Icosahedron?

[jazzlw]

So I successfully constructed a 3D icosahedron in auto cad 2013 out of lines and poly-lines (image attached), but I cant seem to figure out how to convert it into a solid. Is this possible? I have poked around a bit, and cant seem to find any clues... the only similar post I found, the shape was a simple extrusion, so the solution was just to take it back to 2D and extrude, but that does not work as well for an Icosahedron, or other complex shape. Any help would be much appreciated!

Thanks!!

[ibach]

Nice.

Make a cube bigger than your shape and carve it out using your model and SLICE command.

Simple after you have the shape.

[Dadgad]

Welcome to CADTutor.

Nicely done, as Ibach suggested, you can pretty easily do it, but first create a much larger solid

from which you will SLICE it. A sphere, cube, whatever.

The SLICE command offers a 3 point option to define the slicing plane.

I would do this in an isometric view.

You will probably want to change your view a few times while doing it.

Follow the commandline prompts carefully and be careful not to delete the wrong side

after you have SLICED your object. You can opt to leave them BOTH, instead of removing one of them,

then later you could just select and delete all the cut off pieces.

Make sure to save a copy of it, in case you run into any difficulties.

Turn on your END SNAP and go to town.

I hope that you used OSNAPS when you were creating this.

[JD Mather]

Simply create planar surfaces using your wireframe and

then Sculpt.

 

Attach your file here if you can't figure it out.

[ibach]

Sculpt is interesting...

[jazzlw]

Hey Guys,

Thanks a bunch! I ended up using the slice command, which worked nicely. it took me a minute to figure out the three point part (this was before the second reply), but looking at the help page for slice cleared it up nicely. I have attached an image of the result.

Thanks again!

[Dadgad]

Well done, welcome to the wonderful word of 3D modeling.

[togores]

Another way would be using AutoLISP. If you wish to see a series of videos showing how it would work, not for an icosahedron, but for tetrahedrons, hexahedrons, dodecahedrons and a series of assorted surface shapes, you can watch my class at Autodesk University 2012 where you can also download all the necessary source code. The link is http://au.autodesk.com/?nd=au_player#1%0:3202

These objects are created as MESH (Subdivision surface) objects which can be converted to solids by CONVTOSOLID.

Edited January 24, 2013 by togores
Adding image

[ibach]

DO the above, lisp is a great way to use autocad.

[fuccaro]

My way to "solidify" the icosahedron:

First I drew the vireframe. You already completed this step.

 

Next I drew a closed 3d polyline over 3 edges:

 

I drew 3 more polylines lik the first one, and I extruded them. By Polar Array I multiply the solids al around. The heigh of extrusion must be choosen carefully; if it is too long, it will come out on the other side. If it is too short, it will leave an empty space in the middle.

 

Unify all the solids

[Jimmy111]

If you deal with this alot there is a good program for it.

http://www.cadreanalytic.com/cadregeo.htm

 

Not for making the solid but for making the shape itself.