Pat Lyons wrote: > Hello folks, > > Hope you had a nice turkey day and all. > > I'm trying to understand why my Y axis following error is so much worse that > my x and z. I gave them all equal efforts regarding the tuning process, but > Y seems to be much more finicky a mechanical response- oscillations appear > to be a serious issue- I can get it down to about a thou of following error > at constant velocity but the initial lack of acceleration causes a spike in > f-error at the beginning of each move... > I've tried toying with FF1 and FF2 as instructed by several of you, but i > found that if i deviate from the values I've found, the response goes nuts > with skyrocketing f-error. > You might need to tell us more about the machine, especially if a mechanical aspect of the problem is suspected.
What servo amplifiers are you using, what controller board? Using Halscope, you can measure the frequency of the oscillation. If it is 500 Hz, that is half of the default servo frequency. If it is in the 10 - 40 Hz range, that is typical mechanical resonance. If it is a couple Hz, that is typical tuning instability. FF1 and expecially FF2 are used in incredibly small amounts, typically 2 -5 for FF1 and as little as .0002 for FF2. It is VERY easy to overdo these. Jon ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
