6D Shank Measurements
With a calibrated shank tip attached to a T-probe (calibration is per- formed within Tracker Pilot), shank measurements can be taken for sheet metal applications, providing an edge measurement solution. Shank Points is a new Operation that can be used with any measure- ment acquisition mode(discrete, stable or scan). But two new measurement profiles have been added to support this application.
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Discrete Shank Point. This mode is the standard measurement of a point on an edge.
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Discrete Bottom Shank Point. This operation provides the same shank measurement option with the addition of a specified shift relative to the reference plane, designed to account for material thickness.
Shank Plane - measurements require a projection plane to be defined and use this plane definition to define the intersection point of the shank axis and the plane. The tilt of the probe relative to the plane is used to determine the point’s offset in combination with the probe diameter.
This means that the cleanest offset is obtained by holding the probe perpendicular to the edge. Tilting the probe is fine but leaning it such that it trails along the edge should be avoided and could cause an overestimate of the offset.
Override Radius- the radius of the shank probe should be set as part of the calibration process but its default value can be changed within the measurement profile if needed, using this control.
Shank Measurements in SpatialAnalyzer -
Proximity Measurements with a Shank Probe
Shank measurements can also be used with proximity triggers. This makes edge measurements easy to perform by allowing you to trigger points along an edge as you slide a shank probe along it.
To do so perform the following steps:
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Build a vector group to be used for the proximity trigger process. Each vector in this vector group will be used as a trigger such that as the probe’s axis crosses the vector a point will be triggered for you.
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Enable Use Shank option within the Auto-Proximity Scan profile operation. This tells SA to use the shank point not the tip of the probe in the proximity calculation.
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Navigate to Instrument>Automatic Measurement>Auto-Correspond with Proximity Triggers>Vectors. Specify a tolerance zone to consider and a resulting group name and begin the operation.
Double check that the option to measure each point more than once within the proximity dialog is Enabled. If you don’t, it will simply take the first point that is within the proximity tolerance… on the approach and will not find the closest point to the vector intersection.
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Slide the shank probe along the edge of the part to trigger measurements at each of the reference vector locations.
The point that is recorded is the closest point on the shank to the vector origin. Its important, therefore to have a good alignment. If the measure feature deviations significantly from the nominal the compensation can be affected.