Ok, new guy here. I've been playing with ray tracing programs for years, but I'm new to CAD. I know it's not a major step up, but it's big enough that I'm stumbling. I'm familiar with POV-Ray (www.povray.org) and recently downloaded a demo version of Rhino, so I'm limited to 25 saves and no copying. So far I'm up to one model. I like POV, but it's designed to give image outputs, not meshes. Anyway, my question is this: how much gap should there be between objects (like teeth on meshing gears) for a model to print properly? I'm trying to make something along the lines of this: Fisnished it should be about 1 inch in height. The image only shows the gears themselves; the shafts and end caps aren't shown. Any help or suggestions with the gear question, Rhino, or a better CAD program would be appreciated.