Modern Machine Shop is focused on all aspects of metalworking technology - Providing the new product technologies; process solutions; supplier listings; business management; networking; and event information that companies need to be competitive.
Issue link: https://mms.epubxp.com/i/155490
feature Palletized master gage balls are used throughout the cell to establish a precise reference point to verify all dimensions and locations. For example, as seen here, a gage ball is mounted in the ram head of a sinker EDM, and another is mounted on the pallet fixture on the worktable. The center point of each gage ball can be used to establish a common 0, 0, 0 home position to perfectly align an electrode with a workpiece. milling program with PowerMill. The cell technician then uses PowerInspect to ensure the needed critical-to-function requirements are satisfied when the machined electrode is inspected at the CMM. • In-process correction of machining operations based on CMM inspection data. For example, when the CMM detects a slightly undersized electrode, it signals the EDM to adjust the orbiting parameters programmed for the finish burn of that electrode. New offsets are automatically downloaded to update the original program settings. The RFID chip in the pallet holding that electrode identifies it as the one for which the adjusted program is intended. • Automatic sorting of electrodes by size to optimize EDMing time. The strategy is to match e l e c t ro d e s to ro u g h i n g o r f i n i s h i n g s te p s according to their as-machined dimensions. Electrodes nearer the upper limit are best for the high wear conditions encountered in roughing. Those nearer the lower limit can be applied to fine finishing with adjustments to the orbiting routine. Construction of the next sub cell, Rail 2, is scheduled to begin in the first quarter of 2014. This sub cell will consist of a five-axis machining center, surface and ID/OD grinders, and a lathe with live tooling for hard turning. It will also have a CMM and robot. A transfer carousel at the junction of Rail 1 and Rail 2 will enable pallets to move between the sub cells. Rail 5, the last sub cell to be constructed, will be a separate unit located on the opposite side of the shop floor. It will consist of horizontal machining centers for production of mold plates and bases. Plans call for one new cell to be installed each year. The MegaCell is scheduled for completion by the end of 2017. No Duel BetweeN MoDes Mr. Graham says the dual mode capacity of the MegaCell concept embodies an important lesson about mold manufacturing. "What matters isn't the level of automation, but the level of utilization," he points out. In other words, running the sub cell in manual mode doesn't represent a lesser use of its advanced technology, but rather a fuller use of its potential productivity. The cell's capacity to handle custom work adds to its remarkable earning power, because the custom work flows almost as seamlessly as the palletized work. The modes are complementary by design and out of necessity, he says. "Maximizing the time each machine spends with its tool engaged is the key," Mr. Graham says. Ultimately, it makes little difference whether the operator or the robot keeps the machines busy making parts, as long as the machines are as busy as possible." mmsonline.com September 2013 MMS 83