Replying to myself: John Kasunich wrote:
> Do you have adequate stepgen headroom? The following snippet is from > the sample config "stepper_inch.ini": > > > MAX_VELOCITY = 1.2 > > # NOTE: the step generator module applies its own limits to > > # acceleration and velocity. We have discovered that it needs > > # to have a little "headroom" over the accel by the trajectory > > # planner, otherwise it can fall slightly behind during accel > > # and later overshoot as it catches up. In the long term we > > # hope to come up with a clean fix for this problem. In the > > # meantime, please set STEPGEN_MAXACCEL below to a few percent > > # higher than the regular acceleration limit MAX_ACCELERATION > > MAX_ACCELERATION = 20.0 > > STEPGEN_MAXVEL = 1.4 > > STEPGEN_MAXACCEL = 21.0 I know the comment only talks about STEPGEN_MAXACCEL needing headroom, but STEPGEN_MAXVEL does too... I'll try to remember to fix that when I get a chance. > MAX_VELOCITY of 1.2 inches per second means 72 ipm. For 120 ipm, > you need to set MAX_VELOCITY to 2.0, and you need to set STEPGEN_MAXVEL > to something higher than 2.0, perhaps 2.2. If you don't do that you > will get following errors. In versions 2.1.0 and later, STEPGEN_MAXVEL is tested against the max available speed (which depends on BASE_PERIOD and some other factors), and if you ask for more than it can give, it will complain. But this check uses STEPGEN_MAXVEL, not MAX_VELOCITY, since it is only relevant for stepper systems. Regards, John Kasunich ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
