The method used to generate the gcode program almost always needs to have knowledge of the kinematics and use that knowledge to calculate the numbers in the gcode program.
On Feb 28, 2017 8:20 PM, "Charles Steinkuehler" <char...@steinkuehler.net> wrote: > On 2/28/2017 5:52 PM, andy pugh wrote: > > On 26 February 2017 at 22:46, Charles Steinkuehler > > <char...@steinkuehler.net> wrote: > >> The A and B Axis has no > >> dependency on the rotation of the base of the robot arm (joint-0). > >> > >> Is this the expected behavior? > > > > I don't know. > > > > I did notice that the C axis value changes when you rotate the base. > > > > Have you seen http://linuxcnc.org/docs/devel/html/motion/5-axis- > kinematics.html > > ? > > Thanks Andy, somehow I missed that document. I'd gathered most of the > info from reading through some of the 5-axis kinematics code, but it > still doesn't really address my problem. I think the closest it comes > is a couple of places where it mentions "These relationships are > typically used in the CAM post-processor to convert the tool > orientation vectors to rotation angles". To me that implies the CAM > needs to have knowledge about the machine and account for the > kinematics, but it seems like it's far better to do this on the > machine side (where all the kinematics and dimensions are known). > > Perhaps a different way of asking my question: > > Given two types of 5-axis machine, one with A and B pivots on the > spindle, and one with A and B pivots on the table, would identical > gcode be expected to produce identical results on these two machines? > > On the machine with the pivot on the spindle, operation seems > straight-forward: Set the A and B angles, then move around in XYZ to > machine your part. > > On the machine that pivots the table, however, after setting A and B, > if you move around in XY, the Z axis will need to be coordinated with > the part position (since the part is now tilted, moving in X and Y > also affects the effective Z position). > > So is this difference handled in the kinematics, or is it expected to > be handled by post-processing in CAM? > > -- > Charles Steinkuehler > char...@steinkuehler.net > > ------------------------------------------------------------ > ------------------ > 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
