "think" like Fusion.

++

Mark

[MichaelT_123]

Hi Mr. Rob,

It is certainly the tedious job, although there is a benefit of having synapses firing in good direction. Particularly young brains might be primed nicely, but for old f.rts, well it might cause overheating .  

Look at:

https://forums.autodesk.com/t5/fusion-360-design-validate/platonic-solids/m-p/8438153#M176057

Regards

MichaelT

[chrisplyler]

Are you really going to construct it using twenty triangular plates? Why not just model it as a single, solid component?

The only trick is getting "golden ratio" center rectangles. Long sides need a formula as follows:

Short side*(1+sqrt(5))/2

And of course all three of them should be the same size.

Then just do this:

[Anonymous]

---

@chrisplyler wrote:

Are you really going to construct it using twenty triangular plates? Why not just model it as a single, solid component?

The only trick is getting "golden ratio" center rectangles. Long sides need a formula as follows:

Short side*(1+sqrt(5))/2

And of course all three of them should be the same size.

---

I tried this, and ended up with 20 separate patch bodies, instead of a single solid.

EDIT: Nevermind. I screwed up the stitching step. Fixed that and it worked great!

[HotMetalArtist]

Hi, roach374.

The golden ratio rectangle geometry for icosahedron is new to me.

I'm using metal plates to build a physical object. I wanted to model the assembly to see how it shapes up with different sized and different thicknesses. I'll try constructing the solid body you suggest and then extruding new bodies on the faces.

++

Mark

[Anonymous]

@HotMetalArtist It might be better to stop after the patch step and use the "thicken" tool instead, on all the patch bodies.

[chrisplyler]

If you want to create separate triangular plates, the follow my video posted above, but do one thing differently.

Instead of Stitching all the surface triangles together, Thicken them all to your desired plate thickness.

Please note that the short dimension of the rectangles becomes the side dimension of all the triangles.

[Anonymous]

I'm really sorry that I forgot to upload or make any responses to this topic. As I myself already read some replys for the same curious reason. I will actually try to make a video. As it is the first video I hope it turns out well. And I also just wanted to supply you with a link to a object file for the Windows 10 3D objects it's really tiny only 601 byte(https://1drv.ms/u/s!AlSWPJi5lbz54iYPm3BSd5voWrQK?e=mfDuBX )

As I see it you can just view the object online with the option to download.

This was done with Fusion 360. And it doesn't really need any math as some like to put it. 

[Anonymous]

https://knowledge.autodesk.com/community/screencast/4d170199-3a0f-4587-b2e5-45ac5a089e86 

I'm sorry the forum is just stupid. Here is the link to the video! Thanks.

[KristianLaholm]

I only like to add that there are other ways creating the Icosahedron with a lot less work.
And it's parametric driven from one dimension.

Icosahedron
A less then 2 minute workflow screen cast https://knowledge.autodesk.com/community/screencast/18130a94-d85c-4060-87d6-1ac8161edb33
The quantity of the circular pattern is 5 (a bit obscured in the video)

@rob 

[Anonymous]

@

[Anonymous]

@KristianLaholm That's great. But, no one really provided any answers resembling yours at all. And the discussion going on here is whether or not every single side is exactly the same size. As per description of the solid. Anyway it may look promising and I may test it in a couple of years.

[Anonymous]

@KristianLaholm anyway. Where were you with ideas like this when this topic was started. If you want to talk about a speed build. This topic is 3 years old. And I already put in my own work after studying the shape in fusion 360 for two weeks. My grandmother was staying over my house. That's the only reason I finished it.

[Anonymous]

@KristianLaholm as a matter a fact you're like a mayo clinic at this point. Interrupting the teacher. And the sublime to the creator.

[TrippyLighting]

@KristianLaholm very nice work, as usual!. I hadn't seen that version! Thanks for sharing!

[Anonymous]

@rob And I'm not sure if you are looking for ico or dedo herdral.

And I wanted to make a similar contribution to this topic since I see the process the same. It just has a different step. I know this may be solved already one way or another. The problem is simple right now I stumbled upon the 'matching ratio' when looking for your golden ratio. I will include the file. If you study the shape you'll find the relationship simple to be 2:0.75 and 1:2.

I'll try to get back to this topic in a little while.