Hi Chris, At my work place, closed loop systems with steppers has been in use for years. It is a scientific institute and the controller has been developed inhouse. The controller is doing the step generation based on a demanded position. Encoder feedback on the real axis is giving the error. Without a doubt it can be done in linuxcnc. On the daily basis it is not more complicated to tune than another pid system with servos.
So far as I've seen in linuxcnc for a closed loop system with stepper, you only have code for controlling if you don't have a following error too big. I haven't check recently but I haven't seen code for stepper close loops. Linuxcnc guru's advices would be interesting here. Cheers, Yves 2016-01-19 8:04 GMT+01:00 Chris Albertson <albertson.ch...@gmail.com>: > I've read that it is hard to use steppers for closed loop CNC. If this is > still true could some one explain the theory. > > I have a small mill with DRO scales that are good to about .001 inch and > I'd like to put them to use with my planned CNC conversion. I understand > software. I've worked in the field for 30 years and have experience with > Linux (and other OS) device drivers, embedded real time code and so on. > If the problem is simply that no one has bothered to write the code, I can > fix that. But if there is something of a mechanical nature I'm not > thinking of maybe some one can point me at what I need to read up on. > > At least I think I might be able too automatically measure backlash using > the DRO scale data. But my goal is to go closed loop if I can > > -- > > Chris Albertson > Redondo Beach, California > ------------------------------------------------------------------------------ > Site24x7 APM Insight: Get Deep Visibility into Application Performance > APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month > Monitor end-to-end web transactions and take corrective actions now > Troubleshoot faster and improve end-user experience. Signup Now! > http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- Watier Yves ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
