Thanks for the responses. I'm using the trial version of 3 — I just started using the program last week; I'll purchase soon.

I had tried the array method before posting, and couldn't get the one good section "cut out" of the rest of the body because objects weren't perfectly aligned. After being more meticulous about which lines I selected, the array worked, but since the first section wasn't perfect, I still have double (or triple?) lines in places. You'll see that in the top view of the .3dm file.

This is creating a new set of problems:

1) When exporting .stl or .obj at both high and low poly counts, the geometry is not symmetrical and I get artifacts that are not trivial to remedy in other programs (like subsurf lumps and holes in Blender)


2) When insetting/offsetting to create thickness, all calculations fail, whether I select a single surface at a time, or try for the whole object at once (ideal)

3) In order to bypass that problem, I just scaled one section down and arrayed. That worked, but in order to create a lip merging the two surfaces at the top, I tried blending. The first section blended fine, but all subsequent sections failed. Both inside and outside edges are made of many little bits as a result of previous functions. This can't be helping.

With a lot of futzing and time these shapes will probably function, but I'd rather work with clean geometry from the start.

I started with just the interior and exterior curve of the lobe. I was careful (I thought) to make the two lines fall precisely on two dimensions, then rotated one 15°. Is it possible when I swept a surface between those curves, something moved a fraction of a degree?

Thanks again for the help,

Sophie