Trouble with Boolean Union

Hello~ I’m having trouble completing projects because I’m unable to boolean union parts together.

Attached is an example - a bail that I’m trying to attach to a rectangular charm. my go to solution is to trim and join when boolean doesn’t work, but nothing happens when I attempt to trim where they intersect.

any thoughts on what I’m doing wrong?

union.3dm (5.0 MB)

I haven’t looked into why the union or trim fail, but to get you moving you can create the intersection curves between the bail and charm and use those curves to trim each part before joining the two pieces to create a closed object.

HTH
Jeremy

I don’t think there are any errors because with Rhino 7 there are no problems.

The problem lies with these two highlighted microsurfaces in the bail which have a width much smaller than the document tolerance:

Explode the bail, delete the two surfaces and join the remaining bail surfaces to make a closed polysurface and it will boolean union with the charm.

HTH
Jeremy

Hi,

That’s intriguing: I see the same failures in Rhino 7. Can you expand on the process you followed, starting from how you converted the file to Rhino 7 and ending with the boolean union, so we can see what makes your version work?

Regards
Jeremy

I did Export Rhino 8 / Import Rhino 7.
I had the tolerance set to 0.00001.
But Rhino 8 also works with this tolerance.

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The other answers are correct that the micro face is the problem. How did you make the upper part? Whatever command made the part should not have not made that tiny face.

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THANK YOU!

I created upper part by sweeping two shapes together.

.

Bail Curves.3dm (2.4 MB)

@Joshua_Kennedy, Sweep1 does create these microsurfaces with the supplied curves. If you rebuild the bottom curve to 28 points, to match the top one, it doesn’t.

Thank you! I opened RH-85892 about the Sweep making that thin face. I also opened RH-85891 for the boolean since I hope one day we can work around these hard to catch thin faces.

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