HEIDENHAIN ND 1300 VED and Crosshair Systems User Manual

Page 89

Probes

Seeding to avoid erroneous data

The multiple edge probe can be seeded manually using the single edge probe to avoid collecting data over

keyways, protrusions and other feature anomalies. This is accomplished by:

1 Seeding points very close to, and enclosing the area of anomaly using the single edge probe

2 Switching to the multiple edge probe to complete the measurement by probing the reminder

of specified points automatically

Normally, the multiple edge probe attempts to collect the specified number

of points from an even distribution of probed points along the feature edge,

which includes the seed points.

As shown in the example below, when a line without anomalies is probed, the

multiple edge probe is seeded with the two endpoints, and then automatically

probes the remainder of the specified points at locations distributed evenly

between the endpoints.

This process works well when the feature probed includes few or no edge anomalies. However, discon-

tinuous or indistinct edges can lead to data errors if no preventive action is taken.

Since a combination of seeded locations and system-generated locations are used to distribute and probe

points, tightly enclosing any edge anomaly between two seeded points greatly reduces the possibility that

the multiple edge probe will probe the anomaly.

16 Points are specified

for a line

The multiple edge probe is seeded with the endpoints of the line, and evenly distributes the remaining points

The single edge probe seeds the endpoints of the line and then probes additional seed points that enclose the

line anomaly. The multiple edge probe is then selected and the remaining points are probed automatically.

Probing