Page 150 - CITS - Fitter - Trade Theory

FITTER - CITS

MODULE 9

LESSON 25 : Introduction to co-ordinate measuring

machine and its application

Objectives

At the end of this lesson you shall be able to
• state the CMM and its specification
• state the components of CMM
• state the machine structure and application of CMM
• state the precaution of CMM.

Introduction to Coordinate Measuring Machine (CMM) :
A Coordinate Measuring Machine (CMM) is a sophisticated measuring device used in manufacturing and quality
control processes to precisely measure the geometric characteristics of objects. It operates based on Cartesian
coordinates and utilizes a probing system to gather data points from the surface of the object being measured.
These data points are then used to generate detailed 3D models or to verify the dimensions of the object against
the desired specifications.
Components of a CMM:
A Coordinate Measuring Machine (CMM) typically consists of several key components:

1 Frame:
The frame provides the structural support for the entire CMM system. It holds all the other components in place
and ensures stability during measurement operations.
2 Bridge or Arm: -

Depending on the type of CMM (bridge, cantilever, horizontal arm, etc.), there will be a component that supports
the probe and moves it along the X, Y, and Z axes to reach different points on the object being measured.
3 Probe: -

The probe is the part of the CMM that physically touches the surface of the object and collects data points. Probes
can come in various types, including touch-trigger probes, scanning probes, and non-contact probes like laser
scanners.
4 Controller: -
The controller is the brain of the CMM system. It receives input from the user interface or measurement program,
translates it into motion commands for the machine, and processes the data collected by the probe.
5 Drive System: -
The drive system consists of motors, encoders, and other mechanical components responsible for movingthe
probe along the X, Y, and Z axes with precision and accuracy.
6 Software: -
CMM software provides the user interface for programming measurement routines, analyzing collected data,
generating reports, and controlling the overall operation of the CMM system.

7 Workpiece Fixture: -
This component holds the object being measured securely in place during the measurement process, ensuring
consistent positioning and alignment.

8 Touch Probe Stylus: -
The touch probe stylus is the part of the probe that makes contact with the surface of the object. Stylus configurations
can vary depending on the specific measurement requirements, such as size, shape, and material.

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