My goal was to draw something in a CAD program, import it into Mach 3, and let the machine move through its paces to see if anything fell off, went up in smoke, caught fire, etc. I've attached a (crappy Blackberry) video of one of the first few times things worked as expected.
I took a look at Blender and while it seems to be an awesome program, with tools to export g-code for a CNC machine, my head started hurting after a couple of hours of experimenting with it. When I have more time I'll re-visit...
So, I began with Inkscape and the g-code export scripts (see here and here), drew an artistically challenged cube, imported into Mach3 and...success! I didn't actually cut anything at this point for safety reasons, so the router is turned off...the machine moves pretty slowly (i think that's a good thing for now) so the movement isn't that perceptible but I thought the Mach 3 screen was pretty cool :)
https://www.youtube.com/watch?v=usl7gpzmRxo