> Date: Sun, 9 Feb 2014 17:25:03 +0100 > From: br...@tinkerbox.org > 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 >
Don't set them to 0. It doesn't work reliably. Pncconf sets them to 25% more. Does your drives require an enable ? I would check that signal with halmeter or a real meter. While pncconf uses the same numbers as it tunes ( as long as you clicked accept) It doesn't use the same HAL code in the test as in linuxcnc so problems can creep in and bugs are always possible. Chris M ------------------------------------------------------------------------------ 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