On Sun, 9 Feb 2014, bruno wrote: > Date: Sun, 09 Feb 2014 17:25:03 +0100 > From: bruno <br...@tinkerbox.org> > Reply-To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > To: emc-users@lists.sourceforge.net > Subject: Re: [Emc-users] Emc-users Digest, Vol 94, Issue 17 > > > This is a stepper system, trivkins, 3 axis mill. > I kind of assumed that the tuning in pncconf is using the configuration > that it will write, it's not very useful if one tunes things but then > the parameters to use are different... > > so you are referring to these > > * > > /STEPGEN_MAXACCEL = 21.0/- Acceleration limit for the step > generator. This should be 1% to 10% larger than the axis > MAX_ACCELERATION. This value improves the tuning of stepgen's > "position loop". If you have added backlash compensation to an axis > then this should be 1.5 to 2 times greater than MAX_ACCELERATION. > > * > > /STEPGEN_MAXVEL = 1.4/- Older configuration files have a velocity > limit for the step generator as well. If specified, it should also > be 1% to 10% larger than the axis MAX_VELOCITY. Subsequent testing > has shown that use of STEPGEN_MAXVEL does not improve the tuning of > stepgen's position loop. > > looking at the hostmot driver > > * > > /maxaccel/- (Float, RW) Maximum acceleration, in position units per > second per second. If set to 0, the driver will not limit its > acceleration. > > * > > /maxvel/- (Float, RW) Maximum speed, in position units per second. > If set to 0, the driver will choose the maximum velocity based on > the values of steplen and stepspace (at the time that maxvel was set > to 0). > > seems like it would be best to specify 0 for both of those as the per > axis limits would still be in place ? > I am going to play with that and see... thanks for the reply
0 for stepgen_maxaccel will typically not work (you will get joint following errors) unless you have very low latency. I would suggest 25% higher than machine maxaccel for stepgen_maxaccel Also Andys suggestion of widening the ferror limits is a good idea at least until you can find out what going on. > > On 2/9/14 4:04 PM, emc-users-requ...@lists.sourceforge.net wrote: >> Date: Sun, 9 Feb 2014 15:03:40 +0000 >> From: andy pugh<bodge...@gmail.com> >> Subject: Re: [Emc-users] mesa 5i25, pncconf working but not linuxcnc >> To: "Enhanced Machine Controller (EMC)" >> <emc-users@lists.sourceforge.net> >> Message-ID: >> <CAN1+YZV2iQb-AQmWE4TYbxithWSFmSvuMRP-kxk8=jhwpjd...@mail.gmail.com> >> Content-Type: text/plain; charset=ISO-8859-1 >> >> On 9 February 2014 11:30, bruno<br...@tinkerbox.org> wrote: >> >>>> After configuring, I started linuxcnc (with tklinuxcnc as I have opengl >>>> issues with axis right now), and it immediately gives me joint following >>>> errors. No move, nothing. >> It might be that Pncconf doesn't teack following error, or has higher limits. >> >> However, if this is a stepper system then "following error" means >> something slightly different to what it means in a servo system. It >> means that the system has not been able to make the number of steps >> requested. >> >> What this typically means is that the system stepgen accelleration >> numbers are bigger than the step generator limits. Have a look through >> your INI file and check that the step-generator accel limits are "a >> bit" higher than the system and axis limits. >> >> Is the machine a gantry system? The other possibility is that the >> step-generator feedback is going to the wrong axis. >> >> -- 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 > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------------ 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
