I am catching up on my EMAIL, and I've still got 10 EMC digests to read, but I wanted to comment on the quote below. This gives the impression that you are setting the PID values for the servo motor on the bench with nothing attached. This is not a good idea since these settings SHOULD be sluggish in the system.
Remember FORCE = MASS times ACCELERATION. If you are looking for a certain angular acceleration, on the bench you will have very little mass, and so will need very little force. Once you put the motor in the system, the mass will be over 100 times the mass on the bench, and require over 100 times the force. In a like manner, if you've tuned the PID values for the machine you'll be driving, don't run it dry on the bench, it should whip the motor around like a toy, and could break into a motor trashing oscillation. The PID values must be set for the axis you will be driving. If the two axes have drastically different MASSes, then PID values that are optimum for one axis, may cause a system clobbering oscillation when switched to another lighter axis. My limited experience with a FADAL mill had drive cards (with their PID values set) swappable between axes without any problems, but it is best to err on the side of caution. | This is soooo frustrating! When setting the PID the servo's accelerates so | fast I have to clamp the to the bench. When running with the rest of the | system it's just poor performance. ------------------------------------------------------------------------------ Come build with us! The BlackBerry® Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9-12, 2009. Register now! http://p.sf.net/sfu/devconf _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
