On Wed, Oct 08, 2008 at 10:32:47PM -0500, Stuart Stevenson wrote: > Can I effectively bypass the SCR tuning by increasing the gain a > lot (much past what the motor can handle) and using the tuning in EMC > to control the motor. Could this turn the SCR into a dumb amp.
I think increasing the gain will not work but unhooking the tach might. I ran one of mine that way for a while. The performance was not better - it was worse. I was not able to tune the position PID loop to give the same stability and stiffness that the amp was able to do by itself with velocity feedback. My understanding is the way these work is the input to the next stage in the amp (current/torque loop?) is the difference between commanded and feedback velocity. So if you null the feedback you control the next stage fairly directly. In my limited experience, velocity mode is still best. I measured the amp's behavior (tuning is set with resistors, etc) and then set EMC accordingly (maxvel, maxaccel) and tuned with pretty much P/FF1 only. It really works great. ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
