Guyson Corp.’s Model RB-RSSA-8 seven-axis robotic grit-blast machine is configured for precision roughening of component surfaces in a production thermal spray coating cell. The machine features a 54 × 46 × 42-inch blast process chamber, and a single pressure-blast nozzle fed by a 3.5-cu-ft capacity, ASME-certified pressure vessel. Blast nozzle motion is provided by a Fanuc M-10iA robot and is coordinated with component rotation on a servomotor-driven auxiliary axis controlled by the Fanuc R-30iA robot controller. A hollow wrist enables routing of the pressure-blast hose through the articulated robotic arm. A custom-tailored suit isolates the robot from the abrasive environment of the blasting enclosure and seals the back wall of the blast cabinet while accommodating the full range of motion of the nozzle manipulator.
The machine’s spindle, fitted with a jawed chuck or a T-slotted turntable, can be controlled to turn clockwise and counterclockwise to orient the component throughout the blast cycle, or it can rotate at speeds adjustable from 0 to 300 rpm.
During the blast cycle, the grit-blasting system is programmed to consistently maintain the correct nozzle angle, stand-off distance and surface speed to produce uniform surface roughness on target areas of the component, without under- or over-blasting and with no wasted motion.
To control the sizing of the blasting grit and help ensure that surface texture stays within specifications, the blast machine’s media reclaimer stack-up includes a cyclone separator that removes dust and fine particles, as well as a vibratory screen classifier that feeds only grit of the specified size to the pressure pot. The blast pressure is electronically monitored and automatically regulated by closed-loop control to keep it from wandering off the value assigned in the process recipe associated with the component. Blasting grit flow to the blast nozzle also is monitored.
Electronic level sensors detect when the amount of blast media is beginning to get low, and new grit is automatically added before a shortage can compromise the surface preparation process.
Options such as an explosion-vented dust collector, metal ducting between the dust separator and the collector, and an automatic isolation valve between the media reclaimer and the dust collector also are available to handle flammable metallic dust from the grit-blasting operation. Wet dust collectors and automatic fire suppression systems also are available.