On Mon, 19 Mar 2012 14:28:54 -0700, "Bob La Londe"
wrote:

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
.3.70...
"Bob La Londe" fired this volley in news:BlM9r.9099
:

If you have some thoughts on doing that I would be more than glad
to hear them.

Bob,
The only things I can recommend are to use fairly large-diameter piping
and high pressure, ending in multiple small lamilar-flow jets that will
increase the velocity, let you direct the flow close to the heating zone,
and provide significant expansion cooling as they work.

The added velocity will also give you better chip clearance, and drive
you out of the shop with noise -- so wear ear-gear.

Thanks Lloyd. That particular machine is inside an MDF cabinet which helps
a lot for sound deadening. You have to raise your voice to have a
conversation right next to it, but 15 feet away you can have an almost
normal conversation even with the shop doors closed. It could probably be
better, but I put lexan doors on the front rather than more MDF. Currently
the air is just a 1/4" piece of copper tube fed by a 3/8 air line with a
valve in between. It worked pretty good, but consumed prodigious amounts of
air. I am looking at various air volume increaser jets etc. The compressor
on the other side of the room is louder than the noise from the cabinet.


Greetings Bob,
I have air nozzles made by two different makers but they both work the
same. Air comes out of an annular groove at the base of a cone. No air
comes out of the center of the cone. The air does focus to a point
about 4 inches from the nozzle end. And both types of nozzles entrain
lots of air so they are really good for removing chips. I wonder how
well a pin point air blast close to the cutter along with a more
diffuse air blast from farther away would work? One thing I am
seriously considering is CO2 cooling. I've been reading some about
super critical CO2 cooling systems being tried on machine tools.
Apparently one of the advantages when cutting soft materials is that
the cold makes the chip brittle (or at least not so soft) and more
likely to break. The CO2 itself also acts as a cutting fluid.
Eric