On Thursday 13 April 2017 10:41:37 Todd Zuercher wrote: > Here I go again. Unfortunately, the aluminum jig was a big hit, and > now they want more. So I thought I'd take a crack at a trochoirdal > milling path. My first try gave mixed results. Looking for advice. > My CAM software still doesn't have a trochoirdal option, so a faked it > with a line of small circles strung together. I tried milling with a > Vortex 1230 1/4" solid carbide up spiral @ 18000rpm feed rate set to > 100ipm (but due to machine acceleration limits the feed was really > only 60ipm). The path was made with 3/8" circles with a female climb > milling path strung together with a 0.05" step, milling 1/4" deep. It > cut beautifully, for about an inch, then the flutes clogged and the > bit promptly broke. This was a dry test cut in the Mic-6 chewing gum > and I forgot to turn on the air blast. > > Suggestions on where I should go from here? Smaller step? Lower or > higher RPM? Larger circle (to allow faster feed)? I know Getting the > air blast turned on and a squirt of WD-40 will help, but will that be > enough? Better Aluminum stock should also help, I have 3 sheets of > 6061 for the next ones, but I would like to cut a few things from the > Mic-6 scrap left over from the last one. > Smaller step? 50 thou is a bit large for bubble gum alu. Can you devise a way to clear the air? I'm thinking a mist of safflower oil from an atomizer directed at the tool would be just the ticket. It doesn't take much oil, but the mist from the atomizer I built, running on around 20 psi from the shop compressor, is very fine & hangs around in the air for hours, getting into your lungs and making a mess of your glasses if you wear any. But an ounce an hour works wonders on chewing gum alu. I had to do that in cold weather so I didn't have the dust collector running and catching the mist blow-by. The idea is to seal the air away from the freshly cut alu, inhibiting the formation of alu oxide, which is the source of 95% of the cutting heat. Works better if you can arrange the blow so it hits the alu immediately behind the tools cutting edge, covering the alu before it can burn/oxidize. Doesn't need to be a flood, molecular thickness of the deposited oil film is all you need. Ideally, you should not be able to see the oil blowing away, but your finger should come away with oil on it if held downwind of the tool for a couple seconds.
> ----- Original Message ----- > From: "Jon Elson" <el...@pico-systems.com> > To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> Sent: Thursday, February 23, 2017 > 12:54:14 PM > Subject: Re: [Emc-users] Milling Aluminum. > > On 02/23/2017 09:35 AM, Jim Craig wrote: > > Yep, you should have done a HSM slot about 3/8" wide with the 1/4" > > cutter and you would have had little trouble. I try to avoid a > > conventional full width slot in aluminum where possible. lube > > definitely helps or is required. > > Yes, the hardest part of this is what I call the "plowing > cut", where the cutter is cutting the full width into the > material. There's no great way to do this, but ramping down > helps, some. There might be some inventive ways to ramp > several times down the cut, then make a pass at constant > depth taking off the tops of the ramps, then repeat at next > depth, etc. > until you break through. > > I never cut slots the same width as the cutter, I always > somehow manage to plow the first, full-width cut, and then > climb mill the sides to bring the slot to the desired dimension. > > Jon > > ---------------------------------------------------------------------- >-------- Check out the vibrant tech community on one of the world's > most engaging tech sites, SlashDot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > ---------------------------------------------------------------------- >-------- Check out the vibrant tech community on one of the world's > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
