On Mon, 2010-10-11 at 17:18 -0500, Stuart Stevenson wrote: > On Mon, Oct 11, 2010 at 3:33 PM, Chris Radek <[email protected]> wrote: > > > > > Stuart, long ago when we figured out how to set the scaling, you wrote > > this: > > > > > > On Wed, Sep 15, 2010 at 03:32:31PM -0500, Stuart Stevenson wrote: > > > Hi, > > > I checked the DAC output - it was .889 - I changed the scale from 8.89 > > to > > > .889 - the response was back to just like before. > > > The config files to match this picture are available > > > The latest picture is; > > > http://www.mpm1.com:8080/machines/enshu/Screenshot-1.png > > > > > > Unfortunately this picture is gone, but I remember it looking *really* > > good and I commented on it. It was within a few encoder counts on a > > rapid. What happened since then? It seems like you had a major > > regression of some kind. > > > no regression > > http://www.mpm1.com:8080/machines/Screenshot1.png > http://www.mpm1.com:8080/machines/Screenshot2.png > http://www.mpm1.com:8080/machines/Screenshot3.png > http://www.mpm1.com:8080/machines/Screenshot4.png > > The pictures show some of the progression during tuning. Number 4 is the > final result. My questions have been trying to figure out why the traces > have the spikes like they do. But if I read things correctly you are only driving at 4 V (#4 ) not 9 V or so. I set the Mazak at 20 for accel but I also only push it to half speed (3.25 ips).
> I set the max vel at 6.6666 to be just under 400 ipm and the scale at 6 to > give 9 volts output and then tuned from there. This gives motion that looks > and feels good but still has the spikes on the beginning of the accel and > the beginning of the decel until I get close to the final tune and then it > has the spikes on all four corners as shown. I don't have a serious problem > with the machine is it moves I am just trying to figure out why this is. I > should be able to tune it out. > I still want a simple (dumb) amp and let EMC2 close the loop. I understand > a Fanuc servo system is a fine system I just don't believe it is better than > what EMC2 will do by itself, This old Fanuc is probably not as good as what > EMC2 can do. 1980 Fanuc drives are not likely to have the freq response of newer drives. ( 3 phase scr switched on the Mazak). My Servo Dynamics are 2 KHz + drives and DC. Not quite the same as your requirements. > I will shortly bypass the tach feedback on a servo system to take the > servo drives tuning out of the equation. It will probably be the Cinci as > the Enshu does not have tach feedback. We will see how that might work. > A tach is set up at X volts/thousand rpm. EMC2 puts out Y volts/thousand > rpm. I will need to set up two DACS per servo drive and scale between the > two DACs. Hook one to the velocity input and one to the tach feedback input. > This will cause the drive to read the motor speed as matching the requested > speed at all times. This will keep the drive from calculating and adding any > tuning to the output. This will allow EMC2 to close the loop. > having some fun now > thanks > Stuart > Indeed, tuning is always interesting. ;-) Dave ------------------------------------------------------------------------------ Beautiful is writing same markup. Internet Explorer 9 supports standards for HTML5, CSS3, SVG 1.1, ECMAScript5, and DOM L2 & L3. Spend less time writing and rewriting code and more time creating great experiences on the web. Be a part of the beta today. http://p.sf.net/sfu/beautyoftheweb _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
