Page 134 - CITS - Fitter Trade Practical - Volume -2

FITTER - CITS

Stylus/Probe Tip
Stylus of contact type CMM generally has a spherical diameter. Hard materials are often used at the probe tip -
ruby and zirconia being the most common.

In addition to the spherical shape, a needle type with a sharp tip may be used.
Granite Table
In order to realize highly accurate measurement, the surface of a coordinate measuring machine is often a sur-
face plate made of stone. The stone surface plate has a very small change in shape over time and is not easily
scratched, so it has the advantage that it can be used stably for a long time.
Software
There are roughly two types of software for coordinate measuring machines.

The first is software for our own measuring machines that we independently developed for each measuring ma-
chine maker.
The second is software developed by a third-party that can be used by measuring instruments from multiple
manufacturers.
Air bearings
Air bearings have played a crucial role in the development and construction of coordinate measuring machines
(CMMs) and other metrology tools. Since they are frictionless and highly stable, air bearings play a key role in
delivering the precision required in CMM.

Helps in improving repeatability and minimized error motions in CMM., best suitable than mechanical ball and
roller bearings in CMM applications.
Probes

Objectives : At the end of this exercise you shall be able to
• explain probes in CMM
• types of probes
• applications of probes.

Coordinate measuring machines (CMM) probes are transducers that convert physical measurements into electrical
signals by using numerous measuring systems within the probe structure. CMM probes are a broad category of
instruments that use diverse technologies for direct and comparative measurements. Probe tips usually consist of
ruby balls, which contain ideal physical and mechanical properties for probing operations. Probes can be single-
or multi-tip.

Probes faII into two generaI categories:

(Contact probes and Non contact probes)
1 Contact, or tactile probes
a Hard, or fixedprobes
b Touch trigger probes

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CITS : C G & M - Fitter - Exercise 83 & 84