Jim,
You're right that AutoCAD is too weak for this. Cadkey is probably the least powerful (and cheapest) CAD platform you can use. The reason I suggested this is: IF you don't already have a high end CAD system and DON'T have a dedicated software package to analyze complex surfaces, you can generate part programs that measure NORMAL to surfaces without spending $5,000/$25,000. I bought CADKEY for $500, got the Geopak 2100 software with the CMM machine. QBASIC is free. You can use my program for free.

Can you inspect a CATIA nurb surface for $500? If you come up with a cheaper method, let me know. I buy all of my own software, GM, BOEING, Hewlett-Packard, etc, have given me nothing. If you had the choice of a new car or VALISYS, PC-DMIS, or Unigraphics, (which actually do nothing more than my system does) would you spend the money?
Please let me know of any cheaper and better method. Thanks, Pat.