Wasn't there an issue with earlier G540/G250 products? I seem to remember that there was a bug that had to be sorted and it involved low stepping rates.
Greg ----- Original Message ----- From: "Lars Andersson" <[email protected]> To: "'Enhanced Machine Controller (EMC)'" <[email protected]> Sent: Wednesday, July 20, 2011 11:29 AM Subject: Re: [Emc-users] erratic behaviour at low feed rates >I have a G540 that would not step slower than 150 Hz on the Y axis driver. >3 > other drivers stepped as slowly as I cared to try. > I originally had 2.6us step pulses obeying the data sheet requirement of > 2us. > Increasing pulse length to more than 5us fixed (or masked if you wish) > this > issue. The tool to use is "setp parport.0.reset-time 5000" > > /Lars > >> -----Original Message----- >> From: Igor Chudov [mailto:[email protected]] >> Sent: den 15 juli 2011 21:44 >> To: Enhanced Machine Controller (EMC) >> Subject: Re: [Emc-users] erratic behaviour at low feed rates >> >> I had the same issue with erratic behavior, turned out to be a bad >> amplifier. I replaced it. >> >> >> On Fri, Jul 15, 2011 at 2:08 PM, gene heskett <[email protected]> >> wrote: >> >> > On Friday, July 15, 2011 02:55:36 PM Andy Howell did opine: >> > >> > > On 07/15/2011 09:40 AM, gene heskett wrote: >> > > > On Friday, July 15, 2011 10:37:53 AM Daniel Rogge did opine: >> > > >> If you swap the X and Y drivers it will be fairly easy to >> determine >> > > >> whether the problem is with the driver (as Gene suspects) or >> with >> > > >> friction or mechanical linkages (as Jan suspects). If the >> problem >> > > >> stays on Y after swapping drivers, then your driver is absolved, >> > > >> leaving only mechanical or step signal generation problems as >> > > >> possibilities. You can distinguish between these last two by >> only >> > > >> swapping the control leads between drivers while leaving the >> motor >> > > >> leads hooked up as they are now. >> > > >> >> > > >> Rogge >> > > > >> > > > And in any event, please do not silently fix it, the OP should >> post >> > > > what the OP did so that we'll have better info to refer to the >> next >> > > > time it happens. >> > > >> > > All, >> > > >> > > Thanks for all your pointers. I swapped the X and Y >> connectors at >> > the >> > > Geckodrive controller and the problem rotated 90 degrees. >> > >> > Andy: This is pretty solid evidence that it is indeed the gecko, you >> moved >> > the problem amplifier to the other motor. Call Gecko for the next >> step. >> > They may be able to repair it at nominal cost. >> > >> > > I measured >> > > about 0.0067 inches of backlash on the Y axis. I can turn the Y >> shaft >> > > about 10~15 degree with no movement, which agrees with calculated >> value >> > > of 12.06 degrees of backlash. ( 5 TPI screw ) >> > >> > Yikes! This is huge for a ball screw and I would measure it full >> length to >> > see if it is consistent from one end of the screw to the other. If >> it >> > differs by more than half a thou over the length, the screw is worn >> and I >> > would replace the whole assembly. EMC has backlash comp you can >> adjust per >> > axis, but its only good if all cuts are dig cuts, climb cuts will >> pull the >> > table ahead of the screw very easily, and you will not see that with >> a pen >> > in the quill. IOW, replace the whole screw. Being used, I would >> suspect it >> > may have lots of hours doing the same part in the same fixture and >> the >> > screw is just plain worn out in the most used portion. In fact, I >> would, >> > based on that, map all 3 screws at 1 cm or 1/2" intervals. >> > >> > > The X axis backlash is about 0.0005. Both shafts turn freely when >> power >> > > is not applied. I've found some reference on the Hossmachine site >> that >> > > the ballnut backlash can be improved by putting in larger bearings. >> > > I'll try that. >> > > >> > > There seems to be another problem though. I see the X and Y DRO >> values >> > > changing sometimes without any motor movement. This only happens at >> low >> > > speeds. >> > > >> > > I'll investigate that further after I address the backlash issue. >> > > >> > > Thank all for your help. I will let the list know how this was >> resolved. >> > > >> > > Regards, >> > > >> > > Andy >> > > >> > > ------------------------------------------------------------------- >> ----- >> > > ------ AppSumo Presents a FREE Video for the SourceForge Community >> by >> > > Eric Ries, the creator of the Lean Startup Methodology on "Lean >> Startup >> > > Secrets Revealed." This video shows you how to validate your ideas, >> > > optimize your ideas and identify your business strategy. >> > > http://p.sf.net/sfu/appsumosfdev2dev >> > > _______________________________________________ >> > > Emc-users mailing list >> > > [email protected] >> > > https://lists.sourceforge.net/lists/listinfo/emc-users >> > >> > >> > Cheers, gene >> > -- >> > "There are four boxes to be used in defense of liberty: >> > soap, ballot, jury, and ammo. Please use in that order." >> > -Ed Howdershelt (Author) >> > To any truly impartial person, it would be obvious that I am always >> right. >> > >> > >> > --------------------------------------------------------------------- >> --------- >> > AppSumo Presents a FREE Video for the SourceForge Community by Eric >> > Ries, the creator of the Lean Startup Methodology on "Lean Startup >> > Secrets Revealed." This video shows you how to validate your ideas, >> > optimize your ideas and identify your business strategy. >> > http://p.sf.net/sfu/appsumosfdev2dev >> > _______________________________________________ >> > Emc-users mailing list >> > [email protected] >> > https://lists.sourceforge.net/lists/listinfo/emc-users >> > >> ----------------------------------------------------------------------- >> ------- >> AppSumo Presents a FREE Video for the SourceForge Community by Eric >> Ries, the creator of the Lean Startup Methodology on "Lean Startup >> Secrets Revealed." This video shows you how to validate your ideas, >> optimize your ideas and identify your business strategy. >> http://p.sf.net/sfu/appsumosfdev2dev >> _______________________________________________ >> Emc-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/emc-users > > > ------------------------------------------------------------------------------ > 10 Tips for Better Web Security > Learn 10 ways to better secure your business today. Topics covered > include: > Web security, SSL, hacker attacks & Denial of Service (DoS), private keys, > security Microsoft Exchange, secure Instant Messaging, and much more. > http://www.accelacomm.com/jaw/sfnl/114/51426210/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users -------------------------------------------------------------------------------- Internal Virus Database is out of date. 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