10-07-2012, 01:16 PM
COORDINATE MEASURING MACHINE
COORDINATE MEASURING MACHINE.pptx (Size: 612.81 KB / Downloads: 75)
INTRODUCTION
Over the years people have developed fast ways of manufacturing a part but may spend hours trying to inspect the part to make sure that all dimensions are correct. This show the need for the coordinate measuring machine. A machine that can be automated and do precise measurments in a three dimensional space.
CMM
CMM is a device for measuring the physical geometrical characteristics of an object. This machine may be manually controlled by an operator or it may be computer controlled.
PROBES
Touch Trigger Probes:
which actuate when the probe makes contact with the part surface. Various triggering mechanisms are.
Highly sensitive electrical contact switch that emits a signal when tip of probe is deflected from its neutral position.
Trigger actuates when electrical contact is established between probe and (metallic) part surface.
Piezoelectric sensor that generates a signal.
MANUAL DRIVE
In manual drive CMM, the human operator physically move the probe along the machine’s axes to make contact with the part and record the measurements.
The measurements are provided by a digital readout, which the operator can record either manually or with paper print out.
Any calculations on the data must be made by the operator.
MOTOR DRIVEN CMM
A motor-driven CMM with computer-assisted data processing uses electric motors to drive the probe along the machine axes under operator control.
A joystick or similar device is used as the means of controlling the motion.
Motor-drive can be disengaged to permit the operator to physically move the probe.