Types of Coordinate measurement machine
- Fixed Coordinate measurement machine
- Portable coordinate measurement machine
Fixed Coordinate measurement machine
Important features of the CMMs are
- To provide maximum rigidity to machines without excessive weight, all the moving parts, bed, Z-axis carriage, and Z-column are made of hollow box construction.
- ?To compensate systematic error we built a error map matrix file and fed in to the computer so result output will be very precise and accurate
- All machines are equipped with different Measurement software for analysis and calculation of features.
- Temperature sensors are incorporated throughout the machine and interfaced with the computer to be used for compensation of temperature
Main elements of CMM:
- Main Structure
- Probing System
- Machine Control and Computer Hardware
- Software for Three-dimensional Geometry Analysis
Every machine structure consist of three main axis for pr?cis movement in 3 different dimensions X, Y , Z. ?Liner measurement encoders (scales) are fitted on every axis for measurement. There are transducer which reads the direction of movement and give the digital output to computer.
?There are 4 different type of structure
This machine is basically for small shop floor jobs and small floor requirements. This is medium and small type of machine. In this machine we can put part larger size then machine bed, this will not affect machine full travel.
In this machine there is bridge arrangement of y and z axis which travel along the full length x axis. Because of bridge construction this machine is very accurate and reliable. In this machine we generally we do probing from top and this is by far most popular cmm
These types of machine genarlly refer as universal type of machine, this is generally gauge room machine rather than production machine. Some people confuse between cantilever and column type. The deference is movement of x and y axis. This comes in smaller in size
In this type of CMM Z axis and Y axis by two fix support, these two fix support works a X axis as well. Z axis with Y axis can slide over these two supports. These CMMs are very larg size Even up to 10 Meters. Long. These CMMs are best suited for Large type of parts .
This cmm is good for large size of Job where Z axis and Y axis move along the X axis. These machines are very good for dies, CAR body, like large objects. These kinds of machines also referred as layout machines where probe has been replaced with cutter or spindle to perform trimming operations
Next blog will be about Probing System of CMM