Boolean Union

Hello everyone,

I’m a Mac Rhino 5 user having some trouble with boolean unions. My objective is to get a closed polysurface of a cage-like icosahedron built with round cap pipes for 3D printing. Here’s the file: Icosahedron.3dm (3.1 MB)

Methods I’ve tried:
-Checking for surfaces and naked edges (none was found)
-Adjusting tolerance (and here I found something interesting: sometimes running the intersection command under tight tolerance and then splitting under lower tolerance work out for splits that fail at tight tolerance)
-Intersecting + Splitting + Joining
-Exploding all shapes and joining until it works (this ogre method was the only way I got a final solid that was, unfortunately and obviously, an opened polysurface)

I would like to know if any of you would have any thoughts or ideas I could try.
Many thanks!

Hi Estela,

At least in my experience closed surfaces of equal dimensions, arranged in this way at least, often (or generally) fail when attempting to unify them all at once.

Having slightly different size variations (ex.: cheating by making a geometry fully enters or intersects another as opposed to being flushed to each other) - perhaps you’ve already tried that.

You might find useful boolean operation info here

Here I ‘scale’ the ‘diagonal’ pipe just a hair, almost unnoticeable:

and then I run booleanunion again:

note: I ran the same command on the same group of objects and it failed, then it didn’t.

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The other tactic I use is to work with flat end pipes and place a sphere of slightly larger diameter at each intersection, then union in groups. Generally you can get it to work that way. If it’s a 3D printed object, you may not notice the difference.

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Great points! I’m about to try them.

Thank you very much!

Awesome tip, I’ll try this one as well.

Thank you very much!

Finally worked!