http://electronicsam.com/images/matsuura/oscope.jpg
Part of what worked for us was we found a gear that had a profile close to the test gear from the alero docs. http://electronicsam.com/images/matsuura/sensors.jpg Been working great On Wed, 11 Jan 2017 16:03:10 -0500 Gene Heskett <ghesk...@shentel.net> wrote: > On Wednesday 11 January 2017 11:36:18 Jon Elson wrote: > > > On 01/10/2017 10:45 PM, Gene Heskett wrote: > > > On Tuesday 10 January 2017 23:02:28 Jon Elson wrote: > > >> On 01/10/2017 08:39 PM, Gene Heskett wrote: > > >>> But if I hook up the halscope, the apparent quadrature error is > > >>> worthless due to the 1KHz servo-loop timing limiting the > > >>> bandwidth. > > >> > > >> Well, that's why we use hardware encoder counters, as > > >> sampling the quadrature at 1 KHz just isn't fast enough. > > >> > > >> Jon > > > > > > Plz elucidate Jon. Something has got to be better than this. See the > > > pix I posted with the last reply to Peter & the list. The top, > > > white trace in the halscope screen is the quadrature noise, easily > > > 10x the timing wibbles I see on the hitachi's screen. > > > > If you are looking at the quadrature signals at a 1 KHz > > sampling rate, then unless the encoder is moving quite > > slowly, the sampling will be too coarse. That screen shot > > is kind of small (you can take just a single window as the > > screenshot, by the way) but it looks like the duty cycle of > > the encoders is not 50%. That may well be aliasing, as the > > quadrature signals seem to be moving much too close to 1000 > > Hz. You'd get much better results below 100 Hz. Or, with > > Mesa hardware, you can sample these with the base thread. > > > > I can't comment on the velocity output from the Mesa, as I > > don't know their gear (or driver). But, the scale is 2/div, > > meaning the scaled velocity output is jumping around 2 user > > units up and down at a KHz rate. Clearly, not good. > > > > Jon > > > I have found some quadrature error, so I pulled the ats667 mount off and > carved about 5 thou off the divider between the A & B units, jammed a > brass shim into the side of the B pocket to push it toward theA unit, > carved about 5 thou off the side of the divider between them, washed the > oil off several times, glued the A unit in place with a brass shim > pushing it snugly toward the B, jammed a piece of rubber beside the B > unit to push it toward the A unit, perhaps 10 thou change in the > separation, and I'm headed back out to test. Breaking the B unit loose, > and filing about 3 or 4 thou off that side of the B unit so the rubber > shim would shove it that much closer to together raised the minmax about > 10 points on the min, and lowered the max about 25, which have be an > indicator as to the mechanical directions needed. > > Oh, that ground on the vfd control cable I thought might be loose, was. > > the diff in duty cycle, aka time up vs time down? Its about 60/40. If it > was optical, I'd put a pot in series with the leds and adjust for 50% :) > But I haven't a clue how to do that with these ats667's. Darn it. > > Cheers, Gene Heskett > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > Genes Web page <http://geneslinuxbox.net:6309/gene> > > ------------------------------------------------------------------------------ > Developer Access Program for Intel Xeon Phi Processors > Access to Intel Xeon Phi processor-based developer platforms. > With one year of Intel Parallel Studio XE. > Training and support from Colfax. > Order your platform today. http://sdm.link/xeonphi > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. With one year of Intel Parallel Studio XE. Training and support from Colfax. Order your platform today. http://sdm.link/xeonphi _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
