Quantifying Time Dependent Viscoelastic Deformation during Coordinate Metrology Audits
Unmanaged viscoelastic creep under metrology clamping fixtures consumes up to forty percent of engineering tolerances, requiring documented dwell periods.
Tactile Probing
Meaning
Physical contact measurement of a workpiece using a sensitive stylus defines a primary method of dimensional inspection on coordinate measuring machines. Through tactile probing, the instrument registers the exact spatial coordinates of a surface when the stylus deflects upon contact. This technique provides highly accurate and repeatable results on machined metal parts.
This method remains the reference standard for validating high-precision aerospace and automotive components.
Sensor Mechanism
Deflection of the stylus tip triggers an electrical signal that records the machine’s encoder positions. In tactile probing, this trigger can be either dynamic or static depending on the type of probe head used. Modern systems use ruby or diamond tips to minimize wear during repeated contact cycles.
Operational Limitation
Surface finish and material hardness can influence the accuracy of the measurements. When executing tactile probing, soft materials can deform under the contact force, causing a small measurement error. Metrologists must select appropriate force settings to avoid marking or damaging delicate surfaces.
Process Integration
Automated routines allow for rapid data collection on the factory floor. The use of tactile probing ensures that critical part features, such as hole diameters and boss heights, are monitored directly during the machining cycle. This real-time feedback allows operators to adjust tool offsets and maintain tight tolerance bands.