Hi Ed,

> Any pointers on making a MoI file for Shapeway?

The key thing is that you need to generate a completely closed solid STL result.

That means that you need the object to be a closed solid in MoI as well before exporting to STL format.

You can tell if an object is a closed solid or not by selecting it and then looking at the object type indicator in the properties panel here:



If that reads "Joined Srf" instead of "Solid" there, then that means your object is not fully closed. If that's the case you can set up the script from here on a shortcut key to highlight the unjoined edges to see where they are located at:
http://kyticka.webzdarma.cz/3d/moi/#SelectNaked

But if you want to get a solid result at the end, it tends to be easiest to maintain things a solids throughout your modeling process. So for example instead of building a lot of little individual surfaces and joining them together it can be easier to instead work on solid blocks and do booleans to carve things up, because a boolean between 2 solids will result in a solid as well.

- Michael