<b> The Tombstone Advantage </b> Bombardier Aerospace (Wichita, KS), produces Bombardier Learjet Models 40, 45 and 60 business jets. When Drew Hanus, methods engineer, had a project requiring increased productivity, he turned to Advanced Machine & Engineering (AME, Rockford, IL) for assistance. He was already familiar with their products and had previous experience with AME. Dietmar Goellner, CEO of AME and Alvin Goellner, fixturing group product manager along with Jim Park, AME’s representative in Wichita, visited Hanus at the Wichita facility. Bombardier was running 240 different parts through a cell comprised of four horizontal, 4-axis machines with a 28-pallet system and one vertical, 5-axis machine with an 8-pallet system. AME’s team of experts demonstrated the advantages of subplates with hardened precision bushings and hardened threaded inserts on a 2-inch grid system. Because Hanus needed to change parts quickly from one setup to the next, it was shown that grid tombstones and plates, along with modular components, would allow him to locate and align very accurately and quickly on a 2-inch precision grid system. <b> EFFICIENT RESULTS </b> Hanus purchased several full-grid tombstones to be used with their palletized system along with subplates, components and precision dowel screws, which can be used for locating fixture plates onto tombstones or their pallets for quick changeover. Bombardier’s pallets were shipped to AME, where they incorporated bushings and threaded inserts along with locating and mounting holes. A 2-inch grid system was integrated into their pallets and was inspected with AME’s coordinate measuring machine (CMM) , one of the largest in the industry. Calibration blocks were added to check the probe for repeatability of the machines. These show when and where adjustments are needed to hold 0.0002- inch accuracy. A rotary axis check also is done on the fourth axis rotary table to ensure accuracy. Today, 800 different parts are being run through two cells. Monolithic parts are run on one setup. Now, Bombardier enjoys 91% savings on setup time and a total saving of 81% on cycle time over the old dedicated system. “The new system played a major role in allowing us to achieve our Six Sigma goals for this segment of our fabrication process,” Hanus says. “We now have improved set-up time; we are producing better quality parts and saving money in the long run.” Gunmaker Thompson/Center (Rochester, NH) has implemented significant quality changes over the years. The company’s focus has always been to put the best quality firearms into the hands of the consumers, and since Smith & Wesson purchased the company about 10 years ago, their quality improvements have helped them achieve this goal. Still, Thompson/Center encountered challenges while producing so many lengths of barrels for a large breadth of gun styles. Engineering drawings were complicated; measurements varied from one operator to another and some tolerances were too tight for the methods of measurement. Many barrels were cut too short and had to be reworked, or even scrapped. Production and material costs were out of line. A staff engineer discovered a solution: a linear measurement table called ProTable from Accurate Technology (Fletcher, NC). ProTable is a completely portable, battery-operated linear dimension measuring system designed for QC/ QA use on the manufacturing floor. A fixed stop at one end and a moving jaw with digital readout allows linear measurement to be made quickly and accurately up to 19.5 feet. Measurements are displayed in inches, centimeters or millimeters and upper/lower limits, and measurement offsets can be programmed. <b> COMPLETE FEEDBACK </b> With the use of the ProTable, operators locate the firearm style on the control plan chart and set the machine and the ProTable to a specified program. When the machining process is complete, the operator simply places the part onto the ProTable and the digital readout is fixed to flash the message “pass” or “fail.” Each operator is required to measure 100% of all parts produced. “The software also records the number of pieces the operator checked and feeds that information, plus other data, back to our PC,” says Quality Manager Mike DeLisle. “We see everything that the operator has done and it helps us to evaluate operator errors, machine inconsistencies and improvements we can make in the production process.” The ProTable can hold up to 16 various programs for other operations in the shop and operators can check various parts throughout the day. Operators have found the ProTable to be extremely easy and convenient to use—so much so, that Thompson/ Center has purchased two more ProTables and plan to place more in various production locations. <b> SIGNIFICANT SAVINGS </b> The introduction of the ProTable alone has simplified operations at Thompson/Center. The first table created such demand within the company that operators from different shop locations began using the ProTable to measure their parts. “We get significant cost savings and better product from the ProTable,” DeLisle explains. “The product comes out much more consistent and we capture data automatically that has proven to be invaluable to evaluate capabilities on various operations in the shop.” The ProTable is probably the simplest measurement tool on the f loor and yet it is the most effective tool they have for measuring, DeLisle adds. “We’ve invested the time to develop a control system that is unmatched in the industry, and we’ve opened ourselves up to new measurement products on the market and incorporated them into the process,” said Bill Ruger, quality assurance/calibration specialist. “We’ve strategically placed the ProTables in troublesome areas and have improved product quality and throughput dramatically. “Our operators don’t have to walk around the building to check parts,” he continues. “They don’t have to worry about setting up complicated measuring tools or wasting time to get help. They are able to utilize the ProTable in record speed. We’ve not only improved quality, we’ve increased production. Our commitment to quality and investment in quality measurement has saved us in manufacturing costs throughout or shop. And, this has set the stage for years to come.” <b> BENEFITS </b> AME’s tombstone systems allowed for 91% savings in set-up time and 81% reduction in cycle time. AME’s grid tombstones and plates, along with modular components, allow easy and accurate locating and alignment. Calibration blocks within the system show when and where adjustments are needed. Linear measurement can be made quickly and accurately up to 19. 5 feet. The ProTable can hold up to 16 various programs for other operations in the shop and operators can check various parts throughout the day. The ProTable helps reveals operator errors, machine inconsistencies and improvements.
Published by QualityMagazine. View All Articles.
This page can be found at http://digital.bnpmedia.com/article/Case+Study/543584/51357/article.html.