The UC Berkeley Library version of the scanning machine. The machine is shown loaded with three cylinders. During a scan the probe begins at the left and is moved to the right in 1.8mm steps using precision motion controls. Because the probe is all the way to the right in this image, it is shown at the end of a scan. The black table is "floating" on pneumatic isolators that keep a layer of air between the workbench and the white table underneath. This prevents small vibrations, even those which may not be palpable or perceptible to humans, from vibrating the system and effecting measurements.
The UC Berkeley scanning machine without wax cylinders loaded. The beige cylinders on the shaft are locator plugs which slide into the cylinders while they are being scanned, to support them and keep them in place.
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.
The UC Berkeley Library version of the scanning machine. The machine is shown loaded with three cylinders. During a scan the probe begins at the left and is moved to the right in 1.8 mm steps using precision motion controls. Because the probe is all the way to the right in this image, it is shown at the end of a scan. The black table is "floating" on pneumatic isolators that keep a layer of air between the workbench and the white table underneath. This prevents small vibrations, even those which may not be palpable or perceptible to humans, from vibrating the system and effecting measurements.
A close up of the probe (the black cylinder at the right of the image) and a cylinder loaded on the machine (the brown cylinder on the left of the image). The probe shines a white light that is 1.8 mm wide (visible as the white line on the cylinder) and analyzes the intensity and color of reflected light to find the height of 180 points on a surface.
A photo of a cylinder on the scanning machine waiting to be scanned. Some of the grooves are visible as well as damage from mold decay and cleaning solution.