A method was developed for obtaining proper fluid distribution through parallel gun-drilled passages and for being able to inspect the actual drilled passages to guarantee that the designed minimum wall thickness is not violated. This invention uses one feature that addresses both issues mentioned. By machining a “trough” in the center of the cold plate that intersects the gun-drilled passages where they meet in the center, the area where the two drilled passages intersect is removed and any mismatch is eliminated. This allows access for direct inspection of the drill wander. An integral cap, which incorporates orifice features to address the fluid distribution, is then inserted into this trough. This method can also work in a two-layer cold plate where every other fluid passage is for the alternating fluid layer.

Automated Floor Drilling Equipment for the 767

2014-01-227009/16/2014

A new portable floor drilling machine, the 767AFDE, has been designed with a focus on increased reach and speed, ease-of-use, and minimal weight. A 13-foot wide drilling span allows consolidation of 767 section 45 floor drilling into a single swath. A custom CNC interface simplifies machine operations and troubleshooting. Four servo-driven, air-cooled spindles allow high rate drilling through titanium and aluminum. An aluminum space frame optimized for high stiffness/weight ratio allows high speed operation while minimizing aircraft floor deflection. Bridge track tooling interfaces between the machine and the aircraft grid. A vacuum system, offline calibration plate, and transportation dolly complete the cell.

Rediger, Jason, Malcomb, Joseph, Sylvester, Craig

A Comparison between Regular and Vibration-Assisted Drilling in CFRP/Ti6Al4V Stack

2014-01-223609/16/2014

As aircraft programs currently ramp up, productivity of assembly processes needs to be improved while keeping quality, reliability and manufacturing cost requirements. Efficiency of the drilling process still remains an issue particularly in the case of CFRP/metal stacks: hot and long metallic chips are difficult to remove and often damage the surface of CFRP holes. Low frequency axial vibration drilling has been proposed to solve this issue. This innovative drilling process allows breaking up the metallic chips in such a way that jamming is avoided. This paper presents a case of CFRP/Ti6Al4V drilling on a CNC machine where productivity must be increased. A comparison is made between the current regular process and the MITIS drilling process. First the analysis and comparison method is presented. The current process is analyzed and its limits are highlighted. Then the vibration process is implemented and its performances are studied. Both processes are compared according to the

Lonfier, Julian, De Castelbajac, Côme

Dry Drilling of Stackup Composite: Benefits of CO2 Cooling

2014-01-223409/16/2014

The use of composite materials and composite stackups (CO-Ti or CO-Al) in aerospace and automotive applications has been and will continue to grow at a very high rate due to the high strength and low weight of the materials. One key problem manufacturers have using this material is the ability to efficiently drill holes through the layers to install fasteners and other components. This is especially true in stackups of CFRP and titanium due to the desire of drilling dry for the CFRP layer and the need for cooling when drilling the high strength Ti layer. By using CO2 through tool cooling, it is possible to protect both layers. Through work supported by the National Science Foundation (NSF) and Department of Energy (DOE) it is shown that CO2 through tool cooling productivity can be significantly increased while maintaining required hole tolerances in both the composite and Ti layers. Improvements in tool life have been demonstrated when compared to either emulsion or dry drilling. By

Sorbo, Nelson W., Dionne, Jason J.

Flex Track One Sided One Up Assembly

2014-01-227409/16/2014

The Boeing Company is striving to improve quality and reduce defects and injuries through the implementation of lightweight “Right Sized” automated drill and fasten equipment. This has lead to the factory adopting Boeing developed and supplier built flex track drill and countersink machines for drilling fuselage circumferential joins, wing panel to spar and wing splice stringers. The natural evolution of this technology is the addition of fastener installation to enable One Up Assembly. The critical component of One Up Assembly is keeping the joint squeezed tightly together to prevent burrs and debris at the interface. Traditionally this is done by two-sided machines providing concentric clamp up around the hole while it is being drilled. It was proposed that for stiff structure, the joint could be held together by beginning adjacent to a tack fastener, and assemble the joint sequentially using the adjacent hole clamp up from the previous hole to keep the joint clamped up. This process

HansonSmith, Riley, Merkley, Alan

Practical and Portable Automated Machining

2014-01-227509/16/2014

The utilization of new materials and tightening of desired tolerances has driven the advancement of Practical and Portable Automated Machining. Increased demand in volume within the aerospace industry not only requires minimizing the amount of manual operations, but also applying automation inside existing manual fixtures. In the past, manual labor, with drastic limitations on achievable accuracies, has been utilized in areas that machine tools cannot either access or the limited amount of work does not justify the expense of additional machines. Assemblies requiring critical hole alignment or drilling through stack materials often are difficult to achieve using manual operations. The solution is a practical and very portable machining unit that is small enough to fit into otherwise difficult areas and is lightweight enough to be either moved into position by small machines or quickly disassembled/assembled with each subassembly capable of being positioned manually. The criteria for

Neumann, Karl-Erik, Reno, Robert

Automated drilling machine takes the burr out of fuselage joint

TBMG-19843

02/01/2014

More than 1200 large-diameter (up to ¾-in) holes must be drilled into titanium/ carbon stacks for the side-of-body joint on a particular Boeing commercial aircraft fuselage. This is the joint between the upper shell (section 44) of the center fuselage and the lower corresponding section (section 45), which includes the wingbox and the landing gear well.