Combining two contoured surfaces into a single object

Hello all!

I posted a little about my project once before, but I have gotten past my original question.

I am making a guitar top that is to eventually be cut out on a CNC machine. I created a curved surface for the top using contour lines imported from illustrator and the sandbox tool. This took care of the top, but the more complicated part is doing the underside. Since this is a semi-hollow guitar, it has a consistent thickness except for a “tongue” support running down the center. I’ll show what I already have completed:

Here is my thought, and I wanted to ask before I spend 4 hours re-drawing the lines. I need to keep the black outlines (Illustrator drawing) at 0" elevation. The contour lines need to move up so the top will be at 1/4" all the way through (except the tongue). The contours around the tongue are the deepest point on the underside. the edge of the tongue drops at a 90* angle until it hits the bottom.

Any time I try to make the space between contours solid shapes and move them, Sketchup crashes. My thought is that I need to import each of these spaces individually so I can change the elevation. After that is completed, I assume that I can take these two layers and merge them into a single shape.

I am not confident in this approach; really just poking in the dark, here. I hope I have used the correct syntax and that you all understand what I am working towards. I would really appreciate any suggestions or advise!

ALSO: You can see how the sandbox tools made lines appear in the cutaways on the top. Any explanation as to why this is happening?

Sandbox always does this, perhaps by design. It always fills in concave outlines. You must turn on the display of hidden geometry and use the Eraser tool to delete the extraneous faces and edges.


I’m really not clear on what you’re trying to do; could you elucidate?

As far as the original contours showing, From Contours doesn’t touch your original contours, which are what you see. The actual TIN (triangulated irregular network, aka, surface) is enclosed in a group so it doesn’t stick to anything. You can explode it if you want, but get rid of your contours first.