Free and imports native Inventor files... HIGHLY doubt it
However there are free CNC programs that will import step or iges files.
I've used heekscad/cam for linux before and it worked just fine importing a step file to run in my DIY EMC2 based CNC machine.
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2012 Product Design Suite Ultimate
Windows 7 64 bit
90G OCZ SATA 3 SSD (My SSD is faster than your HDD)
Core I7 920 processor, ATI HD6970 graphics card, 12G Corsair RAM
