On 3/1/2011 1:11 AM, Igor Chudov wrote: > I have the W axis working. > > http://www.chudov.com/projects/Bridgeport-Series-II-Interact-2-CNC-Mill/34-Adding-Servo-Control-to-Knee/ > > When commanded, the W axis moves up and down, roughly as instructed, > according to my G0 W... commands. > > It is not super precise or well tuned, yet, but really not so bad and > compares favorably to cranking the knee handle. I will try to evaluate > backlash and such, when I get more time to tune this system. > > For those too lazy to look at pictures, the W axis is a 1,000+ chunk of > metal, moved up and down by a 15:1 DC gearmotor, that turns a shaft that, in > turn, turns a ACME nut on the knee screw. There is a pneumatic assist on the > knee, which helps a lot. > > There is one problem, however: after the motion stops, ppmc.0.DAC.3 does not > go down to zero, and instead stays high, while the system is not moving. I > explain this by remaining under power to move "one more hair distance" > against friction, nothing is moving, and nothing is there to decrease the > output. > > If it decreases a little bit, no disaster should happen, the knee will not > drop, the system is self braking etc. > > Instead, current is provided to the motor, the not enough to move the rotor, > but enough to heat it up too much. > > So. How would I somehow configure EMC to stop providing any current to "W", > when not really moving it? > > i
Igor Off on a tangent, I see one major problem. Uncovered concrete... ;-) Mark ------------------------------------------------------------------------------ Free Software Download: Index, Search & Analyze Logs and other IT data in Real-Time with Splunk. Collect, index and harness all the fast moving IT data generated by your applications, servers and devices whether physical, virtual or in the cloud. Deliver compliance at lower cost and gain new business insights. http://p.sf.net/sfu/splunk-dev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
