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An automated, sleeveless method of coldworking used in either a robotic or traversing slide application is discussed. The coldworking end effector, developed by West Coast Industries, uses the split mandrel coldworking process, thus obviating the need for the complex handling of the split sleeve and its associated costs. Sensors mounted on the end effector provide feedback to the robotic controller, and may be used for Statistical Process Control (SPC). The unit may be used to coldwork 2000 and 7000 series aluminum alloys, with hole sizes ranging from 4.4 mm to 12 mm, and 1.5 mm to 50 mm stackup thickness.

The incorporation of split mandrel coldworking into a single- station, automated wing assembly machine advances the technical quality of automated production. Coldworking innovations, including the CMX process and new puller unit development, combined with new clamp-up technology, have eliminated the need for manual dissasembly and deburring, both costly and time consuming procedures. These advances in automation are illustrated in the development of a next-generation automated unit created for wing production of the Airbus A340-600 wide-body program. This paper describes the implementation of new fastener and coldworking technology that led to the development of this automated manufacturing system.

Coldworking short edge margin applications, using nominal applied expansion levels, may result in the buckling of the short ligament. This paper describes a new coldworking procedure, Multiple Initial Coldworking, utilizing the split mandrel process. This coldworks the hole three times, instead of the usual one time. Static tests conducted on aluminum and titanium sheets analyzed the effect of the new process on low edge margin applications and other hole quality issues. Fatigue tests determined fatigue life increase on the basic process. Three passes at a lower applied expansion produce fatigue results similar to nominal single pass coldworking.

An automated, sleeveless method of coldworking, used in either robotic or traversing slide applications, is discussed. The coldworking end effector, developed by West Coast Industries, uses the split mandrel process, thus obviating the need for the complex handling of the split sleeve, and its associated costs. Sensors mounted on the end effector provide feedback to the robotic controller, and may be used for Statistical Process Control (SPC). The unit may be used to coldwork 2000 and 7000 series aluminum alloys, with hole sizes from 4.4 mm to 12 mm diameter, and 1.5 mm to 50 mm thick material.

Aircraft manufacturers spend millions of dollars reworking blown fastener holes, especially in portable tool drilling situations. Oval, tapered, rifled, and oversize holes are costly rework issues currently commonplace in the industry. The most common causes of imperfectly drilled holes include spindle runout, insufficient clamp and feed force, out-of-balance drill feed forces, spindle windup, and lack of adequate feed control. This paper will focus on a next-generation drilling machine that utilizes a unique combination of hydraulics and pneumatics to solve the problems associated with legacy drilling units. Several design elements will be examined, such as the use of an on-board, 1000 PSI hydraulic pump, controlling both drill feed and clamp force. This greatly reduces the size and weight of the clamp and feed cylinders compared to legacy air systems, while increasing their force and rigidity.