Re: Coordinate Measuring Machine

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Michael Fagan <woodworker88@...> wrote:

>
> Most people operating CMMs aren't taking point clouds or doing any sort of
> scanning. They're taking a few (typically 3-9) points on each feature for
> the purpose of inspection or occasionally reverse engineering. Most often
> the plane or direction of contact is quite predictable.

Correct. A CMM machine is normally not used as a scanner. Instead it is used to verify (inspection) or determine relative location of (reverse engineering) circles, planes, edges, lines, etc. So as you say it is only a few points per item. 3 points and you have defined a plane. Maybe one or two more to average out the surface a little. about 4 - 5 points on a hole and you have the hole location and diameter. All 2D geometry that you probe and the software relates them together in 3D.

There is a newer "scanning" style of probing that is growing. Primarily for parts that are 3D machined and not prismatic. In this the CMM moved along a path and the probe head sweeps the probe back and forth and reads as it goes. Very high end and not needed for most use. Just the special probe heads are in the $15K range.

Tim Goldstein
A2Z Corp
3955 S Mariposa St
Englewood CO 80110
720 385-2118 Phone
877 754-7465 Toll Free

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