Submarine propellers made for the U.S. Navy start from a metal casting having a 20-ft diameter. From start to finish, production of one of these 55-ton propulsion units requires 12 months. One reason the process takes so much time is the machining, which removes nearly 14 tons from a single propeller casting. "Such a time-consuming process may soon be a thing of the past," says Tony Schmitz, a National Institute of Standards and Technology engineer. He points out that NIST tool-wear and surface-finishing experiments led to a better understanding of the parameters of high-speed machining. He also indicates that the discoveries enable an increase in material removal during machining by a factor of ten. Refinements in the tool's path reduce the roughnes of the milled propeller surface, eliminating much of the final hand finishing required for smoothing blade surfaces. For more information, go to www.nist.gov.
This year, Design News is getting a head start on the Fourth of July celebration. In honor of our country and its legacy of engineering innovation -- in all of its forms -- we are taking you on an alphabetical tour through all 50 states to showcase interesting engineering breakthroughs and historically significant events.
Earlier this year paralyzed IndyCar drive Sam Schmidt did the seemingly impossible -- opening the qualifying rounds at Indy by driving a modified Corvette C7 Stingray around the Indianapolis Motor Speedway.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.