Aluminum Milling Coolant ( AGAIN!!! )

Biodiesel (100%)? It's a good lubricant and smells better than petrodiesel.

Laurie Forbes

The Loc-line site applications section shows two examples of vortex chiller guns with Loc-Line nozzles:

The chillers in those pics don't look especially large, it appears it's

They also make a giant 2.5" Loc-Line vacuum hose so you can be color coordinated on the vacuum side as well :)

Just a techie nitpick - commutator brushes produce "arcs" - "sparks" are the things that a grinder makes. (although if the arcs melt or vaporize the commutator or brush material, the flying glowing things would be "sparks.") :-)

(possibly interesting to note - my automatic spell checker doesn't like "commutator" or "vaporize.")

Cheers! Rich

You might find something worthwhile as a cutting lubricant/coolant in the blogs/forums, personal websites.. where home shop EDM machines are being used. I realize that the two types of metalworking are very different, but those guys also need to use non-or-low flammability fluids. The vapor/smoke of some types of otherwise-safe fluids becomes very flammable once the fluids are heated, to the point of being explosive-type reactions if ignited.

BTW, the aerosol cooking sprays that I've used contain alcohols, although the mists of lots of compounds will burn rapidly.. squeezing a piece of orange skin near a flame (at your own risk) will show what's in the skin.

An option/machine modification that may prove worthwhile, would be to duct a fresh air supply to the motor housing/case for cooling the motor, and avoiding getting any mists inside it. A small Dayton squirrel cage blower (similar to the heatgun-sized units) would likely supply a more than adequate flow of clean air. A light-duty flexible duct could provide the necessary ducting without interfering with the drive power for the Z axis motor. Blowers provide air pressures that typical fans don't.. and the air over the motor only needs to be slightly above zero pressure (just a little more than the make-up of the motor's fan displacement).

An alternative spindle motor would be an air motor.. they're capable of very high speeds, but then the mini-mill becomes driven by the big air compressor motor.. but since you may be considering compressed air for cooling vortexes and/or chip evacuation, you'll already be dependent upon compressed air.

I don't know what ATF you were pricing, but for metal cutting purposes, the inexpensive no-brand ATF or power steering fluids at dollar-type stores would be adequate, IMO. Mineral/hydraulic oils generally cover a very wide range of uses.

There is a lot of misuse of terms like water-based.. just because a product is water soluble doesn't mean it contains water (yes, adding water probably makes it flow more easily). So, using some of the newer machine lubricants without adding water may be entirely possible.

I already saw some of the Stream Tek ones online today. They claim a pretty incredible temperature differential. I just might buy one of theirs if I go that way. The price seems pretty reasonable. Not sure about the CFM requirements though. Their medium unit just says requires

...

AFAIK, Crisco has never been lard - it's "hydrogenated" soybean oil. The last family reunion, my aunt and cousin who grow soybeans on their farm were telling everyone to buy more Crisco. ;-)

Cheers! Rich

"Bob La Londe" wrote

Consider evaporation and cutting life of the fluids. as for the recommendations of vortex tubes, the cooling is expensive when you look at the cost of all the compressed air. One place I worked after we looked at vortex cooling of the tools, we set up a refrigerator to cool our cutting slurry. Granted this was an ultrasonic grinding operation not a milling operation.

(snip)

I suppose your car has "arc plugs" then? How about spark-gap transmitters and switches, are they misnamed? What about the Merriam-Webster dictionary? "2 a : a luminous disruptive electrical discharge of very short duration between two conductors separated by a gas (as air) b : the discharge in a spark plug c : the mechanism controlling the discharge in a spark plug "

If there is any difference, "spark" usually refers to a transient discharge and an arc is sustained.

Why do you insist on posting so much crap in such an authoritarian manner when in fact you have no idea?

Cold air will scatter the chips out of the way, but won't do anything for surface finish quality?

MikeB

Chip evacuation will certainly help the finish by eliminating chip welding, the biggest issue.

They use A LOT of air and are damn noisy. If you want one, I'm pretty sure my son still has a unit that he'd let go.

Karl

I'm pretty sure his 30k spindle milling aluminum precludes vortex chiller noise as an issue.

Ask him to throw me a number if so.

bob (AT) yumabassmon (dOt) com

Does the air then really have to be cold to prevent welding? I'm sure the finish would not be nice & shiny with just air.

MikeB

I would think that dispersing chips was all it did you wouldn't need to cool it would you?

You do have to speak up when standing next to it to have a conversation, but when I have a job going I leave my office door open to listen for the metal on metal screams of a crash. My office door is about 25 feet away and sound attenuates exponentially with distance (or so they tell me). I can have a conversation on the phone just fine with the door open.

I beileve that thise mists do not have enough oncentration of oil to be flammable.

I would use something factory made, personally, too many gotchas to work out in DIY equipment of this kind.

I'm sorry I didn't follow this thread, but how in the heck do you use liquid coolant with a 30,000 rpm spindle? Unless something has changed in high-speed machining, that's typically done dry -- even in steel, where, of course, they use high-performance inserts, many of which *can't* be run with liquid coolant.

In production machining at those speeds, it's dry, near-dry, or lean-mist vegetable oil. In aluminum, it is (or was) dry, period.

"anorton" wrote in message news:JcudnXkovLdMQxrQnZ2dnUVZ snipped-for-privacy@earthlink.com...

Sounds to me like _you_ have no idea......that you're saying the same thing! ;>)}