I played with those values, setting stepgen.maxvel and maxaccel to 0 like the doc says in order to not limit it. Not much improvement. Then I tried to increase vastly the MIN_FERROR, and that allows to go through but I get some occasional grinding noise (missed steps I think) when doing a test (back and forth on one axis)
One thing I noticed is that the .hal file written by pncconf does not specify the servo_base_period on the EMCMOT line. What is infuriating is that within pncconf, I can test one axis with fast movement back and forth and it is real nice, smooth, no missed steps... Is there a way to find out which exact parameters pncconf is using when it launches the tuning applet ? On 2/9/14 5:25 PM, bruno wrote: > > 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 > > 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
