brown & sharpe Global 121510, User Manual, Page: 119 / 144

Introduction to CMM
Global User Manual
10-13
Intro. to CMM
An Explanation of Rotation
Not all datum’s are at right angles to other datum’s. For example,
looking at your street map, you see that the Museum is located
on a street that’s neither parallel nor at right angles to the streets
the Hotel, Restaurant and Train Station is on. Thus to determine
how far it is from the Hotel to the Museum, you have to first
translate your key origin to the Hotel and then rotate the key to
be parallel to the street on which the Museum is located. Now
you can easily measure the distance from the Museum to the
Hotel.
Figure 18 Rotation
Maple
A
1
2
3
4
5
B
C
D
E
Birch
Chestnut
Sycam
ore
Elm
Oak
Ritz Hotel
Restaurant
Train Station
Museum
Figure 9
4
0
1
2
3
4
0
1
2
3
4
3
2
1
0