Am 21.10.2009 um 13:02 schrieb Andy Pugh: > 2009/10/21 Haberler Michael <[email protected]>: > >> Here are the configs: >> http://mah.priv.at/cgi-bin/viewvc.cgi/emc-syncmove/?root=CVS > > I suspect that your max axis velocity and accelleration are part of > the problem. They both seem rather low. > Can you run with higher accell rates? 70 is very low, I have been > running 100 as a super-low level in testing to force oscillations. See > of you can manage 300 or more, and you should see a marked > improvement.
good point - I just tried that with acceleration 300 instead of 70 and 45ppr. The wild oscillations are gone : http://mah.priv.at/cgi-bin/viewvc.cgi/emc-syncmove/45ppr-accel300-dampened-oscillation.png?revision=1.1&root=CVS&view=markup It's not a stable loop yet - the initial acceleration and the direction change (45degree angling out of the thread towards the end) still cause a dampened oscillation. It's clearly an improvement. It's ok to call me paranoid but I'm not really comfortable with the result just yet ;-) Would inserting a PID into this "loop" and turning the P-I-D knobs appropriately be a useful way of dealing with the problem? I know the "pins" are buried in the tc - just floating the idea. -Michael > You are running at 240rpm, so 4 revs per second. You have enough axis > speed to thread at 3mm pitch, so there is not a huge problem there, > but for a 1mm pitch thread accellerating at 70mm/s2 is going to take > about 3 spindle turns to reach the required velocity of 4mm/s, during > which time the error will be continually increasing. > > In short, I don't think that 70mm/s2 is reactive enough to thread at > 240rpm. > > -- > atp > > ------------------------------------------------------------------------------ > Come build with us! The BlackBerry(R) Developer Conference in SF, CA > is the only developer event you need to attend this year. Jumpstart > your > developing skills, take BlackBerry mobile applications to market and > stay > ahead of the curve. Join us from November 9 - 12, 2009. Register now! > http://p.sf.net/sfu/devconference > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
