Post on 19-Dec-2015
Islamic University of GazaFaculty of Engineering
Industrial Engineering Department
Prepared byShaima'a A. EL Najjar
Juleat S. EL shamiJumana J. AldaghmaJehad R. Abu reda
23 ,May, 2010
Coordinate Measuring Machine
What IS CMM!?
.•A coordinate measuring machine (CMM): is a device for measuring
the physical geometrical -such as point, line, plane, circle, arc, ellipse,
cylinder, cone and sphere- characteristics of an object.
•Coordinate measuring machines (CMMs) are mechanical systems
designed to move a measuring probe to determine the coordinates of
points on a work piece surface.
•This machine may be manually controlled by an operator or it may be
computer controlled.
•Probes may be mechanical, optical, laser, or white light, among
others.
CMM
CMM Development
• The first CMM was developed by the Ferranti Company of Scotland
in the 1950s as the result of a direct need to measure precision
components in their military products.
• although this machine only had 2 axes.
•The first 3-axis models began appearing in the 1960s (DEA
of Italy) and computer control debuted in the early 1970s.
Description To CMM
•The typical "bridge" CMM is composed of three axes, an X, Y and Z.
These axes are orthogonal to each other in a typical three dimensional
coordinate system.
•The machine will read the input from the touch probe, as directed by
the operator or programmer.
•The machine then uses the X,Y,Z coordinates of each of these points to
determine size and position.
Parts Of CMM
Coordinate-measuring machines include three main components:
1. The main structure which include three axes of motion.
2. Data collection and Reduction system - typically includes a machine
controller, desktop computer and application software.
3.Probing system.
• Probes may be mechanical, optical, laser, or white light, among
others.
• Precision sensors for fast, accurate acquisition of component
dimensions and surface data.
Applications
Common applications for coordinate measuring machines
include:
•Dimensional measurement,
•Profile measurement,
•Orientation,
•Depth mapping,
•Digitizing or Imaging,
•Shaft measurement.
How to use it?
• It uses the probe to indicate the first point of the dimension then by moving the arm of machine to put probe on the other point it calculates the coordinates’ shifting which known by actuators and scale, and that calculated by computer system inside.
• By knowing all dimensions it can calculated the size, shaft .. etc.
Finally ..
• A Coordinate Measuring Machine (CMM) is an instrument that
locates point coordinates on three dimensional structures mainly used
for quality control applications.
•The highly sensitive machine measures parts down to the fraction of
an inch and must be properly maintained and protected to ensure
accurate measurements.
•Specifically, a CMM contains many highly sensitive air bearings on
which the measuring arm floats.