How are you touching off (or otherwise determining the X tool offset for the insert)?
For example, if you calculate the offset assuming a sharp-V geometry (the simplest case), but touch off with the actual tip of the insert (not sharp), the insert will be in deeper than LCNC thinks it is when you touch off. So it will cut deeper later. On Fri, Jun 2, 2017, at 02:14 PM, tom-...@bgp.nu wrote: > Ok, thanks for the responses. I found some thread gauge wires and with them > have determined that we are cutting too deep. This would cause the pointy > peaks and root, so the next question is why are we cutting too deep…? We > believe we are entering the correct value for K (thread depth) but I was > observing the DRO and Linuxcnc seems to be sending the cutter quite a bit > below where it should stop. > > I am going to get some more definitive info what is exactly happening, but I > am now wondering if there is a bug in the G76 cycle (causing it to cut deeper > than it should) or if it is something on my machine… > > -Tom > > > > On Jun 2, 2017, at 12:31 PM, Ed <ate...@mwt.net> wrote: > > > > On 06/02/2017 10:36 AM, tom-...@bgp.nu wrote: > >> There is a custom adjusting screw that I buy commercially and when I get > >> them the threads have a text-book geometry to them. That is, they have a > >> small flat top on the major diameter and small flat bottom at the minor > >> diameter or root. They are made to class 2 or perhaps even class 3. I > >> know that these screws I am getting commercially are made using single > >> point carbide insert tooling on a cnc lathe. > >> By the way, this seems to happen for nearly every thread I have cut on > >> the machine, but I haven’t cared as much in the past as the screws have > >> been for my own purposes, but this one will be used in a product sent to > >> customers. > > SNIP > > > > > >> > >> I am wondering if I am doing something wrong with the insert I am using or > >> what. Any thoughts? > >> > > Get an insert for that particular TPI, it will leave the proper flat on the > > top and bottom of the thread. > > > > Ed. > > > > > > ------------------------------------------------------------------------------ > > 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 -- John Kasunich jmkasun...@fastmail.fm ------------------------------------------------------------------------------ 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
