On Monday 05 December 2016 07:31:51 andy pugh wrote: > On 5 December 2016 at 12:21, Gene Heskett <ghesk...@shentel.net> wrote: > > HSS cutting alu is not a long lasting tool > > Is that based on your theory that Aluminium forms an adamantine > ceramic layer in nanoseconds? > > Even if it does with a milling cutter[1] then it won't with a lathe > cutter as it is a continuous cut.
Not 100% true, but at some point along the cutting edge, usually on the left side of the tool since we usually cut right to left, it is cutting thru the oxide film. The damage in most cases will not be at the cutting tip, but back up the left edge by however deep a cut is being taken. And a retrace retraction of enough (0.01") to prevent the tip from rubbing during the retrace for the next pass becomes very important. That makes a huge diff in how long a carbide chip lasts on TLM, so I am writing that into my code as I re-use it, or for new code. > > Have 2 std $40 bench grinders, no angle setter. Is also maddeningly > > slow at taking off enough to form a proper angle in a reasonable > > time w/o burning up the tool > > You need a cup of water near the grinder. True, and I have a cup sitting there up in the shop building where the si carbide wheel is. But the darned thing has always evaporated dry in between uses and no water to refill it without a painful walk back to the house to get a pitcher of it. Recycled coffee works but has an odor. :) > It doesn't even really > matter if you micro-crack the metal you intend to remove. > > [1] And I don't think it does Not even if you get it visibly red hot. But of course the temper is gone, and then the discolored material must be removed to get back to good metal. Cheers Andy, 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> ------------------------------------------------------------------------------ _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
