Original Date: 07/21/2003
Revision Date: 01/18/2007
Best Practice : Optimizing Machining Set-ups
Mobile workstations proved to be a useful tool for Electric Boat Corporation, Quonset Point Facility to resolve machine set-up problems. Set-up repeatability is better achieved on future hull builds due to photographs of optimum set-ups that are retained electronically and can be readily retrieved.
Machine set-up has always been a problematic process in a machine shop. It can consume a significant amount of time, set-up materials may be shared and are therefore scarce, and may not be documented causing repeatability to decrease. This was an issue for Electric Boat Corporation, Quonset Point Facility (EBQP) because of the complex set-ups that take place to machine and assemble products for a submarine. EBQP addressed this issue in the past, but initiatives to improve set-up efficiency were not sustained, set-up data was not documented, and set-up tooling costs were not justified. Because of recent successes with teaming, EBQP established a process improvement team comprised of a programmer, rigger, management representative, and an operator from each shift to address the area. A logbook was maintained for four to six months recording set-up issues that occurred. Digital photographs were taken on a weekly basis to record operations. When the team reviewed the data, EBQP recognized issues that needed to be addressed.
Because of the size and design of some of the machines, operators traveled distances of 40 feet or more to obtain necessary hardware from storage areas, and multiple trips might be required due to the complexity of the set-up operation. Machining support equipment such as vises, workbenches, and turning tables became a collection area for tooling. Ideas were discussed among the team members, and it was decided that mobile workstations would be well suited for the large complex set-up operations and machines, while more permanent workstations would suffice for smaller ones. The team addressed the mobile workstations first, and drafted several design options that resulted in four mobile workstations being built with each having a special purpose. The first was a workbench that could be mobile or stationary; the second was a clamp cart that carried varying sizes of clamps; the third was a cart for threaded rods and nuts of varying sizes and lengths; and the fourth was a cart for stacking blocks. The team also designed a more stable stacking block system by using an interlocking mechanism to provide stability in the vertical and horizontal positions. Benefits achieved include a reduction of set-up time by as much as 15%, reduction of non- value hours of travel time by operators, new ideas being developed by a diverse process improvement team, more stable set-up through the use of interlocking stacking blocks, and improved repeatability and productivity with the use of digital photographs to capture set-up operations for use in future jobs.
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