On Thursday 04 November 2021 03:44:54 Marcus Bowman wrote: > John, > > I always use single flute router-style cutters (Accupro, from MSC > Industrial at www.mscdirect.co.uk) which are specifically designed > for machining aluminium and are highly polished so the aluminium will > not stick to the flutes. These are jolly expensive cutters, and other > makes are available, etc. I would not use an 'ordinary' endmill on > aluminium (unless you keep your jar of caustic soda handy to dissolve > the welded-on chips in the flutes).I would use a 10 or 12mm cutter at > 2000-3000 rpm, so the tooth peripheral linear speed is a bit faster > than your speeds. I am not using flood coolant, for the same reasons > as you, but do use neat cutting oil around the area being cut. Running > at the same feedrate as you, I would probably take a cut of 50 to 100% > of what you are taking, for roughing, although bear n mind that is a > tooth loading of twice what you are using (1 tooth versus 2). Linear > speed around the same as you, at 120 - 200mm/min. All cuts are climb > cuts, in aluminium.
I use most any old carbide mill of around 3 mill or 1/8" in my 6040 at revs up to 20k and have not lost 1 single mill since building a mister, It uses about 2 ounces an hour of heavily diluted koolmist and water. Just enough to keep the tool and alu plate damp. It doesn't take much. > Marcus > > On 4 Nov 2021, at 06:34, John Dammeyer wrote: > > I used the big 1/2" one for the large pocket and the smaller 5mm one > > for the smaller pocket and profile. The surface finish, given my > > crappy cast aluminium, was really nice. > > > > My mill does have a coolant pump but I don't know if I use the mill > > often enough to fill the reservoir with coolant that then goes > > mouldy and stinky. So I'm working on a compressed air mist coolant > > system. But maybe having a secondary reservoir that pumps out the > > main one and adds an aquarium bubbler would work for the flood > > system. So in the last 12 years I've never used coolant. > > > > John > > > >> -----Original Message----- > >> From: andrew beck [mailto:andrewbeck0...@gmail.com] > >> Sent: November-03-21 10:52 PM > >> To: Enhanced Machine Controller (EMC) > >> Subject: Re: [Emc-users] Project Progress > >> > >> What cutters are you using? > >> > >> As a sideline here in New Zealand I buy and sell tooling so I'm > >> always testing the limits. > >> > >> And can probably advise a bit > >> > >> On Thu, 4 Nov 2021, 11:29 John Dammeyer, <jo...@autoartisans.com> wrote: > >>> I've been using LCNC quite a bit (for me). In the photo there > >>> are two steel spring collars that were entirely done with the > >>> mill. I could have left them as large disks with just a stepped > >>> hole and the set screw holes but what's the fun in that. > >>> > >>> > >>> http://www.autoartisans.com/mill/SpindleControl/TrialFitOnSpindleC > >>>over-1.jpg > >>> > >>> The spindle cover casting (10lbs of scrap aluminium) was machined > >>> in the places I needed flat surfaces and to get rid of a bit of > >>> sag in the casting mostly for looks. I'd occasionally spray a bit > >>> of WD-40 but mostly just held the shop vac to clean up the chips. > >>> > >>> http://www.autoartisans.com/mill/SpindleControl/SpindleCoverplate- > >>>4.jpg > >>> > >>> Essentially between 1000 and 2000 RPM, 2 flute 1/2" end mill, 25% > >>> step over, about 2.5 to 5 IPM IPM and a depth of cut of about 0.1" > >>> for each pass. This created chips that did not melt onto the tool > >>> bit and left a quite nice smooth finish. > >>> > >>> But with those parameters it did take quite a while. OTOH, it ran > >>> automatically and other than check on it periodically and vacuum > >>> or blow away chips I could do other things nearby. > >>> > >>> If I enter the parameters into Machinist Toolbox with a target RPM > >>> of 1500 I see it suggests a tool feed rate of 21 IPM. I think > >>> that would melt the chips without flood coolant. Since I didn't > >>> want to screw it up and have to cast it all over again I was very > >>> conservative. > >>> > >>> Was I too conservative on this? It's been suggested by a friend > >>> who runs MACH3 that he dials in a much faster feed and spindle > >>> rate and then hauls back on the sliders to reduce it to very slow > >>> and then in small steps bumps up the speed until it feels right. > >>> > >>> > >>> > >>> Suggestions are welcome. > >>> Thanks > >>> John > >>> _______________________________________________ > >>> Emc-users mailing list > >>> Emc-users@lists.sourceforge.net > >>> https://lists.sourceforge.net/lists/listinfo/emc-users > >> > >> _______________________________________________ > >> Emc-users mailing list > >> Emc-users@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/emc-users > > > > _______________________________________________ > > 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, 1940) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
