thanks for the explanation. I tried 0 backlash and the reversals caused no error. Then I used the values you suggested for ferror and min_ferror, that still works with low backlash. I will experiment with higher scale (microstepping) and ferror in order to use the correct backlash required by the machine. And work on lowering the backlash...
Thanks everybody for the help in figuring this out ! On 2/10/14 7:51 AM, emc-users-requ...@lists.sourceforge.net wrote: > Date: Sun, 9 Feb 2014 23:00:31 +0000 > From: andy pugh<bodge...@gmail.com> > Subject: Re: [Emc-users] mesa 5i25, pncconf working but not linuxcnc > (bruno) > To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > Message-ID: > <can1+yzwzkq7j5+yec08m4xc7qgkygtggwh9b8dqn2uurrqa...@mail.gmail.com> > Content-Type: text/plain; charset=ISO-8859-1 > > On 9 February 2014 20:52, bruno<br...@tinkerbox.org> wrote: > >> >- if I stop the movement and continue in the same direction : no >> >problem, it will start moving (and stop) smoothly >> >- if I stop the movement and go jog in the opposite direction, I >> >immediately get a following error. > This points very strongly to the problem being the backlash > compensation. (which won't be active in pncconf). > > In fact you have a backlash compensation of 0.05 and an f-error of > 0.005. So on every reversal you are_automatically_ out of position by > 10x your f-error limit. > > Your step scale of 314 steps per mm means that you have a resolution > of 0.003mm, so your f-error is 1 microstep. That's pretty tight, > especially for the high-speed f-error. > Try 0.015 for min_ferror and 0.1 for f-error and things should run > rather better. > > -- atp If you can't fix it, you don't own it. > http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ Managing the Performance of Cloud-Based Applications Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. Read the Whitepaper. http://pubads.g.doubleclick.net/gampad/clk?id=121051231&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
