On Saturday, February 19, 2011 09:04:03 am cogoman did opine: > Kent suggested I add some information about stepper motor speed > limitations to the wiki. I tend to never finish anything because it's > never good enough. This isn't good enough, but it's up there. > > It's titled: > > * Stepper Motor Speed Limitations > > <http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Stepper_Motor_Speed_Limita > tions> > > > You can point out whatever isn't very clear. I'd like to make it better > than it is, but I'm going to take a breather before I do any major > edits. > > Thanks for any comments. I think I would carry the base thread speed discussion on to show what the choice of a base thread speed vs the smoothness of a speed change would be. The graph shows it but requires the newbie to do quite a bit of reading between the lines. It should be re-arranged to show what the speed changes will be when approaching full speed with a given base thread timing. It is well done in all other respects.
I must say also that since the complete step is now handled in one cycle of the base thread, I haven't noticed my motors playing tunes as they change speeds, it is MUCH less obvious, and that has opened up another octave on the maximum speed for me. In fact, I have slowed my base thread to about half of the maximum my box can do without appearing to effect its performance at driving the machine. Its quite happy with a 50 u-second base thread, which in turn makes the video back plot in axis a lot closer to real time. That elderly mobo can be pushed to under 25 u-seconds but other things like the video get pretty laggy then. -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) <http://tinyurl.com/ddg5bz> There are times when truth is stranger than fiction and lunch time is one of them. ------------------------------------------------------------------------------ The ultimate all-in-one performance toolkit: Intel(R) Parallel Studio XE: Pinpoint memory and threading errors before they happen. Find and fix more than 250 security defects in the development cycle. Locate bottlenecks in serial and parallel code that limit performance. http://p.sf.net/sfu/intel-dev2devfeb _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
