Extrude inner and outer line to a volume

Rhino Rhino for Windows
1

I have two closed lines. I plan to extrude the area between the lines to a volume. I have tried this, but the lines ar separately extruded to surfaces.
grafik
I tried to connect these surfaces to a volume, but that do not work. What can I do ?

2

Hi -

Do you have the Solid option enabled in the ExtrudeCrv command?
Or, perhaps, the outer curve was not closed in the area where the cylinders are located?
If all else fails, post a 3dm file…
-wim

3

I checked the solid option and the closed surfaces.Helmholz_Layer.3dm (4.2 MB)

4

Hi -

I wrote that the curve might not be closed. It turns out that your input curves are all individual lines. You need to join these to be able to create a closed poly surface. But that alone isn’t enough. The curves need to be closed. In your file, when joined, the two input curves are still open at the locations indicated in this picture:
image

You need to fix that first.
-wim

5

I just have not found the command for constructing a closed line than has staight segments.

6

Hi -

It sounds like you should spend some time on the “Learn” page to get some of the basics.

You already have the single lines so you can Join but need to Move the end points that are overlapping together. To make a single polyline, use the Polyline command.
-wim

7

thanks, that works