I have a lathe and mill that I bought with Anilam controls, they get position from the Anilam DRO scales. The servos use tachometer feedback to the drive and the scales are connected to the control. These are stable even with backlash, I'm not saying backlash is good, just that the backlash doesn't cause oscillation problems. With backlash, I can knock the table 0.0005 out of position and the motor will turn slowly until the error is corrected, if I knock it out 0.001 the motor turns much faster to correct the error. The motor to drive seems to be a velocity loop and the control seems to put out a command proportional to the error.
On the lathe I never got the original Anilam control to work so I converted it to EMC2. Same drives and everything, I just ran the position encoders into the EMC2 control and used P and I to get it running good. A little bit of I gain seemed to make up for offsets in the command, sometimes the servos can drift a little with 0V input and it can change with temperature. Anyway as long as the control is ON when I power up the drives, everything behaves properly. Roger Neal -----Original Message----- From: erik.555.gr...@gmail.com Sent: Tuesday, May 22, 2012 8:43 AM To: emc-users@lists.sourceforge.net Subject: [Emc-users] Servo system and glass encoder scales for positionfeedback Are there any major dis-advantages to using glass scales as position feedback for a servo system versus using encoders directly attached to the motors. I could see where backlash might be an issue but if using precision ground ballscrews........ ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
