Basically I'm measuring a bunch of parts for a capability study. Long story short I need to get true position on four similar features. For this instance I'm not sure how to accurately pull this off with the feature inside PC-DMIS since I'm trying to get it from 3 midpoints (1 in x, 1 in y, 1 in z). I figure I can use all the deviations and export the numbers into my excel and just formula it out. I would think the formula for a radius of a sphere would be the same for true position where TP would be the same as r. In that case r^2=x^2+y^2+z^2, or TP = SQRT(x*x+y*y+z*z). But on another forum post I saw, TP = SQRT(x^2+y^2++z^2)*2. What gives with the *2? They said that was for a circle? My shape is virtually a rectangular box. I don't understand how the middle of one object could be different from the middle of another object if it's "borders" were arranged differently?
Would, TP = SQRT(xdev^2+ydev^2+zdev^2), be the correct formula for getting TP on a rectangular box relative to called out datums?
True position is a bilateral zone. The formula you give will calculate the deviation in one direction so this is half of the true position value. Multiply by two to get the full width of the bilateral zone.
True position is a bilateral zone. The formula you give will calculate the deviation in one direction so this is half of the true position value. Multiply by two to get the full width of the bilateral zone.