Robert Roland wrote in
:

On Mon, 14 Nov 2011 13:37:37 -0800 (PST), Rex
wrote:

I suspect one of those air-powered Vortex cooling units would be real
handy when machining plastics.

I think I read somewhere that those can be made at home fairly easily.
Not quite up to the efficiency of professionally made ones, but good
enough to be useful.

The full name of the device is "Hilsch Vortex Tube". A Google search
brings up some interesting hits, such as:
http://www.instructables.com/id/The-Hilsch-vortex-tube/

The problem is that they take a lot more air than most home shops can
supply. Lots of CFM at moderately high pressures.

Doug White