On Mon, 2007-10-15 at 11:05 -0500, Chris Radek wrote: > On Mon, Oct 15, 2007 at 10:49:05AM -0500, Jon Elson wrote: > > > > Lines A and B are separated by about 1/3 of a second. If your > > spindle speed is roughly 180 RPM, then they are separated by one > > turn of the spindle. EMC decides which turn is best to sync to. > > See my other message for a description of what's really happening > here. > > At the start of a spindle synchronized move (which can be made up of > several adjacent G33 commands) EMC always stops motion and waits for > the next index. > > Chris >
The only reason I put the G4's in was to try attenuate the low acceleration problem. I wonder if it is worth fixing. I am getting the impression that the spindle index is what starts the selected axis movement. Then for each spindle pulse there after, a multiplier for each axis is applied to determine each axis command, which is then passed to the normal PID loop to compensate for movement limitations. The remaining piece is where in XYZ space to start, which is just the location of the tool when the G33 started. Subsequent G33's will have the same starting point if XYZ doesn't change and spindle zero never changes. Based on this -- questions that come to mind are: - Can a K be applied to each axis? Such as G33 z1.0 k0.050 x0.100 k0.010. I suppose, I could just try it and see what happens. - In my graph, the movement correction over shot the (wrong) target on both sides over the course of one second. With decent PID settings, I would have thought that the movement would have been a brief ramp to the target with small corrections from the bottom towards the target line. This suggest a different feedback loop being used? - How could subsequent G33's latch onto the last index of the previous G33 before the current G33 is invoked? What persists between G33 calls? - Can I latch on Index plus 26? I suppose this can be done by calculating the XYZ movement for 26 counts and adjusting XYZ and latching on Index. I really need to get some real work done, so I'll stop now (crowd cheers). -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC lathe Bridgeport mill conversion pending Zubal lathe conversion pending) ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
