HEIDENHAIN IK 5494-2D - Manual (Page 135)

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4
Probes
Finding features when part variations exist
The Pattern Finder probe is often included in programs to locate features when part variability would make
it difficult or impossible without operator intervention. In these cases, the part is fixtured and a reliable
datum is established, but part
variability causes the repeat-
ability of certain feature loca-
tions to be low. The program
steps for finding and measur-
ing a feature when a part datum
exists but part variability is an
issue are diagrammed here.
When these program steps run, the feature will be located by the Pattern Finder probe and moved to the
center of the field of view so that a video probe can be reliably positioned for measurement. Without these
steps, part variability would make video probe positioning unreliable without operator intervention.
The steps described above are shown in the following example of measuring the top-left hole of a pattern
of six holes in a printed circuit board.
Move to the feature
The programmer moves the stage to place the pattern of six
holes under the video camera.
Teach and fire the Pattern Finder
The Pattern Finder probe is positioned over the top-left hole,
re sized and taught the hole pattern. Then the probe is fired to
return a point at the center of the hole pattern. The program-
mer clicks OK to
complete the measurement.
The Pattern Finder probe is positioned... taught the hole pattern... and fired to return a point at
the center of the hole
Video Probe Descriptions