On Wednesday 10 April 2013 11:43:50 Steve Blackmore did opine: > On Tue, 09 Apr 2013 17:11:00 -0400, you wrote: > >On Tue, Apr 9, 2013, at 05:04 PM, Steve Blackmore wrote: > >> On Tue, 09 Apr 2013 19:18:13 +0200, you wrote: > >> >I tried your value, and it seem you are really close to the max > >> >frequency drive for the stepper. > >> > >> Claude - if that were so it would not work with identical settings > >> under Mach3. Same step frequency, same drivers same PC same > >> everything. > > > >It might be close to the limits of the EMC step pulse generator (which > >aren't neccessarily the same as those of the Mach step pulse > >generator). Personally I think that is unlikely, but the test is > >relatively straightforward. You could reduce by just a factor of two > >instead of ten, the key is to drop it by a significant factor on both > >systems and see if the difference is still there. If the misbehavior > >is still there, that pretty much rules out step generator limits. > > Hi John - if I reduce the feed by 50% and the acceleration by 50% it > still does it. The router maximum reliable rate is 5200mm/min and is > devalued to 4000 for a margin of safety. PC only has a worse latency of > around 6500. > > The router can and does manage the 3600 mm/min feed easily in both mach > and LinuxCNC, but slows horribly on line to arc or arc to line > transitions in LinuxCNC. Arc to arc is ok, as is line to line? > > Steve Blackmore
FWIW, I noted that despite a g64.1 P.001 at the top of the file, my carving of that brass handle yesterday on a 2.6.0-pre install, was also coming to a complete stop at those straight line to arc transitions, 4 times per loop, not all of which have a bunch of math between them. So I'd guess on that job, it wasted a minute of the 41 it took to run the final version. I wasn't going that fast anyway, trying to hold down bit flex in 3/4" of a .125" 2 flute end mill, F=5 ipm IIRC with smallish cuts in the .007 x .011 thou range, made nice sandy brass swarf, but the stops sure were obvious. Its doing little if any blending, but the stops also did not leave an obviously noticeable mark so the finish was not adversely effected. 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) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! My views <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> Many are called, few are chosen. Fewer still get to do the choosing. A pen in the hand of this president is far more dangerous than a gun in the hands of 200 million law-abiding citizens. ------------------------------------------------------------------------------ Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis & visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
