Sometimes, it is a matter of going for what's most readily available at the moment. The machine that can handle what's at hand. It may not be good for the longer run. But at present, it may be the thing that you can acquire right away. However, sometimes you have to step back. You have to take into account the bigger picture. You have to assess how long you really plan to be cutting metal. Does the machine of the moment provide the sort of longevity that matches with your timeframe? Or is it something less? Will it mean that before too long you'll be getting another? And how does the math work on that?
The Mycenter-HX1000i from Kitamura Machinery of USA (www.kitamura-machinery.com) is a horizontal machining center built, well, as the saying goes, "Like they used to make 'em." This is a serious machine. It has a 39.37 x 39.37-in. worktable that can handle a 6,600-lb. load. The maximum workpiece size, diameter by height, is 80.71 x 61.02 in. A 57.09-in. tombstone fixture (up to 61.02-in. high) can be put on the table. An indexer provides positioning to 7plusmn;1 arc second with a Curvic coupling. The machine has a 50-taper spindle and a 40-hp spindle motor that provides from 20 to 8,000 rpm. The spindle has a gear-driven setup, a four-speed geared head. One interesting aspect of that is that the geared head is said to be more energy-efficient than a direct-drive head.
The machine has X, Y, Z travel of 80.31 in., 51.97 in., and 53.94 in., respectively.
A word about the fundamentals. The HX1000i has induction-hardened, solid boxed ways. Meehanite castings are used to provide high degrees of stiffness. And here's where the "like they used to" comes in: there is hand-scraping of mating surfaces and hand-fitting of the components. That's right: people are working the surfaces by hand to help provide high levels of physical, not geometry-offset, accuracy. What's more, the guideways are equipped with ultra-high-precision twin ballscrews mated to a pair of servomotors. Not only does this provide a rapid feedrate of 1,417 ipm, but contributes to overall precision in machining. The machine has a positioning accuracy of 7plusmn;0.000079 in. over the full stroke of the machine and a repeatability of 7plusmn;0.000039 in.
Because a machine of this size is likely to do some heavy machining, there is a ballscrew cooling system that employs chilled oil to maintain the temperature of the ballscrews. In addition, there is what's called the "Intelligent Advanced Control" system that deploys sensors and a machine efficiency monitor, which provide values to make machine offsets such that the displacement is minimized to less than 0.0002 in.
The standard automatic toolchanger handles 150 tools. Toolchange time is three seconds tool-to-tool, and a minimum of seven seconds chip-to-chip.
The machine is equipped with a Kitamura-Fanuc 16iMB control that provides the capability to handle anything from general machining to complex contouring.
In an era when it is about redeployment of resources, a solidly built piece of equipment fits the bill better than something that has a certain sell-by date to it.