Re: Machining Aluminum Dry

On a manual mill I have used a plastic food container or the like. Sit it on the table, clamp the work from outside, fill the container (with plain water, or a water soluble cutting coolant like (but not limited to) SC520 and water) to cover the work.
For rough to medium work the bottom of the plastic container is even enough. For really accurate work I use a sacrificial piece and skim it.
BTW the plain water is for machining non-machinable alumina ceramic with diamond tools. On a small scale this is surprisingly cheap to do. I sometimes use a brush to circulate the water and - well they aren't chips, the grindings?
Peter Fairbrother
On 05/11/2024 23:40, Bob La Londe wrote:

First off let me emphasize I firmly believe based on hearsay, direct knowledge, experience, and the opinions of experts that a flood of water soluble cutting coolant like (but not limited to) SC520 and water is the magic sauce.
 In my journey to that conclusion I tried a variety of other options from standing there for hours with a spray can of WD40, to crappy little home made mist systems, to brushed on cutting oil, to air blast, to vortex tubes, and even ran flood *transmission fluid for a while.  Flood transmission fluid was the best until I went to flood water soluble coolant.
 As I bragged shamelessly about in another post I finally got around to buying another CNC wood ripper.  Wood Ripper 2.  Wood Ripper 1 has been disassembled and the parts stacked out of the way for some time.  Like with Wood Ripper 1, Wood Ripper 2 was not intended to be used with metals.  Atleast not initially, but now some of the projects seeping into my front brain involve sheet aluminum.  I suspect some aluminum cutting will be coming along sooner than originally planned.
 Now before anybody says, "Well I cut aluminum dry or with just a little cutting oil brushed on all the time," I know.  I actually do too.  On the manual knee mill I cut blanks square and to length all the time before taking them over to one of the CNC mills.  A very light spray of WD40 is what I usually go with.  Tap Magic is a little better, but a spray can of WD40 is so much easier.  A quick sprits and wave and start turning the handle almost as fast as I can.  Typically I make a rough pass in climb to remove the bulk and a spring pass in conventional to clean it up.  I know that may sound backwards to some, but it works.  I do this with a 1/2 inch 3 Flute Alumacut mill from *Rogue Systems Inc, and the one in the tool tray by that machine is several years old.  With smaller mills I have run into problems, but that big old polished 1/2 inch mill is amazing.  Chips just fly, and big ones.  Once it gets a little warm on the spring pass it can throw chips back on the finished surface and they will stick if it doesn't get a sprits of WD first.
 Well on the new Onefinitey Elite I'd need an enclosure 64 x 68 inches roughly square (bigger really) and the mother of catch basins to run flood coolant.
 When I was still fighting flood every way I could I tried some of the coatings that are supposed to be the juice for aluminum, and honestly... well they aren't.  ZrN, PVD Diamond, etc.
 So now with this new machine coming into the shop I am regressing.  I'm looking for a less than full flood answer to cutting aluminum without chip welding, breaking cutters, and ruining work pieces.  So far my best compromise might be spray mist with a vacuum recovery system.  Hopefully the liquid from the mist would drop out in the separator like chips do.
 For now my conclusion is still that based on hearsay, direct knowledge, experience, and the opinions of experts that a flood of water soluble cutting coolant like (but not limited to) SC520 and water is the magic sauce.
 *  Yes flood transmission fluid worked, the parts looked great, cutter life was very good, and my shop smelled like a turbo hydro 350 burning up because somebody put the wrong clutch piston in it during a rebuild. It would consume the fluid.  Either burning it or vaporizing it, but it produced great results.
 **  Rogue Systems Inc is a small (one man maybe) CNC grinding shop in the PNW (No Snag, I don't think he's a slug) that produces a range of solid carbide ball nose and square end mills sold on eBay and on his own website.  Carbide Tool Source.  His Alumacut end mills are every bit as good as any other aluminum geometry mill I have tried and a little cheaper than most.  He also makes the least expensive solid carbide multi flute single form thread mills I have run across.  Well and a few other things.  Solid carbide boring bars, multi form thread mills, and some other cool stuff.