andy pugh wrote: > On 7 October 2011 03:10, Bruce Klawiter <[email protected]> wrote: > >> I am converting my Anilam M to EMC2 with Pico Systems, PPMC. >> I am having a hell of a time doing the PID tuning with the linear scales >> 10um. >> > > Not an answer to your question, but I do wonder how Anilam did it. > After all, the machine used to work. > > It might be instructive to consider the differences between the > controllers, to see what is currently not happening, but used to. > > Ignoring position control, does the machine achieve good velocity > control for any given input voltage to the amps? (this might be rather > "exciting" to test). > It is mostly working now. He has a following error of about 3 encoder counts, max. That sounds as good as it is going to get. Bruce stated that the original machine could hold .0005" tolerances on parts. I find this hard to believe with an encoder resolution of .0004". Maybe a good machinist could get it to make consistent parts with some dimension held to +/- .0005", but it is not believable that arbitrary parts could be made with accuracy nearly equal to the resolution.
There may also be some encoder noise problem, or maybe RT latency issues in the system. Jon ------------------------------------------------------------------------------ All of the data generated in your IT infrastructure is seriously valuable. Why? It contains a definitive record of application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-d2dcopy2 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
