I can't close a hole in a open polymesh surface

I have tried the suggestions in the forum like untrim hole and a few others that I cant remember the names of. Nothing seems to work.

There is a hole in both ends of my surface that I can’t get rid of. I need to make it a solid for some Boolean functions.
I’m very new to Rhino and am stuck for ideas. Here is the model with the holes in it.TheresAHoleInIt.3dm (680.9 KB)

Hi David - first off: the title is a bit misleading as there are no mesh objects in this file. We call this type of object a polysurface.

Secondly, the holes at the ends are not really a problem. The edges at those locations are planar and simply capping the object would close these holes.

The problem is that two pairs of surfaces on one side of the object are overlapping each other and you will have to fix that first.

In the attached, I have just deleted a few surfaces (placed on a separate layer so that you can see which ones) and then mirrored good surfaces from the other side of the object. After that, a few extra surfaces in between are created with the EdgeSrf command. Joining all of these creates a closed object.

TheresAHoleInIt-wd.3dm (2.3 MB)

Note that there are a few very narrow slices of surfaces that I overlooked at first. You’re getting very close to the document tolerances on these and you should generally avoid creating these.

Thanks Wim
I did what you said sort of. I removed all but one quarter, patched the hole and then mirrored in x and y. I didn’t notice the dissymmetry until you pointed it out.

I ended up using Patch on the hole.