MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
OK... made the 2 sections with thicker walls under the stringer, please find in downloads.
You can only see the bow section because the others are on other layers... you can switch on by clicking on the (20) boxes under the 3d window where there is a little ball in there. With "shift" you can activate more than one layer.
In section 90+ you can see that I'am also still learning blender. I cutted the section at stl edges because I did't know that blender can calculate boolean operations ;-)