To inspect a component on a CMM machine, the following information is required:-
- Type of feature required for inspection
- Hole
- Slot
- Surface Point
- Edge Point
- Rectangular slot
- Nominal values for the X,Y,Z co-ordinates to inform the absolute position of that feature in 3-D space
- Nominal values for the I,J,K vectors in order to inform of the angle in the plane of that feature is lying in
- Linear nominal values such Diameter for holes, and Lengths and Widths for Slots.
This type of information is generally obtained from either an engineering component drawing, CAD (Computer Aided Design) interrogation, or measured directly against a CAD surface model of a part as shown in Figure 6.
Figure 6: A picture showing components being dimensionally assessed against the nominal CAD surface
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