With no look-ahead, it might work well for those who use the fourth axis as a way to rotate the part only to expose a new side for more 3D milling. In other words, you don’t need look ahead if you are not cutting will rotating.
But if all four axes are moving at the same time, looking ahead would be important. Lookahead is easy to program and understand if the kinematics is trivial. 3D milling is what they call “trivial kinematics”. But as soon as the relation between movement in the part’s x,y,z space and the machines axis space is not direct the math gets harder by quite a lot. I usually ran away when the solution involves things like Jobobian matrixes and the like. You can avoid all this if all four axis don't move at the same time. > On Jul 4, 2023, at 3:23 PM, Sam Sokolik <samco...@gmail.com> wrote: > >> >> The problem seems to be that our trajectory planner lack the ability to >> look ahead for any rotary axis. This means that a coordinated move that >> includes a rotary move will be dysfunctional at best. > > > I read that as - poor look ahead - not 'doesn't work' > > On Tue, Jul 4, 2023 at 5:21 PM Sam Sokolik <samco...@gmail.com> wrote: > >> Lol - then I guess I read too far into it.. I have run 4th axis rotary >> motion just fine.. >> >> On Tue, Jul 4, 2023 at 5:15 PM andy pugh <bodge...@gmail.com> wrote: >> >>> On Tue, 4 Jul 2023 at 22:50, Sam Sokolik <samco...@gmail.com> wrote: >>>> >>>> He is not saying it doesn't work... >>> >>> Actually, he did say that. >>> >>> -- >>> atp >>> "A motorcycle is a bicycle with a pandemonium attachment and is >>> designed for the especial use of mechanical geniuses, daredevils and >>> lunatics." >>> — George Fitch, Atlanta Constitution Newspaper, 1912 >>> >>> >>> _______________________________________________ >>> Emc-users mailing list >>> Emc-users@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/emc-users >>> >> > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
