What is Translation?
Suppose you need to know how far a specific feature of a workpiece is from another feature (Figure 8). Take, for example, the distance to the centers of each of four holes from a central hole. To do this you would first measure the central hole, translate the origin to the center of this hole, and then measure each of the four surrounding holes. Moving the starting point (origin) of the measurement from its present position to another place on the workpiece is called translation. The CMM does this mathematically when you request an alignment routine from its geometric measuring software.
In terms of our street map, once you arrive at your hotel and decide to eat at a legendary restaurant on your visit to the city, you need to find it on the map. The hotel now becomes your new starting point, or origin. By knowing your location, you can tell by looking at the map that you will have to travel two blocks west along Maple Street to reach the restaurant (Figure 6).