Tag
#datums
2 topics across all disciplines.
Datums and datum reference frames
Why three datums and not one, how 3-2-1 location removes six degrees of freedom, what datum precedence actually changes, and why the fixture, the gauge and the drawing must all agree.
Locating schemes and functional build
Reference point systems and master locating points, why the same holes must be used from press shop to final assembly, and how functional build differs from building every part to nominal.