Machining Aluminum For The 'Vette - Metal Technologies, Makino - Brief Article

Automotive Manufacturing & Production, May, 2001

The name of the company is Metal Technologies. It's based in Bedford, IN. A tier-two supplier. It supplies Alcoa Automotive Castings. Which, in turn, supplies front and rear cross members machined from A356-T6 aluminum castings to an OEM. The front supports an engine and other components.

The rear cradles the transmission. Both connect to the frame and the wheels.

Oh, about the car that uses them: the Chevrolet Corvette.

One of the things that is required of Metal Technologies is that it supplies machined components pronto. Parts shipped out on a Monday morning are being installed on vehicles by that afternoon. Parts shipped out on Monday afternoon are being installed the following morning.

With a schedule like that, one thing is for certain. Reliability in machining is a must. And there is a second certainty, too: So is accuracy. There's little time for scrap.

So how are they doing it? With four high-speed horizontal machining centers. The A99 from Makino (Mason, OH).

Listen to Randy Lovelace, process engineer at Metal Technologies: "The A99 allows us to machine this large part 20 to 25% faster than we would typically be able to do."

First, size. There is a 40 x 40 [in..sup.3] envelope size. Second, speed. The A99 has a maximum spindle speed of 12,000 rpm.

The machining for each casting is performed in two setups. Parts are hydraulically clamped in place. About that, general manager Craig Duncan says, "When you're machining these parts at the speeds and feeds that we are, the parts have to be rigid. Because of the way we set up the tombstones on the machining centers, we feel like we have the best solution for machining this part at high speeds."

The roughing is performed at 5,700 rpm. Finishing is done at 10,000 rpm.

And as for the aforementioned scrap: scrap rates are down 19% compared with the previous machining source.

A monorail system is used to transfer the parts from the loading area to and from the machines.

Metal Technologies is doing a good job. This is evidenced by the fact that it is working with Alcoa and GM on the next cross member for the next Corvette (and Cadillac).