Making Short Work Of Small Lots

"Multi-tasking" is a word typically associated with the consequences of ever-changing human job descriptions. For the people at Mazak Corporation, however, the word applies equally to metalworking machines. To demonstrate the flexibility of its Integrex 100SY five-axis machining centers, Mazak recently put a new twist on a project that might be called for in a NASCAR machine shop.

Starting with a solid, 4.5-inch diameter, 2.75-inch billet of 6061 aluminum, the machine produced a finished piston in only 17 minutes with a single setup. These precision pistons require a combination of turning, milling and drilling operations that would normally involve separate setups on multiple machines. The finished part requires 20 different machining steps, plus a transfer step midway through the cycle when the part is moved automatically from one headstock to the other. Each step in the cycle—including machining compression ring and oiler grooves, drilling oil holes, milling valve clearance and combustion bowl cavities and finish turning the O.D.—demands the utmost precision.

To complete this part, the Integrex machine uses 16 tools from its 20-tool ATC. The machine changes tools in 1.1 seconds, and its single-pocket turret incorporates a 10,000- rpm spindle with a maximum torque of 36 foot-pounds. The turret has a Y-axis movement range of 4.72 inches and a B-axis travel range of 225 degrees. Additionally, the main spindle's C-axis capability allows the machine to perform precision contouring. Both the main and secondary spindles are 6,000-rpm types capable of C-axis indexing in increments of 0.001 inch. The machine incorporates a 6-inch chuck, and its maximum machining diameter (and swing over carriage) is 18.5 inches. It accommodates a maximum bar diameter of 2 inches.

The ability to machine complex parts in a single setup suggests two types of manufacturing applications. First, in cases where a short time span from the CAD design to the finished part is desired, the Integrex is well-suited for producing prototypes. Second, it can quickly produce small lots of high-value parts that otherwise would necessitate disrupting a machine shop's normal workflow.

According to Mazak's marketing manager, George Yamane, the Integrex fits the definition of a machining center. "Only five out of 16 tools used in this operation are turning tools, while there are 11 rotary tools," he says. "Actual machining time for the rotary tools represents more than 80 percent of the total cycle time."

In addition to its precision contouring capability, the machine can execute crosscuts, angular milling, boring, tapping and off-center drilling. It also features high rapid-traverse rates of 1,181 ipm (X axis), 1,299 ipm (Z axis) and 1,024 ipm (Y axis). While this machine is not designed for quantity part production, its five axes of movement provide substantial flexibility in machining various special order parts in small lots. With its single setup capability, the machine reduces the costs of labor, fixtures and tooling, while offering precise dimensional quality.