On Wed, 30 Apr 2014, Curtis Dutton wrote: > Date: Wed, 30 Apr 2014 14:37:34 -0400 > From: Curtis Dutton <curtd...@gmail.com> > Reply-To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> > Subject: [Emc-users] Leadshine ACS806 - Large f-error at higher speeds - what > is acceptable? > > I recently installed an ACS806 brushless drive along with a BLM57130 > leadshine motor. The motor is a 130W motor with a 4000ppr encoder. > > The controller is a step and direction type, with the encoder feedback > passed back through to linuxcnc via a mesa 5i25 and a 7i86s.. So I'm using > the drive to run the PID loop but having linuxcnc watch my f-error. > > I've replaced a 500oz/in stepper motor with it on a medium sized cnc wood > shaping router. > > > I have tuned it up and it seems to be tuned well, and has a low following > error (< 0.01mm) at about 400mm/min and below. > > The problem is that it seems to rapidly increase from there. 0.1mm around > 3000mm/min and 1.5mm at around 12000mm/min.
Not sure why this would happen but what tuning options are available for the drives PID loop? A suitable amount of I term should be able to pull this in. Another option is to close the position PID loop in linuxcnc by setting the stepgen to velocity mode and adding a PID loop with just P, FF1 and a bit of I and getting the feedback position from the encoders > > > Does anyone have experience with these drives? I've tried to utilize feed > forward but it doesn't seem to make a difference. > > > > Being that this is my first servo drive, what would be a typical f-error > for various types of machinery? > > Say for instance what would the following error be on a 1000in/min high > dollar cnc vmc. > > What do people with home shop mills see? > > > Thanks, > Curtis > ------------------------------------------------------------------------------ > "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE > Instantly run your Selenium tests across 300+ browser/OS combos. Get > unparalleled scalability from the best Selenium testing platform available. > Simple to use. Nothing to install. Get started now for free." > http://p.sf.net/sfu/SauceLabs > _______________________________________________ > 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. ------------------------------------------------------------------------------ "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available. Simple to use. Nothing to install. Get started now for free." http://p.sf.net/sfu/SauceLabs _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
