Mike Bordner wrote:What would cause the actual part to be so far off?
I notice that you didn't add tabs to restrain the part. Is it possible that the part shifted during the cut? From what I can see of your settings, they look otherwise fine. I suggest trying to run it again, this time with at least 2 tabs on each long side. Make the tabs .020" or so to give stability, you will sand them off once the job is done. Ignore all that if you are using a vacuum table!