ROBOTIC GRIT-BLAST MACHINE FINISHES PRECISELY

Guyson Corporation (Saratoga Springs, NY)has introduced a robotic gritblasting system that enables consistent production of a specified finish on a wide variety of complex-shaped components. The Model RB-9 is designed to offer precision and flexibility in critical surface preparation work.

A six-axis robot with a suitable payload and range of motion serves as a nozzle manipulator when mated with a rotary table blast cabinet having a 48 in x 48 in x 48 in work envelope.

Rotation of the turntable is powered by a servomotor and controlled as a seventh axis of robotic motion, allowing extremely accurate positioning and movement of the work piece during automated blasting routines. Thus, the RB-9 is capable of constantly maintaining a specific nozzle angle, offset (stand-off distance) and surface speed as it follows the intricate contours of components in execution of the programmed grit blasting process.

The RB-9 can be optionally equipped with a crane slot in the roof of the blast cabinet to facilitate loading and unloading of heavy workpieces by an overhead hoist. Access to the blast enclosure is provided by two full-width doors with abrasion-protected view windows.

The entire blasting chamber and turntable are lined with quarter-inch-thick bonded rubber sheeting to resist the abrasive effects of harsh grit media. Supplied with either suction-blast or pressure-blast media delivery, the Model RB-9 is commonly provided with an enhanced media reclamation system that includes a vibrating screen classifier to separate larger or smaller particles from the blasting grit of the exact mesh size specified for the surface preparation process. The robotic gritblast system can also feature media level sensors and an automatic dispensing hopper to replenish the supply of blasting grit before a low media level could compromise the precision finishing results.

Among the human-machine interface configurations offered by the finishing system designer and builder is a freestanding control console with a touch-screen panel. Blast process parameters associated with up to 100 different robotic blasting routines are stored by the system's programmable logic controller and recalled at a finger's touch.

Guyson has also introduced a robotic shot peening system that changes blast heads to automatically perform multiple peening operations without manual adjustments or other human intervention. So equipped, a single robotic shot peener can do a variety of metallurgical shot peening processes that would otherwise require two or more automated blast machines.

The tool-changing robot blast machine features a slotted rack inside the shot peening chamber, where the blasting tools are stored by the nozzle manipulator when not in use. The assortment of tools required is determined by the range of components to be shot peened and the peening process specifications, but may include straight nozzles of different bore sizes, a lance with an angled nozzle for ID peening, a rotary lance tool for small ID peening or a blasting tool that delivers a different size of peening shot.

One wall of the 86 in x 78 in x 78 inch peening cabinet has a large opening fitted with a custom-tailored protective suit for the articulated 6-axis robotic arm. The laminated fabric seals the rubber-lined blast chamber, which is fabricated from 1/2 in thick continuously welded steel plate, and isolates the robot from the harsh shot peening environment while accommodating the full range of motion of the robotic nozzle manipulator.

The shot peening machine is equipped with a 3,000 lb capacity, 65 in diameter turntable that is driven by a servomotor and controlled as a seventh axis of robotic motion. The rotary lance peening nozzle also has a servomotor drive, and rotation of the nozzle is programmed through the robot controller as an eighth axis.

Critical to compliance with stringent aerospace shot peening specifications, the robotic nozzle manipulator is capable of repeatably following the contours of complex-shaped components while constantly and accurately maintaining the correct stand-off distance, nozzle angle and surface speed required for the precisely controlled cold-working metal treatment process.

Prospective users of robotic grit-blasting or surface preparation systems are invited to submit sample components for free laboratory testing and application engineering evaluation at the blast machine builder's factory in northeastern New York State.

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For more information, contact J. C. Carson of Guyson Corporation, 13 Grande Boulevard, Saratoga Springs, NY 12866-9090, 518-587-7894, ext. 7226, at jcarson@guyson.com, www.guyson.com.