I wonder what material is that?
Why the end bit does not broke?
How the hell can a machine milling in that extreme high speed?

http://www.datrondynamics.com/VideoZone/Videos340kb/HighSpeedH.wmv

after this I think that I am so slow......

George!

My guess is its not on steppers and its not home made 

A fast spindle on a rigid machine cutting aluminium with carbide tooling.

If you want impressive machining look at these : http://www.youtube.com/results?search_type=search_playlists&search_query=matsuura+5+axis&uni=1

Graham

Site saws 60,000 RPM spindle and ethanol coolant. Also that material is thinner than it looks.

It is all about the bit load per rev. Each flute of the bit can cut a certain amount and not overload. The faster you can turn the spindle allows you to feed faster and still have the same cut amount for each flute.

Now a s long as you have the power to turn the spindle at extrem RPM AND the power to feed at extreme high feedrates then the load on the bit flute is always the same as long as the same ratio to RPM and feed remain the same.

this holds true up to the point that you can no longer supply the proper coolant to keep everything going. FOr extrem high feedrates a high pressure volume coolant sytem is required.

BUT let that coolant get overworked and have 1 flute LOADUP and the bit will be history as well as the part. The failure happens at extreme speed as well (;-)

(;-) TP