CMM was Re: Hacking Cheap Digital calipers...

Lee,

CMM is Co-ordinate Measuring Machine. It is essentially a VERY
accurate cartesian (usually) 3 axis platform which looks a lot like a
bridge style (generally) CNC mill. In place of the cutter/spindle is
a "sensing" probe(with replaceable tips of different lengths,
sizes,bends, and shapes; often sapphire tipped). Older CMM's were
largely manually controlled (like the jog CNC function), and the
position was displayed on a digital read out (DRO). Newer machines
are amazing in their automation and capabilities! Amazing in price
also!

A CMM is used to VERIFY or DETERMINE the TRUE dimensions of a "given"
manufactured part. As an example, the probe tip can be placed on
three points of what is 'supposed to be' a flat surface (plane).
Additional points "probed" will show with great precision "just" how
flat the plane REALLY is... Same with 'straight-ness' of a linear
part, or 'round-ness' of a hole or cylinder.

Hope this helps.

Ballendo

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Hi Mariano,
Does C.M.M stand for Computer Machine Measurement?
I've been thinking about adding a multiplexed LED drive off the
extra port of the 16C558. that way it could be stand alone too.
-Lee