Scanning V/S Feature Measurement

[Chikoo]

CMM Gurus,

I am using IGES and Iterative alignment to inspect one of our part. I know part is uneven shrink and nothing is consistence on it.
Whenever I measure features like cylinder or circle I can see large difference between nominal and actual and that was expected.

Problem is if I use scan feature on surface of part with linear open I do not see much difference between nominal and actual values. What I am doing wrong here? (I do not have scanning probe I am using TP20 for collecting scan points)

Thanks in Advance
Yatish Patel
281-363-6579

[Matthew D. Hoedeman]

After you select the START, DIRECTION and END points, you must click on GENERATE. Then, CREATE but DO NOT EXECUTE the scan from the scan window. Execute it from the EDIT window. If you do NOT click on GENERATE, then the scan nominals will be the original touches made by the scan. Also, make sure that EXECUTE option is NORMAL and that NOMINALS is set to master. Both these are in the scan window.