On 11/6/2016 1:57 PM, Robert Ellenberg wrote: > On Sun, Nov 6, 2016 at 2:46 PM Danny Miller <dan...@austin.rr.com> wrote: > >> I did some rotary stuff on Mach3 and was baffled by similar issues. >> >> Seems like it'd be CAM's job to manage the feedrate, and calculate for >> the work radius. That would make sense if you were cutting a cylinder >> and the G-code move was "X moves 3 inches, A rotates 100 times, feed X >> at 1.5 inches/min" >> >> But if the cartesians aren't moving- which is common- the F value has no >> meaning at all if it's cartesian. There is no way for G-code language >> to communicate "polar Feed = 200 deg/sec" and it's nonsense to combine >> polar and cartesian vectors into a single scalar for a feedrate. >> > The F word is overloaded. If there's no cartesian motion, then it treats > the number as degrees per min instead of in per min. That sounds like a bad idea. The interp of F jumps around to a totally different thing if there's no cartesian motion? So if you MDI in "G1 X1 A200 F3" it does one thing if you're at X=2 and a totally different thing if you're at X=1? Or does the inclusion of any linear axis mode it over to cartesian? Well, but, you couldn't do that- if you're already at X=1, F3 is all polar and it's impossible to interpret as a linear feedrate since there's no linear motion.
What if X moves 0.001" and that gets optimized out? > > Seems like the logical answer is amending G-code Feedrate with syntax >> for an angular vector in addition to cartesian, but no CAM pkg would >> support it. > > The "proper" way as I understand it is to use inverse time when doing both > linear and angular moves. It's perfectly sensible to say "move X inches and > A degress within T seconds". Huh, ok, yeah inverse-time does make sense. > ------------------------------------------------------------------------------ Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. With one year of Intel Parallel Studio XE. Training and support from Colfax. Order your platform today. http://sdm.link/xeonphi _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
