Robotic Finish Grinding System

An aluminum casting company wanted to reduce the strain produced on its operators by performing repetitive hand grinding operations on their cast aluminum parts. Finish grinding was identified as the highest ROI for an initial automated system.

The company’s specialized casting process is typically leveraged towards low volume runs, with a high mix of different parts. Therefore, the system would need to be designed to meet the following objectives:

• Ability to accommodate frequent part changeovers, with minimal downtime.
• Ease of programming (new part path generation)
• Achieve a consistent, uniform finish
• Achieve a repeatable cycle time and higher throughput

Premier generated several system arrangements for the customer’s consideration. The selected system arrangement consisted of two adjacent cells each comprised of the following components:

• A Fanuc CRX collaborative robot mounted onto a Macron Dynamic’s RTU (robot transport unit).
• Each robot was equipped with a Dynabrade 5” orbital sander attached to a Ferrobotics ACF (active contact flange).
• Two part load/unload stations, each comprised of a t-slot table and a safety mat
• Dedicated part fixtures, constructed from low-cost MDF “bread” boards and applied 3D printed fixture blocks, would be loaded/unloaded onto the tables by an operator.
• The safety mat would detect the presence of an operator (at a station) and the robot would be inhibited from this station by Fanuc’s dual check safety (DCS) software.
• Robot motion path programs were generated for each part face using a combination of hand teaching and Fanuc’s Roboguide simulation software.
• Process adjustments for grind force, robot speed, and motion path can be made through a local HMI.
• Additional features of the system included using the robot to touch off on a part for part verification, logging of the time on part for predictive media change, and an overhead monitor to display OEE production data.

Benefits

• The system arrangement minimizes downtime, by providing the ability for an operator to exchange a part at one part station, while the robot processes a part at the other part station.
• The dedicated MDF boards eliminate the time required to tear down and erect traditional modular workholding fixtures.
• The ACF is a compliance device which delivers a constant, programmable force of the media against the part, ensuring a consistent uniform finish.
• The CRX robot includes a hand-teaching function, facilitating motion path teaching and touch-up.

Result

Premier delivers a custom automated solution that meets the customer’s objectives of a reduction in labor strain, repeatable & improved part quality, and higher throughput.