On Sun, Dec 12, 2021 at 12:39 PM Gene Heskett <ghesk...@shentel.net> wrote:
> On Sun, 12 Dec, 2021 at 2:54 PM, Chris Albertson < > albertson.ch...@gmail.com> wrote: > > > To: enhanced machine controller (emc) > I'm surprised that people don't use kinematics to remove the residual > alignment errors that can't be mechanically removed. Of course, you can't > remove tool orientation errors this way. If the z-axis is a few > milliradians "off" the tool will also be "off" but kinematics can > compensate for the X, Y error associated with variable Z movement. > > That said, I can't measure this kind of low-level stuff so I don't worry > about it. > > You should be able to lead the Z- column over at 45 degrees and still hit > X, Y point spot on. (it would work only for a spherical tool) > > > > If it was moveable Chris, but its not, the column is fixed, but the head > can be No, you never want to do that. My point was that there could be an absurd amount of error and you should still be able to work with it by telling the kinematics system the column meets the Y axis at 89.9 degrees. I'd think we are talking arc minutes at most here for a real milling machine. But there are home-made CNC machine made with rails mounted to a plywood base. BTW, even with the 0.1-degree error, you still have good accuracy with realistic Z-axis moves. > > rotated 90 degrees either way and I have several times. That works quite > well. > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
