Well, the one reference to ethanol coolant I made early in this thread was on a 60,000 to 80,000 rpm machine.
30,000 rpm is not all that hard to achieve nor is it some magic number, or even expensive if you can stand a certain amount of run out. Heck, even Harbor Freight rotary tools turn at 15K and they aren't very expensive at all.
A lot of the high speed (commercial) stuff on You Tube uses what looks like water soluble or water based flood coolants.
I suppose so, but why would you pull heat from *ahead* of the cut?
With aluminum and most advanced cutter materials, you don't begin to approach the surface speeds that would result in unacceptable temperatures, with any cutter than you can spin at those speeds. And power rarely is a problem, so reducing cutting forces doesn't mean much compared to machining steel.
Teeny cutters are typically made from micrograin carbide. When used in aluminum, they're often diamond-coated, especially for use in modern automotive castings and other precision castings, which are hypereutectic or nearly so, and abrasive as hell. Those cutters can take a lot of heat.
I usually skip over the "which coolant for aluminum" threads because, like this one, they generate a lot of ideas going off in all directions. But, for the record, the basic idea is that you don't need coolant for most applications, at least, to keep the tool cool. You will get a small improvement in tool life using a good lubricant. But, traditionally, coolants haven't been used. Kerosene was used as a lubricant in the first half of the last century, mostly to improve surface finish, but sometimes to deal with edge build-up problems. That became a bigger issue with carbides.
Lubricants, and coolants to some degree, can reduce edge build-up, which can be a problem in some applications. In milling with carbide tools, however, the primary use of soluble-oil coolants has been for chip control, particularly in small-shop and batch-production applications.
But, as always, I'm behind on the thinking in many facets of machining. I use HSS for almost everything, so edge build-up isn't a big issue for me. And my hobby projects are machined mostly in 2024 T4, which I get as scraps, and that alloy does not present much of a build-up problem for me, on my small lathe. I use a lot of positive rake on aluminum and I make sure the edges are sharp and the chip-flow area is smooth.
I machine aluminum dry on my manual Bridgeport and I get a nice & shiny finish as long as there is no chip welding. Just manually blowing chips clear with an ordinary shop blow gun works fine.
Dispersing the chips is sufficient at manual Bridgeport RPMs, i.e. 2,700 RPM. At your RPM and with the tiny cutters you use the cooling may help. Certainly it is easy enough to try just normal compressed air.
Perhaps but there is real interest in machining Be, plutonium and those sorts of things in inert environments these days. Know what I mean, Jelly Bean? LOL
I just finished making a manifold about 10 minutes ago to do just that with a Lokline on one side and a quick coupling nipple on top. Sadly I broke the little control valve on the Lokline so I had to regulate the flow with the compressor regulator. I tried plane compressed air a while back, and it seemed to help a tiny bit, but I was turning half the speed at the time. My poor little 30 gallon compressor is certainly cycling on quite often this time. Would have just used my long air gun with a bungee cord around the trigger, but I couldn't find it.
You know. This whole thread I think has gone off kilter. I probably should have said "lubricant" rather than coolant. Even a film of WD on the surface of aluminum seems to make a noticeable difference. I just don't want to spray or pour WD unsupervised into a cabinet with a brush motor spindle in it. Well, that and I didn't plan the cabinet very well. It would probably take 2-3 gallons to make sure I had a good flow through the filter screen basket back into the pump.
Crisco shortening has always been made from vegetable oil. It was a high-tech replacement for lard waaaaaay back, in 1911. (No, Tawm, Crisco is not rendered from old guns.)
Now, do you know any girls who want to throw a Crisco party?
-- "I probably became a libertarian through exposure to tough-minded professors" James Buchanan, Armen Alchian, Milton Friedman "who encouraged me to think with my brain instead of my heart. I learned that you have to evaluate the effects of public policy as opposed to intentions." -- Walter E. Williams
I didn't look at that link, but at IMTS there was at least one demo of cryo-machining using LN2 for coolant. It looked nifty, but I'll stick to using my LN2 for making ice cream.
I use the loc-line mag base with a quick connect. The valve helps in regulating the air, but you need to use a fine nozzle and adjust your air pressure. I use a 1/16" nozzle and was running about 15 PSI on my regulator without a valve in the loc-line the last time I used it.
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