How to substract a closed solid polysurface by a tube inside it

I would like to know, please, how to substract a solid closed polysurface by a tube, inside it, that is too, a closed polysurface. The radius of the tube has various sizes.
I give you here screenshots. At the end, it is impossible to do it, i have the message that “there is no intersect surface, impossible”.
Can you please help me? :slight_smile:
Thanks so much! :slight_smile:![


Picture 3

And Picture 5. Thanks so much if you can help me! :grinning:

Rhino does not by default let you subtract solids that do not intersect to make a hollow body like that. The workaround is to select your two tubes, call _NonManifoldMerge, followed by _CreateRegions. That will force Rhino to create a ‘disjoint solid’.

The question is, what do you want to do with this afterward?

1 Like

Could you not extend the inner parts through the end of the outer? That is if your looking for the outer to be the keeper.?—- Mark

1 Like

Hi Mark!
Yes, i tried too to extend more at the outside the smaller volume, and even, doing the boolean substraction, it says “boolean failed”, as i give you here the screenshot.

Doing “_NonManifoldMerge”, i have this:

That’s only to be done on disjoint solids like the one in your first post, not ones that intersect like in the one above.

1 Like

But then, after doing “_NonManifoldMerge”, i am doing"_createRegions", Rhino asks me to choose a polysurface, i click on the all merge surface, and then, after, nothing is happen, do you know why? :slight_smile:

Please post the file you used…

Doing more long the smaller tube, it seems it is ok! :slight_smile:
Like this on my screeshot.
Now, i am going to try what you say about the first screenshot!
At the moment i finish, i post!
Thanks so much! :slight_smile:

Hi! Thanks so much, this is ok! :slight_smile: