10,000 RPM spindle speed on a BP

Why not? One of the biggest disadvantages of a BP is the lousy 4000
RPM spindle speed. Certainly you can't do this with a varispeed head
without loosing the varidiscs. If you are using a Vector based VFD you
can use a modern motor and just eliminate the varidisc nightmare
assembly. One would need to come up with some easy to change gearing
that can send the speed up to the 10,000 range. I wonder if the
spindle would need a quality high speed balancing job?
Something to think about if you do a lot of aluminum or other soft
material. Every VMC that I looked at had a spindle speed that went up
to at least 15,000 rpm.
Probably want to start out with a 2hp, 3450 rpm motor,have the ability
to drive the spindle directly with a 3:1 ratio and get 10,000+ rpm's.
Reverse the 3:1 ratio (reducing speed) and get all your lower speeds.
(in conbination with the Hi/Lo setting.)
Take a look at this picture of a setup done by Paul Babin of Babin
Machinery.

http://img.photobucket.com/albums/v223/polaraligned/BP%20drive/BPwithoutvaridiscs.jpg

A set of 2 stacked pulleys to reverse the ratio would work fine.
Just one belt change and you are off into milling territory once only
a VMC could handle.

Of course, this is best used on your CNC mill and not your manual mill.

Is this nuts?
Any thoughts?

Scott