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 like your work and hope for more of your ideas here.
I am going for the developing markets, so minimal cost is the objective.
Shipping powders (and components) is too costly and if someone is getting it for free, they will be inspired.
Thinking on a larger scale, I think filling an already made 'C' profile filament with the powder will be most accessible, your extruder will be good for this. Maybe it could be hand cranked and solar heated also. Just need the C profile die/tip.
If sand can be used in the filament, it really opens the possibilities up for larger scale printing.