Boolean difference fails

Hi everyone, i’m new here…

I started to use Rhino recentlly, and i have a small problem, maybe someone can help me out? :slight_smile:

The problem is that it will not cut the ring out of the cilinder??? (black design in the link)
It works with all other solids but not with this one??? i don’t know why??

Now i use the Chamfer tool, it worked, but it is not a constructed shape…! Therefore i need to know wat i did wrong?? :slight_smile:

Files incl. dropbox link:

Txs for reading and reactions.

Read through this KB support article.
It will get you pointed in the right direction.

Hello John, why this boolean difference fails?
BooleanFailsInV5-WorksInV4.3dm (545.3 KB)

Hi Davide,

I’m surprised this would work anywhere. If you call “What” on the blue object, you can see it has edge tolerances of nearly one unit. You can also see how bad it is by exploding and rebuilding the edges. Please explain exactly how it was created so we can fix the problem in the creation code.

We are working on tests to detect bad geometry like this that can cause problems further down the line. We are also developing better feedback from boolean operations to indicate where and why failure occurs.

Chuck Welsh
Robert McNeel and Associates