Hi Stefan, I'll be looking at your geometry in just a bit, but re: this part:

> I think I've hit a bug in MoI. When I select this isect (solid object) and do an export, it
> creates the 6kb file. I had to "save as" the entire file in order to produce a proper .3dm file.

In the "Save As" file, it looks like all the objects are hidden. When you do a File > Export, only selected objects are written to the file, and hidden objects are not selected.

If you wanted to only write just one single object, you would need to show it, and then select it before doing the Export. If you hide it before doing the export it will become hidden and also unselected and so won't be exported.

Hope that makes sense, let me know if it doesn't.

- Michael