On Monday 02 April 2018 11:53:41 Marius Liebenberg wrote: > Gene it is sitting fully submerged and that groove is on the top half > of the bearing so it should have a lot of oil on the bearing surface.
How much oil is in the pocket that submerges it? A heavy weight thick oil seems like its not advantageous at all. If it can circulate to dissipate the heat, seems all that would be needed. Drain & refill with clean stuff occasionally, anytime any cloudiness shows up in it. Ought to outlast us, certainly me. :) > I dont need more than 1000 or 1500 RPM for the plastics. That should do nicely then. Coolant assumed on the plastics of course. :) > ------ Original Message ------ > From: "Gene Heskett" <ghesk...@shentel.net> > To: emc-users@lists.sourceforge.net > Sent: 2018-04-02 17:33:21 > Subject: Re: [Emc-users] What RPM > > >On Monday 02 April 2018 10:23:33 Marius Liebenberg wrote: > >> Hi > >> I have had this piece of machine in the store for a long time. I > >>think > >> it was used to decant fishing line to the smaller plastic reels. > >> I have a need for a small dedicated lathe that will onpy cut soft > >> materials like plastic and aluminium occasionally. > >> The spindle in the picture is what is currently fitted to the > >> machine and I would like to refurbish and use it. The question I > >> have is what RPM will I be able to run the spindle seeing that it > >> uses these brass bearings? > > > >I am seeing an unusual lube distribution system in those bushings. Is > >there a lube pump and reservoir associated? Something that would > > assure a continuous flow of lube into the end grooves and thence > > lengthwise thru the groove I can see running lengthwise in the left > > half of each? With such a system running, and delivering a 1/2 cup > > of clean 0 to 5w oil a minute, I could see it spinning 30k revs. The > > rev limit would be how much heat the viscosity of the oil used was > > caused to be generated. Monitor with an IR thermometer. Personally, > > the oil will start to fail at around 300F, so seeing 150F on the > > bushing holder would make me slow it down. > > > >If nothing of that sort of circulating lubricant exists, and its > > equipt with flip cap oilers, then some 30-50w oil to try and hold > > the hydrodynamic film, refreshed hourly might allow 2500 revs, > > depending on the load and any imbalance that might exist. Because > > the hydrodynamic forces are rpm dependent, there is of course a > > minimum speed that should > >be maintained when its carrying any lateral load. > > > >I get the impression that what little evidence of wear I see was > > caused by this minimum speed being violated, probably at startup and > > shutdown times. The small cross-section of the shaft will allow > > some flexure under load which may have overpowered the > > hydrodynamics, allowing some metal to metal contact, and that might > > have worn the bushings a bit bell-mouthed. With sharp tooling and > > copious coolant, it should do plastics and alu at decent cutting > > speeds just fine. Add the forced lube > >and 10k+ rpms should be doable. Watch it with an IR thermometer, and > >let > >it tell you when it needs forced lube. > > > >> ----------------------------- > >> Regards / Groete > >> > >> Marius D. Liebenberg > >> +27 82 698 3251 > >> +27 12 743 6064 > > > >-- > >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 > > ---------------------------------------------------------------------- >-------- 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
