Todd, from theoretical deliberations I would say: give either the drive or the output of the pid a fixed offset to take care of the downward force of the head. So the whole is balanced statically before you try to tune the PID.
j. On Wed, Oct 31, 2012 at 8:32 PM, Todd Zuercher <[email protected]>wrote: > > > I am having some trouble tuning the servo on a new setup. It is using a > Mesa 5i25-7i77 combo running Teknics SST-3100-U drives running in analog > torque mode. > > Where I am having the most trouble is on the Z and W axis. They are > vertical, with no counter ballance driven by a lead screw. After a lot of > effort tuning I have found that the PID error is not the same as f-error. > The PID is showing very little error but the f-error is very proportional > to the velocity. Why are the two errors no t the same? Any suggestions > on ways to fix or improve it? O r a better idea of the source of the > problem? > > > > here is a link to the discussion on the LinuxCNC Forum. > > > http://www.linuxcnc.org/index.php/english/forum/10-advanced-configuration/24800-servo-tuning-advice/26154 > http://www.linuxcnc.org/index.php/english/forum/10-advanced-configuration/24800-servo-tuning-advice/26154 > > > > -- > > ======================================== > > Todd Zuercher > mailto:[email protected] > > ======================================== > > ------------------------------------------------------------------------------ > Everyone hates slow websites. So do we. > Make your web apps faster with AppDynamics > Download AppDynamics Lite for free today: > http://p.sf.net/sfu/appdyn_sfd2d_oct > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_sfd2d_oct _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
