I always use an exit taper... JT
On 9/4/2016 3:03 AM, Kirk Wallace wrote: > On 09/04/2016 12:01 AM, andy pugh wrote: >> On 3 September 2016 at 23:24, Kirk Wallace <[email protected]> >> wrote: >>> I just finished a first pass at G76 tapered threading. >>> My code is here: >>> http://www.wallacecompany.com/tmp/G76/G76-7b.cc >> Just so we don't tread on each-others's toes here. >> You appear to be using D to define the taper? >> I know why you chose this, it is because nothing else is available. >> However it clashes with my (un-merged) multi-spindle patch: >> https://github.com/LinuxCNC/linuxcnc/blob/andypugh/JA14_multispindle/configs/sim/axis/lathe_multispindle/README >> >> Ideally I would use E for spindle number, but E is taken. I suspect >> that entry and exit tapers are very rarely used, and that E is >> "wasted" but we probably shouldn't go breaking existing G-code. >> >> Perhaps the Cabal needs to decide who gets to claim D in G76 :-) > The D conflict is new to me, so I don't know how to respond. I too > thought entry/exit tapers would be rarely used but Smid seems to have > them in his threading examples, so I thought it would be worth the > effort to provide for them. > >> Is your pitch defined along the Z axis, or along the surface? Is Steve >> B still around? > The lead is along the Z axis, in other words the feed is adjusted using > the tangent of the thread taper angle for any tapers used. (Crud, I > forgot to check if it is the included angle or the angle to the axis. I > need to fix this.) > > Even with two line codes, Fanuc has multiple features encoded in a > parameter's value, such as two digits for one feature and two for > another. This would tend to break old LinuxCNC code, except E uses > 0,1,2, and 3 for the entry taper locations. Adding a tens digit might be > used for something. Adding a G76.1 code may be an option too. > > ------------------------------------------------------------------------------ _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
