Alignment is most important factor when we are doing inspection of any part on the CMM. To understand the alignment first we need to understand few terminologies of Coordinate Systems. There are two types of coordinate system in measurement process generally we used.
1. PCS ? Part Coordinate System
2. MCS- Machine coordinate System
PCS- Part Coordinate System is origin on the part coordinate system. This is an origin where all ? ? dimension start in the part
MCS- Machine coordinate system is the origin of the CMM. This is the reference of the Coordinate Measuring Machine
To create an Alignment on the CMM means we need to move Machine Coordinate System to Part Coordinate System so that you will get all dimensions and result as per Part Coordinate System.?There are several ways to do the alignment on CMM machine. Basic fundamental to move machine coordinate system to part coordinate is to lock the 6 Degree of freedom of the part on machine.
Following are few methods to do the alignment
1. Plane Line Point ? This method is also called 3-2-1 in some software. This method is require two direction and one point to lock all 6 degree of freedom
2. Reference Point System– This method is used maximum 6 features and minimum 3 features to lock 6 degree of freedom
3. Best Fit Alignment- This method is can be used n number of features in all three direction to do the alignment