How does Probe WCS work?

[chohmanQ74YB]

I am trying to figure out how the probe WCS works within a program. I am machining many parts with a vise stop G54 setup and I am trying to match machined features from OP1 (one side of the part) to OP2 (the other side of the part). I notice that vise stops combined with the operator have a level of error which can translate features up to 0.01". I have OP2 of a part shown below which roughs out the material, faces, probes the part, then chamfers and engraves. 

My intention with the probe is to find the part in space after roughing and facing to eliminate any errors from setup, update the WCS and continue machining. 

If I perform an X and Y web with the probe how does this effect G54? Does it set it to the middle of the part? Does G54 reset to the original vise stop setup WCS?

[a.laasW8M6T]

Hi

Your WCS stays in the same location on the part, but The probing cycle sets the center of the block relative to the WCS

[programming2C78B]

Why not use your hard jaw as Y, and find the center of X? You can mill through all the stock on op1 (on the X ends) or use a block to help probe the overhang.