The use of a narrow profile posts or Skinny Fixture increases build speed and flexibility while improving quality of aluminum aircraft panels fastened in one-up assembly cells. Aluminum aircraft panels are made up of an outer skin and a series of stringers. The components must be held in accurate relative positions while preliminary fasteners are installed. By using narrow fixture posts in conjunction with deep drop stringer side machine tools, the fastening machine can apply fasteners at tighter initial spacing. The spacing is gained by providing clearances that allows the centerline of the fastening system to work closer to the post than previously achieved with deep fixture posts and short stringer side tooling.
At one time the standard process was to hold the parts in manual tack cells and after tacking the panels are moved to a separate automated fastening cell. One-up assembly fixtures improve the process by reducing manual processes while minimizing component handling. A typical one--up fixture has large tooling posts that interfere with the automated fastening process. The Skinny Fixture uses contoured posts fully indexing the skins and stringers. The parts come in as individual components and are held to within j0.25mm. No manual tacks or temporary fasteners are required.
Narrow profile posts fully integrated with the fastening machine allow customers and programmers to final fasten up to 80% of a panel without moving posts or pulsing a panel. To access the remaining fasteners the Skinny Fixture can be used as part of a pulse line or as a single cell with moving posts. Full fastener coverage is gained either by pulsing the panel to a mating line or moving each post during the process. With a pulse line, the second position posts would be configured to hold the panel in the previously fastened zone. When moving posts, clearance is instead gained by translating the posts in X by a sufficient distance to clear the unfastened region.
