The image shows the probe and the laser on the scanning machine. The probe measure the height at 180 points on a surface in its range. The probe can only focus on a surface in its .35 mm range. Wax cylinders typically have deformations in their surface or have some elliptical eccentricity on the order of 5mm. If the probe remained stationary then the cylinder would wander in and out of its range as it rotated. To compensate for this, the laser, whose 25 mm range is far larger than the out of roundness of the cylinder surface, measures the height of the cylinder as it rotates and relays that data to a focusing motor that moves the probe closer or farther from the cylinder to ensure that the surface stays in its range.
The image shows the probe and the laser on the scanning machine. The probe measure the height at 180 points on a surface in its range. The probe can only focus on a surface in its .35 mm range. Wax cylinders typically have deformations in their surface or have some elliptical eccentricity on the order of 5mm. If the probe remained stationary then the cylinder would wander in and out of its range as it rotated. To compensate for this, the laser, whose 25 mm range is far larger than the out of roundness of the cylinder surface, measures the height of the cylinder as it rotates and relays that data to a focusing motor that moves the probe closer or farther from the cylinder to ensure that the surface stays in its range.
