This part is reasonably big, which will help with the CMM's calcuation of this feature. The more you spread your points out, the more accuracy and precision you will get, so take your points as close to the edge as you reasonably can. Use a large ruby w/ a short stem.
You are definitely on the edge of what’s possible with accuracy and repeatability, but I think it will pull it off. Remember, your GR&R will improve by the square root of the number of measurements you take. In other words, if this is a repeatability thing, you can measure the part 4 times, average the readings, and be twice as certain.
