Convert revolved solid to mesh

[Siz]

Hello All,

 

New to this community so please be gentle.

I have been using AutoCAD for over 20 years for architectural type work in 2D. I'm now embarking on a personal hobby of 3D modelling for manufacturing small components. And I'm stuck at the first hurdle.
I have created a very simple solid using 'revolve' - basically a sphere with a hole though it. When I convert this to a mesh for export to STL file, the conversion distorts the shape, losing all dimensional accuracy and neatness. From my image, hopefully, you can see the difference between the solid on the left and converted and smoothed mesh on the right. The red line shows the original required profile.

Can you help me retain the true dimensions of the 'sphere' in conversion?

 

Is it normal practice to create objects in solids and then convert to mesh for STL export, or would it be better practice to create components from meshes to begin with? (and that'll need a whole new list of questions about trimming primitives...!)

Thanks for your help.

 

Siz.

EDIT: Ah, I actually just remembered that that the original revolved entity was (necessarily) formed from an elipse and not an arc (i.e the 'sphere' is actually slighly obloid). That's possibly where AutoCAD is falling over...???

 

 

 

 

 

Edited September 11, 2022 by Siz

[Cad64]

There's no need to convert to mesh. Just export your solid to .stl.

Take a look at the links below.

 

About Exporting Stereolithography STL Files

To Export 3D Solids to an STL File

[Siz]

Ah, that's helpful, Cad64. Thanks.

But, in any case, is this issue repairable, as stated? (just for the sake of learning...)

 

Cheers.

[Cad64]

Well, you could always UNDO back to a point before you converted the object to mesh, unless you already saved and closed the file. In that case, you're stuck with the mesh.

 

You could also try the CONVTOSOLID command, but I doubt it will put the model back to its original form.

 

When I'm working in 3D, I always save incrementally. Whenever I get to a point where I'm going to do something to drastically alter the model in a way that would be destructive or undoable, I will do a SaveAs and save out a copy of the file. That way I can always go back to a previous file if something goes wrong.

 

 

 

 

[Siz]

 

Oh, I've no problem recreating this - it took only a few minutes (and I'm no stranger to AutoCAD crashing on me which teaches a person to save frequently!) I just wondered what the workaround was to stop this from happening with ovoid shapes... if I ever wanted to do this in the future...

[mhupp]

The problem with stl's is its converting into small triangles so things will never be 100% circular. Their is a command you can use on the solid before exporting to stl that will reduce this, but i can't remember what it is. I'll ask my boss tomorrow since he's the one who told me about it.

[SLW210]

What is FACETRES?

 

 

[mhupp]

Yep that's it set it to 10 for the highest resolution.