On Friday 04 August 2017 09:45:14 Jon Elson wrote: > On 08/03/2017 09:52 AM, Gene Heskett wrote: > > On Thursday 03 August 2017 06:54:02 andy pugh wrote: > >> You probably want CBN (or conventional abrasive) for HSS. Diamond > >> is Carbon. Carbon dissolves in steel. > > > > At room temps? > > The local temperature where the diamond hits the metal is likely NOT > to be room temp.
This is no doubt true. > Unless you grind at low speed under water, there > will be some damage to the diamond. Not under water, but an old fashioned kerosene lamp wick, stuck in a tomato can of K2 with the other end laying on the rotating disk, which is diamond side up, and a small piece of scrap alu laying on top of it for additional contact weight, keeps the disk wet with k2. There is a "pile" of k2 against the leading face of the tool about 1/8" high. K2 of course is also a hydrocarbon, and possibly saturated enough to lower the diamond damage rate? Something never studied at length here. I left it running last night, taking nominally .180" off the bottom of the tools last 5/16", and will measure that to see how much more I need to take off to get a tool .0505" wide, which should give enough clearance it won't gall the SS and seize it in the action. I have a 70 yo drawing of the barrel butt, with dimensions, from a smithing book of the era, but 100 years ago I suspect they were treated as guidelines, because the barrels of the day, and the action I have, miss those measurements by as much as 10 thou! (according to my measuring tools) So I'm going to machine to fit. That also means I will need to re-sharpen the flat (with rake angle) end face several times. So before I start, I will make a stickout gauge so I can restore that as I sharpen, and shorten, the tool. I'll see if I can locate some layout blue to help me see where the interference is as I approach the fit. Or borrow one of the better halves candles for sooting it. But first, take another thou, maybe 2 out of the front spindle bearing cap, I have a low frequency chatter that is coming from the headstock, which goes away for a few minutes after I dribble about 20 drops of 10w into each oil cap. There was nearly 20 thou of shims in the rear bearing when I loaded on the cargo van, and that slop was visible! All shims gone there, so any further tightening till have to be done my lapping the cap. About 4 thou left in the front cap yet. At 1500 revs, the caps will get up to 115 degrees, but that seems to be wearing in now that the rear cap is about right. But IMO 10W is too thick, and much of the heat is oil viscosity related, so the 10W is about to be replaced by 0W20 synthetic. > Jon Thanks 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 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
