New Type of Probe Excels at Digitizing
Fully digital probes are especially effective at accurate digitizing routines (like reverse engineering cylinder head ports) using a long stylus.
According to Centroid, its fully digital probe with a long 140-mm stylus delivers ten times the accuracy of a traditional kinematic probe during digitizing operations such as those commonly performed on cylinder head intake and exhaust ports.
According to Centroid, an issue with traditional kinematic probes (and to a lesser extent with more costly strain-gage probes) is measurement error due to pre-travel variation, or “lobing.” Centroid is a manufacturer of five-axis machines for cylinder head porting, four-axis machines for engine block work and CNCs for retrofit applications. During 3D digitizing routines, for example, lobing occurs because the force required to trigger a kinematic probe differs depending on the geometry of the part and the direction that the probe approaches a part. In addition, lobing error becomes greater as stylus length increases, reducing measurement accuracy and introducing distortion to the data when probing deep into part features such as engine block cylinders and cylinder head intake and exhaust ports.
As a result, Centroid has developed what it calls a third class of touch-trigger probes—fully digital probes. With a 140-mm stylus, these probes are said to deliver ten times the accuracy than the kinematic probe.