On Friday 18 March 2016 16:00:27 Nicklas Karlsson wrote: > I have seen and run machinekit, it is linuxcnc. I have also read about > BeagleBone. There are plenty of devices suitable to generate the > pulses but at which rate should pulses generated? Constant > acceleration between different speeds?
Ideally, the accel (and decel) should be t=rc curve or close, because at the higher speeds, the motors torque is falling like a rock so the accel ability is less and less as it speeds up. On slowdown the curve should be reversed left for right because the motors torque is increasing as it slows, so you can slow it even faster. But I believe the huge majority of our controllers use pretty close to a straight line ramp going either direction. If thats not the case, someone please correct me. Which said another way, speed vs acceleration is a tradeoff. I can usually double the rapids achieved, but its at the cost of slower acceleration, so one has to establish what you consider a reasonable response time to get to the commanded speed. Too slow accels and it never reaches the commanded speed so the execution is slowed even if the rapids are quicker than stink. > On Fri, 18 Mar 2016 12:50:21 -0700 > > "John Dammeyer" <jo...@autoartisans.com> wrote: > > You might look at the Replicape and a BeagleBone Black. There are > > several other capes including one with a standard DB-25 parallel > > port that run LinuxCNC on the Beagle. Search for MachineKit. > > > > John > > > > > -----Original Message----- > > > From: Nicklas Karlsson [mailto:nicklas.karlsso...@gmail.com] > > > Sent: March-18-16 12:27 PM > > > To: Enhanced Machine Controller (EMC) > > > Subject: Re: [Emc-users] Stepper, ideal pulses without feedback > > > > > > > > > Nice box and standard port is always good, I should think about > > > it. > > > > Steppers > > > > > are for an xyz engraver so it is essentially a mini CNC machine > > > without > > > > tool > > > > > changer. > > > > > > > > > > > > On Fri, 18 Mar 2016 12:00:55 -0700 > > > > > > "John Dammeyer" <jo...@autoartisans.com> wrote: > > > > You are welcome to look at my Electronic Lead Screw Code. > > > > Follow the > > > > > > link > > > > > > > to the code. It's written for a PIC in C. > > > > John > > > > > > > > > > > > "ELS! Nothing else works as well for your Lathe" > > > > Automation Artisans Inc. > > > > http://www.autoartisans.com/ELS/ > > > > Ph. 1 250 544 4950 > > > > > > > > > -----Original Message----- > > > > > From: Nicklas Karlsson [mailto:nicklas.karlsso...@gmail.com] > > > > > Sent: March-18-16 11:46 AM > > > > > To: emc-users@lists.sourceforge.net > > > > > Subject: [Emc-users] Stepper, ideal pulses without feedback > > > > > > > > > > > > > > > I am planning to use a micro controller for stepper step pulse > > > > generation. > > > > > > I > > > > > > > > > have considered to use an inverter card but special purpose > > > > > stepper > > > > > > > > circuits > > > > > > > > > are cheap so I use one of these instead. It should be possible > > > > > to feed > > > > > > > > timer > > > > > > > > > values then toggle should happen via DMA timer output compare > > > > > values. > > > > > > > > > > Can anyone suggest how an ideal step generation curve should > > > > > look? Constant acceleration up to top speed? Constant > > > > > deceleration from top speed to zero? Or just stop generating > > > > > pulses? > > > > > > > > > > Regards Nicklas Karlsson > > > > -------------------------------------------------------------------- > >-------- > > > > > > -- > > > > > > > > > Transform Data into Opportunity. > > > > > Accelerate data analysis in your applications with > > > > > Intel Data Analytics Acceleration Library. > > > > > Click to learn more. > > > > > http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/41 > > > > >40 _______________________________________________ > > > > > Emc-users mailing list > > > > > Emc-users@lists.sourceforge.net > > > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > -------------------------------------------------------------------- > >-------- -- > > > > > > Transform Data into Opportunity. > > > > Accelerate data analysis in your applications with > > > > Intel Data Analytics Acceleration Library. > > > > Click to learn more. > > > > http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 > > > > _______________________________________________ > > > > Emc-users mailing list > > > > Emc-users@lists.sourceforge.net > > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > -------------------------------------------------------------------- > >-------- -- > > > > > Transform Data into Opportunity. > > > Accelerate data analysis in your applications with > > > Intel Data Analytics Acceleration Library. > > > Click to learn more. > > > http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 > > > _______________________________________________ > > > Emc-users mailing list > > > Emc-users@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > -------------------------------------------------------------------- > >---------- Transform Data into Opportunity. > > Accelerate data analysis in your applications with > > Intel Data Analytics Acceleration Library. > > Click to learn more. > > http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > ---------------------------------------------------------------------- >-------- Transform Data into Opportunity. > Accelerate data analysis in your applications with > Intel Data Analytics Acceleration Library. > Click to learn more. > http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
