On Friday, June 08, 2012 07:06:47 PM Jon Elson did opine: > John Thornton wrote: > > I've cut the same threads at rpm's from 100 to 2000 (by accident) and > > the pitch is perfect. I've seen a video where a guy was turning his > > spindle by hand back and forth and EMC was keeping perfect pitch, iirc > > the guy was positioning the stock for a recut of the threads. > > One thing that is important is that the trajectory planner needs to be > running at the > full servo period, not at some submultiple. So, in the .ini file, the > SERVO_PERIOD > and TRAJ_PERIOD should be set to the same value. If the TRAJ_PERIOD > is set to a larger value, it will cause a significant time lag that > causes the > Z axis to lag behind. When reversing, this lag becomes doubled as a > position error. > Oh cute, no relation to bow legged either. :(
> Jon Hummm, Okaaayyy, but what does it use if TRAJ_PERIOD is not specified? It is not in my current .ini file. Somewhat stepgenconf generated. Heavily diddled since. Second, I just toured the show hal config screens and found no signals or pins/params that correspond to the FF0-FF1 and FF2 settings that stepgen had about 3 or 4 major revisions (2.1/2.2) ago. The .2.f-error in particular, seems to be a direct function of the speed it is moving at, with no apparent attempt to correct it, regardless of running distance, back to a real 0.0 reading. The error isn't large, 150 u-volts max during a G0 retrace move. I can recall when the AXIS sections for the steppers had FF0-FF1 and FF2 settings in the .ini file but that was years ago... So how do we do those corrections now? > ------------------------------------------------------------------------ > ------ 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 > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users 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) My web page: <http://coyoteden.dyndns-free.com:85/gene> What good is an obscenity trial except to popularize literature? -- Nero Wolfe, "The League of Frightened Men" ------------------------------------------------------------------------------ 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
