OMFG.
STL files uses a CAD.
I know how to use Caddsman. I learn a little bit of it at school for DT (Design and Techonology). Unfortunately, I can only do basic 3D shapes without curves. If I learn a bit more...
Well, Caddsman uses .dab files or something like that, not sure if it's convertable to an .stl file. I'm sure whatever program that is native to an .stl file works similar to Caddsman.
avwave: From your post, I assume you know how to use whatever program that uses .stl files?