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.
I think this will work very well, especially if one could design something that could pack the 'core-mixture' evenly around a talcum powdered PLA piece. Have a look at this: http://reprap.org/wiki/High_Temperature_Metal_Casting#Coreshttp://reprap.org/wiki/High_Te...
myfordboy really knows his stuff!