Think you can turn a nice finish?

[Swede]

I stumbled across this video on a science web site.

These machines use a diamond tool + air, and some unbelievably rigid machinery, to turn copper down to nearly the atomic level for some sort of optical purpose. Neat stuff!

[ame]http://www.youtube.com/watch?v=vAvfrrlMZg4&feature=player_embedded[/ame]

 

[steamer]

1/4 to 1 nanometer PV finishes are quite common in copper and optical grade aluminum

Whats a nanometer?

1 billionth of a meter.....3.939 x 10 -8 inches or .00000003934 inches.... .03934 millionths of and inch

For scale....take a human hair that is .003" of an inch IN DIAMETER.

Lay it down on the ground.....now take 999999999 more and lay them next to it side by side so that they are all touching and laying in line.

That line would stretch fo 47 miles......and that 47 miles would be a meter in comparison

Now divide a singular hair into 4 pieces the long way....that's .25 nanometer.

The linear glass scales on the machines have a resolution of 39 picometers (39 x 10-12 or .000000000039m ) ........keep in mind a hydrogen atom has a diameter of 50 picometers......

The machines have no metal to metal contact anywhere and are all running with hydrostatic ways with either hydrostatic or aerostatic spindles. the way systems underneath the fabric bellows way covers are bathed in oil for temperature stability. The oil temperature is carefully controlled as is the temperature of the spindles and the air surrounding the machine usually. Air temperature control is 1/4 C +/-

The bases of the machines are solid granite or epoxy granite and are supported on air isolation.

And they cut copper and aluminum to these tolerances like you and I breath.

Cool Stuff.

Dave

 

[rleete]

I see that everyday. My company cuts lenses. Mostly Fresnel lenses, for solar applications.

The diamond machinists scoff at my crude engines.

 

[Swede]

Awesome! So the spindle bearings are pneumatic? That'd be the only way I can think of to even come partway to such incredible tolerances.

Or are they hydraulic? I'd think air, being compressible, wouldn't perform as well as an incompressible hydrocarbon or some other working fluid.

The feed must be unbelievably fine, too, even with extremely high RPM's.

 

[steamer]

They've been done both ways That one is aerostatic
radial clearance is about. 0002"

Dont let it run out of air! The spindle will touch down and its toast!

Dave