Sven Wesley wrote: > I can cannot see any changes in speed even if I push put all my body weight > on the Z-axis, it just runs super easy and the motors never gets warm. It > doesn't _seem_ to be a force/power problem. > I have put so much money and time in building a servo system. It's REALLY > annoying if I have to go back to steppers. To me, these eBay-items looks > pretty small too. Are they really going to make it? > I am now CONVINCED that your problem is a step timing issue, possibly a step-vs-direction setup time issue. I am also sure the Rutex has some kind of a fault output, but you may not be using it. I remember the fault window is programmable, as opposed to Gecko's fixed limit.
If you were to put stepper motors and a stepper drive on the machine, you might well have the exact same problem - many people have. The timing of the step/direction pulses MUST meet what the manufacturer needs. If the manufacturer's specs are non-existant or just wrong, that makes fixing this much harder. The basic problem is either the drive fails to detect some of the step pulses, often just after a direction change, or counts a step pulse in the wrong direction. Gecko once had a problem with the pulse multiplier in their Gecko 210 (stepper) and 340 (servo) where if the direction changed while the multiplier was still putting out multiplied pulses, those steps would go in the wrong direction. It led to errors in fractions of the commanded steps. The fix was to either remove the pulse multiplier or make sure the software didn't generate a step pulse for some specific time after a direction change. That's just one possible way such a problem could happen. Unless somebody knows the specific settings for your drives, you may need to systematically explore the range of settings and motion to see if you can identify which adjustment affects the problem. And, if you find a setting that makes it WORSE, that may be an important clue to what the underlying problem is. You can make a chain of short moves in the same direction, with a pause between each move, and see if there is no error. Then, make moves back and forth, with delay between each move - again, check for error. Then, move back and forth with NO delay between moves. Does this make the error worse? If you see it is worse with back and forth moves with no delay than either of the other movements, that is a BIG clue it has something to do with step timing vs the direction signal. Jon ------------------------------------------------------------------------------ Come build with us! The BlackBerry® 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/devconf _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
