On Sunday, January 29, 2012 06:37:43 PM andy pugh did opine: > On 29 January 2012 17:31, gene heskett <ghesk...@wdtv.com> wrote: > > What if the spring is either too much or too little, this seems to > > invite the need for a non-symmetrical FF0 function. > > You could account for the constant offset with the PID bias term.
I realized that Andy, at about the same time I was pulling on my coat to head for the shop. With strong enough steppers its moot in any event. But that doesn't negate the fact that with the load offset, you have more rapids available going one way than the other. So you wind up tweaking for the slowest direction. Often by reducing accel to what it can handle, then raising vel a bit. 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> If we see the light at the end of the tunnel, it's the light of an oncoming train. -- Robert Lowell ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
