On May 16, 2012, at 10:54 AM, Jon Elson wrote: > Jeshua Lacock wrote: >> Greetings, >> >> I now mostly have my new Pico System's Universal Stepper Controller (USC) >> and Gecko Interface working with my Gecko 320 drives. >> >> When I first got it going, my X and Z drives "jumped" repeatedly until I >> turned the damping up. But my Y drive keeps "jumping" even with the damping >> and gain at max. I tried various combinations of gain and damping, but no >> matter what I do (unless the limit is set to all but off) I can't seem to >> get the Y drive to dither. >> > Does it do this jumping if you hit F1 (out of E-stop) but not F2 (machine on)? > If so, then there must be something wrong with the encoder signal path > through the Gecko Interface.
Hi Jon, Yes, and you are correct, I apparently had the A/B signals crossed somewhere. I can now command all three axises to move in the closed loop mode! However, in open loop mode, without power to the servos it is stable and works as a DRO. In open loop mode with power on I see the DRO jitter around +/-0.0005 which I assume is normal dithering behavior. But shortly after I hit F2 I get a fault and error message "joint following error X". I assume I need to increase the error tolerance? Any idea why this only happens in open loop mode? > If not, then it is a servo tuning issue in LinuxCNC, > not in the Gecko drive. You do have to tune these servos. When you say it > jumps, does in move some distance and then trip a fault on the Gecko or > following > error in EMC? If so, the OUTPUT_SCALE parameter in the [AXIS_1] > section of the .ini file may need to be flipped to the opposite sign. > If it is just rough, turn the P parameter down in that section. Then, you > need to do the whole tuning procedure. See the writeup in the wiki > http://wiki.linuxcnc.org/cgi-bin/wiki.pl?PWM_Servo_Amplifiers That will prove to be very useful for the next saga! > This was written for my PWM servo amps, but all the same info applies. > You need to get familiar with Halscope, if you aren't already, and observe > the response of the system to jog commands. If you get stuck, you > can send me a screenshot of the halscope screen and I'll try to interpret > what is happening. Great, thank you! Best, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated <http://3DTOPO.com> Phone: 208.462.4171 ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
