On Sun, 5 May 2013, Marius Liebenberg wrote: > Date: Sun, 05 May 2013 08:27:38 +0200 > From: Marius Liebenberg <[email protected]> > Reply-To: "Enhanced Machine Controller (EMC)" > <[email protected]> > To: "Enhanced Machine Controller (EMC)" <[email protected]> > Subject: Re: [Emc-users] Creep in X axis > > Hi Peter > Yes, the dro reads "0" but the travel was more than the requested > amount. In one direction only. > The process is like this: > - Home the x axis > - G0 X6000 > - Measure the travel = 6000 > - G0 X0 > - measure the travel = -70
Since the error is only with the X axis, this suggests a couple of possibilites: Are the drives AC servos so the encoder signals are in fact coming from the drives, not the encoder? If this is the case, is it possible tha the X axis drive is either faulty or improperly setup as regards encoder outputs? Are you using differential signaling from the drive/encoder to the 7I33? If so, is the 7I33 setup for differential inputs is the error affected by velocity? (same error if you move at 1/2 the speed?) that is, is it possible you are running into a count rate limitation somewhere? what is the encoder/drive simulated encoder resolution (counts per MM) and maximum X velocity? > > On 2013/05/04 06:55 PM, Peter C. Wallace wrote: >> On Sat, 4 May 2013, Marius Liebenberg wrote: >> >>> Date: Sat, 04 May 2013 09:08:40 +0200 >>> From: Marius Liebenberg <[email protected]> >>> Reply-To: "Enhanced Machine Controller (EMC)" >>> <[email protected]> >>> To: [email protected] >>> Subject: [Emc-users] Creep in X axis >>> >>> Hi All, >>> I have a problem on a machine that is confusing me (not to difficult to >>> do these days). It is a servo system using mesa 5i23 and 7i33 cards. I >>> have calibrated the x axis and during testing I find that the x axis >>> will go from the home position (using G0 x6000) to the correct distance. >>> Then when I say (G0 x0) it will go to x-70. It has a linear overshoot >>> across the range but just in one direction. Now from that same position >>> if I go (G0 x6000) it will travel exactly 6000mm. So it would seem that >>> the calibration figures are correct. >>> I did the PID tuning and it is pretty close to perfect. Any suggestions >>> where to look? >> >> >> Are you saying the physical position overshoots by ~1% (and the DRO >> reads 0) when you do the G0 x0? >> >> >> >> >> >> >>> >>> -- >>> Regards / Groete >>> >>> Marius D. Liebenberg >>> MasterCut cc >>> Cel: +27 82 698 3251 >>> Tel: +27 12 743 6064 >>> Fax: +27 86 551 8029 >>> Skype: marius_d.liebenberg >>> Skype Me^(TM)! <skype:marius_d.liebenberg?call> >>> Get Skype <http://www.skype.com/go/download> and call me for free. >>> >>> >>> >>> >>> --- >>> avast! Antivirus: Outbound message clean. >>> Virus Database (VPS): 130503-1, 2013/05/03 >>> Tested on: 2013/05/04 09:08:41 AM >>> avast! - copyright (c) 1988-2013 AVAST Software. >>> http://www.avast.com >>> >>> >>> ------------------------------------------------------------------------------ >>> >>> Get 100% visibility into Java/.NET code with AppDynamics Lite >>> It's a free troubleshooting tool designed for production >>> Get down to code-level detail for bottlenecks, with <2% overhead. >>> Download for free and get started troubleshooting in minutes. >>> http://p.sf.net/sfu/appdyn_d2d_ap2 >>> _______________________________________________ >>> Emc-users mailing list >>> [email protected] >>> https://lists.sourceforge.net/lists/listinfo/emc-users >>> >> >> Peter Wallace >> Mesa Electronics >> >> (\__/) >> (='.'=) This is Bunny. Copy and paste bunny into your >> (")_(") signature to help him gain world domination. >> >> >> > > -- > Regards / Groete > > Marius D. Liebenberg > MasterCut cc > Cel: +27 82 698 3251 > Tel: +27 12 743 6064 > Fax: +27 86 551 8029 > Skype: marius_d.liebenberg > Skype Me^(TM)! <skype:marius_d.liebenberg?call> > Get Skype <http://www.skype.com/go/download> and call me for free. > > > > > --- > avast! Antivirus: Outbound message clean. > Virus Database (VPS): 130504-0, 2013/05/04 > Tested on: 2013/05/05 08:27:40 AM > avast! - copyright (c) 1988-2013 AVAST Software. > http://www.avast.com > > > ------------------------------------------------------------------------------ > Get 100% visibility into Java/.NET code with AppDynamics Lite > It's a free troubleshooting tool designed for production > Get down to code-level detail for bottlenecks, with <2% overhead. > Download for free and get started troubleshooting in minutes. > http://p.sf.net/sfu/appdyn_d2d_ap2 > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------------ Get 100% visibility into Java/.NET code with AppDynamics Lite It's a free troubleshooting tool designed for production Get down to code-level detail for bottlenecks, with <2% overhead. Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap2 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
