Bob La Londe wrote:
What is the big key to the speed of this machine?

http://video.google.com/videoplay?do...53814431369082


Looks like they are cutting about 1/4 plate at a really aggressive rate.
I read a book on some early experiments at Boeing with high speed
machining in the late 60's I think. They were running a huge
Cincinnatti horizontal mill with a 1/2" end mill at 75,000 RPM and 80
Hp, 600 IPM feeds and 640 cu. inches of aluminum removal per minute.
These numbers made my head spin, 80 Hp into a 1/2" end mill!
YIKES! I put the book back and figured I'd never get into that class of
machining.

Part of the trick is to maintain totally INSANE feedrates to keep the
heat generation moving along as fast as possible. Much of the heat goes
off in the chip, but you want to prevent the aluminum, especially, from
warming up much. I think the tests I refer to may have been run dry, to
protect the carbide tools and also because at these metal removal rates
all you'd be doing is boiling a huge amount of water and not really
cooling the work or tool much.

Jon