On Saturday 08 December 2012 18:16:35 andy pugh did opine: > On 8 December 2012 18:06, Gene Heskett <[email protected]> wrote: > > One of the problems I've seen occasionally with the previous setup I > > ran most of last summer, was that the trip was bidirectional, and if > > the spindle was turning at a good rate when the stop button was hit, > > the error developed because of the perceived spindle over-speed, > > usually tripped the the thing too, a minor pita. > > Well, in that case you probably want to use "comp" as you already are. > That's unidirectional. > > But you are saying that you want to have the trip threshold > proportional to speed. > The way to do that is probably to pass spindle speed feedback into > sum2 (noting that sum2 has gain and offset, so you can > play games like sum2 spindle-speed and spindle speed * -0.1 to have > 90% of spindle speed on the output. )
Printed FFR. This is something I will try, Andy, if I don't seem to get the results I want by parameter adjustments. I've been hiding inside, logged into it, and playing with my-lathe.hal most of the afternoon, and currently have a huge lowpass between the requested spindle-speed from Axis, needed so it doesn't clear the fuse with a huge 0-400 revs change the gcode might issue, with lowpass0.out feeding both pid.0.command and near.0.in1. and near.0.in2 connected to encoder.0.velocity -> lowpass.1.in, gain .2 for a bit of noise filtering and lowpass.1.out -> near.0.in2. But it hasn't been in person live tested yet. I could work on this a bit more intelligently if I drilled out a 5x20 fuse and the holder cap to put an AC-DC ammeter I cobbled up years ago for the mills spindle, into this circuit so I had a better clue as to how hard the motor was actually working. Thanks Andy. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! Yow! I just went below the poverty line! I was taught to respect my elders, but its getting harder and harder to find any... ------------------------------------------------------------------------------ LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial Remotely access PCs and mobile devices and provide instant support Improve your efficiency, and focus on delivering more value-add services Discover what IT Professionals Know. Rescue delivers http://p.sf.net/sfu/logmein_12329d2d _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
