A slide show about a company's "green" initiatives usually means I'm in for a generally uninspiring outline of moves that reduce machine energy consumption by 10%. A worthwhile endeavor, for sure, but not the sort of thing that really sells the need to embed sustainability thinking in machine design.
That changed at the venerable International Manufacturing Technology Show (IMTS) last month in Chicago during a presentation by MAG-IAS titled "Green Manufacturing Techniques and Machine Design." Doug Watts, the machining center builder's vice president of engineering, outlined an honest to goodness, game-changing project: to entirely eliminate the use of coolant in a titanium machining center.
[pullquote]Based on a cryogenic process that uses a through-spindle/through-tool liquid nitrogen (-320 °F) flow to control the machining zone temperature, MAG says it's planned for use in the production of Lockheed Martin's F-35 Lightning II stealth fighter.
Watts made a few compelling points. Nitrogen is not a greenhouse gas. The process eliminates disposal, management and usage systems associated with flood coolants. It eliminates cleaners needed to remove coolant residue from machine and parts. Liquid nitrogen is inexpensive. It eliminates hazards related to aerosolized flood coolants. It's easily safeguarded with an oxygen sensor. There are clear cost advantages along with environmental improvement.
Nice, but that's not what got me. As I watched the cryogenic demo on a MAG VMC in their booth, I wondered aloud about the difficulty of generating real interest in this on the basis of environmental improvement/responsibility, even though it clearly has a game-changing impact in that regard.
I think it was Jay Rozzi, principal engineer of Creare, the cryogenics specialists in the project, who in so many words said that, while the initial objectives were for the coolant, they realized fairly early in the project that processing rates for titanium could double because of this process. Yeah, double. Watts said that tool life might improve tenfold. "There'll be lots of interest in a process that does that," Rozzi smiled. Productivity increases like that would massively impact the oft-talked-about titanium-cutting spindle shortage, particularly in aerospace.
The lesson is clear. Get past conventional thinking. To many designers, reducing cooling use would be the limit to their thinking. Eliminating it wasn't, um, realistic.
Now, this group might not have originated the idea of cryogenic milling, but they're the ones who decided to go at it hard, and now are close to commercialization.
Because of that boldness, they hit a motherlode of mostly unforeseen productivity improvements that will practically sell themselves.
That's the way it should work. Responsible design and performance improvement are not mutually exclusive. They're just not always obvious at first.
